mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-24 13:43:28 +00:00
3616218b5a
- Generally we just drop the #ifdef CONFIG_SYS_LONGHELP and endif lines and use U_BOOT_LONGHELP to declare the same variable name as before - In a few places, either rename the variable to follow convention or introduce the variable as it was being done inline before. Signed-off-by: Tom Rini <trini@konsulko.com> Reviewed-by: Simon Glass <sjg@chromium.org>
162 lines
3.5 KiB
C
162 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* (C) Copyright 2022 Microsoft Corporation <www.microsoft.com>
|
|
* Stephen Carlson <stcarlso@linux.microsoft.com>
|
|
*
|
|
* PCI Express Maximum Packet Size (MPS) configuration
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <bootretry.h>
|
|
#include <cli.h>
|
|
#include <command.h>
|
|
#include <console.h>
|
|
#include <dm.h>
|
|
#include <init.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/io.h>
|
|
#include <pci.h>
|
|
|
|
#define PCI_MPS_SAFE 0
|
|
#define PCI_MPS_PEER2PEER 1
|
|
|
|
static int pci_mps_find_safe(struct udevice *bus, unsigned int *min_mps,
|
|
unsigned int *n)
|
|
{
|
|
struct udevice *dev;
|
|
int res = 0, addr;
|
|
unsigned int mpss;
|
|
u32 regval;
|
|
|
|
if (!min_mps || !n)
|
|
return -EINVAL;
|
|
|
|
for (device_find_first_child(bus, &dev);
|
|
dev;
|
|
device_find_next_child(&dev)) {
|
|
addr = dm_pci_find_capability(dev, PCI_CAP_ID_EXP);
|
|
if (addr <= 0)
|
|
continue;
|
|
|
|
res = dm_pci_read_config32(dev, addr + PCI_EXP_DEVCAP,
|
|
®val);
|
|
if (res != 0)
|
|
return res;
|
|
mpss = (unsigned int)(regval & PCI_EXP_DEVCAP_PAYLOAD);
|
|
*n += 1;
|
|
if (mpss < *min_mps)
|
|
*min_mps = mpss;
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
static int pci_mps_set_bus(struct udevice *bus, unsigned int target)
|
|
{
|
|
struct udevice *dev;
|
|
u32 mpss, target_mps = (u32)(target << 5);
|
|
u16 mps;
|
|
int res = 0, addr;
|
|
|
|
for (device_find_first_child(bus, &dev);
|
|
dev && res == 0;
|
|
device_find_next_child(&dev)) {
|
|
addr = dm_pci_find_capability(dev, PCI_CAP_ID_EXP);
|
|
if (addr <= 0)
|
|
continue;
|
|
|
|
res = dm_pci_read_config32(dev, addr + PCI_EXP_DEVCAP,
|
|
&mpss);
|
|
if (res != 0)
|
|
return res;
|
|
|
|
/* Do not set device above its maximum MPSS */
|
|
mpss = (mpss & PCI_EXP_DEVCAP_PAYLOAD) << 5;
|
|
if (target_mps < mpss)
|
|
mps = (u16)target_mps;
|
|
else
|
|
mps = (u16)mpss;
|
|
res = dm_pci_clrset_config16(dev, addr + PCI_EXP_DEVCTL,
|
|
PCI_EXP_DEVCTL_PAYLOAD, mps);
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* Sets the MPS of each PCI Express device to the specified policy.
|
|
*/
|
|
static int pci_mps_set(int policy)
|
|
{
|
|
struct udevice *bus;
|
|
int i, res = 0;
|
|
/* 0 = 128B, min value for hotplug */
|
|
unsigned int mps = 0;
|
|
|
|
if (policy == PCI_MPS_SAFE) {
|
|
unsigned int min_mps = PCI_EXP_DEVCAP_PAYLOAD_4096B, n = 0;
|
|
|
|
/* Find maximum MPS supported by all devices */
|
|
for (i = 0;
|
|
uclass_get_device_by_seq(UCLASS_PCI, i, &bus) == 0 &&
|
|
res == 0;
|
|
i++)
|
|
res = pci_mps_find_safe(bus, &min_mps, &n);
|
|
|
|
/* If no devices were found, do not reconfigure */
|
|
if (n == 0)
|
|
return res;
|
|
mps = min_mps;
|
|
}
|
|
|
|
/* This message is checked by the sandbox test */
|
|
printf("Setting MPS of all devices to %uB\n", 128U << mps);
|
|
for (i = 0;
|
|
uclass_get_device_by_seq(UCLASS_PCI, i, &bus) == 0 && res == 0;
|
|
i++)
|
|
res = pci_mps_set_bus(bus, mps);
|
|
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* PCI MPS tuning commands
|
|
*
|
|
* Syntax:
|
|
* pci_mps safe
|
|
* pci_mps peer2peer
|
|
*/
|
|
static int do_pci_mps(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
|
|
{
|
|
char cmd = 'u';
|
|
int ret = 0;
|
|
|
|
if (argc > 1)
|
|
cmd = argv[1][0];
|
|
|
|
switch (cmd) {
|
|
case 's': /* safe */
|
|
ret = pci_mps_set(PCI_MPS_SAFE);
|
|
break;
|
|
case 'p': /* peer2peer/hotplug */
|
|
ret = pci_mps_set(PCI_MPS_PEER2PEER);
|
|
break;
|
|
default: /* usage, help */
|
|
goto usage;
|
|
}
|
|
|
|
return ret;
|
|
usage:
|
|
return CMD_RET_USAGE;
|
|
}
|
|
|
|
/***************************************************/
|
|
|
|
U_BOOT_LONGHELP(pci_mps,
|
|
"safe\n"
|
|
" - Set PCI Express MPS of all devices to safe values\n"
|
|
"pci_mps peer2peer\n"
|
|
" - Set PCI Express MPS of all devices to support hotplug and peer-to-peer DMA\n");
|
|
|
|
U_BOOT_CMD(pci_mps, 2, 0, do_pci_mps,
|
|
"configure PCI Express MPS", pci_mps_help_text);
|