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android-kvm / linux / a440e4d7618cbe232e4f96dea805bcb89f79b18c / . / drivers / net / ipa / gsi.c
blob: 14d9a791924bf9b6b16f53cba222ec6ff20cf2bf [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
* Copyright (C) 2018-2020 Linaro Ltd.
*/
#include <linux/types.h>
#include <linux/bits.h>
#include <linux/bitfield.h>
#include <linux/mutex.h>
#include <linux/completion.h>
#include <linux/io.h>
#include <linux/bug.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/netdevice.h>
#include "gsi.h"
#include "gsi_reg.h"
#include "gsi_private.h"
#include "gsi_trans.h"
#include "ipa_gsi.h"
#include "ipa_data.h"
#include "ipa_version.h"
/**
* DOC: The IPA Generic Software Interface
*
* The generic software interface (GSI) is an integral component of the IPA,
* providing a well-defined communication layer between the AP subsystem
* and the IPA core. The modem uses the GSI layer as well.
*
* -------- ---------
* | | | |
* | AP +<---. .----+ Modem |
* | +--. | | .->+ |
* | | | | | | | |
* -------- | | | | ---------
* v | v |
* --+-+---+-+--
* | GSI |
* |-----------|
* | |
* | IPA |
* | |
* -------------
*
* In the above diagram, the AP and Modem represent "execution environments"
* (EEs), which are independent operating environments that use the IPA for
* data transfer.
*
* Each EE uses a set of unidirectional GSI "channels," which allow transfer
* of data to or from the IPA. A channel is implemented as a ring buffer,
* with a DRAM-resident array of "transfer elements" (TREs) available to
* describe transfers to or from other EEs through the IPA. A transfer
* element can also contain an immediate command, requesting the IPA perform
* actions other than data transfer.
*
* Each TRE refers to a block of data--also located DRAM. After writing one
* or more TREs to a channel, the writer (either the IPA or an EE) writes a
* doorbell register to inform the receiving side how many elements have
* been written.
*
* Each channel has a GSI "event ring" associated with it. An event ring
* is implemented very much like a channel ring, but is always directed from
* the IPA to an EE. The IPA notifies an EE (such as the AP) about channel
* events by adding an entry to the event ring associated with the channel.
* The GSI then writes its doorbell for the event ring, causing the target
* EE to be interrupted. Each entry in an event ring contains a pointer
* to the channel TRE whose completion the event represents.
*
* Each TRE in a channel ring has a set of flags. One flag indicates whether
* the completion of the transfer operation generates an entry (and possibly
* an interrupt) in the channel's event ring. Other flags allow transfer
* elements to be chained together, forming a single logical transaction.
* TRE flags are used to control whether and when interrupts are generated
* to signal completion of channel transfers.
*
* Elements in channel and event rings are completed (or consumed) strictly
* in order. Completion of one entry implies the completion of all preceding
* entries. A single completion interrupt can therefore communicate the
* completion of many transfers.
*
* Note that all GSI registers are little-endian, which is the assumed
* endianness of I/O space accesses. The accessor functions perform byte
* swapping if needed (i.e., for a big endian CPU).
*/
/* Delay period for interrupt moderation (in 32KHz IPA internal timer ticks) */
#define GSI_EVT_RING_INT_MODT (32 * 1) /* 1ms under 32KHz clock */
#define GSI_CMD_TIMEOUT 5 /* seconds */
#define GSI_CHANNEL_STOP_RX_RETRIES 10
#define GSI_CHANNEL_MODEM_HALT_RETRIES 10
#define GSI_MHI_EVENT_ID_START 10 /* 1st reserved event id */
#define GSI_MHI_EVENT_ID_END 16 /* Last reserved event id */
#define GSI_ISR_MAX_ITER 50 /* Detect interrupt storms */
/* An entry in an event ring */
struct gsi_event {
__le64 xfer_ptr;
__le16 len;
u8 reserved1;
u8 code;
__le16 reserved2;
u8 type;
u8 chid;
};
/** gsi_channel_scratch_gpi - GPI protocol scratch register
* @max_outstanding_tre:
* Defines the maximum number of TREs allowed in a single transaction
* on a channel (in bytes). This determines the amount of prefetch
* performed by the hardware. We configure this to equal the size of
* the TLV FIFO for the channel.
* @outstanding_threshold:
* Defines the threshold (in bytes) determining when the sequencer
* should update the channel doorbell. We configure this to equal
* the size of two TREs.
*/
struct gsi_channel_scratch_gpi {
u64 reserved1;
u16 reserved2;
u16 max_outstanding_tre;
u16 reserved3;
u16 outstanding_threshold;
};
/** gsi_channel_scratch - channel scratch configuration area
*
* The exact interpretation of this register is protocol-specific.
* We only use GPI channels; see struct gsi_channel_scratch_gpi, above.
*/
union gsi_channel_scratch {
struct gsi_channel_scratch_gpi gpi;
struct {
u32 word1;
u32 word2;
u32 word3;
u32 word4;
} data;
};
/* Check things that can be validated at build time. */
static void gsi_validate_build(void)
{
/* This is used as a divisor */
BUILD_BUG_ON(!GSI_RING_ELEMENT_SIZE);
/* Code assumes the size of channel and event ring element are
* the same (and fixed). Make sure the size of an event ring
* element is what's expected.
*/
BUILD_BUG_ON(sizeof(struct gsi_event) != GSI_RING_ELEMENT_SIZE);
/* Hardware requires a 2^n ring size. We ensure the number of
* elements in an event ring is a power of 2 elsewhere; this
* ensure the elements themselves meet the requirement.
*/
BUILD_BUG_ON(!is_power_of_2(GSI_RING_ELEMENT_SIZE));
/* The channel element size must fit in this field */
BUILD_BUG_ON(GSI_RING_ELEMENT_SIZE > field_max(ELEMENT_SIZE_FMASK));
/* The event ring element size must fit in this field */
BUILD_BUG_ON(GSI_RING_ELEMENT_SIZE > field_max(EV_ELEMENT_SIZE_FMASK));
}
/* Return the channel id associated with a given channel */
static u32 gsi_channel_id(struct gsi_channel *channel)
{
return channel - &channel->gsi->channel[0];
}
/* Update the GSI IRQ type register with the cached value */
static void gsi_irq_type_update(struct gsi *gsi, u32 val)
{
gsi->type_enabled_bitmap = val;
iowrite32(val, gsi->virt + GSI_CNTXT_TYPE_IRQ_MSK_OFFSET);
}
static void gsi_irq_type_enable(struct gsi *gsi, enum gsi_irq_type_id type_id)
{
gsi_irq_type_update(gsi, gsi->type_enabled_bitmap | BIT(type_id));
}
static void gsi_irq_type_disable(struct gsi *gsi, enum gsi_irq_type_id type_id)
{
gsi_irq_type_update(gsi, gsi->type_enabled_bitmap & ~BIT(type_id));
}
/* Turn off all GSI interrupts initially */
static void gsi_irq_setup(struct gsi *gsi)
{
u32 adjust;
/* Disable all interrupt types */
gsi_irq_type_update(gsi, 0);
/* Clear all type-specific interrupt masks */
iowrite32(0, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_MSK_OFFSET);
iowrite32(0, gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_MSK_OFFSET);
iowrite32(0, gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);
iowrite32(0, gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_MSK_OFFSET);
/* Reverse the offset adjustment for inter-EE register offsets */
adjust = gsi->version < IPA_VERSION_4_5 ? 0 : GSI_EE_REG_ADJUST;
iowrite32(0, gsi->virt + adjust + GSI_INTER_EE_SRC_CH_IRQ_OFFSET);
iowrite32(0, gsi->virt + adjust + GSI_INTER_EE_SRC_EV_CH_IRQ_OFFSET);
iowrite32(0, gsi->virt + GSI_CNTXT_GSI_IRQ_EN_OFFSET);
}
/* Turn off all GSI interrupts when we're all done */
static void gsi_irq_teardown(struct gsi *gsi)
{
/* Nothing to do */
}
static void gsi_irq_ieob_enable(struct gsi *gsi, u32 evt_ring_id)
{
bool enable_ieob = !gsi->ieob_enabled_bitmap;
u32 val;
gsi->ieob_enabled_bitmap |= BIT(evt_ring_id);
val = gsi->ieob_enabled_bitmap;
iowrite32(val, gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_MSK_OFFSET);
/* Enable the interrupt type if this is the first channel enabled */
if (enable_ieob)
gsi_irq_type_enable(gsi, GSI_IEOB);
}
static void gsi_irq_ieob_disable(struct gsi *gsi, u32 evt_ring_id)
{
u32 val;
gsi->ieob_enabled_bitmap &= ~BIT(evt_ring_id);
/* Disable the interrupt type if this was the last enabled channel */
if (!gsi->ieob_enabled_bitmap)
gsi_irq_type_disable(gsi, GSI_IEOB);
val = gsi->ieob_enabled_bitmap;
iowrite32(val, gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_MSK_OFFSET);
}
/* Enable all GSI_interrupt types */
static void gsi_irq_enable(struct gsi *gsi)
{
u32 val;
/* Global interrupts include hardware error reports. Enable
* that so we can at least report the error should it occur.
