blob: 002e514485100b52e1ecf323de0e9dc5e2ae9741 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
* Copyright (C) 2019-2020 Linaro Ltd.
*/
#include <linux/types.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/bitfield.h>
#include <linux/dma-direction.h>
#include "gsi.h"
#include "gsi_trans.h"
#include "ipa.h"
#include "ipa_endpoint.h"
#include "ipa_table.h"
#include "ipa_cmd.h"
#include "ipa_mem.h"
/**
* DOC: IPA Immediate Commands
*
* The AP command TX endpoint is used to issue immediate commands to the IPA.
* An immediate command is generally used to request the IPA do something
* other than data transfer to another endpoint.
*
* Immediate commands are represented by GSI transactions just like other
* transfer requests, represented by a single GSI TRE. Each immediate
* command has a well-defined format, having a payload of a known length.
* This allows the transfer element's length field to be used to hold an
* immediate command's opcode. The payload for a command resides in DRAM
* and is described by a single scatterlist entry in its transaction.
* Commands do not require a transaction completion callback. To commit
* an immediate command transaction, either gsi_trans_commit_wait() or
* gsi_trans_commit_wait_timeout() is used.
*/
/* Some commands can wait until indicated pipeline stages are clear */
enum pipeline_clear_options {
pipeline_clear_hps = 0x0,
pipeline_clear_src_grp = 0x1,
pipeline_clear_full = 0x2,
};
/* IPA_CMD_IP_V{4,6}_{FILTER,ROUTING}_INIT */
struct ipa_cmd_hw_ip_fltrt_init {
__le64 hash_rules_addr;
__le64 flags;
__le64 nhash_rules_addr;
};
/* Field masks for ipa_cmd_hw_ip_fltrt_init structure fields */
#define IP_FLTRT_FLAGS_HASH_SIZE_FMASK GENMASK_ULL(11, 0)
#define IP_FLTRT_FLAGS_HASH_ADDR_FMASK GENMASK_ULL(27, 12)
#define IP_FLTRT_FLAGS_NHASH_SIZE_FMASK GENMASK_ULL(39, 28)
#define IP_FLTRT_FLAGS_NHASH_ADDR_FMASK GENMASK_ULL(55, 40)
/* IPA_CMD_HDR_INIT_LOCAL */
struct ipa_cmd_hw_hdr_init_local {
__le64 hdr_table_addr;
__le32 flags;
__le32 reserved;
};
/* Field masks for ipa_cmd_hw_hdr_init_local structure fields */
#define HDR_INIT_LOCAL_FLAGS_TABLE_SIZE_FMASK GENMASK(11, 0)
#define HDR_INIT_LOCAL_FLAGS_HDR_ADDR_FMASK GENMASK(27, 12)
/* IPA_CMD_REGISTER_WRITE */
/* For IPA v4.0+, this opcode gets modified with pipeline clear options */
#define REGISTER_WRITE_OPCODE_SKIP_CLEAR_FMASK GENMASK(8, 8)
#define REGISTER_WRITE_OPCODE_CLEAR_OPTION_FMASK GENMASK(10, 9)
struct ipa_cmd_register_write {
__le16 flags; /* Unused/reserved for IPA v3.5.1 */
__le16 offset;
__le32 value;
__le32 value_mask;
__le32 clear_options; /* Unused/reserved for IPA v4.0+ */
};
/* Field masks for ipa_cmd_register_write structure fields */
/* The next field is present for IPA v4.0 and above */
#define REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK GENMASK(14, 11)
/* The next field is present for IPA v3.5.1 only */
#define REGISTER_WRITE_FLAGS_SKIP_CLEAR_FMASK GENMASK(15, 15)
/* The next field and its values are present for IPA v3.5.1 only */
#define REGISTER_WRITE_CLEAR_OPTIONS_FMASK GENMASK(1, 0)
