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d678a59d2d
When bringing in the series 'arm: dts: am62-beagleplay: Fix Beagleplay Ethernet"' I failed to notice that b4 noticed it was based on next and so took that as the base commit and merged that part of next to master. This reverts commitc8ffd1356d, reversing changes made to2ee6f3a5f7. 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 <common.h>
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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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