*/
iowrite32(BIT(ERROR_INT), gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);
gsi_irq_type_update(gsi, gsi->type_enabled_bitmap | BIT(GSI_GLOB_EE));
/* General GSI interrupts are reported to all EEs; if they occur
* they are unrecoverable (without reset). A breakpoint interrupt
* also exists, but we don't support that. We want to be notified
* of errors so we can report them, even if they can't be handled.
*/
val = BIT(BUS_ERROR);
val |= BIT(CMD_FIFO_OVRFLOW);
val |= BIT(MCS_STACK_OVRFLOW);
iowrite32(val, gsi->virt + GSI_CNTXT_GSI_IRQ_EN_OFFSET);
gsi_irq_type_update(gsi, gsi->type_enabled_bitmap | BIT(GSI_GENERAL));
}
/* Disable all GSI interrupt types */
static void gsi_irq_disable(struct gsi *gsi)
{
gsi_irq_type_update(gsi, 0);
/* Clear the type-specific interrupt masks set by gsi_irq_enable() */
iowrite32(0, gsi->virt + GSI_CNTXT_GSI_IRQ_EN_OFFSET);
iowrite32(0, gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);
}
/* Return the virtual address associated with a ring index */
void *gsi_ring_virt(struct gsi_ring *ring, u32 index)
{
/* Note: index *must* be used modulo the ring count here */
return ring->virt + (index % ring->count) * GSI_RING_ELEMENT_SIZE;
}
/* Return the 32-bit DMA address associated with a ring index */
static u32 gsi_ring_addr(struct gsi_ring *ring, u32 index)
{
return (ring->addr & GENMASK(31, 0)) + index * GSI_RING_ELEMENT_SIZE;
}
/* Return the ring index of a 32-bit ring offset */
static u32 gsi_ring_index(struct gsi_ring *ring, u32 offset)
{
return (offset - gsi_ring_addr(ring, 0)) / GSI_RING_ELEMENT_SIZE;
}
/* Issue a GSI command by writing a value to a register, then wait for
* completion to be signaled. Returns true if the command completes
* or false if it times out.
*/
static bool
gsi_command(struct gsi *gsi, u32 reg, u32 val, struct completion *completion)
{
reinit_completion(completion);
iowrite32(val, gsi->virt + reg);
return !!wait_for_completion_timeout(completion, GSI_CMD_TIMEOUT * HZ);
}
/* Return the hardware's notion of the current state of an event ring */
static enum gsi_evt_ring_state
gsi_evt_ring_state(struct gsi *gsi, u32 evt_ring_id)
{
u32 val;
val = ioread32(gsi->virt + GSI_EV_CH_E_CNTXT_0_OFFSET(evt_ring_id));
return u32_get_bits(val, EV_CHSTATE_FMASK);
}
/* Issue an event ring command and wait for it to complete */
static void evt_ring_command(struct gsi *gsi, u32 evt_ring_id,
enum gsi_evt_cmd_opcode opcode)
{
struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id];
struct completion *completion = &evt_ring->completion;
struct device *dev = gsi->dev;
bool success;
u32 val;
/* We only perform one event ring command at a time, and event
* control interrupts should only occur when such a command
* is issued here. Only permit *this* event ring to trigger
* an interrupt, and only enable the event control IRQ type
* when we expect it to occur.
*
* There's a small chance that a previous command completed
* after the interrupt was disabled, so make sure we have no
* pending interrupts before we enable them.
*/
iowrite32(~0, gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_CLR_OFFSET);
val = BIT(evt_ring_id);
iowrite32(val, gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_MSK_OFFSET);
gsi_irq_type_enable(gsi, GSI_EV_CTRL);
val = u32_encode_bits(evt_ring_id, EV_CHID_FMASK);
val |= u32_encode_bits(opcode, EV_OPCODE_FMASK);
success = gsi_command(gsi, GSI_EV_CH_CMD_OFFSET, val, completion);
/* Disable the interrupt again */
gsi_irq_type_disable(gsi, GSI_EV_CTRL);
iowrite32(0, gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_MSK_OFFSET);
if (success)
return;
dev_err(dev, "GSI command %u for event ring %u timed out, state %u\n",
opcode, evt_ring_id, evt_ring->state);
}
/* Allocate an event ring in NOT_ALLOCATED state */
static int gsi_evt_ring_alloc_command(struct gsi *gsi, u32 evt_ring_id)
{
struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id];
/* Get initial event ring state */
evt_ring->state = gsi_evt_ring_state(gsi, evt_ring_id);
if (evt_ring->state != GSI_EVT_RING_STATE_NOT_ALLOCATED) {
dev_err(gsi->dev, "event ring %u bad state %u before alloc\n",
evt_ring_id, evt_ring->state);
return -EINVAL;
}
evt_ring_command(gsi, evt_ring_id, GSI_EVT_ALLOCATE);
/* If successful the event ring state will have changed */
if (evt_ring->state == GSI_EVT_RING_STATE_ALLOCATED)
return 0;
dev_err(gsi->dev, "event ring %u bad state %u after alloc\n",
evt_ring_id, evt_ring->state);
return -EIO;
}
/* Reset a GSI event ring in ALLOCATED or ERROR state. */
static void gsi_evt_ring_reset_command(struct gsi *gsi, u32 evt_ring_id)
{
struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id];
enum gsi_evt_ring_state state = evt_ring->state;
if (state != GSI_EVT_RING_STATE_ALLOCATED &&
state != GSI_EVT_RING_STATE_ERROR) {
dev_err(gsi->dev, "event ring %u bad state %u before reset\n",
evt_ring_id, evt_ring->state);
return;
}
evt_ring_command(gsi, evt_ring_id, GSI_EVT_RESET);
/* If successful the event ring state will have changed */
if (evt_ring->state == GSI_EVT_RING_STATE_ALLOCATED)
return;
dev_err(gsi->dev, "event ring %u bad state %u after reset\n",
evt_ring_id, evt_ring->state);
}
/* Issue a hardware de-allocation request for an allocated event ring */
static void gsi_evt_ring_de_alloc_command(struct gsi *gsi, u32 evt_ring_id)
{
struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id];
if (evt_ring->state != GSI_EVT_RING_STATE_ALLOCATED) {
dev_err(gsi->dev, "event ring %u state %u before dealloc\n",
evt_ring_id, evt_ring->state);
return;
}
evt_ring_command(gsi, evt_ring_id, GSI_EVT_DE_ALLOC);
/* If successful the event ring state will have changed */
if (evt_ring->state == GSI_EVT_RING_STATE_NOT_ALLOCATED)
return;
dev_err(gsi->dev, "event ring %u bad state %u after dealloc\n",
evt_ring_id, evt_ring->state);
}
/* Fetch the current state of a channel from hardware */
static enum gsi_channel_state gsi_channel_state(struct gsi_channel *channel)
{
u32 channel_id = gsi_channel_id(channel);
void *virt = channel->gsi->virt;
u32 val;
val = ioread32(virt + GSI_CH_C_CNTXT_0_OFFSET(channel_id));
return u32_get_bits(val, CHSTATE_FMASK);
}
/* Issue a channel command and wait for it to complete */
static void
gsi_channel_command(struct gsi_channel *channel, enum gsi_ch_cmd_opcode opcode)
{
struct completion *completion = &channel->completion;
u32 channel_id = gsi_channel_id(channel);
struct gsi *gsi = channel->gsi;
struct device *dev = gsi->dev;
bool success;
u32 val;
/* We only perform one channel command at a time, and channel
* control interrupts should only occur when such a command is
* issued here. So we only permit *this* channel to trigger
* an interrupt and only enable the channel control IRQ type
* when we expect it to occur.
*
* There's a small chance that a previous command completed
* after the interrupt was disabled, so make sure we have no
* pending interrupts before we enable them.
