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// SPDX-License-Identifier: GPL-2.0+
/*
* PCI autoconfiguration library
*
* Author: Matt Porter <mporter@mvista.com>
*
* Copyright 2000 MontaVista Software Inc.
* Copyright (c) 2021 Maciej W. Rozycki <macro@orcam.me.uk>
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <log.h>
#include <pci.h>
#include <time.h>
#include "pci_internal.h"
/* the user can define CFG_SYS_PCI_CACHE_LINE_SIZE to avoid problems */
#ifndef CFG_SYS_PCI_CACHE_LINE_SIZE
#define CFG_SYS_PCI_CACHE_LINE_SIZE 8
#endif
static void dm_pciauto_setup_device(struct udevice *dev,
struct pci_region *mem,
struct pci_region *prefetch,
struct pci_region *io)
{
u32 bar_response;
pci_size_t bar_size;
u16 cmdstat = 0;
int bar, bar_nr = 0;
int bars_num;
u8 header_type;
int rom_addr;
pci_addr_t bar_value;
struct pci_region *bar_res = NULL;
int found_mem64 = 0;
u16 class;
dm_pci_read_config16(dev, PCI_COMMAND, &cmdstat);
cmdstat = (cmdstat & ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) |
PCI_COMMAND_MASTER;
dm_pci_read_config8(dev, PCI_HEADER_TYPE, &header_type);
header_type &= 0x7f;
switch (header_type) {
case PCI_HEADER_TYPE_NORMAL:
bars_num = 6;
break;
case PCI_HEADER_TYPE_BRIDGE:
bars_num = 2;
break;
case PCI_HEADER_TYPE_CARDBUS:
/* CardBus header does not have any BAR */
bars_num = 0;
break;
default:
/* Skip configuring BARs for unknown header types */
bars_num = 0;
break;
}
for (bar = PCI_BASE_ADDRESS_0;
bar < PCI_BASE_ADDRESS_0 + (bars_num * 4); bar += 4) {
int ret = 0;
/* Tickle the BAR and get the response */
dm_pci_write_config32(dev, bar, 0xffffffff);
dm_pci_read_config32(dev, bar, &bar_response);
/* If BAR is not implemented (or invalid) go to the next BAR */
if (!bar_response || bar_response == 0xffffffff)
continue;
found_mem64 = 0;
/* Check the BAR type and set our address mask */
if (bar_response & PCI_BASE_ADDRESS_SPACE) {
bar_size = bar_response & PCI_BASE_ADDRESS_IO_MASK;
bar_size &= ~(bar_size - 1);
bar_res = io;
debug("PCI Autoconfig: BAR %d, I/O, size=0x%llx, ",
bar_nr, (unsigned long long)bar_size);
} else {
if ((bar_response & PCI_BASE_ADDRESS_MEM_TYPE_MASK) ==
PCI_BASE_ADDRESS_MEM_TYPE_64) {
u32 bar_response_upper;
u64 bar64;
dm_pci_write_config32(dev, bar + 4, 0xffffffff);
dm_pci_read_config32(dev, bar + 4,
&bar_response_upper);
bar64 = ((u64)bar_response_upper << 32) |
bar_response;
bar_size = ~(bar64 & PCI_BASE_ADDRESS_MEM_MASK)
+ 1;
found_mem64 = 1;
} else {
bar_size = (u32)(~(bar_response &
PCI_BASE_ADDRESS_MEM_MASK) + 1);
}
if (prefetch &&
(bar_response & PCI_BASE_ADDRESS_MEM_PREFETCH))
bar_res = prefetch;
else
bar_res = mem;
debug("PCI Autoconfig: BAR %d, %s%s, size=0x%llx, ",
bar_nr, bar_res == prefetch ? "Prf" : "Mem",
found_mem64 ? "64" : "",
(unsigned long long)bar_size);
}
ret = pciauto_region_allocate(bar_res, bar_size,
&bar_value, found_mem64);
if (ret)
printf("PCI: Failed autoconfig bar %x\n", bar);
if (!ret) {
/* Write it out and update our limit */
dm_pci_write_config32(dev, bar, (u32)bar_value);
if (found_mem64) {
bar += 4;
#ifdef CONFIG_SYS_PCI_64BIT
dm_pci_write_config32(dev, bar,
(u32)(bar_value >> 32));
#else
/*
* If we are a 64-bit decoder then increment to
* the upper 32 bits of the bar and force it to
* locate in the lower 4GB of memory.