/* IPA_CMD_IP_PACKET_INIT */
struct ipa_cmd_ip_packet_init {
u8 dest_endpoint;
u8 reserved[7];
};
/* Field masks for ipa_cmd_ip_packet_init dest_endpoint field */
#define IPA_PACKET_INIT_DEST_ENDPOINT_FMASK GENMASK(4, 0)
/* IPA_CMD_DMA_SHARED_MEM */
/* For IPA v4.0+, this opcode gets modified with pipeline clear options */
#define DMA_SHARED_MEM_OPCODE_SKIP_CLEAR_FMASK GENMASK(8, 8)
#define DMA_SHARED_MEM_OPCODE_CLEAR_OPTION_FMASK GENMASK(10, 9)
struct ipa_cmd_hw_dma_mem_mem {
__le16 clear_after_read; /* 0 or DMA_SHARED_MEM_CLEAR_AFTER_READ */
__le16 size;
__le16 local_addr;
__le16 flags;
__le64 system_addr;
};
/* Flag allowing atomic clear of target region after reading data (v4.0+)*/
#define DMA_SHARED_MEM_CLEAR_AFTER_READ GENMASK(15, 15)
/* Field masks for ipa_cmd_hw_dma_mem_mem structure fields */
#define DMA_SHARED_MEM_FLAGS_DIRECTION_FMASK GENMASK(0, 0)
/* The next two fields are present for IPA v3.5.1 only. */
#define DMA_SHARED_MEM_FLAGS_SKIP_CLEAR_FMASK GENMASK(1, 1)
#define DMA_SHARED_MEM_FLAGS_CLEAR_OPTIONS_FMASK GENMASK(3, 2)
/* IPA_CMD_IP_PACKET_TAG_STATUS */
struct ipa_cmd_ip_packet_tag_status {
__le64 tag;
};
#define IP_PACKET_TAG_STATUS_TAG_FMASK GENMASK_ULL(63, 16)
/* Immediate command payload */
union ipa_cmd_payload {
struct ipa_cmd_hw_ip_fltrt_init table_init;
struct ipa_cmd_hw_hdr_init_local hdr_init_local;
struct ipa_cmd_register_write register_write;
struct ipa_cmd_ip_packet_init ip_packet_init;
struct ipa_cmd_hw_dma_mem_mem dma_shared_mem;
struct ipa_cmd_ip_packet_tag_status ip_packet_tag_status;
};
static void ipa_cmd_validate_build(void)
{
/* The sizes of a filter and route tables need to fit into fields
* in the ipa_cmd_hw_ip_fltrt_init structure. Although hashed tables
* might not be used, non-hashed and hashed tables have the same
* maximum size. IPv4 and IPv6 filter tables have the same number
* of entries, as and IPv4 and IPv6 route tables have the same number
* of entries.
*/
#define TABLE_SIZE (TABLE_COUNT_MAX * IPA_TABLE_ENTRY_SIZE)
#define TABLE_COUNT_MAX max_t(u32, IPA_ROUTE_COUNT_MAX, IPA_FILTER_COUNT_MAX)
BUILD_BUG_ON(TABLE_SIZE > field_max(IP_FLTRT_FLAGS_HASH_SIZE_FMASK));
BUILD_BUG_ON(TABLE_SIZE > field_max(IP_FLTRT_FLAGS_NHASH_SIZE_FMASK));
#undef TABLE_COUNT_MAX
#undef TABLE_SIZE
}
#ifdef IPA_VALIDATE
/* Validate a memory region holding a table */
bool ipa_cmd_table_valid(struct ipa *ipa, const struct ipa_mem *mem,
bool route, bool ipv6, bool hashed)
{
struct device *dev = &ipa->pdev->dev;
u32 offset_max;
offset_max = hashed ? field_max(IP_FLTRT_FLAGS_HASH_ADDR_FMASK)
: field_max(IP_FLTRT_FLAGS_NHASH_ADDR_FMASK);
if (mem->offset > offset_max ||
ipa->mem_offset > offset_max - mem->offset) {
dev_err(dev, "IPv%c %s%s table region offset too large "
"(0x%04x + 0x%04x > 0x%04x)\n",
ipv6 ? '6' : '4', hashed ? "hashed " : "",
route ? "route" : "filter",
ipa->mem_offset, mem->offset, offset_max);
return false;
}
if (mem->offset > ipa->mem_size ||
mem->size > ipa->mem_size - mem->offset) {
dev_err(dev, "IPv%c %s%s table region out of range "
"(0x%04x + 0x%04x > 0x%04x)\n",