*/
iowrite32(~0, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_CLR_OFFSET);
val = BIT(channel_id);
iowrite32(val, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_MSK_OFFSET);
gsi_irq_type_enable(gsi, GSI_CH_CTRL);
val = u32_encode_bits(channel_id, CH_CHID_FMASK);
val |= u32_encode_bits(opcode, CH_OPCODE_FMASK);
success = gsi_command(gsi, GSI_CH_CMD_OFFSET, val, completion);
/* Disable the interrupt again */
gsi_irq_type_disable(gsi, GSI_CH_CTRL);
iowrite32(0, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_MSK_OFFSET);
if (success)
return;
dev_err(dev, "GSI command %u for channel %u timed out, state %u\n",
opcode, channel_id, gsi_channel_state(channel));
}
/* Allocate GSI channel in NOT_ALLOCATED state */
static int gsi_channel_alloc_command(struct gsi *gsi, u32 channel_id)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
struct device *dev = gsi->dev;
enum gsi_channel_state state;
/* Get initial channel state */
state = gsi_channel_state(channel);
if (state != GSI_CHANNEL_STATE_NOT_ALLOCATED) {
dev_err(dev, "channel %u bad state %u before alloc\n",
channel_id, state);
return -EINVAL;
}
gsi_channel_command(channel, GSI_CH_ALLOCATE);
/* If successful the channel state will have changed */
state = gsi_channel_state(channel);
if (state == GSI_CHANNEL_STATE_ALLOCATED)
return 0;
dev_err(dev, "channel %u bad state %u after alloc\n",
channel_id, state);
return -EIO;
}
/* Start an ALLOCATED channel */
static int gsi_channel_start_command(struct gsi_channel *channel)
{
struct device *dev = channel->gsi->dev;
enum gsi_channel_state state;
state = gsi_channel_state(channel);
if (state != GSI_CHANNEL_STATE_ALLOCATED &&
state != GSI_CHANNEL_STATE_STOPPED) {
dev_err(dev, "channel %u bad state %u before start\n",
gsi_channel_id(channel), state);
return -EINVAL;
}
gsi_channel_command(channel, GSI_CH_START);
/* If successful the channel state will have changed */
state = gsi_channel_state(channel);
if (state == GSI_CHANNEL_STATE_STARTED)
return 0;
dev_err(dev, "channel %u bad state %u after start\n",
gsi_channel_id(channel), state);
return -EIO;
}
/* Stop a GSI channel in STARTED state */
static int gsi_channel_stop_command(struct gsi_channel *channel)
{
struct device *dev = channel->gsi->dev;
enum gsi_channel_state state;
state = gsi_channel_state(channel);
/* Channel could have entered STOPPED state since last call
* if it timed out. If so, we're done.
*/
if (state == GSI_CHANNEL_STATE_STOPPED)
return 0;
if (state != GSI_CHANNEL_STATE_STARTED &&
state != GSI_CHANNEL_STATE_STOP_IN_PROC) {
dev_err(dev, "channel %u bad state %u before stop\n",
gsi_channel_id(channel), state);
return -EINVAL;
}
gsi_channel_command(channel, GSI_CH_STOP);
/* If successful the channel state will have changed */
state = gsi_channel_state(channel);
if (state == GSI_CHANNEL_STATE_STOPPED)
return 0;
/* We may have to try again if stop is in progress */
if (state == GSI_CHANNEL_STATE_STOP_IN_PROC)
return -EAGAIN;
dev_err(dev, "channel %u bad state %u after stop\n",
gsi_channel_id(channel), state);
return -EIO;
}
/* Reset a GSI channel in ALLOCATED or ERROR state. */
static void gsi_channel_reset_command(struct gsi_channel *channel)
{
struct device *dev = channel->gsi->dev;
enum gsi_channel_state state;
msleep(1); /* A short delay is required before a RESET command */
state = gsi_channel_state(channel);
if (state != GSI_CHANNEL_STATE_STOPPED &&
state != GSI_CHANNEL_STATE_ERROR) {
/* No need to reset a channel already in ALLOCATED state */
if (state != GSI_CHANNEL_STATE_ALLOCATED)
dev_err(dev, "channel %u bad state %u before reset\n",
gsi_channel_id(channel), state);
return;
}
gsi_channel_command(channel, GSI_CH_RESET);
/* If successful the channel state will have changed */
state = gsi_channel_state(channel);
if (state != GSI_CHANNEL_STATE_ALLOCATED)
dev_err(dev, "channel %u bad state %u after reset\n",
gsi_channel_id(channel), state);
}
/* Deallocate an ALLOCATED GSI channel */
static void gsi_channel_de_alloc_command(struct gsi *gsi, u32 channel_id)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
struct device *dev = gsi->dev;
enum gsi_channel_state state;
state = gsi_channel_state(channel);
if (state != GSI_CHANNEL_STATE_ALLOCATED) {
dev_err(dev, "channel %u bad state %u before dealloc\n",
channel_id, state);
return;
}
gsi_channel_command(channel, GSI_CH_DE_ALLOC);
/* If successful the channel state will have changed */
state = gsi_channel_state(channel);
if (state != GSI_CHANNEL_STATE_NOT_ALLOCATED)
dev_err(dev, "channel %u bad state %u after dealloc\n",
channel_id, state);
}
/* Ring an event ring doorbell, reporting the last entry processed by the AP.
* The index argument (modulo the ring count) is the first unfilled entry, so
* we supply one less than that with the doorbell. Update the event ring
* index field with the value provided.
*/
static void gsi_evt_ring_doorbell(struct gsi *gsi, u32 evt_ring_id, u32 index)
{
struct gsi_ring *ring = &gsi->evt_ring[evt_ring_id].ring;
u32 val;
ring->index = index; /* Next unused entry */
/* Note: index *must* be used modulo the ring count here */
val = gsi_ring_addr(ring, (index - 1) % ring->count);
iowrite32(val, gsi->virt + GSI_EV_CH_E_DOORBELL_0_OFFSET(evt_ring_id));
}
/* Program an event ring for use */
static void gsi_evt_ring_program(struct gsi *gsi, u32 evt_ring_id)
{
struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id];
size_t size = evt_ring->ring.count * GSI_RING_ELEMENT_SIZE;
u32 val;
/* We program all event rings as GPI type/protocol */
val = u32_encode_bits(GSI_CHANNEL_TYPE_GPI, EV_CHTYPE_FMASK);
val |= EV_INTYPE_FMASK;
val |= u32_encode_bits(GSI_RING_ELEMENT_SIZE, EV_ELEMENT_SIZE_FMASK);
iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_0_OFFSET(evt_ring_id));
val = u32_encode_bits(size, EV_R_LENGTH_FMASK);
iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_1_OFFSET(evt_ring_id));
/* The context 2 and 3 registers store the low-order and
* high-order 32 bits of the address of the event ring,
* respectively.
*/
val = evt_ring->ring.addr & GENMASK(31, 0);
iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_2_OFFSET(evt_ring_id));
val = evt_ring->ring.addr >> 32;
iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_3_OFFSET(evt_ring_id));
/* Enable interrupt moderation by setting the moderation delay */
val = u32_encode_bits(GSI_EVT_RING_INT_MODT, MODT_FMASK);
val |= u32_encode_bits(1, MODC_FMASK); /* comes from channel */
iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_8_OFFSET(evt_ring_id));
/* No MSI write data, and MSI address high and low address is 0 */
iowrite32(0, gsi->virt + GSI_EV_CH_E_CNTXT_9_OFFSET(evt_ring_id));
iowrite32(0, gsi->virt + GSI_EV_CH_E_CNTXT_10_OFFSET(evt_ring_id));
iowrite32(0, gsi->virt + GSI_EV_CH_E_CNTXT_11_OFFSET(evt_ring_id));
/* We don't need to get event read pointer updates */
iowrite32(0, gsi->virt + GSI_EV_CH_E_CNTXT_12_OFFSET(evt_ring_id));
iowrite32(0, gsi->virt + GSI_EV_CH_E_CNTXT_13_OFFSET(evt_ring_id));
/* Finally, tell the hardware we've completed event 0 (arbitrary) */
gsi_evt_ring_doorbell(gsi, evt_ring_id, 0);
}
/* Return the last (most recent) transaction completed on a channel. */
static struct gsi_trans *gsi_channel_trans_last(struct gsi_channel *channel)
{
struct gsi_trans_info *trans_info = &channel->trans_info;
struct gsi_trans *trans;
spin_lock_bh(&trans_info->spinlock);
if (!list_empty(&trans_info->complete))
trans = list_last_entry(&trans_info->complete,
struct gsi_trans, links);
else if (!list_empty(&trans_info->polled))
trans = list_last_entry(&trans_info->polled,
struct gsi_trans, links);
else
trans = NULL;
/* Caller will wait for this, so take a reference */
if (trans)
refcount_inc(&trans->refcount);
spin_unlock_bh(&trans_info->spinlock);
return trans;
}
/* Wait for transaction activity on a channel to complete */
static void gsi_channel_trans_quiesce(struct gsi_channel *channel)
{
struct gsi_trans *trans;
/* Get the last transaction, and wait for it to complete */
trans = gsi_channel_trans_last(channel);
if (trans) {
wait_for_completion(&trans->completion);
gsi_trans_free(trans);
}
}
/* Stop channel activity. Transactions may not be allocated until thawed. */
static void gsi_channel_freeze(struct gsi_channel *channel)
{
gsi_channel_trans_quiesce(channel);
napi_disable(&channel->napi);
gsi_irq_ieob_disable(channel->gsi, channel->evt_ring_id);
}
/* Allow transactions to be used on the channel again. */
static void gsi_channel_thaw(struct gsi_channel *channel)
{
gsi_irq_ieob_enable(channel->gsi, channel->evt_ring_id);
napi_enable(&channel->napi);
}
/* Program a channel for use */
static void gsi_channel_program(struct gsi_channel *channel, bool doorbell)
{
size_t size = channel->tre_ring.count * GSI_RING_ELEMENT_SIZE;
u32 channel_id = gsi_channel_id(channel);
union gsi_channel_scratch scr = { };
struct gsi_channel_scratch_gpi *gpi;
struct gsi *gsi = channel->gsi;
u32 wrr_weight = 0;
u32 val;
/* Arbitrarily pick TRE 0 as the first channel element to use */
channel->tre_ring.index = 0;
/* We program all channels as GPI type/protocol */
val = u32_encode_bits(GSI_CHANNEL_TYPE_GPI, CHTYPE_PROTOCOL_FMASK);
if (channel->toward_ipa)
val |= CHTYPE_DIR_FMASK;
val |= u32_encode_bits(channel->evt_ring_id, ERINDEX_FMASK);
val |= u32_encode_bits(GSI_RING_ELEMENT_SIZE, ELEMENT_SIZE_FMASK);
iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_0_OFFSET(channel_id));
val = u32_encode_bits(size, R_LENGTH_FMASK);
iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_1_OFFSET(channel_id));
/* The context 2 and 3 registers store the low-order and
* high-order 32 bits of the address of the channel ring,
* respectively.