*/
dm_pci_write_config32(dev, bar, 0x00000000);
#endif
}
}
cmdstat |= (bar_response & PCI_BASE_ADDRESS_SPACE) ?
PCI_COMMAND_IO : PCI_COMMAND_MEMORY;
debug("\n");
bar_nr++;
}
/* Configure the expansion ROM address */
if (header_type == PCI_HEADER_TYPE_NORMAL ||
header_type == PCI_HEADER_TYPE_BRIDGE) {
rom_addr = (header_type == PCI_HEADER_TYPE_NORMAL) ?
PCI_ROM_ADDRESS : PCI_ROM_ADDRESS1;
dm_pci_write_config32(dev, rom_addr, 0xfffffffe);
dm_pci_read_config32(dev, rom_addr, &bar_response);
if (bar_response) {
bar_size = -(bar_response & ~1);
debug("PCI Autoconfig: ROM, size=%#x, ",
(unsigned int)bar_size);
if (pciauto_region_allocate(mem, bar_size, &bar_value,
false) == 0) {
dm_pci_write_config32(dev, rom_addr, bar_value);
}
cmdstat |= PCI_COMMAND_MEMORY;
debug("\n");
}
}
/* PCI_COMMAND_IO must be set for VGA device */
dm_pci_read_config16(dev, PCI_CLASS_DEVICE, &class);
if (class == PCI_CLASS_DISPLAY_VGA)
cmdstat |= PCI_COMMAND_IO;
dm_pci_write_config16(dev, PCI_COMMAND, cmdstat);
dm_pci_write_config8(dev, PCI_CACHE_LINE_SIZE,
CFG_SYS_PCI_CACHE_LINE_SIZE);
dm_pci_write_config8(dev, PCI_LATENCY_TIMER, 0x80);
}
/*
* Check if the link of a downstream PCIe port operates correctly.
*
* For that check if the optional Data Link Layer Link Active status gets
* on within a 200ms period or failing that wait until the completion of
* that period and check if link training has shown the completed status
* continuously throughout the second half of that period.
*
* Observation with the ASMedia ASM2824 Gen 3 switch indicates it takes
* 11-44ms to indicate the Data Link Layer Link Active status at 2.5GT/s,
* though it may take a couple of link training iterations.
*/
static bool dm_pciauto_exp_link_stable(struct udevice *dev, int pcie_off)
{
u64 loops = 0, trcount = 0, ntrcount = 0, flips = 0;
bool dllla, lnktr, plnktr;
u16 exp_lnksta;
pci_dev_t bdf;
u64 end;
dm_pci_read_config16(dev, pcie_off + PCI_EXP_LNKSTA, &exp_lnksta);
plnktr = !!(exp_lnksta & PCI_EXP_LNKSTA_LT);
end = get_ticks() + usec_to_tick(200000);
do {
dm_pci_read_config16(dev, pcie_off + PCI_EXP_LNKSTA,
&exp_lnksta);
dllla = !!(exp_lnksta & PCI_EXP_LNKSTA_DLLLA);
lnktr = !!(exp_lnksta & PCI_EXP_LNKSTA_LT);
flips += plnktr ^ lnktr;
if (lnktr) {
ntrcount = 0;
trcount++;
} else {
ntrcount++;
}
loops++;
plnktr = lnktr;
} while (!dllla && get_ticks() < end);
bdf = dm_pci_get_bdf(dev);
debug("PCI Autoconfig: %02x.%02x.%02x: Fixup link: DL active: %u; "
"%3llu flips, %6llu loops of which %6llu while training, "
"final %6llu stable\n",
PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf),
(unsigned int)dllla,
(unsigned long long)flips, (unsigned long long)loops,
(unsigned long long)trcount, (unsigned long long)ntrcount);
return dllla || ntrcount >= loops / 2;
}
/*
* Retrain the link of a downstream PCIe port by hand if necessary.
