Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 17581ad8 authored by Venkatesh Pallipadi's avatar Venkatesh Pallipadi Committed by Ingo Molnar
Browse files

gpu/drm, x86, PAT: PAT support for io_mapping_* 



Make io_mapping_create_wc and io_mapping_free go through PAT to make sure
that there are no memory type aliases.

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 7880f746

arch/x86/include/asm/iomap.h

+4 −1
Original line number Diff line number Diff line
@@ -24,7 +24,10 @@ 
#include <asm/tlbflush.h>



int

is_io_mapping_possible(resource_size_t base, unsigned long size);

reserve_io_memtype_wc(u64 base, unsigned long size, pgprot_t *prot);



void

free_io_memtype(u64 base, unsigned long size);



void *

iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot);

arch/x86/mm/iomap_32.c

+40 −2
Original line number Diff line number Diff line
@@ -21,13 +21,13 @@ 
#include <linux/module.h>



#ifdef CONFIG_X86_PAE

int

static int

is_io_mapping_possible(resource_size_t base, unsigned long size)

{

	return 1;

}

#else

int

static int

is_io_mapping_possible(resource_size_t base, unsigned long size)

{

	/* There is no way to map greater than 1 << 32 address without PAE */
@@ -38,6 +38,44 @@ is_io_mapping_possible(resource_size_t base, unsigned long size) 
}

#endif



int

reserve_io_memtype_wc(u64 base, unsigned long size, pgprot_t *prot)

{

	unsigned long ret_flag;



	if (!is_io_mapping_possible(base, size))

		goto out_err;



	if (!pat_enabled) {

		*prot = pgprot_noncached(PAGE_KERNEL);

		return 0;

	}



	if (reserve_memtype(base, base + size, _PAGE_CACHE_WC, &ret_flag))

		goto out_err;



	if (ret_flag == _PAGE_CACHE_WB)

		goto out_free;



	if (kernel_map_sync_memtype(base, size, ret_flag))

		goto out_free;



	*prot = __pgprot(__PAGE_KERNEL | ret_flag);

	return 0;



out_free:

	free_memtype(base, base + size);

out_err:

	return -EINVAL;

}



void

free_io_memtype(u64 base, unsigned long size)

{

	if (pat_enabled)

		free_memtype(base, base + size);

}



/* Map 'pfn' using fixed map 'type' and protections 'prot'

 */

void *

include/linux/io-mapping.h

+4 −2
Original line number Diff line number Diff line
@@ -49,8 +49,9 @@ static inline struct io_mapping * 
io_mapping_create_wc(resource_size_t base, unsigned long size)

{

	struct io_mapping *iomap;

	pgprot_t prot;



	if (!is_io_mapping_possible(base, size))

	if (!reserve_io_memtype_wc(base, size, &prot))

		return NULL;



	iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
@@ -59,13 +60,14 @@ io_mapping_create_wc(resource_size_t base, unsigned long size) 


	iomap->base = base;

	iomap->size = size;

	iomap->prot = pgprot_writecombine(__pgprot(__PAGE_KERNEL));

	iomap->prot = prot;

	return iomap;

}



static inline void

io_mapping_free(struct io_mapping *mapping)

{

	free_io_memtype(mapping->base, mapping->size);

	kfree(mapping);

}