*/
val = channel->tre_ring.addr & GENMASK(31, 0);
iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_2_OFFSET(channel_id));
val = channel->tre_ring.addr >> 32;
iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_3_OFFSET(channel_id));
/* Command channel gets low weighted round-robin priority */
if (channel->command)
wrr_weight = field_max(WRR_WEIGHT_FMASK);
val = u32_encode_bits(wrr_weight, WRR_WEIGHT_FMASK);
/* Max prefetch is 1 segment (do not set MAX_PREFETCH_FMASK) */
/* We enable the doorbell engine for IPA v3.5.1 */
if (gsi->version == IPA_VERSION_3_5_1 && doorbell)
val |= USE_DB_ENG_FMASK;
/* v4.0 introduces an escape buffer for prefetch. We use it
* on all but the AP command channel.
*/
if (gsi->version != IPA_VERSION_3_5_1 && !channel->command) {
/* If not otherwise set, prefetch buffers are used */
if (gsi->version < IPA_VERSION_4_5)
val |= USE_ESCAPE_BUF_ONLY_FMASK;
else
val |= u32_encode_bits(GSI_ESCAPE_BUF_ONLY,
PREFETCH_MODE_FMASK);
}
iowrite32(val, gsi->virt + GSI_CH_C_QOS_OFFSET(channel_id));
/* Now update the scratch registers for GPI protocol */
gpi = &scr.gpi;
gpi->max_outstanding_tre = gsi_channel_trans_tre_max(gsi, channel_id) *
GSI_RING_ELEMENT_SIZE;
gpi->outstanding_threshold = 2 * GSI_RING_ELEMENT_SIZE;
val = scr.data.word1;
iowrite32(val, gsi->virt + GSI_CH_C_SCRATCH_0_OFFSET(channel_id));
val = scr.data.word2;
iowrite32(val, gsi->virt + GSI_CH_C_SCRATCH_1_OFFSET(channel_id));
val = scr.data.word3;
iowrite32(val, gsi->virt + GSI_CH_C_SCRATCH_2_OFFSET(channel_id));
/* We must preserve the upper 16 bits of the last scratch register.
* The next sequence assumes those bits remain unchanged between the
* read and the write.
*/
val = ioread32(gsi->virt + GSI_CH_C_SCRATCH_3_OFFSET(channel_id));
val = (scr.data.word4 & GENMASK(31, 16)) | (val & GENMASK(15, 0));
iowrite32(val, gsi->virt + GSI_CH_C_SCRATCH_3_OFFSET(channel_id));
/* All done! */
}
static void gsi_channel_deprogram(struct gsi_channel *channel)
{
/* Nothing to do */
}
/* Start an allocated GSI channel */
int gsi_channel_start(struct gsi *gsi, u32 channel_id)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
int ret;
mutex_lock(&gsi->mutex);
ret = gsi_channel_start_command(channel);
mutex_unlock(&gsi->mutex);
gsi_channel_thaw(channel);
return ret;
}
/* Stop a started channel */
int gsi_channel_stop(struct gsi *gsi, u32 channel_id)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
u32 retries;
int ret;
gsi_channel_freeze(channel);
/* RX channels might require a little time to enter STOPPED state */
retries = channel->toward_ipa ? 0 : GSI_CHANNEL_STOP_RX_RETRIES;
mutex_lock(&gsi->mutex);
do {
ret = gsi_channel_stop_command(channel);
if (ret != -EAGAIN)
break;
msleep(1);
} while (retries--);
mutex_unlock(&gsi->mutex);
/* Thaw the channel if we need to retry (or on error) */
if (ret)
gsi_channel_thaw(channel);
return ret;
}
/* Reset and reconfigure a channel, (possibly) enabling the doorbell engine */
void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool doorbell)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
mutex_lock(&gsi->mutex);
gsi_channel_reset_command(channel);
/* Due to a hardware quirk we may need to reset RX channels twice. */
if (gsi->version == IPA_VERSION_3_5_1 && !channel->toward_ipa)
gsi_channel_reset_command(channel);
gsi_channel_program(channel, doorbell);
gsi_channel_trans_cancel_pending(channel);
mutex_unlock(&gsi->mutex);
}
/* Stop a STARTED channel for suspend (using stop if requested) */
int gsi_channel_suspend(struct gsi *gsi, u32 channel_id, bool stop)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
if (stop)
return gsi_channel_stop(gsi, channel_id);
gsi_channel_freeze(channel);
return 0;
}
/* Resume a suspended channel (starting will be requested if STOPPED) */
int gsi_channel_resume(struct gsi *gsi, u32 channel_id, bool start)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
if (start)
return gsi_channel_start(gsi, channel_id);
gsi_channel_thaw(channel);
return 0;
}
/**
* gsi_channel_tx_queued() - Report queued TX transfers for a channel
* @channel: Channel for which to report
*
* Report to the network stack the number of bytes and transactions that
* have been queued to hardware since last call. This and the next function
* supply information used by the network stack for throttling.
*
* For each channel we track the number of transactions used and bytes of
* data those transactions represent. We also track what those values are
* each time this function is called. Subtracting the two tells us
* the number of bytes and transactions that have been added between
* successive calls.
*
* Calling this each time we ring the channel doorbell allows us to
* provide accurate information to the network stack about how much
* work we've given the hardware at any point in time.
*/
void gsi_channel_tx_queued(struct gsi_channel *channel)
{
u32 trans_count;
u32 byte_count;
byte_count = channel->byte_count - channel->queued_byte_count;
trans_count = channel->trans_count - channel->queued_trans_count;
channel->queued_byte_count = channel->byte_count;
channel->queued_trans_count = channel->trans_count;
ipa_gsi_channel_tx_queued(channel->gsi, gsi_channel_id(channel),
trans_count, byte_count);
}
/**
* gsi_channel_tx_update() - Report completed TX transfers
* @channel: Channel that has completed transmitting packets
* @trans: Last transation known to be complete
*
* Compute the number of transactions and bytes that have been transferred
* over a TX channel since the given transaction was committed. Report this
* information to the network stack.
*
* At the time a transaction is committed, we record its channel's
* committed transaction and byte counts *in the transaction*.
* Completions are signaled by the hardware with an interrupt, and
* we can determine the latest completed transaction at that time.
*
* The difference between the byte/transaction count recorded in
* the transaction and the count last time we recorded a completion
* tells us exactly how much data has been transferred between
* completions.
*
* Calling this each time we learn of a newly-completed transaction
* allows us to provide accurate information to the network stack
* about how much work has been completed by the hardware at a given
* point in time.