*
* This is needed at least where a downstream port of the ASMedia ASM2824
* Gen 3 switch is wired to the upstream port of the Pericom PI7C9X2G304
* Gen 2 switch, and observed with the Delock Riser Card PCI Express x1 >
* 2 x PCIe x1 device, P/N 41433, plugged into the SiFive HiFive Unmatched
* board.
*
* In such a configuration the switches are supposed to negotiate the link
* speed of preferably 5.0GT/s, falling back to 2.5GT/s. However the link
* continues switching between the two speeds indefinitely and the data
* link layer never reaches the active state, with link training reported
* repeatedly active ~84% of the time. Forcing the target link speed to
* 2.5GT/s with the upstream ASM2824 device makes the two switches talk to
* each other correctly however. And more interestingly retraining with a
* higher target link speed afterwards lets the two successfully negotiate
* 5.0GT/s.
*
* As this can potentially happen with any device and is cheap in the case
* of correctly operating hardware, let's do it for all downstream ports,
* for root complexes, PCIe switches and PCI/PCI-X to PCIe bridges.
*
* First check if automatic link training may have failed to complete, as
* indicated by the optional Data Link Layer Link Active status being off
* and the Link Bandwidth Management Status indicating that hardware has
* changed the link speed or width in an attempt to correct unreliable
* link operation. If this is the case, then check if the link operates
* correctly by seeing whether it is being trained excessively. If it is,
* then conclude the link is broken.
*
* In that case restrict the speed to 2.5GT/s, observing that the Target
* Link Speed field is sticky and therefore the link will stay restricted
* even after a device reset is later made by an OS that is unaware of the
* problem. With the speed restricted request that the link be retrained
* and check again if the link operates correctly. If not, then set the
* Target Link Speed back to the original value.
*
* This requires the presence of the Link Control 2 register, so make sure
* the PCI Express Capability Version is at least 2. Also don't try, for
* obvious reasons, to limit the speed if 2.5GT/s is the only link speed
* supported.
*/
static void dm_pciauto_exp_fixup_link(struct udevice *dev, int pcie_off)
{
u16 exp_lnksta, exp_lnkctl, exp_lnkctl2;
u16 exp_flags, exp_type, exp_version;
u32 exp_lnkcap;
pci_dev_t bdf;
dm_pci_read_config16(dev, pcie_off + PCI_EXP_FLAGS, &exp_flags);
exp_version = exp_flags & PCI_EXP_FLAGS_VERS;
if (exp_version < 2)
return;
exp_type = (exp_flags & PCI_EXP_FLAGS_TYPE) >> 4;
switch (exp_type) {
case PCI_EXP_TYPE_ROOT_PORT:
case PCI_EXP_TYPE_DOWNSTREAM:
case PCI_EXP_TYPE_PCIE_BRIDGE:
break;
default:
return;
}
dm_pci_read_config32(dev, pcie_off + PCI_EXP_LNKCAP, &exp_lnkcap);