ipv6 ? '6' : '4', hashed ? "hashed " : "",
route ? "route" : "filter",
mem->offset, mem->size, ipa->mem_size);
return false;
}
return true;
}
/* Validate the memory region that holds headers */
static bool ipa_cmd_header_valid(struct ipa *ipa)
{
const struct ipa_mem *mem = &ipa->mem[IPA_MEM_MODEM_HEADER];
struct device *dev = &ipa->pdev->dev;
u32 offset_max;
u32 size_max;
u32 size;
offset_max = field_max(HDR_INIT_LOCAL_FLAGS_HDR_ADDR_FMASK);
if (mem->offset > offset_max ||
ipa->mem_offset > offset_max - mem->offset) {
dev_err(dev, "header table region offset too large "
"(0x%04x + 0x%04x > 0x%04x)\n",
ipa->mem_offset + mem->offset, offset_max);
return false;
}
size_max = field_max(HDR_INIT_LOCAL_FLAGS_TABLE_SIZE_FMASK);
size = ipa->mem[IPA_MEM_MODEM_HEADER].size;
size += ipa->mem[IPA_MEM_AP_HEADER].size;
if (mem->offset > ipa->mem_size || size > ipa->mem_size - mem->offset) {
dev_err(dev, "header table region out of range "
"(0x%04x + 0x%04x > 0x%04x)\n",
mem->offset, size, ipa->mem_size);
return false;
}
return true;
}
/* Indicate whether an offset can be used with a register_write command */
static bool ipa_cmd_register_write_offset_valid(struct ipa *ipa,
const char *name, u32 offset)
{
struct ipa_cmd_register_write *payload;
struct device *dev = &ipa->pdev->dev;
u32 offset_max;
u32 bit_count;
/* The maximum offset in a register_write immediate command depends
* on the version of IPA. IPA v3.5.1 supports a 16 bit offset, but
* newer versions allow some additional high-order bits.
*/
bit_count = BITS_PER_BYTE * sizeof(payload->offset);
if (ipa->version != IPA_VERSION_3_5_1)
bit_count += hweight32(REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK);
BUILD_BUG_ON(bit_count > 32);
offset_max = ~0 >> (32 - bit_count);
if (offset > offset_max || ipa->mem_offset > offset_max - offset) {
dev_err(dev, "%s offset too large 0x%04x + 0x%04x > 0x%04x)\n",
ipa->mem_offset + offset, offset_max);
return false;
}
return true;
}
/* Check whether offsets passed to register_write are valid */
static bool ipa_cmd_register_write_valid(struct ipa *ipa)
{
const char *name;
u32 offset;
offset = ipa_reg_filt_rout_hash_flush_offset(ipa->version);
name = "filter/route hash flush";
if (!ipa_cmd_register_write_offset_valid(ipa, name, offset))
return false;
offset = IPA_REG_ENDP_STATUS_N_OFFSET(IPA_ENDPOINT_COUNT);
name = "maximal endpoint status";
if (!ipa_cmd_register_write_offset_valid(ipa, name, offset))
return false;
return true;
}
bool ipa_cmd_data_valid(struct ipa *ipa)
{
if (!ipa_cmd_header_valid(ipa))
return false;
if (!ipa_cmd_register_write_valid(ipa))
return false;
return true;
}
#endif /* IPA_VALIDATE */
int ipa_cmd_pool_init(struct gsi_channel *channel, u32 tre_max)
{
struct gsi_trans_info *trans_info = &channel->trans_info;
struct device *dev = channel->gsi->dev;
int ret;
/* This is as good a place as any to validate build constants */
ipa_cmd_validate_build();
/* Even though command payloads are allocated one at a time,
* a single transaction can require up to tlv_count of them,
* so we treat them as if that many can be allocated at once.
