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Commit 136939a2 authored by Bjorn Helgaas's avatar Bjorn Helgaas Committed by Linus Torvalds
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[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: default avatarBjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: "Tolentino, Matthew E" <matthew.e.tolentino@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: default avatar"Luck, Tony" <tony.luck@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 3ed3bce8

arch/ia64/kernel/efi.c

+20 −21
Original line number Diff line number Diff line
@@ -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;

}

drivers/char/mem.c

+6 −12
Original line number Diff line number Diff line
@@ -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,

include/asm-ia64/io.h

+2 −2
Original line number Diff line number Diff line
@@ -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.

include/linux/efi.h

+2 −0
Original line number Diff line number Diff line
@@ -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);