From 9b50ffb0c0281bc5a08ccd56ae9bb84296c28f38 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Fri, 30 Mar 2007 10:34:05 -0600 Subject: [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 Signed-off-by: Tony Luck --- arch/ia64/mm/ioremap.c | 60 +++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 55 insertions(+), 5 deletions(-) (limited to 'arch/ia64/mm') diff --git a/arch/ia64/mm/ioremap.c b/arch/ia64/mm/ioremap.c index 1bc0c172726..2a140627dfd 100644 --- a/arch/ia64/mm/ioremap.c +++ b/arch/ia64/mm/ioremap.c @@ -1,5 +1,5 @@ /* - * (c) Copyright 2006 Hewlett-Packard Development Company, L.P. + * (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P. * Bjorn Helgaas * * This program is free software; you can redistribute it and/or modify @@ -10,11 +10,13 @@ #include #include #include +#include +#include #include #include static inline void __iomem * -__ioremap (unsigned long phys_addr, unsigned long size) +__ioremap (unsigned long phys_addr) { return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr); } @@ -22,8 +24,13 @@ __ioremap (unsigned long phys_addr, unsigned long size) void __iomem * ioremap (unsigned long phys_addr, unsigned long size) { + void __iomem *addr; + struct vm_struct *area; + unsigned long offset; + pgprot_t prot; u64 attr; unsigned long gran_base, gran_size; + unsigned long page_base; /* * For things in kern_memmap, we must use the same attribute @@ -34,7 +41,7 @@ ioremap (unsigned long phys_addr, unsigned long size) if (attr & EFI_MEMORY_WB) return (void __iomem *) phys_to_virt(phys_addr); else if (attr & EFI_MEMORY_UC) - return __ioremap(phys_addr, size); + return __ioremap(phys_addr); /* * Some chipsets don't support UC access to memory. If @@ -45,7 +52,42 @@ ioremap (unsigned long phys_addr, unsigned long size) if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB) return (void __iomem *) phys_to_virt(phys_addr); - return __ioremap(phys_addr, size); + /* + * WB is not supported for the whole granule, so we can't use + * the region 7 identity mapping. If we can safely cover the + * area with kernel page table mappings, we can use those + * instead. + */ + page_base = phys_addr & PAGE_MASK; + size = PAGE_ALIGN(phys_addr + size) - page_base; + if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) { + prot = PAGE_KERNEL; + + /* + * Mappings have to be page-aligned + */ + offset = phys_addr & ~PAGE_MASK; + phys_addr &= PAGE_MASK; + + /* + * Ok, go for it.. + */ + area = get_vm_area(size, VM_IOREMAP); + if (!area) + return NULL; + + area->phys_addr = phys_addr; + addr = (void __iomem *) area->addr; + if (ioremap_page_range((unsigned long) addr, + (unsigned long) addr + size, phys_addr, prot)) { + vunmap((void __force *) addr); + return NULL; + } + + return (void __iomem *) (offset + (char __iomem *)addr); + } + + return __ioremap(phys_addr); } EXPORT_SYMBOL(ioremap); @@ -55,6 +97,14 @@ ioremap_nocache (unsigned long phys_addr, unsigned long size) if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB) return NULL; - return __ioremap(phys_addr, size); + return __ioremap(phys_addr); } EXPORT_SYMBOL(ioremap_nocache); + +void +iounmap (volatile void __iomem *addr) +{ + if (REGION_NUMBER(addr) == RGN_GATE) + vunmap((void *) ((unsigned long) addr & PAGE_MASK)); +} +EXPORT_SYMBOL(iounmap); -- cgit v1.2.3