*/
ret = gsi_trans_pool_init_dma(dev, &trans_info->cmd_pool,
sizeof(union ipa_cmd_payload),
tre_max, channel->tlv_count);
if (ret)
return ret;
/* Each TRE needs a command info structure */
ret = gsi_trans_pool_init(&trans_info->info_pool,
sizeof(struct ipa_cmd_info),
tre_max, channel->tlv_count);
if (ret)
gsi_trans_pool_exit_dma(dev, &trans_info->cmd_pool);
return ret;
}
void ipa_cmd_pool_exit(struct gsi_channel *channel)
{
struct gsi_trans_info *trans_info = &channel->trans_info;
struct device *dev = channel->gsi->dev;
gsi_trans_pool_exit(&trans_info->info_pool);
gsi_trans_pool_exit_dma(dev, &trans_info->cmd_pool);
}
static union ipa_cmd_payload *
ipa_cmd_payload_alloc(struct ipa *ipa, dma_addr_t *addr)
{
struct gsi_trans_info *trans_info;
struct ipa_endpoint *endpoint;
endpoint = ipa->name_map[IPA_ENDPOINT_AP_COMMAND_TX];
trans_info = &ipa->gsi.channel[endpoint->channel_id].trans_info;
return gsi_trans_pool_alloc_dma(&trans_info->cmd_pool, addr);
}
/* If hash_size is 0, hash_offset and hash_addr ignored. */
void ipa_cmd_table_init_add(struct gsi_trans *trans,
enum ipa_cmd_opcode opcode, u16 size, u32 offset,
dma_addr_t addr, u16 hash_size, u32 hash_offset,
dma_addr_t hash_addr)
{
struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
enum dma_data_direction direction = DMA_TO_DEVICE;
struct ipa_cmd_hw_ip_fltrt_init *payload;
union ipa_cmd_payload *cmd_payload;
dma_addr_t payload_addr;
u64 val;
/* Record the non-hash table offset and size */
offset += ipa->mem_offset;
val = u64_encode_bits(offset, IP_FLTRT_FLAGS_NHASH_ADDR_FMASK);
val |= u64_encode_bits(size, IP_FLTRT_FLAGS_NHASH_SIZE_FMASK);
/* The hash table offset and address are zero if its size is 0 */
if (hash_size) {
/* Record the hash table offset and size */
hash_offset += ipa->mem_offset;
val |= u64_encode_bits(hash_offset,
IP_FLTRT_FLAGS_HASH_ADDR_FMASK);
val |= u64_encode_bits(hash_size,
IP_FLTRT_FLAGS_HASH_SIZE_FMASK);
}
cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
payload = &cmd_payload->table_init;
/* Fill in all offsets and sizes and the non-hash table address */
if (hash_size)
payload->hash_rules_addr = cpu_to_le64(hash_addr);
payload->flags = cpu_to_le64(val);
payload->nhash_rules_addr = cpu_to_le64(addr);
gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
direction, opcode);
}
/* Initialize header space in IPA-local memory */
void ipa_cmd_hdr_init_local_add(struct gsi_trans *trans, u32 offset, u16 size,
dma_addr_t addr)
{
struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
enum ipa_cmd_opcode opcode = IPA_CMD_HDR_INIT_LOCAL;
enum dma_data_direction direction = DMA_TO_DEVICE;
struct ipa_cmd_hw_hdr_init_local *payload;
union ipa_cmd_payload *cmd_payload;
dma_addr_t payload_addr;
u32 flags;
offset += ipa->mem_offset;
/* With this command we tell the IPA where in its local memory the
* header tables reside. The content of the buffer provided is
* also written via DMA into that space. The IPA hardware owns
* the table, but the AP must initialize it.
