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Commit ecd32842 authored by Vinil Cheeramvelil's avatar Vinil Cheeramvelil Committed by Rom Lemarchand
Browse files

ion: Handle the memory mapping correctly on x86 



This patch modifies the ion page pool code to address
limitation in x86 PAT. When one physical page is mapped
to multiple virtual pages, the same cache policy
should be used. Add set_memory_wc/uc call to avoid aliases.
If not, all mappings will be cached(write back).

Change-Id: I98ee8902df0c80135dddfa998c4ca4c2bb44e40e
Signed-off-by: default avatarZhebin Jin <zhebin.jin@intel.com>
Signed-off-by: default avatarVinil Cheeramvelil <vinil.cheeramvelil@intel.com>
parent 78917d6a

drivers/staging/android/ion/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -33,3 +33,10 @@ config ION_TEGRA 
	help

	  Choose this option if you wish to use ion on an nVidia Tegra.



config ION_POOL_CACHE_POLICY

	bool "Ion set page pool cache policy"

	depends on ION

	default y if X86

	help

	  Choose this option if need to explicity set cache policy of the

	  pages in the page pool.

drivers/staging/android/ion/ion_page_pool.c

+8 −0
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ static void *ion_page_pool_alloc_pages(struct ion_page_pool *pool) 


	if (!page)

		return NULL;

	ion_page_pool_alloc_set_cache_policy(pool, page);



	ion_pages_sync_for_device(NULL, page, PAGE_SIZE << pool->order,

						DMA_BIDIRECTIONAL);

	return page;
@@ -38,6 +40,7 @@ static void *ion_page_pool_alloc_pages(struct ion_page_pool *pool) 
static void ion_page_pool_free_pages(struct ion_page_pool *pool,

				     struct page *page)

{

	ion_page_pool_free_set_cache_policy(pool, page);

	__free_pages(page, pool->order);

}
@@ -103,6 +106,11 @@ void ion_page_pool_free(struct ion_page_pool *pool, struct page *page) 
		ion_page_pool_free_pages(pool, page);

}



void ion_page_pool_free_immediate(struct ion_page_pool *pool, struct page *page)

{

	ion_page_pool_free_pages(pool, page);

}



static int ion_page_pool_total(struct ion_page_pool *pool, bool high)

{

	int count = pool->low_count;

drivers/staging/android/ion/ion_priv.h

+34 −0
Original line number Diff line number Diff line
@@ -26,6 +26,9 @@ 
#include <linux/sched.h>

#include <linux/shrinker.h>

#include <linux/types.h>

#ifdef CONFIG_ION_POOL_CACHE_POLICY

#include <asm/cacheflush.h>

#endif



#include "ion.h"
@@ -380,6 +383,37 @@ struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order); 
void ion_page_pool_destroy(struct ion_page_pool *);

struct page *ion_page_pool_alloc(struct ion_page_pool *);

void ion_page_pool_free(struct ion_page_pool *, struct page *);

void ion_page_pool_free_immediate(struct ion_page_pool *, struct page *);



#ifdef CONFIG_ION_POOL_CACHE_POLICY

static inline void ion_page_pool_alloc_set_cache_policy

				(struct ion_page_pool *pool,

				struct page *page){

	void *va = page_address(page);



	if (va)

		set_memory_wc((unsigned long)va, 1 << pool->order);

}



static inline void ion_page_pool_free_set_cache_policy

				(struct ion_page_pool *pool,

				struct page *page){

	void *va = page_address(page);



	if (va)

		set_memory_wb((unsigned long)va, 1 << pool->order);



}

#else

static inline void ion_page_pool_alloc_set_cache_policy

				(struct ion_page_pool *pool,

				struct page *page){ }



static inline void ion_page_pool_free_set_cache_policy

				(struct ion_page_pool *pool,

				struct page *page){ }

#endif





/** ion_page_pool_shrink - shrinks the size of the memory cached in the pool

 * @pool:		the pool

drivers/staging/android/ion/ion_system_heap.c

+4 −2
Original line number Diff line number Diff line
@@ -85,7 +85,9 @@ static void free_buffer_page(struct ion_system_heap *heap, 


	if (!cached && !(buffer->private_flags & ION_PRIV_FLAG_SHRINKER_FREE)) {

		struct ion_page_pool *pool = heap->pools[order_to_index(order)];



		if (buffer->private_flags & ION_PRIV_FLAG_SHRINKER_FREE)

			ion_page_pool_free_immediate(pool, page);

		else

			ion_page_pool_free(pool, page);

	} else {

		__free_pages(page, order);