Commit 8519635c authored by Hans de Goede's avatar Hans de Goede Committed by Mauro Carvalho Chehab
Browse files

media: atomisp: hmm_bo: Simplify alloc_private_pages() 



Since lack_mem starts initialized to true, alloc_private_pages() will
always set order to HMM_MIN_ORDER aka 0 / will always alloc 1 page at
a time.

So all the magic to decrease order if allocs fail is not necessary
and can be removed.

Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
parent e0ae3048

drivers/staging/media/atomisp/include/hmm/hmm_bo.h

+0 −3
Original line number Diff line number Diff line
@@ -65,9 +65,6 @@ 
#define	check_bo_null_return_void(bo)	\

	check_null_return_void(bo, "NULL hmm buffer object.\n")



#define	HMM_MAX_ORDER		3

#define	HMM_MIN_ORDER		0



#define	ISP_VM_START	0x0

#define	ISP_VM_SIZE	(0x7FFFFFFF)	/* 2G address space */

#define	ISP_PTR_NULL	NULL

drivers/staging/media/atomisp/pci/hmm/hmm_bo.c

+10 −73
Original line number Diff line number Diff line
@@ -44,16 +44,6 @@ 
#include "hmm/hmm_common.h"

#include "hmm/hmm_bo.h"



static unsigned int order_to_nr(unsigned int order)

{

	return 1U << order;

}



static unsigned int nr_to_order_bottom(unsigned int nr)

{

	return fls(nr) - 1;

}



static int __bo_init(struct hmm_bo_device *bdev, struct hmm_buffer_object *bo,

		     unsigned int pgnr)

{
@@ -653,13 +643,10 @@ static void free_private_bo_pages(struct hmm_buffer_object *bo, 
static int alloc_private_pages(struct hmm_buffer_object *bo)

{

	int ret;

	unsigned int pgnr, order, blk_pgnr, alloc_pgnr;

	unsigned int pgnr, blk_pgnr, alloc_pgnr;

	struct page *pages;

	gfp_t gfp = GFP_NOWAIT | __GFP_NOWARN; /* REVISIT: need __GFP_FS too? */

	int i, j;

	int failure_number = 0;

	bool reduce_order = false;

	bool lack_mem = true;



	pgnr = bo->pgnr;
@@ -667,58 +654,17 @@ static int alloc_private_pages(struct hmm_buffer_object *bo) 
	alloc_pgnr = 0;



	while (pgnr) {

		order = nr_to_order_bottom(pgnr);

		/*

		 * if be short of memory, we will set order to 0

		 * everytime.

		 */

		if (lack_mem)

			order = HMM_MIN_ORDER;

		else if (order > HMM_MAX_ORDER)

			order = HMM_MAX_ORDER;

retry:

		/*

		 * When order > HMM_MIN_ORDER, for performance reasons we don't

		 * want alloc_pages() to sleep. In case it fails and fallbacks

		 * to HMM_MIN_ORDER or in case the requested order is originally

		 * the minimum value, we can allow alloc_pages() to sleep for

		 * robustness purpose.

		 *

		 * REVISIT: why __GFP_FS is necessary?

		 */

		if (order == HMM_MIN_ORDER) {

		gfp &= ~GFP_NOWAIT;

		gfp |= __GFP_RECLAIM | __GFP_FS;

		}



		pages = alloc_pages(gfp, order);

		pages = alloc_pages(gfp, 0); // alloc 1 page

		if (unlikely(!pages)) {

			/*

			 * in low memory case, if allocation page fails,

			 * we turn to try if order=0 allocation could

			 * succeed. if order=0 fails too, that means there is

			 * no memory left.

			 */

			if (order == HMM_MIN_ORDER) {

			dev_err(atomisp_dev,

				"%s: cannot allocate pages\n",

				__func__);

			goto cleanup;

			}

			order = HMM_MIN_ORDER;

			failure_number++;

			reduce_order = true;

			/*

			 * if fail two times continuously, we think be short

			 * of memory now.

			 */

			if (failure_number == 2) {

				lack_mem = true;

				failure_number = 0;

			}

			goto retry;

		} else {

			blk_pgnr = order_to_nr(order);

			blk_pgnr = 1;



			/*

			 * set memory to uncacheable -- UC_MINUS
@@ -728,7 +674,7 @@ static int alloc_private_pages(struct hmm_buffer_object *bo) 
				dev_err(atomisp_dev,

					"set page uncacheablefailed.\n");



				__free_pages(pages, order);

				__free_pages(pages, 0);



				goto cleanup;

			}
@@ -738,15 +684,6 @@ static int alloc_private_pages(struct hmm_buffer_object *bo) 
			}



			pgnr -= blk_pgnr;



			/*

			 * if order is not reduced this time, clear

			 * failure_number.

			 */

			if (reduce_order)

				reduce_order = false;

			else

				failure_number = 0;

		}

	}