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media: atomisp: hmm_bo: Simplify alloc_private_pages()

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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: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
This commit is contained in:
Hans de Goede 2022-08-13 17:38:45 +02:00 committed by Mauro Carvalho Chehab
parent e0ae3048b3
commit 8519635cb2
2 changed files with 10 additions and 76 deletions
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3
drivers/staging/media/atomisp/include/hmm/hmm_bo.h
View File

@ -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

83
drivers/staging/media/atomisp/pci/hmm/hmm_bo.c
View File

@ -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;
}
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;
dev_err(atomisp_dev,
"%s: cannot allocate pages\n",
__func__);
goto cleanup;
} else {
blk_pgnr = order_to_nr(order);
blk_pgnr = 1;
/*
* set memory to uncacheable -- UC_MINUS
@ -728,7 +674,7 @@ retry:
dev_err(atomisp_dev,
"set page uncacheablefailed.\n");
__free_pages(pages, order);
__free_pages(pages, 0);
goto cleanup;
}
@ -738,15 +684,6 @@ retry:
}
pgnr -= blk_pgnr;
/*
* if order is not reduced this time, clear
* failure_number.
*/
if (reduce_order)
reduce_order = false;
else
failure_number = 0;
}
}