if ((exp_lnkcap & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
return;
dm_pci_read_config16(dev, pcie_off + PCI_EXP_LNKSTA, &exp_lnksta);
if ((exp_lnksta & (PCI_EXP_LNKSTA_LBMS | PCI_EXP_LNKSTA_DLLLA)) !=
PCI_EXP_LNKSTA_LBMS)
return;
if (dm_pciauto_exp_link_stable(dev, pcie_off))
return;
bdf = dm_pci_get_bdf(dev);
printf("PCI Autoconfig: %02x.%02x.%02x: "
"Downstream link non-functional\n",
PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
printf("PCI Autoconfig: %02x.%02x.%02x: "
"Retrying with speed restricted to 2.5GT/s...\n",
PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
dm_pci_read_config16(dev, pcie_off + PCI_EXP_LNKCTL, &exp_lnkctl);
dm_pci_read_config16(dev, pcie_off + PCI_EXP_LNKCTL2, &exp_lnkctl2);
dm_pci_write_config16(dev, pcie_off + PCI_EXP_LNKCTL2,
(exp_lnkctl2 & ~PCI_EXP_LNKCTL2_TLS) |
PCI_EXP_LNKCTL2_TLS_2_5GT);
dm_pci_write_config16(dev, pcie_off + PCI_EXP_LNKCTL,
exp_lnkctl | PCI_EXP_LNKCTL_RL);
if (dm_pciauto_exp_link_stable(dev, pcie_off)) {
printf("PCI Autoconfig: %02x.%02x.%02x: Succeeded!\n",
PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
} else {
printf("PCI Autoconfig: %02x.%02x.%02x: Failed!\n",
PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
dm_pci_write_config16(dev, pcie_off + PCI_EXP_LNKCTL2,
exp_lnkctl2);
dm_pci_write_config16(dev, pcie_off + PCI_EXP_LNKCTL,
exp_lnkctl | PCI_EXP_LNKCTL_RL);
}
}
void dm_pciauto_prescan_setup_bridge(struct udevice *dev, int sub_bus)
{
struct pci_region *pci_mem;
struct pci_region *pci_prefetch;
struct pci_region *pci_io;
u16 cmdstat, prefechable_64;
u8 io_32;
struct udevice *ctlr = pci_get_controller(dev);
struct pci_controller *ctlr_hose = dev_get_uclass_priv(ctlr);
int pcie_off;
pci_mem = ctlr_hose->pci_mem;
pci_prefetch = ctlr_hose->pci_prefetch;
pci_io = ctlr_hose->pci_io;
dm_pci_read_config16(dev, PCI_COMMAND, &cmdstat);
dm_pci_read_config16(dev, PCI_PREF_MEMORY_BASE, &prefechable_64);
prefechable_64 &= PCI_PREF_RANGE_TYPE_MASK;
dm_pci_read_config8(dev, PCI_IO_BASE, &io_32);
io_32 &= PCI_IO_RANGE_TYPE_MASK;
/* Configure bus number registers */
dm_pci_write_config8(dev, PCI_PRIMARY_BUS,
PCI_BUS(dm_pci_get_bdf(dev)) - dev_seq(ctlr));
dm_pci_write_config8(dev, PCI_SECONDARY_BUS, sub_bus - dev_seq(ctlr));
dm_pci_write_config8(dev, PCI_SUBORDINATE_BUS, 0xff);
if (pci_mem) {
/* Round memory allocator to 1MB boundary */
pciauto_region_align(pci_mem, 0x100000);
/*
* Set up memory and I/O filter limits, assume 32-bit
* I/O space
*/
dm_pci_write_config16(dev, PCI_MEMORY_BASE,
((pci_mem->bus_lower & 0xfff00000) >> 16) &
PCI_MEMORY_RANGE_MASK);
cmdstat |= PCI_COMMAND_MEMORY;
}
if (pci_prefetch) {
/* Round memory allocator to 1MB boundary */
pciauto_region_align(pci_prefetch, 0x100000);
/*
