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03de305ec4
As part of bringing the master branch back in to next, we need to allow for all of these changes to exist here. Reported-by: Jonas Karlman <jonas@kwiboo.se> Signed-off-by: Tom Rini <trini@konsulko.com>
162 lines
3.5 KiB
C
162 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* (C) Copyright 2022 Microsoft Corporation <www.microsoft.com>
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* Stephen Carlson <stcarlso@linux.microsoft.com>
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*
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* PCI Express Maximum Packet Size (MPS) configuration
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*/
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#include <bootretry.h>
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#include <cli.h>
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#include <command.h>
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#include <console.h>
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#include <dm.h>
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#include <init.h>
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#include <asm/processor.h>
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#include <asm/io.h>
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#include <pci.h>
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#define PCI_MPS_SAFE 0
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#define PCI_MPS_PEER2PEER 1
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static int pci_mps_find_safe(struct udevice *bus, unsigned int *min_mps,
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unsigned int *n)
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{
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struct udevice *dev;
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int res = 0, addr;
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unsigned int mpss;
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u32 regval;
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if (!min_mps || !n)
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return -EINVAL;
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for (device_find_first_child(bus, &dev);
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dev;
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device_find_next_child(&dev)) {
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addr = dm_pci_find_capability(dev, PCI_CAP_ID_EXP);
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if (addr <= 0)
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continue;
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res = dm_pci_read_config32(dev, addr + PCI_EXP_DEVCAP,
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®val);
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if (res != 0)
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return res;
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mpss = (unsigned int)(regval & PCI_EXP_DEVCAP_PAYLOAD);
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*n += 1;
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if (mpss < *min_mps)
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*min_mps = mpss;
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}
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return res;
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}
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static int pci_mps_set_bus(struct udevice *bus, unsigned int target)
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{
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struct udevice *dev;
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u32 mpss, target_mps = (u32)(target << 5);
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u16 mps;
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int res = 0, addr;
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for (device_find_first_child(bus, &dev);
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dev && res == 0;
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device_find_next_child(&dev)) {
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addr = dm_pci_find_capability(dev, PCI_CAP_ID_EXP);
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if (addr <= 0)
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continue;
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res = dm_pci_read_config32(dev, addr + PCI_EXP_DEVCAP,
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&mpss);
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if (res != 0)
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return res;
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/* Do not set device above its maximum MPSS */
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mpss = (mpss & PCI_EXP_DEVCAP_PAYLOAD) << 5;
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if (target_mps < mpss)
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mps = (u16)target_mps;
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else
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mps = (u16)mpss;
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res = dm_pci_clrset_config16(dev, addr + PCI_EXP_DEVCTL,
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PCI_EXP_DEVCTL_PAYLOAD, mps);
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}
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return res;
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}
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/*
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* Sets the MPS of each PCI Express device to the specified policy.
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*/
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static int pci_mps_set(int policy)
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{
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struct udevice *bus;
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int i, res = 0;
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/* 0 = 128B, min value for hotplug */
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unsigned int mps = 0;
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if (policy == PCI_MPS_SAFE) {
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unsigned int min_mps = PCI_EXP_DEVCAP_PAYLOAD_4096B, n = 0;
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/* Find maximum MPS supported by all devices */
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for (i = 0;
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uclass_get_device_by_seq(UCLASS_PCI, i, &bus) == 0 &&
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res == 0;
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i++)
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res = pci_mps_find_safe(bus, &min_mps, &n);
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/* If no devices were found, do not reconfigure */
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if (n == 0)
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return res;
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mps = min_mps;
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}
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/* This message is checked by the sandbox test */
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printf("Setting MPS of all devices to %uB\n", 128U << mps);
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for (i = 0;
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uclass_get_device_by_seq(UCLASS_PCI, i, &bus) == 0 && res == 0;
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i++)
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res = pci_mps_set_bus(bus, mps);
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return res;
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}
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/*
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* PCI MPS tuning commands
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*
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* Syntax:
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* pci_mps safe
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* pci_mps peer2peer
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*/
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static int do_pci_mps(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
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{
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char cmd = 'u';
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int ret = 0;
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if (argc > 1)
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cmd = argv[1][0];
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switch (cmd) {
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case 's': /* safe */
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ret = pci_mps_set(PCI_MPS_SAFE);
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break;
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case 'p': /* peer2peer/hotplug */
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ret = pci_mps_set(PCI_MPS_PEER2PEER);
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break;
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default: /* usage, help */
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goto usage;
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}
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return ret;
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usage:
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return CMD_RET_USAGE;
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}
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/***************************************************/
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U_BOOT_LONGHELP(pci_mps,
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"safe\n"
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" - Set PCI Express MPS of all devices to safe values\n"
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"pci_mps peer2peer\n"
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" - Set PCI Express MPS of all devices to support hotplug and peer-to-peer DMA\n");
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U_BOOT_CMD(pci_mps, 2, 0, do_pci_mps,
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"configure PCI Express MPS", pci_mps_help_text);
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