Commit 0c3c8a18 authored by Suresh Siddha's avatar Suresh Siddha Committed by Ingo Molnar
Browse files

x86, PAT: Remove duplicate memtype reserve in devmem mmap 



/dev/mem mmap code was doing memtype reserve/free for a while now.
Recently we added memtype tracking in remap_pfn_range, and /dev/mem mmap
uses it indirectly. So, we don't need seperate tracking in /dev/mem code
any more. That means another ~100 lines of code removed :-).

Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212709.085210000@intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent b6ff32d9

arch/x86/include/asm/pat.h

+0 −4
Original line number Diff line number Diff line
@@ -18,9 +18,5 @@ extern int free_memtype(u64 start, u64 end); 


extern int kernel_map_sync_memtype(u64 base, unsigned long size,

		unsigned long flag);

extern void map_devmem(unsigned long pfn, unsigned long size,

		       struct pgprot vma_prot);

extern void unmap_devmem(unsigned long pfn, unsigned long size,

			 struct pgprot vma_prot);



#endif /* _ASM_X86_PAT_H */

arch/x86/mm/pat.c

+2 −58
Original line number Diff line number Diff line
@@ -536,9 +536,7 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size) 
int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,

				unsigned long size, pgprot_t *vma_prot)

{

	u64 offset = ((u64) pfn) << PAGE_SHIFT;

	unsigned long flags = -1;

	int retval;

	unsigned long flags = _PAGE_CACHE_WB;



	if (!range_is_allowed(pfn, size))

		return 0;
@@ -566,65 +564,11 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, 
	}

#endif



	/*

	 * With O_SYNC, we can only take UC_MINUS mapping. Fail if we cannot.

	 *

	 * Without O_SYNC, we want to get

	 * - WB for WB-able memory and no other conflicting mappings

	 * - UC_MINUS for non-WB-able memory with no other conflicting mappings

	 * - Inherit from confliting mappings otherwise

	 */

	if (flags != -1) {

		retval = reserve_memtype(offset, offset + size, flags, NULL);

	} else {

		retval = reserve_memtype(offset, offset + size,

					_PAGE_CACHE_WB, &flags);

	}



	if (retval < 0)

		return 0;



	if (((pfn < max_low_pfn_mapped) ||

	     (pfn >= (1UL<<(32 - PAGE_SHIFT)) && pfn < max_pfn_mapped)) &&

	    ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {

		free_memtype(offset, offset + size);

		printk(KERN_INFO

		"%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n",

			current->comm, current->pid,

			cattr_name(flags),

			offset, (unsigned long long)(offset + size));

		return 0;

	}



	*vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) |

			     flags);

	return 1;

}



void map_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)

{

	unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK);

	u64 addr = (u64)pfn << PAGE_SHIFT;

	unsigned long flags;



	reserve_memtype(addr, addr + size, want_flags, &flags);

	if (flags != want_flags) {

		printk(KERN_INFO

		"%s:%d /dev/mem expected mapping type %s for %Lx-%Lx, got %s\n",

			current->comm, current->pid,

			cattr_name(want_flags),

			addr, (unsigned long long)(addr + size),

			cattr_name(flags));

	}

}



void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)

{

	u64 addr = (u64)pfn << PAGE_SHIFT;



	free_memtype(addr, addr + size);

}



/*

 * Change the memory type for the physial address range in kernel identity

 * mapping space if that range is a part of identity map.
@@ -662,8 +606,8 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, 
{

	int is_ram = 0;

	int ret;

	unsigned long flags;

	unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK);

	unsigned long flags = want_flags;



	is_ram = pat_pagerange_is_ram(paddr, paddr + size);

drivers/char/mem.c

+0 −27
Original line number Diff line number Diff line
@@ -301,33 +301,7 @@ static inline int private_mapping_ok(struct vm_area_struct *vma) 
}

#endif



void __attribute__((weak))

map_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)

{

	/* nothing. architectures can override. */

}



void __attribute__((weak))

unmap_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)

{

	/* nothing. architectures can override. */

}



static void mmap_mem_open(struct vm_area_struct *vma)

{

	map_devmem(vma->vm_pgoff,  vma->vm_end - vma->vm_start,

			vma->vm_page_prot);

}



static void mmap_mem_close(struct vm_area_struct *vma)

{

	unmap_devmem(vma->vm_pgoff,  vma->vm_end - vma->vm_start,

			vma->vm_page_prot);

}



static struct vm_operations_struct mmap_mem_ops = {

	.open  = mmap_mem_open,

	.close = mmap_mem_close,

#ifdef CONFIG_HAVE_IOREMAP_PROT

	.access = generic_access_phys

#endif
@@ -362,7 +336,6 @@ static int mmap_mem(struct file * file, struct vm_area_struct * vma) 
			    vma->vm_pgoff,

			    size,

			    vma->vm_page_prot)) {

		unmap_devmem(vma->vm_pgoff, size, vma->vm_page_prot);

		return -EAGAIN;

	}

	return 0;

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