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authorBjorn Helgaas <bjorn.helgaas@hp.com>2007-03-30 12:34:05 -0400
committerTony Luck <tony.luck@intel.com>2007-03-30 12:37:41 -0400
commit9b50ffb0c0281bc5a08ccd56ae9bb84296c28f38 (patch)
tree85462c93df91c2fdd0c8fc31643158e9e5cf6734 /arch/ia64/mm/ioremap.c
parentc4add2e537e6f60048dce8dc518254e7e605301d (diff)
[IA64] make ioremap avoid unsupported attributes
Example memory map (from HP sx1000 with VGA enabled): 0x00000 - 0x9FFFF supports only WB (cacheable) access 0xA0000 - 0xBFFFF supports only UC (uncacheable) access 0xC0000 - 0xFFFFF supports only WB (cacheable) access pci_read_rom() indirectly uses ioremap(0xC0000) to read the shadow VGA option ROM. ioremap() used to default to a 16MB or 64MB UC kernel identity mapping, which would cause an MCA when reading 0xC0000 since only WB is supported there. X uses reads the option ROM to initialize devices. A smaller test case is: # echo 1 > /sys/bus/pci/devices/0000:aa:03.0/rom # cp /sys/bus/pci/devices/0000:aa:03.0/rom x To avoid this, we can use the same ioremap_page_range() strategy that most architectures use for all ioremaps. These page table mappings come out of the vmalloc area. On ia64, these are in region 5 (0xA... addresses) and typically use 16KB or 64KB mappings instead of 16MB or 64MB mappings. The smaller mappings give more flexibility to use the correct attributes. Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64/mm/ioremap.c')
-rw-r--r--arch/ia64/mm/ioremap.c60
1 files changed, 55 insertions, 5 deletions
diff --git a/arch/ia64/mm/ioremap.c b/arch/ia64/mm/ioremap.c
index 1bc0c172726f..2a140627dfd6 100644
--- a/arch/ia64/mm/ioremap.c
+++ b/arch/ia64/mm/ioremap.c
@@ -1,5 +1,5 @@
1/* 1/*
2 * (c) Copyright 2006 Hewlett-Packard Development Company, L.P. 2 * (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P.
3 * Bjorn Helgaas <bjorn.helgaas@hp.com> 3 * Bjorn Helgaas <bjorn.helgaas@hp.com>
4 * 4 *
5 * This program is free software; you can redistribute it and/or modify 5 * This program is free software; you can redistribute it and/or modify
@@ -10,11 +10,13 @@
10#include <linux/compiler.h> 10#include <linux/compiler.h>
11#include <linux/module.h> 11#include <linux/module.h>
12#include <linux/efi.h> 12#include <linux/efi.h>
13#include <linux/io.h>
14#include <linux/vmalloc.h>
13#include <asm/io.h> 15#include <asm/io.h>
14#include <asm/meminit.h> 16#include <asm/meminit.h>
15 17
16static inline void __iomem * 18static inline void __iomem *
17__ioremap (unsigned long phys_addr, unsigned long size) 19__ioremap (unsigned long phys_addr)
18{ 20{
19 return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr); 21 return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr);
20} 22}
@@ -22,8 +24,13 @@ __ioremap (unsigned long phys_addr, unsigned long size)
22void __iomem * 24void __iomem *
23ioremap (unsigned long phys_addr, unsigned long size) 25ioremap (unsigned long phys_addr, unsigned long size)
24{ 26{
27 void __iomem *addr;
28 struct vm_struct *area;
29 unsigned long offset;
30 pgprot_t prot;
25 u64 attr; 31 u64 attr;
26 unsigned long gran_base, gran_size; 32 unsigned long gran_base, gran_size;
33 unsigned long page_base;
27 34
28 /* 35 /*
29 * For things in kern_memmap, we must use the same attribute 36 * For things in kern_memmap, we must use the same attribute
@@ -34,7 +41,7 @@ ioremap (unsigned long phys_addr, unsigned long size)
34 if (attr & EFI_MEMORY_WB) 41 if (attr & EFI_MEMORY_WB)
35 return (void __iomem *) phys_to_virt(phys_addr); 42 return (void __iomem *) phys_to_virt(phys_addr);
36 else if (attr & EFI_MEMORY_UC) 43 else if (attr & EFI_MEMORY_UC)
37 return __ioremap(phys_addr, size); 44 return __ioremap(phys_addr);
38 45
39 /* 46 /*
40 * Some chipsets don't support UC access to memory. If 47 * Some chipsets don't support UC access to memory. If
@@ -45,7 +52,42 @@ ioremap (unsigned long phys_addr, unsigned long size)
45 if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB) 52 if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB)
46 return (void __iomem *) phys_to_virt(phys_addr); 53 return (void __iomem *) phys_to_virt(phys_addr);
47 54
48 return __ioremap(phys_addr, size); 55 /*
56 * WB is not supported for the whole granule, so we can't use
57 * the region 7 identity mapping. If we can safely cover the
58 * area with kernel page table mappings, we can use those
59 * instead.
60 */
61 page_base = phys_addr & PAGE_MASK;
62 size = PAGE_ALIGN(phys_addr + size) - page_base;
63 if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) {
64 prot = PAGE_KERNEL;
65
66 /*
67 * Mappings have to be page-aligned
68 */
69 offset = phys_addr & ~PAGE_MASK;
70 phys_addr &= PAGE_MASK;
71
72 /*
73 * Ok, go for it..
74 */
75 area = get_vm_area(size, VM_IOREMAP);
76 if (!area)
77 return NULL;
78
79 area->phys_addr = phys_addr;
80 addr = (void __iomem *) area->addr;
81 if (ioremap_page_range((unsigned long) addr,
82 (unsigned long) addr + size, phys_addr, prot)) {
83 vunmap((void __force *) addr);
84 return NULL;
85 }
86
87 return (void __iomem *) (offset + (char __iomem *)addr);
88 }
89
90 return __ioremap(phys_addr);
49} 91}
50EXPORT_SYMBOL(ioremap); 92EXPORT_SYMBOL(ioremap);
51 93
@@ -55,6 +97,14 @@ ioremap_nocache (unsigned long phys_addr, unsigned long size)
55 if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB) 97 if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB)
56 return NULL; 98 return NULL;
57 99
58 return __ioremap(phys_addr, size); 100 return __ioremap(phys_addr);
59} 101}
60EXPORT_SYMBOL(ioremap_nocache); 102EXPORT_SYMBOL(ioremap_nocache);
103
104void
105iounmap (volatile void __iomem *addr)
106{
107 if (REGION_NUMBER(addr) == RGN_GATE)
108 vunmap((void *) ((unsigned long) addr & PAGE_MASK));
109}
110EXPORT_SYMBOL(iounmap);