*/
cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
payload = &cmd_payload->hdr_init_local;
payload->hdr_table_addr = cpu_to_le64(addr);
flags = u32_encode_bits(size, HDR_INIT_LOCAL_FLAGS_TABLE_SIZE_FMASK);
flags |= u32_encode_bits(offset, HDR_INIT_LOCAL_FLAGS_HDR_ADDR_FMASK);
payload->flags = cpu_to_le32(flags);
gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
direction, opcode);
}
void ipa_cmd_register_write_add(struct gsi_trans *trans, u32 offset, u32 value,
u32 mask, bool clear_full)
{
struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
struct ipa_cmd_register_write *payload;
union ipa_cmd_payload *cmd_payload;
u32 opcode = IPA_CMD_REGISTER_WRITE;
dma_addr_t payload_addr;
u32 clear_option;
u32 options;
u16 flags;
/* pipeline_clear_src_grp is not used */
clear_option = clear_full ? pipeline_clear_full : pipeline_clear_hps;
if (ipa->version != IPA_VERSION_3_5_1) {
u16 offset_high;
u32 val;
/* Opcode encodes pipeline clear options */
/* SKIP_CLEAR is always 0 (don't skip pipeline clear) */
val = u16_encode_bits(clear_option,
REGISTER_WRITE_OPCODE_CLEAR_OPTION_FMASK);
opcode |= val;
/* Extract the high 4 bits from the offset */
offset_high = (u16)u32_get_bits(offset, GENMASK(19, 16));
offset &= (1 << 16) - 1;
/* Extract the top 4 bits and encode it into the flags field */
flags = u16_encode_bits(offset_high,
REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK);
options = 0; /* reserved */
} else {
flags = 0; /* SKIP_CLEAR flag is always 0 */
options = u16_encode_bits(clear_option,
REGISTER_WRITE_CLEAR_OPTIONS_FMASK);
}
cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
payload = &cmd_payload->register_write;
payload->flags = cpu_to_le16(flags);
payload->offset = cpu_to_le16((u16)offset);
payload->value = cpu_to_le32(value);
payload->value_mask = cpu_to_le32(mask);
payload->clear_options = cpu_to_le32(options);
gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
DMA_NONE, opcode);
}
/* Skip IP packet processing on the next data transfer on a TX channel */
static void ipa_cmd_ip_packet_init_add(struct gsi_trans *trans, u8 endpoint_id)
{
struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
enum ipa_cmd_opcode opcode = IPA_CMD_IP_PACKET_INIT;
enum dma_data_direction direction = DMA_TO_DEVICE;
struct ipa_cmd_ip_packet_init *payload;
union ipa_cmd_payload *cmd_payload;
dma_addr_t payload_addr;
/* assert(endpoint_id <
field_max(IPA_PACKET_INIT_DEST_ENDPOINT_FMASK)); */
cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
payload = &cmd_payload->ip_packet_init;
payload->dest_endpoint = u8_encode_bits(endpoint_id,
IPA_PACKET_INIT_DEST_ENDPOINT_FMASK);
gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
direction, opcode);
}
/* Use a DMA command to read or write a block of IPA-resident memory */
void ipa_cmd_dma_shared_mem_add(struct gsi_trans *trans, u32 offset, u16 size,
dma_addr_t addr, bool toward_ipa)
{
struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
enum ipa_cmd_opcode opcode = IPA_CMD_DMA_SHARED_MEM;
struct ipa_cmd_hw_dma_mem_mem *payload;
union ipa_cmd_payload *cmd_payload;
enum dma_data_direction direction;
dma_addr_t payload_addr;
u16 flags;
/* size and offset must fit in 16 bit fields */
/* assert(size > 0 && size <= U16_MAX); */
/* assert(offset <= U16_MAX && ipa->mem_offset <= U16_MAX - offset); */
offset += ipa->mem_offset;
cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
payload = &cmd_payload->dma_shared_mem;
/* payload->clear_after_read was reserved prior to IPA v4.0. It's
* never needed for current code, so it's 0 regardless of version.