*/
static void
gsi_channel_tx_update(struct gsi_channel *channel, struct gsi_trans *trans)
{
u64 byte_count = trans->byte_count + trans->len;
u64 trans_count = trans->trans_count + 1;
byte_count -= channel->compl_byte_count;
channel->compl_byte_count += byte_count;
trans_count -= channel->compl_trans_count;
channel->compl_trans_count += trans_count;
ipa_gsi_channel_tx_completed(channel->gsi, gsi_channel_id(channel),
trans_count, byte_count);
}
/* Channel control interrupt handler */
static void gsi_isr_chan_ctrl(struct gsi *gsi)
{
u32 channel_mask;
channel_mask = ioread32(gsi->virt + GSI_CNTXT_SRC_CH_IRQ_OFFSET);
iowrite32(channel_mask, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_CLR_OFFSET);
while (channel_mask) {
u32 channel_id = __ffs(channel_mask);
struct gsi_channel *channel;
channel_mask ^= BIT(channel_id);
channel = &gsi->channel[channel_id];
complete(&channel->completion);
}
}
/* Event ring control interrupt handler */
static void gsi_isr_evt_ctrl(struct gsi *gsi)
{
u32 event_mask;
event_mask = ioread32(gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_OFFSET);
iowrite32(event_mask, gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_CLR_OFFSET);
while (event_mask) {
u32 evt_ring_id = __ffs(event_mask);
struct gsi_evt_ring *evt_ring;
event_mask ^= BIT(evt_ring_id);
evt_ring = &gsi->evt_ring[evt_ring_id];
evt_ring->state = gsi_evt_ring_state(gsi, evt_ring_id);
complete(&evt_ring->completion);
}
}
/* Global channel error interrupt handler */
static void
gsi_isr_glob_chan_err(struct gsi *gsi, u32 err_ee, u32 channel_id, u32 code)
{
if (code == GSI_OUT_OF_RESOURCES) {
dev_err(gsi->dev, "channel %u out of resources\n", channel_id);
complete(&gsi->channel[channel_id].completion);
return;
}
/* Report, but otherwise ignore all other error codes */
dev_err(gsi->dev, "channel %u global error ee 0x%08x code 0x%08x\n",
channel_id, err_ee, code);
}
/* Global event error interrupt handler */
static void
gsi_isr_glob_evt_err(struct gsi *gsi, u32 err_ee, u32 evt_ring_id, u32 code)
{
if (code == GSI_OUT_OF_RESOURCES) {
struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id];
u32 channel_id = gsi_channel_id(evt_ring->channel);
complete(&evt_ring->completion);
dev_err(gsi->dev, "evt_ring for channel %u out of resources\n",
channel_id);
return;
}
/* Report, but otherwise ignore all other error codes */
dev_err(gsi->dev, "event ring %u global error ee %u code 0x%08x\n",
evt_ring_id, err_ee, code);
}
/* Global error interrupt handler */
static void gsi_isr_glob_err(struct gsi *gsi)
{
enum gsi_err_type type;
enum gsi_err_code code;
u32 which;
u32 val;
u32 ee;
/* Get the logged error, then reinitialize the log */
val = ioread32(gsi->virt + GSI_ERROR_LOG_OFFSET);
iowrite32(0, gsi->virt + GSI_ERROR_LOG_OFFSET);
iowrite32(~0, gsi->virt + GSI_ERROR_LOG_CLR_OFFSET);
ee = u32_get_bits(val, ERR_EE_FMASK);
type = u32_get_bits(val, ERR_TYPE_FMASK);
which = u32_get_bits(val, ERR_VIRT_IDX_FMASK);
code = u32_get_bits(val, ERR_CODE_FMASK);
if (type == GSI_ERR_TYPE_CHAN)
gsi_isr_glob_chan_err(gsi, ee, which, code);
else if (type == GSI_ERR_TYPE_EVT)
gsi_isr_glob_evt_err(gsi, ee, which, code);
else /* type GSI_ERR_TYPE_GLOB should be fatal */
dev_err(gsi->dev, "unexpected global error 0x%08x\n", type);
}
/* Generic EE interrupt handler */
static void gsi_isr_gp_int1(struct gsi *gsi)
{
u32 result;
u32 val;
/* This interrupt is used to handle completions of the two GENERIC
* GSI commands. We use these to allocate and halt channels on
* the modem's behalf due to a hardware quirk on IPA v4.2. Once
* allocated, the modem "owns" these channels, and as a result we
* have no way of knowing the channel's state at any given time.
*
* It is recommended that we halt the modem channels we allocated
* when shutting down, but it's possible the channel isn't running
* at the time we issue the HALT command. We'll get an error in
* that case, but it's harmless (the channel is already halted).
*
* For this reason, we silently ignore a CHANNEL_NOT_RUNNING error
* if we receive it.
*/
val = ioread32(gsi->virt + GSI_CNTXT_SCRATCH_0_OFFSET);
result = u32_get_bits(val, GENERIC_EE_RESULT_FMASK);
switch (result) {
case GENERIC_EE_SUCCESS:
case GENERIC_EE_CHANNEL_NOT_RUNNING:
gsi->result = 0;
break;
case GENERIC_EE_RETRY:
gsi->result = -EAGAIN;
break;
default:
dev_err(gsi->dev, "global INT1 generic result %u\n", result);
gsi->result = -EIO;
break;
}
complete(&gsi->completion);
}
/* Inter-EE interrupt handler */
static void gsi_isr_glob_ee(struct gsi *gsi)
{
u32 val;
val = ioread32(gsi->virt + GSI_CNTXT_GLOB_IRQ_STTS_OFFSET);
if (val & BIT(ERROR_INT))
gsi_isr_glob_err(gsi);
iowrite32(val, gsi->virt + GSI_CNTXT_GLOB_IRQ_CLR_OFFSET);
val &= ~BIT(ERROR_INT);
if (val & BIT(GP_INT1)) {
val ^= BIT(GP_INT1);
gsi_isr_gp_int1(gsi);
}
if (val)
dev_err(gsi->dev, "unexpected global interrupt 0x%08x\n", val);
}
/* I/O completion interrupt event */
static void gsi_isr_ieob(struct gsi *gsi)
{
u32 event_mask;
event_mask = ioread32(gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_OFFSET);
iowrite32(event_mask, gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_CLR_OFFSET);
while (event_mask) {
u32 evt_ring_id = __ffs(event_mask);
event_mask ^= BIT(evt_ring_id);
gsi_irq_ieob_disable(gsi, evt_ring_id);
napi_schedule(&gsi->evt_ring[evt_ring_id].channel->napi);
}
}
/* General event interrupts represent serious problems, so report them */
static void gsi_isr_general(struct gsi *gsi)
{
struct device *dev = gsi->dev;
u32 val;
val = ioread32(gsi->virt + GSI_CNTXT_GSI_IRQ_STTS_OFFSET);
iowrite32(val, gsi->virt + GSI_CNTXT_GSI_IRQ_CLR_OFFSET);
dev_err(dev, "unexpected general interrupt 0x%08x\n", val);
}
/**
* gsi_isr() - Top level GSI interrupt service routine
* @irq: Interrupt number (ignored)
* @dev_id: GSI pointer supplied to request_irq()
*
* This is the main handler function registered for the GSI IRQ. Each type
* of interrupt has a separate handler function that is called from here.
*/
static irqreturn_t gsi_isr(int irq, void *dev_id)
{
struct gsi *gsi = dev_id;
u32 intr_mask;
u32 cnt = 0;
/* enum gsi_irq_type_id defines GSI interrupt types */
while ((intr_mask = ioread32(gsi->virt + GSI_CNTXT_TYPE_IRQ_OFFSET))) {
/* intr_mask contains bitmask of pending GSI interrupts */
do {
u32 gsi_intr = BIT(__ffs(intr_mask));
intr_mask ^= gsi_intr;
switch (gsi_intr) {
case BIT(GSI_CH_CTRL):
gsi_isr_chan_ctrl(gsi);
break;
case BIT(GSI_EV_CTRL):
gsi_isr_evt_ctrl(gsi);
break;
case BIT(GSI_GLOB_EE):
gsi_isr_glob_ee(gsi);
break;
case BIT(GSI_IEOB):
gsi_isr_ieob(gsi);
break;
case BIT(GSI_GENERAL):
gsi_isr_general(gsi);
break;
default:
dev_err(gsi->dev,
"unrecognized interrupt type 0x%08x\n",
gsi_intr);
break;
}
} while (intr_mask);
if (++cnt > GSI_ISR_MAX_ITER) {
dev_err(gsi->dev, "interrupt flood\n");
break;
}
}
return IRQ_HANDLED;
}
static int gsi_irq_init(struct gsi *gsi, struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
unsigned int irq;
int ret;
ret = platform_get_irq_byname(pdev, "gsi");
if (ret <= 0) {
dev_err(dev, "DT error %d getting \"gsi\" IRQ property\n", ret);
return ret ? : -EINVAL;
}
irq = ret;
ret = request_irq(irq, gsi_isr, 0, "gsi", gsi);
if (ret) {
dev_err(dev, "error %d requesting \"gsi\" IRQ\n", ret);
return ret;
}
gsi->irq = irq;
return 0;
}
static void gsi_irq_exit(struct gsi *gsi)
{
free_irq(gsi->irq, gsi);
}
/* Return the transaction associated with a transfer completion event */
static struct gsi_trans *gsi_event_trans(struct gsi_channel *channel,
struct gsi_event *event)
{
u32 tre_offset;
u32 tre_index;
/* Event xfer_ptr records the TRE it's associated with */
tre_offset = le64_to_cpu(event->xfer_ptr) & GENMASK(31, 0);
tre_index = gsi_ring_index(&channel->tre_ring, tre_offset);
return gsi_channel_trans_mapped(channel, tre_index);
}
/**
* gsi_evt_ring_rx_update() - Record lengths of received data
* @evt_ring: Event ring associated with channel that received packets
* @index: Event index in ring reported by hardware
*
* Events for RX channels contain the actual number of bytes received into
* the buffer. Every event has a transaction associated with it, and here
* we update transactions to record their actual received lengths.
*
* This function is called whenever we learn that the GSI hardware has filled
* new events since the last time we checked. The ring's index field tells
* the first entry in need of processing. The index provided is the
* first *unfilled* event in the ring (following the last filled one).
*
* Events are sequential within the event ring, and transactions are
* sequential within the transaction pool.
*
* Note that @index always refers to an element *within* the event ring.
*/
static void gsi_evt_ring_rx_update(struct gsi_evt_ring *evt_ring, u32 index)
{
struct gsi_channel *channel = evt_ring->channel;
struct gsi_ring *ring = &evt_ring->ring;
struct gsi_trans_info *trans_info;
struct gsi_event *event_done;
struct gsi_event *event;
struct gsi_trans *trans;
u32 byte_count = 0;
u32 old_index;
u32 event_avail;
trans_info = &channel->trans_info;
/* We'll start with the oldest un-processed event. RX channels
* replenish receive buffers in single-TRE transactions, so we
* can just map that event to its transaction. Transactions
* associated with completion events are consecutive.
