blob: 818150dc0a66a84ce3306b73f4aacb7754510b95 [file] [log] [blame] [edit]
/*
* Generic PCI host controller as described in PCI Bus Binding to Open Firmware
*
* Copyright (C) 2016, Red Hat Inc, Alexander Gordeev <agordeev@redhat.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2.
*/
#include "libcflat.h"
#include "devicetree.h"
#include "alloc.h"
#include "pci.h"
#include "asm/pci.h"
#include "asm/io.h"
#include "pci-host-generic.h"
#include <linux/pci_regs.h>
static struct pci_host_bridge *pci_host_bridge;
static int of_flags_to_pci_type(u32 of_flags)
{
static int type_map[] = {
[1] = PCI_BASE_ADDRESS_SPACE_IO,
[2] = PCI_BASE_ADDRESS_MEM_TYPE_32,
[3] = PCI_BASE_ADDRESS_MEM_TYPE_64
};
int idx = (of_flags >> 24) & 0x03;
int res;
assert(idx > 0);
res = type_map[idx];
if (of_flags & 0x40000000)
res |= PCI_BASE_ADDRESS_MEM_PREFETCH;
return res;
}
static int pci_bar_type(u32 bar)
{
if (bar & PCI_BASE_ADDRESS_SPACE)
return PCI_BASE_ADDRESS_SPACE_IO;
else
return bar & (PCI_BASE_ADDRESS_MEM_TYPE_MASK |
PCI_BASE_ADDRESS_MEM_PREFETCH);
}
/*
* Probe DT for a generic PCI host controller
* See kernel Documentation/devicetree/bindings/pci/host-generic-pci.txt
* and function gen_pci_probe() in drivers/pci/host/pci-host-generic.c
*/
static struct pci_host_bridge *pci_dt_probe(void)
{
struct pci_host_bridge *host;
const void *fdt = dt_fdt();
const struct fdt_property *prop;
struct dt_pbus_reg base;
struct dt_device dt_dev;
struct dt_bus dt_bus;
struct pci_addr_space *as;
fdt32_t *data;
u32 bus, bus_max;
u32 nac, nsc, nac_root, nsc_root;
int nr_range_cells, nr_addr_spaces;
int ret, node, len, i;
if (!dt_available()) {
printf("No device tree found\n");
return NULL;
}
dt_bus_init_defaults(&dt_bus);
dt_device_init(&dt_dev, &dt_bus, NULL);
node = fdt_path_offset(fdt, "/");
assert(node >= 0);
ret = dt_get_nr_cells(node, &nac_root, &nsc_root);
assert(ret == 0);
assert(nac_root == 1 || nac_root == 2);
node = fdt_node_offset_by_compatible(fdt, node,
"pci-host-ecam-generic");
if (node == -FDT_ERR_NOTFOUND) {
printf("No PCIe ECAM compatible controller found\n");
return NULL;
}
assert(node >= 0);
prop = fdt_get_property(fdt, node, "device_type", &len);
assert(prop && len == 4 && !strcmp((char *)prop->data, "pci"));
dt_device_bind_node(&dt_dev, node);
ret = dt_pbus_get_base(&dt_dev, &base);
assert(ret == 0);
prop = fdt_get_property(fdt, node, "bus-range", &len);
if (prop == NULL) {
assert(len == -FDT_ERR_NOTFOUND);
bus = 0x00;
bus_max = 0xff;
} else {
data = (fdt32_t *)prop->data;
bus = fdt32_to_cpu(data[0]);
bus_max = fdt32_to_cpu(data[1]);
assert(bus <= bus_max);
}
assert(bus_max < base.size / (1 << PCI_ECAM_BUS_SHIFT));
ret = dt_get_nr_cells(node, &nac, &nsc);
assert(ret == 0);
assert(nac == 3 && nsc == 2);
prop = fdt_get_property(fdt, node, "ranges", &len);
assert(prop != NULL);
nr_range_cells = nac + nsc + nac_root;
nr_addr_spaces = (len / 4) / nr_range_cells;
assert(nr_addr_spaces);
host = malloc(sizeof(*host) +
sizeof(host->addr_space[0]) * nr_addr_spaces);
assert(host != NULL);
host->start = base.addr;
host->size = base.size;
host->bus = bus;
host->bus_max = bus_max;
host->nr_addr_spaces = nr_addr_spaces;
data = (fdt32_t *)prop->data;
as = &host->addr_space[0];
for (i = 0; i < nr_addr_spaces; i++) {
/*
* The PCI binding encodes the PCI address with three
* cells as follows:
*
* phys.hi cell: npt000ss bbbbbbbb dddddfff rrrrrrrr
* phys.mid cell: hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh
* phys.lo cell: llllllll llllllll llllllll llllllll
*
* PCI device bus address and flags are encoded into phys.high
* PCI 64 bit address is encoded into phys.mid and phys.low
*/
as->type = of_flags_to_pci_type(fdt32_to_cpu(data[0]));