* Set up memory and I/O filter limits, assume 32-bit
* I/O space
*/
dm_pci_write_config16(dev, PCI_PREF_MEMORY_BASE,
(((pci_prefetch->bus_lower & 0xfff00000) >> 16) &
PCI_PREF_RANGE_MASK) | prefechable_64);
if (prefechable_64 == PCI_PREF_RANGE_TYPE_64)
#ifdef CONFIG_SYS_PCI_64BIT
dm_pci_write_config32(dev, PCI_PREF_BASE_UPPER32,
pci_prefetch->bus_lower >> 32);
#else
dm_pci_write_config32(dev, PCI_PREF_BASE_UPPER32, 0x0);
#endif
cmdstat |= PCI_COMMAND_MEMORY;
} else {
/* We don't support prefetchable memory for now, so disable */
dm_pci_write_config16(dev, PCI_PREF_MEMORY_BASE, 0xfff0 |
prefechable_64);
dm_pci_write_config16(dev, PCI_PREF_MEMORY_LIMIT, 0x0 |
prefechable_64);
if (prefechable_64 == PCI_PREF_RANGE_TYPE_64) {
dm_pci_write_config16(dev, PCI_PREF_BASE_UPPER32, 0x0);
dm_pci_write_config16(dev, PCI_PREF_LIMIT_UPPER32, 0x0);
}
}
if (pci_io) {
/* Round I/O allocator to 4KB boundary */
pciauto_region_align(pci_io, 0x1000);
dm_pci_write_config8(dev, PCI_IO_BASE,
(((pci_io->bus_lower & 0x0000f000) >> 8) &
PCI_IO_RANGE_MASK) | io_32);
if (io_32 == PCI_IO_RANGE_TYPE_32)
dm_pci_write_config16(dev, PCI_IO_BASE_UPPER16,
(pci_io->bus_lower & 0xffff0000) >> 16);
cmdstat |= PCI_COMMAND_IO;
} else {
/* Disable I/O if unsupported */
dm_pci_write_config8(dev, PCI_IO_BASE, 0xf0 | io_32);
dm_pci_write_config8(dev, PCI_IO_LIMIT, 0x0 | io_32);
if (io_32 == PCI_IO_RANGE_TYPE_32) {
dm_pci_write_config16(dev, PCI_IO_BASE_UPPER16, 0x0);
dm_pci_write_config16(dev, PCI_IO_LIMIT_UPPER16, 0x0);
}
}
/* For PCIe devices see if we need to retrain the link by hand */
pcie_off = dm_pci_find_capability(dev, PCI_CAP_ID_EXP);
if (pcie_off)
dm_pciauto_exp_fixup_link(dev, pcie_off);
/* Enable memory and I/O accesses, enable bus master */
dm_pci_write_config16(dev, PCI_COMMAND, cmdstat | PCI_COMMAND_MASTER);
}
void dm_pciauto_postscan_setup_bridge(struct udevice *dev, int sub_bus)
{
struct pci_region *pci_mem;
struct pci_region *pci_prefetch;
struct pci_region *pci_io;
struct udevice *ctlr = pci_get_controller(dev);
struct pci_controller *ctlr_hose = dev_get_uclass_priv(ctlr);
pci_mem = ctlr_hose->pci_mem;
pci_prefetch = ctlr_hose->pci_prefetch;
pci_io = ctlr_hose->pci_io;
/* Configure bus number registers */
dm_pci_write_config8(dev, PCI_SUBORDINATE_BUS, sub_bus - dev_seq(ctlr));
if (pci_mem) {
/* Round memory allocator to 1MB boundary */
pciauto_region_align(pci_mem, 0x100000);
dm_pci_write_config16(dev, PCI_MEMORY_LIMIT,
((pci_mem->bus_lower - 1) >> 16) &
PCI_MEMORY_RANGE_MASK);
}
if (pci_prefetch) {
u16 prefechable_64;
dm_pci_read_config16(dev, PCI_PREF_MEMORY_LIMIT,
&prefechable_64);
prefechable_64 &= PCI_PREF_RANGE_TYPE_MASK;
/* Round memory allocator to 1MB boundary */
pciauto_region_align(pci_prefetch, 0x100000);
dm_pci_write_config16(dev, PCI_PREF_MEMORY_LIMIT,