*/
old_index = ring->index;
event = gsi_ring_virt(ring, old_index);
trans = gsi_event_trans(channel, event);
/* Compute the number of events to process before we wrap,
* and determine when we'll be done processing events.
*/
event_avail = ring->count - old_index % ring->count;
event_done = gsi_ring_virt(ring, index);
do {
trans->len = __le16_to_cpu(event->len);
byte_count += trans->len;
/* Move on to the next event and transaction */
if (--event_avail)
event++;
else
event = gsi_ring_virt(ring, 0);
trans = gsi_trans_pool_next(&trans_info->pool, trans);
} while (event != event_done);
/* We record RX bytes when they are received */
channel->byte_count += byte_count;
channel->trans_count++;
}
/* Initialize a ring, including allocating DMA memory for its entries */
static int gsi_ring_alloc(struct gsi *gsi, struct gsi_ring *ring, u32 count)
{
size_t size = count * GSI_RING_ELEMENT_SIZE;
struct device *dev = gsi->dev;
dma_addr_t addr;
/* Hardware requires a 2^n ring size, with alignment equal to size */
ring->virt = dma_alloc_coherent(dev, size, &addr, GFP_KERNEL);
if (ring->virt && addr % size) {
dma_free_coherent(dev, size, ring->virt, ring->addr);
dev_err(dev, "unable to alloc 0x%zx-aligned ring buffer\n",
size);
return -EINVAL; /* Not a good error value, but distinct */
} else if (!ring->virt) {
return -ENOMEM;
}
ring->addr = addr;
ring->count = count;
return 0;
}
/* Free a previously-allocated ring */
static void gsi_ring_free(struct gsi *gsi, struct gsi_ring *ring)
{
size_t size = ring->count * GSI_RING_ELEMENT_SIZE;
dma_free_coherent(gsi->dev, size, ring->virt, ring->addr);
}
/* Allocate an available event ring id */
static int gsi_evt_ring_id_alloc(struct gsi *gsi)
{
u32 evt_ring_id;
if (gsi->event_bitmap == ~0U) {
dev_err(gsi->dev, "event rings exhausted\n");
return -ENOSPC;
}
evt_ring_id = ffz(gsi->event_bitmap);
gsi->event_bitmap |= BIT(evt_ring_id);
return (int)evt_ring_id;
}
/* Free a previously-allocated event ring id */
static void gsi_evt_ring_id_free(struct gsi *gsi, u32 evt_ring_id)
{
gsi->event_bitmap &= ~BIT(evt_ring_id);
}
/* Ring a channel doorbell, reporting the first un-filled entry */
void gsi_channel_doorbell(struct gsi_channel *channel)
{
struct gsi_ring *tre_ring = &channel->tre_ring;
u32 channel_id = gsi_channel_id(channel);
struct gsi *gsi = channel->gsi;
u32 val;
/* Note: index *must* be used modulo the ring count here */
val = gsi_ring_addr(tre_ring, tre_ring->index % tre_ring->count);
iowrite32(val, gsi->virt + GSI_CH_C_DOORBELL_0_OFFSET(channel_id));
}
/* Consult hardware, move any newly completed transactions to completed list */
static void gsi_channel_update(struct gsi_channel *channel)
{
u32 evt_ring_id = channel->evt_ring_id;
struct gsi *gsi = channel->gsi;
struct gsi_evt_ring *evt_ring;
struct gsi_trans *trans;
struct gsi_ring *ring;
u32 offset;
u32 index;
evt_ring = &gsi->evt_ring[evt_ring_id];
ring = &evt_ring->ring;
/* See if there's anything new to process; if not, we're done. Note
* that index always refers to an entry *within* the event ring.
*/
offset = GSI_EV_CH_E_CNTXT_4_OFFSET(evt_ring_id);
index = gsi_ring_index(ring, ioread32(gsi->virt + offset));
if (index == ring->index % ring->count)
return;
/* Get the transaction for the latest completed event. Take a
* reference to keep it from completing before we give the events
* for this and previous transactions back to the hardware.
*/
trans = gsi_event_trans(channel, gsi_ring_virt(ring, index - 1));
refcount_inc(&trans->refcount);
/* For RX channels, update each completed transaction with the number
* of bytes that were actually received. For TX channels, report
* the number of transactions and bytes this completion represents
* up the network stack.
*/
if (channel->toward_ipa)
gsi_channel_tx_update(channel, trans);
else
gsi_evt_ring_rx_update(evt_ring, index);
gsi_trans_move_complete(trans);
/* Tell the hardware we've handled these events */
gsi_evt_ring_doorbell(channel->gsi, channel->evt_ring_id, index);
gsi_trans_free(trans);
}
/**
* gsi_channel_poll_one() - Return a single completed transaction on a channel
* @channel: Channel to be polled
*
* Return: Transaction pointer, or null if none are available
*
* This function returns the first entry on a channel's completed transaction
* list. If that list is empty, the hardware is consulted to determine
* whether any new transactions have completed. If so, they're moved to the
* completed list and the new first entry is returned. If there are no more
* completed transactions, a null pointer is returned.
*/
static struct gsi_trans *gsi_channel_poll_one(struct gsi_channel *channel)
{
struct gsi_trans *trans;
/* Get the first transaction from the completed list */
trans = gsi_channel_trans_complete(channel);
if (!trans) {
/* List is empty; see if there's more to do */
gsi_channel_update(channel);
trans = gsi_channel_trans_complete(channel);
}
if (trans)
gsi_trans_move_polled(trans);
return trans;
}
/**
* gsi_channel_poll() - NAPI poll function for a channel
* @napi: NAPI structure for the channel
* @budget: Budget supplied by NAPI core
*
* Return: Number of items polled (<= budget)
*
* Single transactions completed by hardware are polled until either
* the budget is exhausted, or there are no more. Each transaction
* polled is passed to gsi_trans_complete(), to perform remaining
* completion processing and retire/free the transaction.
*/
static int gsi_channel_poll(struct napi_struct *napi, int budget)
{
struct gsi_channel *channel;
int count = 0;
channel = container_of(napi, struct gsi_channel, napi);
while (count < budget) {
struct gsi_trans *trans;
count++;
trans = gsi_channel_poll_one(channel);
if (!trans)
break;
gsi_trans_complete(trans);
}
if (count < budget) {
napi_complete(&channel->napi);
gsi_irq_ieob_enable(channel->gsi, channel->evt_ring_id);
}
return count;
}
/* The event bitmap represents which event ids are available for allocation.
* Set bits are not available, clear bits can be used. This function
* initializes the map so all events supported by the hardware are available,
* then precludes any reserved events from being allocated.
*/
static u32 gsi_event_bitmap_init(u32 evt_ring_max)
{
u32 event_bitmap = GENMASK(BITS_PER_LONG - 1, evt_ring_max);
event_bitmap |= GENMASK(GSI_MHI_EVENT_ID_END, GSI_MHI_EVENT_ID_START);
return event_bitmap;
}
/* Setup function for event rings */
static void gsi_evt_ring_setup(struct gsi *gsi)
{
/* Nothing to do */
}
/* Inverse of gsi_evt_ring_setup() */
static void gsi_evt_ring_teardown(struct gsi *gsi)
{
/* Nothing to do */
}
/* Setup function for a single channel */
static int gsi_channel_setup_one(struct gsi *gsi, u32 channel_id)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
u32 evt_ring_id = channel->evt_ring_id;
int ret;
if (!channel->gsi)
return 0; /* Ignore uninitialized channels */
ret = gsi_evt_ring_alloc_command(gsi, evt_ring_id);
if (ret)
return ret;
gsi_evt_ring_program(gsi, evt_ring_id);
ret = gsi_channel_alloc_command(gsi, channel_id);
if (ret)
goto err_evt_ring_de_alloc;
gsi_channel_program(channel, true);
if (channel->toward_ipa)
netif_tx_napi_add(&gsi->dummy_dev, &channel->napi,
gsi_channel_poll, NAPI_POLL_WEIGHT);
else
netif_napi_add(&gsi->dummy_dev, &channel->napi,
gsi_channel_poll, NAPI_POLL_WEIGHT);
return 0;
err_evt_ring_de_alloc:
/* We've done nothing with the event ring yet so don't reset */
gsi_evt_ring_de_alloc_command(gsi, evt_ring_id);
return ret;
}
/* Inverse of gsi_channel_setup_one() */
static void gsi_channel_teardown_one(struct gsi *gsi, u32 channel_id)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
u32 evt_ring_id = channel->evt_ring_id;
if (!channel->gsi)
return; /* Ignore uninitialized channels */
netif_napi_del(&channel->napi);
gsi_channel_deprogram(channel);
gsi_channel_de_alloc_command(gsi, channel_id);
gsi_evt_ring_reset_command(gsi, evt_ring_id);
gsi_evt_ring_de_alloc_command(gsi, evt_ring_id);
}
static int gsi_generic_command(struct gsi *gsi, u32 channel_id,
enum gsi_generic_cmd_opcode opcode)
{
struct completion *completion = &gsi->completion;
bool success;
u32 val;
/* The error global interrupt type is always enabled (until we
* teardown), so we won't change that. A generic EE command
* completes with a GSI global interrupt of type GP_INT1. We
* only perform one generic command at a time (to allocate or
* halt a modem channel) and only from this function. So we
* enable the GP_INT1 IRQ type here while we're expecting it.