as->pci_start = ((u64)fdt32_to_cpu(data[1]) << 32) |
fdt32_to_cpu(data[2]);
if (nr_range_cells == 6) {
as->start = fdt32_to_cpu(data[3]);
as->size = ((u64)fdt32_to_cpu(data[4]) << 32) |
fdt32_to_cpu(data[5]);
} else {
as->start = ((u64)fdt32_to_cpu(data[3]) << 32) |
fdt32_to_cpu(data[4]);
as->size = ((u64)fdt32_to_cpu(data[5]) << 32) |
fdt32_to_cpu(data[6]);
}
data += nr_range_cells;
as++;
}
return host;
}
static bool pci_alloc_resource(struct pci_dev *dev, int bar_num, u64 *addr)
{
struct pci_host_bridge *host = pci_host_bridge;
struct pci_addr_space *as = &host->addr_space[0];
u32 bar;
u64 size, pci_addr;
int type, i;
*addr = INVALID_PHYS_ADDR;
size = pci_bar_size(dev, bar_num);
if (!size)
return false;
bar = pci_bar_get(dev, bar_num);
type = pci_bar_type(bar);
if (type & PCI_BASE_ADDRESS_MEM_TYPE_MASK)
type &= ~PCI_BASE_ADDRESS_MEM_PREFETCH;
for (i = 0; i < host->nr_addr_spaces; i++) {
if (as->type == type)
break;
as++;
}
if (i >= host->nr_addr_spaces) {
printf("%s: warning: can't satisfy request for ", __func__);
pci_dev_print_id(dev);
printf(" ");
pci_bar_print(dev, bar_num);
printf("\n");
return false;
}
pci_addr = ALIGN(as->pci_start + as->allocated, size);
size += pci_addr - (as->pci_start + as->allocated);
assert(as->allocated + size <= as->size);
*addr = pci_addr;
as->allocated += size;
return true;
}
bool pci_probe(void)
{
struct pci_dev pci_dev;
pcidevaddr_t dev;
u8 header;
u32 cmd;
int i;
assert(!pci_host_bridge);
pci_host_bridge = pci_dt_probe();
if (!pci_host_bridge)
return false;
for (dev = 0; dev < PCI_DEVFN_MAX; dev++) {
if (!pci_dev_exists(dev))
continue;
pci_dev_init(&pci_dev, dev);
/* We are only interested in normal PCI devices */
header = pci_config_readb(dev, PCI_HEADER_TYPE);
if ((header & PCI_HEADER_TYPE_MASK) != PCI_HEADER_TYPE_NORMAL)
continue;
cmd = PCI_COMMAND_SERR | PCI_COMMAND_PARITY;
for (i = 0; i < PCI_BAR_NUM; i++) {
u64 addr;
if (pci_alloc_resource(&pci_dev, i, &addr)) {
pci_bar_set_addr(&pci_dev, i, addr);
if (pci_bar_is_memory(&pci_dev, i))
cmd |= PCI_COMMAND_MEMORY;
else
cmd |= PCI_COMMAND_IO;
}
if (pci_bar_is64(&pci_dev, i))
i++;
}
pci_config_writew(dev, PCI_COMMAND, cmd);
}
return true;
}
/*
* This function is to be called from pci_translate_addr() to provide
* mapping between this host bridge's PCI busses address and CPU physical
* address.
*/
phys_addr_t pci_host_bridge_get_paddr(u64 pci_addr)
{
struct pci_host_bridge *host = pci_host_bridge;
struct pci_addr_space *as = &host->addr_space[0];
int i;
for (i = 0; i < host->nr_addr_spaces; i++) {
if (pci_addr >= as->pci_start &&
pci_addr < as->pci_start + as->size)
return as->start + (pci_addr - as->pci_start);
as++;
}
return INVALID_PHYS_ADDR;
}
static void __iomem *pci_get_dev_conf(struct pci_host_bridge *host, int devfn)
{
return (void __iomem *)(unsigned long)
host->start + (devfn << PCI_ECAM_DEVFN_SHIFT);
}
u8 pci_config_readb(pcidevaddr_t dev, u8 off)
{
void __iomem *conf = pci_get_dev_conf(pci_host_bridge, dev);
return readb(conf + off);
}
u16 pci_config_readw(pcidevaddr_t dev, u8 off)
{
void __iomem *conf = pci_get_dev_conf(pci_host_bridge, dev);
return readw(conf + off);
}
u32 pci_config_readl(pcidevaddr_t dev, u8 off)
{
void __iomem *conf = pci_get_dev_conf(pci_host_bridge, dev);
return readl(conf + off);
}
void pci_config_writeb(pcidevaddr_t dev, u8 off, u8 val)
{
void __iomem *conf = pci_get_dev_conf(pci_host_bridge, dev);
writeb(val, conf + off);
}
void pci_config_writew(pcidevaddr_t dev, u8 off, u16 val)
{
void __iomem *conf = pci_get_dev_conf(pci_host_bridge, dev);
writew(val, conf + off);
}
void pci_config_writel(pcidevaddr_t dev, u8 off, u32 val)
{
void __iomem *conf = pci_get_dev_conf(pci_host_bridge, dev);
writel(val, conf + off);
}