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0637a70a5d
Some buggy systems can machine check when config space accesses happen for some non existent devices. i386/x86-64 do some early device scans that might trigger this. Allow pci=noearly to disable this. Also when type 1 is disabling also don't do any early accesses which are always type1. This moves the pci= configuration parsing to be a early parameter. I don't think this can break anything because it only changes a single global that is only used by PCI. Cc: gregkh@suse.de Cc: Trammell Hudson <hudson@osresearch.net> Signed-off-by: Andi Kleen <ak@suse.de>
53 lines
1.3 KiB
C
53 lines
1.3 KiB
C
#include <linux/kernel.h>
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#include <linux/pci.h>
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#include <asm/pci-direct.h>
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#include <asm/io.h>
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#include "pci.h"
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/* Direct PCI access. This is used for PCI accesses in early boot before
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the PCI subsystem works. */
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#define PDprintk(x...)
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u32 read_pci_config(u8 bus, u8 slot, u8 func, u8 offset)
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{
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u32 v;
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outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
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v = inl(0xcfc);
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if (v != 0xffffffff)
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PDprintk("%x reading 4 from %x: %x\n", slot, offset, v);
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return v;
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}
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u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset)
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{
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u8 v;
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outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
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v = inb(0xcfc + (offset&3));
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PDprintk("%x reading 1 from %x: %x\n", slot, offset, v);
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return v;
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}
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u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset)
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{
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u16 v;
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outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
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v = inw(0xcfc + (offset&2));
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PDprintk("%x reading 2 from %x: %x\n", slot, offset, v);
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return v;
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}
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void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset,
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u32 val)
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{
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PDprintk("%x writing to %x: %x\n", slot, offset, val);
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outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
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outl(val, 0xcfc);
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}
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int early_pci_allowed(void)
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{
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return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) ==
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PCI_PROBE_CONF1;
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}
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