*/
val = BIT(ERROR_INT) | BIT(GP_INT1);
iowrite32(val, gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);
/* First zero the result code field */
val = ioread32(gsi->virt + GSI_CNTXT_SCRATCH_0_OFFSET);
val &= ~GENERIC_EE_RESULT_FMASK;
iowrite32(val, gsi->virt + GSI_CNTXT_SCRATCH_0_OFFSET);
/* Now issue the command */
val = u32_encode_bits(opcode, GENERIC_OPCODE_FMASK);
val |= u32_encode_bits(channel_id, GENERIC_CHID_FMASK);
val |= u32_encode_bits(GSI_EE_MODEM, GENERIC_EE_FMASK);
success = gsi_command(gsi, GSI_GENERIC_CMD_OFFSET, val, completion);
/* Disable the GP_INT1 IRQ type again */
iowrite32(BIT(ERROR_INT), gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);
if (success)
return gsi->result;
dev_err(gsi->dev, "GSI generic command %u to channel %u timed out\n",
opcode, channel_id);
return -ETIMEDOUT;
}
static int gsi_modem_channel_alloc(struct gsi *gsi, u32 channel_id)
{
return gsi_generic_command(gsi, channel_id,
GSI_GENERIC_ALLOCATE_CHANNEL);
}
static void gsi_modem_channel_halt(struct gsi *gsi, u32 channel_id)
{
u32 retries = GSI_CHANNEL_MODEM_HALT_RETRIES;
int ret;
do
ret = gsi_generic_command(gsi, channel_id,
GSI_GENERIC_HALT_CHANNEL);
while (ret == -EAGAIN && retries--);
if (ret)
dev_err(gsi->dev, "error %d halting modem channel %u\n",
ret, channel_id);
}
/* Setup function for channels */
static int gsi_channel_setup(struct gsi *gsi)
{
u32 channel_id = 0;
u32 mask;
int ret;
gsi_evt_ring_setup(gsi);
gsi_irq_enable(gsi);
mutex_lock(&gsi->mutex);
do {
ret = gsi_channel_setup_one(gsi, channel_id);
if (ret)
goto err_unwind;
} while (++channel_id < gsi->channel_count);
/* Make sure no channels were defined that hardware does not support */
while (channel_id < GSI_CHANNEL_COUNT_MAX) {
struct gsi_channel *channel = &gsi->channel[channel_id++];
if (!channel->gsi)
continue; /* Ignore uninitialized channels */
dev_err(gsi->dev, "channel %u not supported by hardware\n",
channel_id - 1);
channel_id = gsi->channel_count;
goto err_unwind;
}
/* Allocate modem channels if necessary */
mask = gsi->modem_channel_bitmap;
while (mask) {
u32 modem_channel_id = __ffs(mask);
ret = gsi_modem_channel_alloc(gsi, modem_channel_id);
if (ret)
goto err_unwind_modem;
/* Clear bit from mask only after success (for unwind) */
mask ^= BIT(modem_channel_id);
}
mutex_unlock(&gsi->mutex);
return 0;
err_unwind_modem:
/* Compute which modem channels need to be deallocated */
mask ^= gsi->modem_channel_bitmap;
while (mask) {
channel_id = __fls(mask);
mask ^= BIT(channel_id);
gsi_modem_channel_halt(gsi, channel_id);
}
err_unwind:
while (channel_id--)
gsi_channel_teardown_one(gsi, channel_id);
mutex_unlock(&gsi->mutex);
gsi_irq_disable(gsi);
gsi_evt_ring_teardown(gsi);
return ret;
}
/* Inverse of gsi_channel_setup() */
static void gsi_channel_teardown(struct gsi *gsi)
{
u32 mask = gsi->modem_channel_bitmap;
u32 channel_id;
mutex_lock(&gsi->mutex);
while (mask) {
channel_id = __fls(mask);
mask ^= BIT(channel_id);
gsi_modem_channel_halt(gsi, channel_id);
}
channel_id = gsi->channel_count - 1;
do
gsi_channel_teardown_one(gsi, channel_id);
while (channel_id--);
mutex_unlock(&gsi->mutex);
gsi_irq_disable(gsi);
gsi_evt_ring_teardown(gsi);
}
/* Setup function for GSI. GSI firmware must be loaded and initialized */
int gsi_setup(struct gsi *gsi)
{
struct device *dev = gsi->dev;
u32 val;
int ret;
/* Here is where we first touch the GSI hardware */
val = ioread32(gsi->virt + GSI_GSI_STATUS_OFFSET);
if (!(val & ENABLED_FMASK)) {
dev_err(dev, "GSI has not been enabled\n");
return -EIO;
}
gsi_irq_setup(gsi);
val = ioread32(gsi->virt + GSI_GSI_HW_PARAM_2_OFFSET);
gsi->channel_count = u32_get_bits(val, NUM_CH_PER_EE_FMASK);
if (!gsi->channel_count) {
dev_err(dev, "GSI reports zero channels supported\n");
return -EINVAL;
}
if (gsi->channel_count > GSI_CHANNEL_COUNT_MAX) {
dev_warn(dev,
"limiting to %u channels; hardware supports %u\n",
GSI_CHANNEL_COUNT_MAX, gsi->channel_count);
gsi->channel_count = GSI_CHANNEL_COUNT_MAX;
}
gsi->evt_ring_count = u32_get_bits(val, NUM_EV_PER_EE_FMASK);
if (!gsi->evt_ring_count) {
dev_err(dev, "GSI reports zero event rings supported\n");
return -EINVAL;
}
if (gsi->evt_ring_count > GSI_EVT_RING_COUNT_MAX) {
dev_warn(dev,
"limiting to %u event rings; hardware supports %u\n",
GSI_EVT_RING_COUNT_MAX, gsi->evt_ring_count);
gsi->evt_ring_count = GSI_EVT_RING_COUNT_MAX;
}
/* Initialize the error log */
iowrite32(0, gsi->virt + GSI_ERROR_LOG_OFFSET);
/* Writing 1 indicates IRQ interrupts; 0 would be MSI */
iowrite32(1, gsi->virt + GSI_CNTXT_INTSET_OFFSET);
ret = gsi_channel_setup(gsi);
if (ret)
gsi_irq_teardown(gsi);
return ret;
}
/* Inverse of gsi_setup() */
void gsi_teardown(struct gsi *gsi)
{
gsi_channel_teardown(gsi);
gsi_irq_teardown(gsi);
}
/* Initialize a channel's event ring */
static int gsi_channel_evt_ring_init(struct gsi_channel *channel)
{
struct gsi *gsi = channel->gsi;
struct gsi_evt_ring *evt_ring;
int ret;
ret = gsi_evt_ring_id_alloc(gsi);
if (ret < 0)
return ret;
channel->evt_ring_id = ret;
evt_ring = &gsi->evt_ring[channel->evt_ring_id];
evt_ring->channel = channel;
ret = gsi_ring_alloc(gsi, &evt_ring->ring, channel->event_count);
if (!ret)
return 0; /* Success! */
dev_err(gsi->dev, "error %d allocating channel %u event ring\n",
ret, gsi_channel_id(channel));
gsi_evt_ring_id_free(gsi, channel->evt_ring_id);
return ret;
}
/* Inverse of gsi_channel_evt_ring_init() */
static void gsi_channel_evt_ring_exit(struct gsi_channel *channel)
{
u32 evt_ring_id = channel->evt_ring_id;
struct gsi *gsi = channel->gsi;
struct gsi_evt_ring *evt_ring;
evt_ring = &gsi->evt_ring[evt_ring_id];
gsi_ring_free(gsi, &evt_ring->ring);
gsi_evt_ring_id_free(gsi, evt_ring_id);
}
/* Init function for event rings */
static void gsi_evt_ring_init(struct gsi *gsi)
{
u32 evt_ring_id = 0;
gsi->event_bitmap = gsi_event_bitmap_init(GSI_EVT_RING_COUNT_MAX);
gsi->ieob_enabled_bitmap = 0;
do
init_completion(&gsi->evt_ring[evt_ring_id].completion);
while (++evt_ring_id < GSI_EVT_RING_COUNT_MAX);
}
/* Inverse of gsi_evt_ring_init() */
static void gsi_evt_ring_exit(struct gsi *gsi)
{
/* Nothing to do */
}
static bool gsi_channel_data_valid(struct gsi *gsi,
const struct ipa_gsi_endpoint_data *data)
{
#ifdef IPA_VALIDATION
u32 channel_id = data->channel_id;
struct device *dev = gsi->dev;
/* Make sure channel ids are in the range driver supports */
if (channel_id >= GSI_CHANNEL_COUNT_MAX) {
dev_err(dev, "bad channel id %u; must be less than %u\n",
channel_id, GSI_CHANNEL_COUNT_MAX);
return false;
}
if (data->ee_id != GSI_EE_AP && data->ee_id != GSI_EE_MODEM) {
dev_err(dev, "bad EE id %u; not AP or modem\n", data->ee_id);
return false;
}
if (!data->channel.tlv_count ||
data->channel.tlv_count > GSI_TLV_MAX) {
dev_err(dev, "channel %u bad tlv_count %u; must be 1..%u\n",
channel_id, data->channel.tlv_count, GSI_TLV_MAX);
return false;
}
/* We have to allow at least one maximally-sized transaction to
* be outstanding (which would use tlv_count TREs). Given how
* gsi_channel_tre_max() is computed, tre_count has to be almost
* twice the TLV FIFO size to satisfy this requirement.
