forked from luck/tmp_suning_uos_patched
aae3e318d0
If the legacy PCI init fails, then there are no PCI config space accesors available, but the code continues and tries to scan the busses, which fails due to the lack of config space accessors. Return right away, if the last init fallback fails. Switch the few printks to pr_info while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Bjorn Helgaas <helgaas@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: linux-pci@vger.kernel.org Link: http://lkml.kernel.org/r/20170316215057.047576516@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
75 lines
1.5 KiB
C
75 lines
1.5 KiB
C
/*
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* legacy.c - traditional, old school PCI bus probing
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*/
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#include <linux/init.h>
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#include <linux/export.h>
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#include <linux/pci.h>
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#include <asm/pci_x86.h>
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/*
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* Discover remaining PCI buses in case there are peer host bridges.
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* We use the number of last PCI bus provided by the PCI BIOS.
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*/
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static void pcibios_fixup_peer_bridges(void)
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{
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int n;
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if (pcibios_last_bus <= 0 || pcibios_last_bus > 0xff)
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return;
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DBG("PCI: Peer bridge fixup\n");
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for (n=0; n <= pcibios_last_bus; n++)
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pcibios_scan_specific_bus(n);
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}
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int __init pci_legacy_init(void)
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{
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if (!raw_pci_ops)
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return 1;
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pr_info("PCI: Probing PCI hardware\n");
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pcibios_scan_root(0);
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return 0;
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}
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void pcibios_scan_specific_bus(int busn)
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{
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int devfn;
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u32 l;
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if (pci_find_bus(0, busn))
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return;
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for (devfn = 0; devfn < 256; devfn += 8) {
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if (!raw_pci_read(0, busn, devfn, PCI_VENDOR_ID, 2, &l) &&
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l != 0x0000 && l != 0xffff) {
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DBG("Found device at %02x:%02x [%04x]\n", busn, devfn, l);
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pr_info("PCI: Discovered peer bus %02x\n", busn);
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pcibios_scan_root(busn);
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return;
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}
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}
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}
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EXPORT_SYMBOL_GPL(pcibios_scan_specific_bus);
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static int __init pci_subsys_init(void)
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{
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/*
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* The init function returns an non zero value when
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* pci_legacy_init should be invoked.
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*/
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if (x86_init.pci.init()) {
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if (pci_legacy_init()) {
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pr_info("PCI: System does not support PCI\n");
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return -ENODEV;
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}
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}
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pcibios_fixup_peer_bridges();
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x86_init.pci.init_irq();
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pcibios_init();
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return 0;
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}
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subsys_initcall(pci_subsys_init);
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