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Commit 7880f746 authored by Venkatesh Pallipadi's avatar Venkatesh Pallipadi Committed by Ingo Molnar
Browse files

gpu/drm, x86, PAT: routine to keep identity map in sync 



Add a function to check and keep identity maps in sync, when changing
any memory type. One of the follow on patches will also use this
routine.

Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Keith Packard <keithp@keithp.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 4ab0d47d

arch/x86/include/asm/pat.h

+3 −0
Original line number Diff line number Diff line
@@ -19,4 +19,7 @@ extern int free_memtype(u64 start, u64 end); 


extern void pat_disable(char *reason);



extern int kernel_map_sync_memtype(u64 base, unsigned long size,

		unsigned long flag);



#endif /* _ASM_X86_PAT_H */

arch/x86/mm/pat.c

+29 −17
Original line number Diff line number Diff line
@@ -624,6 +624,33 @@ void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot) 
	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.

 */

int kernel_map_sync_memtype(u64 base, unsigned long size, unsigned long flags)

{

	unsigned long id_sz;



	if (!pat_enabled || base >= __pa(high_memory))

		return 0;



	id_sz = (__pa(high_memory) < base + size) ?

				__pa(high_memory) - base :

				size;



	if (ioremap_change_attr((unsigned long)__va(base), id_sz, flags) < 0) {

		printk(KERN_INFO

			"%s:%d ioremap_change_attr failed %s "

			"for %Lx-%Lx\n",

			current->comm, current->pid,

			cattr_name(flags),

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

		return -EINVAL;

	}

	return 0;

}



/*

 * Internal interface to reserve a range of physical memory with prot.

 * Reserved non RAM regions only and after successful reserve_memtype,
@@ -633,7 +660,7 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, 
				int strict_prot)

{

	int is_ram = 0;

	int id_sz, ret;

	int ret;

	unsigned long flags;

	unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK);
@@ -670,23 +697,8 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, 
				     flags);

	}



	/* Need to keep identity mapping in sync */

	if (paddr >= __pa(high_memory))

		return 0;



	id_sz = (__pa(high_memory) < paddr + size) ?

				__pa(high_memory) - paddr :

				size;



	if (ioremap_change_attr((unsigned long)__va(paddr), id_sz, flags) < 0) {

	if (kernel_map_sync_memtype(paddr, size, flags) < 0) {

		free_memtype(paddr, paddr + size);

		printk(KERN_ERR

			"%s:%d reserve_pfn_range ioremap_change_attr failed %s "

			"for %Lx-%Lx\n",

			current->comm, current->pid,

			cattr_name(flags),

			(unsigned long long)paddr,

			(unsigned long long)(paddr + size));

		return -EINVAL;

	}

	return 0;