*/
if (data->channel.tre_count < 2 * data->channel.tlv_count - 1) {
dev_err(dev, "channel %u TLV count %u exceeds TRE count %u\n",
channel_id, data->channel.tlv_count,
data->channel.tre_count);
return false;
}
if (!is_power_of_2(data->channel.tre_count)) {
dev_err(dev, "channel %u bad tre_count %u; not power of 2\n",
channel_id, data->channel.tre_count);
return false;
}
if (!is_power_of_2(data->channel.event_count)) {
dev_err(dev, "channel %u bad event_count %u; not power of 2\n",
channel_id, data->channel.event_count);
return false;
}
#endif /* IPA_VALIDATION */
return true;
}
/* Init function for a single channel */
static int gsi_channel_init_one(struct gsi *gsi,
const struct ipa_gsi_endpoint_data *data,
bool command)
{
struct gsi_channel *channel;
u32 tre_count;
int ret;
if (!gsi_channel_data_valid(gsi, data))
return -EINVAL;
/* Worst case we need an event for every outstanding TRE */
if (data->channel.tre_count > data->channel.event_count) {
tre_count = data->channel.event_count;
dev_warn(gsi->dev, "channel %u limited to %u TREs\n",
data->channel_id, tre_count);
} else {
tre_count = data->channel.tre_count;
}
channel = &gsi->channel[data->channel_id];
memset(channel, 0, sizeof(*channel));
channel->gsi = gsi;
channel->toward_ipa = data->toward_ipa;
channel->command = command;
channel->tlv_count = data->channel.tlv_count;
channel->tre_count = tre_count;
channel->event_count = data->channel.event_count;
init_completion(&channel->completion);
ret = gsi_channel_evt_ring_init(channel);
if (ret)
goto err_clear_gsi;
ret = gsi_ring_alloc(gsi, &channel->tre_ring, data->channel.tre_count);
if (ret) {
dev_err(gsi->dev, "error %d allocating channel %u ring\n",
ret, data->channel_id);
goto err_channel_evt_ring_exit;
}
ret = gsi_channel_trans_init(gsi, data->channel_id);
if (ret)
goto err_ring_free;
if (command) {
u32 tre_max = gsi_channel_tre_max(gsi, data->channel_id);
ret = ipa_cmd_pool_init(channel, tre_max);
}
if (!ret)
return 0; /* Success! */
gsi_channel_trans_exit(channel);
err_ring_free:
gsi_ring_free(gsi, &channel->tre_ring);
err_channel_evt_ring_exit:
gsi_channel_evt_ring_exit(channel);
err_clear_gsi:
channel->gsi = NULL; /* Mark it not (fully) initialized */
return ret;
}
/* Inverse of gsi_channel_init_one() */
static void gsi_channel_exit_one(struct gsi_channel *channel)
{
if (!channel->gsi)
return; /* Ignore uninitialized channels */
if (channel->command)
ipa_cmd_pool_exit(channel);
gsi_channel_trans_exit(channel);
gsi_ring_free(channel->gsi, &channel->tre_ring);
gsi_channel_evt_ring_exit(channel);
}
/* Init function for channels */
static int gsi_channel_init(struct gsi *gsi, u32 count,
const struct ipa_gsi_endpoint_data *data)
{
bool modem_alloc;
int ret = 0;
u32 i;
/* IPA v4.2 requires the AP to allocate channels for the modem */
modem_alloc = gsi->version == IPA_VERSION_4_2;
gsi_evt_ring_init(gsi);
/* The endpoint data array is indexed by endpoint name */
for (i = 0; i < count; i++) {
bool command = i == IPA_ENDPOINT_AP_COMMAND_TX;
if (ipa_gsi_endpoint_data_empty(&data[i]))
continue; /* Skip over empty slots */
/* Mark modem channels to be allocated (hardware workaround) */
if (data[i].ee_id == GSI_EE_MODEM) {
if (modem_alloc)
gsi->modem_channel_bitmap |=
BIT(data[i].channel_id);
continue;
}
ret = gsi_channel_init_one(gsi, &data[i], command);
if (ret)
goto err_unwind;
}
return ret;
err_unwind:
while (i--) {
if (ipa_gsi_endpoint_data_empty(&data[i]))
continue;
if (modem_alloc && data[i].ee_id == GSI_EE_MODEM) {
gsi->modem_channel_bitmap &= ~BIT(data[i].channel_id);
continue;
}
gsi_channel_exit_one(&gsi->channel[data->channel_id]);
}
gsi_evt_ring_exit(gsi);
return ret;
}
/* Inverse of gsi_channel_init() */
static void gsi_channel_exit(struct gsi *gsi)
{
u32 channel_id = GSI_CHANNEL_COUNT_MAX - 1;
do
gsi_channel_exit_one(&gsi->channel[channel_id]);
while (channel_id--);
gsi->modem_channel_bitmap = 0;
gsi_evt_ring_exit(gsi);
}
/* Init function for GSI. GSI hardware does not need to be "ready" */
int gsi_init(struct gsi *gsi, struct platform_device *pdev,
enum ipa_version version, u32 count,
const struct ipa_gsi_endpoint_data *data)
{
struct device *dev = &pdev->dev;
struct resource *res;
resource_size_t size;
u32 adjust;
int ret;
gsi_validate_build();
gsi->dev = dev;
gsi->version = version;
/* The GSI layer performs NAPI on all endpoints. NAPI requires a
* network device structure, but the GSI layer does not have one,
* so we must create a dummy network device for this purpose.
*/
init_dummy_netdev(&gsi->dummy_dev);
/* Get GSI memory range and map it */
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "gsi");
if (!res) {
dev_err(dev, "DT error getting \"gsi\" memory property\n");
return -ENODEV;
}
size = resource_size(res);
if (res->start > U32_MAX || size > U32_MAX - res->start) {
dev_err(dev, "DT memory resource \"gsi\" out of range\n");
return -EINVAL;
}
/* Make sure we can make our pointer adjustment if necessary */
adjust = gsi->version < IPA_VERSION_4_5 ? 0 : GSI_EE_REG_ADJUST;
if (res->start < adjust) {
dev_err(dev, "DT memory resource \"gsi\" too low (< %u)\n",
adjust);
return -EINVAL;
}
gsi->virt = ioremap(res->start, size);
if (!gsi->virt) {
dev_err(dev, "unable to remap \"gsi\" memory\n");
return -ENOMEM;
}
/* Adjust register range pointer downward for newer IPA versions */
gsi->virt -= adjust;
init_completion(&gsi->completion);
ret = gsi_irq_init(gsi, pdev);
if (ret)
goto err_iounmap;
ret = gsi_channel_init(gsi, count, data);
if (ret)
goto err_irq_exit;
mutex_init(&gsi->mutex);
return 0;
err_irq_exit:
gsi_irq_exit(gsi);
err_iounmap:
iounmap(gsi->virt);
return ret;
}
/* Inverse of gsi_init() */
void gsi_exit(struct gsi *gsi)
{
mutex_destroy(&gsi->mutex);
gsi_channel_exit(gsi);
gsi_irq_exit(gsi);
iounmap(gsi->virt);
}
/* The maximum number of outstanding TREs on a channel. This limits
* a channel's maximum number of transactions outstanding (worst case
* is one TRE per transaction).
*
* The absolute limit is the number of TREs in the channel's TRE ring,
* and in theory we should be able use all of them. But in practice,
* doing that led to the hardware reporting exhaustion of event ring
* slots for writing completion information. So the hardware limit
* would be (tre_count - 1).
*
* We reduce it a bit further though. Transaction resource pools are
* sized to be a little larger than this maximum, to allow resource
* allocations to always be contiguous. The number of entries in a
* TRE ring buffer is a power of 2, and the extra resources in a pool
* tends to nearly double the memory allocated for it. Reducing the
* maximum number of outstanding TREs allows the number of entries in
* a pool to avoid crossing that power-of-2 boundary, and this can
* substantially reduce pool memory requirements. The number we
* reduce it by matches the number added in gsi_trans_pool_init().
*/
u32 gsi_channel_tre_max(struct gsi *gsi, u32 channel_id)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
/* Hardware limit is channel->tre_count - 1 */
return channel->tre_count - (channel->tlv_count - 1);
}
/* Returns the maximum number of TREs in a single transaction for a channel */
u32 gsi_channel_trans_tre_max(struct gsi *gsi, u32 channel_id)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
return channel->tlv_count;
}