From: Bjorn Helgaas Date: Sun, 26 Mar 2006 09:37:05 +0000 (-0800) Subject: [PATCH] EFI, /dev/mem: simplify efi_mem_attribute_range() X-Git-Tag: v2.6.17-rc1~650 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=136939a2b5aa4302281215745ccd567e1df2e8d4;p=linux-2.6 [PATCH] EFI, /dev/mem: simplify efi_mem_attribute_range() Pass the size, not a pointer to the size, to efi_mem_attribute_range(). This function validates memory regions for the /dev/mem read/write/mmap paths. The pointer allows arches to reduce the size of the range, but I think that's unnecessary complexity. Simplifying it will let me use efi_mem_attribute_range() to improve the ia64 ioremap() implementation. Signed-off-by: Bjorn Helgaas Cc: Matt Domsch Cc: "Tolentino, Matthew E" Cc: "Brown, Len" Cc: Andi Kleen Acked-by: "Luck, Tony" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c index 9990320b6f..2993748c13 100644 --- a/arch/ia64/kernel/efi.c +++ b/arch/ia64/kernel/efi.c @@ -677,27 +677,34 @@ EXPORT_SYMBOL(efi_mem_attributes); /* * Determines whether the memory at phys_addr supports the desired * attribute (WB, UC, etc). If this returns 1, the caller can safely - * access *size bytes at phys_addr with the specified attribute. + * access size bytes at phys_addr with the specified attribute. */ -static int -efi_mem_attribute_range (unsigned long phys_addr, unsigned long *size, u64 attr) +int +efi_mem_attribute_range (unsigned long phys_addr, unsigned long size, u64 attr) { + unsigned long end = phys_addr + size; efi_memory_desc_t *md = efi_memory_descriptor(phys_addr); - unsigned long md_end; - if (!md || (md->attribute & attr) != attr) + /* + * Some firmware doesn't report MMIO regions in the EFI memory + * map. The Intel BigSur (a.k.a. HP i2000) has this problem. + * On those platforms, we have to assume UC is valid everywhere. + */ + if (!md || (md->attribute & attr) != attr) { + if (attr == EFI_MEMORY_UC && !efi_memmap_has_mmio()) + return 1; return 0; + } do { - md_end = efi_md_end(md); - if (phys_addr + *size <= md_end) + unsigned long md_end = efi_md_end(md); + + if (end <= md_end) return 1; md = efi_memory_descriptor(md_end); - if (!md || (md->attribute & attr) != attr) { - *size = md_end - phys_addr; - return 1; - } + if (!md || (md->attribute & attr) != attr) + return 0; } while (md); return 0; } @@ -708,7 +715,7 @@ efi_mem_attribute_range (unsigned long phys_addr, unsigned long *size, u64 attr) * control access size. */ int -valid_phys_addr_range (unsigned long phys_addr, unsigned long *size) +valid_phys_addr_range (unsigned long phys_addr, unsigned long size) { return efi_mem_attribute_range(phys_addr, size, EFI_MEMORY_WB); } @@ -723,7 +730,7 @@ valid_phys_addr_range (unsigned long phys_addr, unsigned long *size) * because that doesn't appear in the boot-time EFI memory map. */ int -valid_mmap_phys_addr_range (unsigned long phys_addr, unsigned long *size) +valid_mmap_phys_addr_range (unsigned long phys_addr, unsigned long size) { if (efi_mem_attribute_range(phys_addr, size, EFI_MEMORY_WB)) return 1; @@ -731,14 +738,6 @@ valid_mmap_phys_addr_range (unsigned long phys_addr, unsigned long *size) if (efi_mem_attribute_range(phys_addr, size, EFI_MEMORY_UC)) return 1; - /* - * Some firmware doesn't report MMIO regions in the EFI memory map. - * The Intel BigSur (a.k.a. HP i2000) has this problem. In this - * case, we can't use the EFI memory map to validate mmap requests. - */ - if (!efi_memmap_has_mmio()) - return 1; - return 0; } diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 26d0116b48..5245ba1649 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -88,21 +88,15 @@ static inline int uncached_access(struct file *file, unsigned long addr) } #ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE -static inline int valid_phys_addr_range(unsigned long addr, size_t *count) +static inline int valid_phys_addr_range(unsigned long addr, size_t count) { - unsigned long end_mem; - - end_mem = __pa(high_memory); - if (addr >= end_mem) + if (addr + count > __pa(high_memory)) return 0; - if (*count > end_mem - addr) - *count = end_mem - addr; - return 1; } -static inline int valid_mmap_phys_addr_range(unsigned long addr, size_t *size) +static inline int valid_mmap_phys_addr_range(unsigned long addr, size_t size) { return 1; } @@ -119,7 +113,7 @@ static ssize_t read_mem(struct file * file, char __user * buf, ssize_t read, sz; char *ptr; - if (!valid_phys_addr_range(p, &count)) + if (!valid_phys_addr_range(p, count)) return -EFAULT; read = 0; #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED @@ -177,7 +171,7 @@ static ssize_t write_mem(struct file * file, const char __user * buf, unsigned long copied; void *ptr; - if (!valid_phys_addr_range(p, &count)) + if (!valid_phys_addr_range(p, count)) return -EFAULT; written = 0; @@ -249,7 +243,7 @@ static int mmap_mem(struct file * file, struct vm_area_struct * vma) { size_t size = vma->vm_end - vma->vm_start; - if (!valid_mmap_phys_addr_range(vma->vm_pgoff << PAGE_SHIFT, &size)) + if (!valid_mmap_phys_addr_range(vma->vm_pgoff << PAGE_SHIFT, size)) return -EINVAL; vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, diff --git a/include/asm-ia64/io.h b/include/asm-ia64/io.h index 0d9bcc36f2..acba019b08 100644 --- a/include/asm-ia64/io.h +++ b/include/asm-ia64/io.h @@ -88,8 +88,8 @@ phys_to_virt (unsigned long address) } #define ARCH_HAS_VALID_PHYS_ADDR_RANGE -extern int valid_phys_addr_range (unsigned long addr, size_t *count); /* efi.c */ -extern int valid_mmap_phys_addr_range (unsigned long addr, size_t *count); +extern int valid_phys_addr_range (unsigned long addr, size_t count); /* efi.c */ +extern int valid_mmap_phys_addr_range (unsigned long addr, size_t count); /* * The following two macros are deprecated and scheduled for removal. diff --git a/include/linux/efi.h b/include/linux/efi.h index c7c5dd3161..d15725470a 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -292,6 +292,8 @@ extern void efi_enter_virtual_mode (void); /* switch EFI to virtual mode, if pos extern u64 efi_get_iobase (void); extern u32 efi_mem_type (unsigned long phys_addr); extern u64 efi_mem_attributes (unsigned long phys_addr); +extern int efi_mem_attribute_range (unsigned long phys_addr, unsigned long size, + u64 attr); extern int __init efi_uart_console_only (void); extern void efi_initialize_iomem_resources(struct resource *code_resource, struct resource *data_resource);