(((pci_prefetch->bus_lower - 1) >> 16) &
PCI_PREF_RANGE_MASK) | prefechable_64);
if (prefechable_64 == PCI_PREF_RANGE_TYPE_64)
#ifdef CONFIG_SYS_PCI_64BIT
dm_pci_write_config32(dev, PCI_PREF_LIMIT_UPPER32,
(pci_prefetch->bus_lower - 1) >> 32);
#else
dm_pci_write_config32(dev, PCI_PREF_LIMIT_UPPER32, 0x0);
#endif
}
if (pci_io) {
u8 io_32;
dm_pci_read_config8(dev, PCI_IO_LIMIT,
&io_32);
io_32 &= PCI_IO_RANGE_TYPE_MASK;
/* Round I/O allocator to 4KB boundary */
pciauto_region_align(pci_io, 0x1000);
dm_pci_write_config8(dev, PCI_IO_LIMIT,
((((pci_io->bus_lower - 1) & 0x0000f000) >> 8) &
PCI_IO_RANGE_MASK) | io_32);
if (io_32 == PCI_IO_RANGE_TYPE_32)
dm_pci_write_config16(dev, PCI_IO_LIMIT_UPPER16,
((pci_io->bus_lower - 1) & 0xffff0000) >> 16);
}
}
/*
* HJF: Changed this to return int. I think this is required
* to get the correct result when scanning bridges
*/
int dm_pciauto_config_device(struct udevice *dev)
{
struct pci_region *pci_mem;
struct pci_region *pci_prefetch;
struct pci_region *pci_io;
unsigned int sub_bus = PCI_BUS(dm_pci_get_bdf(dev));
unsigned short class;
struct udevice *ctlr = pci_get_controller(dev);
struct pci_controller *ctlr_hose = dev_get_uclass_priv(ctlr);
int ret;
pci_mem = ctlr_hose->pci_mem;
pci_prefetch = ctlr_hose->pci_prefetch;
pci_io = ctlr_hose->pci_io;
dm_pci_read_config16(dev, PCI_CLASS_DEVICE, &class);
switch (class) {
case PCI_CLASS_BRIDGE_PCI:
debug("PCI Autoconfig: Found P2P bridge, device %d\n",
PCI_DEV(dm_pci_get_bdf(dev)));
dm_pciauto_setup_device(dev, pci_mem, pci_prefetch, pci_io);
ret = dm_pci_hose_probe_bus(dev);
if (ret < 0)
return log_msg_ret("probe", ret);
sub_bus = ret;
break;
case PCI_CLASS_BRIDGE_CARDBUS:
/*
* just do a minimal setup of the bridge,
* let the OS take care of the rest
*/
dm_pciauto_setup_device(dev, pci_mem, pci_prefetch, pci_io);
debug("PCI Autoconfig: Found P2CardBus bridge, device %d\n",
PCI_DEV(dm_pci_get_bdf(dev)));
break;
#if defined(CONFIG_PCIAUTO_SKIP_HOST_BRIDGE)
case PCI_CLASS_BRIDGE_OTHER:
debug("PCI Autoconfig: Skipping bridge device %d\n",
PCI_DEV(dm_pci_get_bdf(dev)));
break;
#endif
#if defined(CONFIG_ARCH_MPC834X)
case PCI_CLASS_BRIDGE_OTHER:
/*
* The host/PCI bridge 1 seems broken in 8349 - it presents
* itself as 'PCI_CLASS_BRIDGE_OTHER' and appears as an _agent_
* device claiming resources io/mem/irq.. we only allow for
* the PIMMR window to be allocated (BAR0 - 1MB size)
*/
debug("PCI Autoconfig: Broken bridge found, only minimal config\n");
dm_pciauto_setup_device(dev, 0, hose->pci_mem,
hose->pci_prefetch, hose->pci_io);
break;
#endif
case PCI_CLASS_PROCESSOR_POWERPC: /* an agent or end-point */
debug("PCI AutoConfig: Found PowerPC device\n");
/* fall through */
default:
dm_pciauto_setup_device(dev, pci_mem, pci_prefetch, pci_io);
break;
}
return sub_bus;
}