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72407514c9
On ARM64 PROBE_ONLY PCI systems resources are not currently claimed, therefore they can't be enabled since they do not have a valid parent pointer; this in turn prevents enabling PCI devices on ARM64 PROBE_ONLY systems, causing PCI devices initialization to fail. To solve this issue, resources must be claimed when devices are added on PROBE_ONLY systems, which ensures that the resource hierarchy is validated and the resource tree is sane, but this requires changes in the ARM64 resource management that can affect adversely existing PCI set-ups (claiming resources on !PROBE_ONLY systems might break existing ARM64 PCI platform implementations). As a temporary solution in preparation for a proper resources claiming implementation in ARM64 core, to enable PCI PROBE_ONLY systems on ARM64, this patch adds a pcibios_enable_device() arch implementation that simply prevents enabling resources on PROBE_ONLY systems (mirroring ARM behaviour). This is always a safe thing to do because on PROBE_ONLY systems the configuration space set-up can be considered immutable, and it is in preparation of proper resource claiming that would finally validate the PCI resources tree in the ARM64 arch implementation on PROBE_ONLY systems. For !PROBE_ONLY systems resources enablement in pcibios_enable_device() on ARM64 is implemented as in current PCI core, leaving the behaviour unchanged. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
87 lines
1.9 KiB
C
87 lines
1.9 KiB
C
/*
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* Code borrowed from powerpc/kernel/pci-common.c
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*
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* Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
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* Copyright (C) 2014 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2 as published by the Free Software Foundation.
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*
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*/
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#include <linux/acpi.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/of_pci.h>
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#include <linux/of_platform.h>
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#include <linux/slab.h>
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#include <asm/pci-bridge.h>
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/*
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* Called after each bus is probed, but before its children are examined
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*/
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void pcibios_fixup_bus(struct pci_bus *bus)
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{
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/* nothing to do, expected to be removed in the future */
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}
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/*
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* We don't have to worry about legacy ISA devices, so nothing to do here
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*/
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resource_size_t pcibios_align_resource(void *data, const struct resource *res,
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resource_size_t size, resource_size_t align)
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{
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return res->start;
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}
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/**
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* pcibios_enable_device - Enable I/O and memory.
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* @dev: PCI device to be enabled
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* @mask: bitmask of BARs to enable
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*/
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int pcibios_enable_device(struct pci_dev *dev, int mask)
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{
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if (pci_has_flag(PCI_PROBE_ONLY))
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return 0;
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return pci_enable_resources(dev, mask);
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}
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/*
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* Try to assign the IRQ number from DT when adding a new device
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*/
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int pcibios_add_device(struct pci_dev *dev)
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{
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dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
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return 0;
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}
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/*
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* raw_pci_read/write - Platform-specific PCI config space access.
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*/
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int raw_pci_read(unsigned int domain, unsigned int bus,
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unsigned int devfn, int reg, int len, u32 *val)
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{
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return -ENXIO;
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}
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int raw_pci_write(unsigned int domain, unsigned int bus,
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unsigned int devfn, int reg, int len, u32 val)
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{
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return -ENXIO;
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}
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#ifdef CONFIG_ACPI
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/* Root bridge scanning */
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struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
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{
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/* TODO: Should be revisited when implementing PCI on ACPI */
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return NULL;
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}
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#endif
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