*/
payload->size = cpu_to_le16(size);
payload->local_addr = cpu_to_le16(offset);
/* payload->flags:
* direction: 0 = write to IPA, 1 read from IPA
* Starting at v4.0 these are reserved; either way, all zero:
* pipeline clear: 0 = wait for pipeline clear (don't skip)
* clear_options: 0 = pipeline_clear_hps
* Instead, for v4.0+ these are encoded in the opcode. But again
* since both values are 0 we won't bother OR'ing them in.
*/
flags = toward_ipa ? 0 : DMA_SHARED_MEM_FLAGS_DIRECTION_FMASK;
payload->flags = cpu_to_le16(flags);
payload->system_addr = cpu_to_le64(addr);
direction = toward_ipa ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
direction, opcode);
}
static void ipa_cmd_ip_tag_status_add(struct gsi_trans *trans, u64 tag)
{
struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
enum ipa_cmd_opcode opcode = IPA_CMD_IP_PACKET_TAG_STATUS;
enum dma_data_direction direction = DMA_TO_DEVICE;
struct ipa_cmd_ip_packet_tag_status *payload;
union ipa_cmd_payload *cmd_payload;
dma_addr_t payload_addr;
/* assert(tag <= field_max(IP_PACKET_TAG_STATUS_TAG_FMASK)); */
cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
payload = &cmd_payload->ip_packet_tag_status;
payload->tag = u64_encode_bits(tag, IP_PACKET_TAG_STATUS_TAG_FMASK);
gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
direction, opcode);
}
/* Issue a small command TX data transfer */
static void ipa_cmd_transfer_add(struct gsi_trans *trans, u16 size)
{
struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
enum dma_data_direction direction = DMA_TO_DEVICE;
enum ipa_cmd_opcode opcode = IPA_CMD_NONE;
union ipa_cmd_payload *payload;
dma_addr_t payload_addr;
/* assert(size <= sizeof(*payload)); */
/* Just transfer a zero-filled payload structure */
payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
direction, opcode);
}
void ipa_cmd_tag_process_add(struct gsi_trans *trans)
{
struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
struct ipa_endpoint *endpoint;
endpoint = ipa->name_map[IPA_ENDPOINT_AP_LAN_RX];
ipa_cmd_register_write_add(trans, 0, 0, 0, true);
ipa_cmd_ip_packet_init_add(trans, endpoint->endpoint_id);
ipa_cmd_ip_tag_status_add(trans, 0xcba987654321);
ipa_cmd_transfer_add(trans, 4);
}
/* Returns the number of commands required for the tag process */
u32 ipa_cmd_tag_process_count(void)
{
return 4;
}
void ipa_cmd_tag_process(struct ipa *ipa)
{
u32 count = ipa_cmd_tag_process_count();
struct gsi_trans *trans;
trans = ipa_cmd_trans_alloc(ipa, count);
if (trans) {
ipa_cmd_tag_process_add(trans);
gsi_trans_commit_wait(trans);
} else {
dev_err(&ipa->pdev->dev,
"error allocating %u entry tag transaction\n", count);
}
}
static struct ipa_cmd_info *
ipa_cmd_info_alloc(struct ipa_endpoint *endpoint, u32 tre_count)
{
struct gsi_channel *channel;
channel = &endpoint->ipa->gsi.channel[endpoint->channel_id];
return gsi_trans_pool_alloc(&channel->trans_info.info_pool, tre_count);
}
/* Allocate a transaction for the command TX endpoint */
struct gsi_trans *ipa_cmd_trans_alloc(struct ipa *ipa, u32 tre_count)
{
struct ipa_endpoint *endpoint;
struct gsi_trans *trans;
endpoint = ipa->name_map[IPA_ENDPOINT_AP_COMMAND_TX];
trans = gsi_channel_trans_alloc(&ipa->gsi, endpoint->channel_id,
tre_count, DMA_NONE);
if (trans)
trans->info = ipa_cmd_info_alloc(endpoint, tre_count);
return trans;
}