[Nouveau] [PATCH 4/5] drm/ttm: add ttm_sg_tt_init
He, Roger
Hongbo.He at amd.com
Tue Mar 6 01:52:28 UTC 2018
Patch 1: Acked-by: Roger He <Hongbo.He at amd.com>
Patch 2~5: Reviewed-by: Roger He <Hongbo.He at amd.com>
-----Original Message-----
From: dri-devel [mailto:dri-devel-bounces at lists.freedesktop.org] On Behalf Of Christian K?nig
Sent: Monday, March 05, 2018 8:07 PM
To: dri-devel at lists.freedesktop.org; amd-gfx at lists.freedesktop.org; Ben Skeggs <bskeggs at redhat.com>; Ilia Mirkin <imirkin at alum.mit.edu>; nouveau <nouveau at lists.freedesktop.org>
Subject: Re: [PATCH 4/5] drm/ttm: add ttm_sg_tt_init
Ping?
Am 27.02.2018 um 13:07 schrieb Christian König:
> Hi guys,
>
> at least on amdgpu and radeon the page array allocated by
> ttm_dma_tt_init is completely unused in the case of DMA-buf sharing.
> So I'm trying to get rid of that by only allocating the DMA address
> array.
>
> Now the only other user of DMA-buf together with ttm_dma_tt_init is
> Nouveau. So my question is are you guys using the page array anywhere
> in your kernel driver in case of a DMA-buf sharing?
>
> If no then I could just make this the default behavior for all drivers
> and save quite a bit of memory for everybody.
>
> Thanks,
> Christian.
>
> Am 27.02.2018 um 12:49 schrieb Christian König:
>> This allows drivers to only allocate dma addresses, but not a page
>> array.
>>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> ---
>> drivers/gpu/drm/ttm/ttm_tt.c | 54
>> ++++++++++++++++++++++++++++++++++++--------
>> include/drm/ttm/ttm_tt.h | 2 ++
>> 2 files changed, 47 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c
>> b/drivers/gpu/drm/ttm/ttm_tt.c index 8e0b525cda00..971133106ec2
>> 100644
>> --- a/drivers/gpu/drm/ttm/ttm_tt.c
>> +++ b/drivers/gpu/drm/ttm/ttm_tt.c
>> @@ -108,6 +108,16 @@ static int
>> ttm_dma_tt_alloc_page_directory(struct ttm_dma_tt *ttm)
>> return 0;
>> }
>> +static int ttm_sg_tt_alloc_page_directory(struct ttm_dma_tt *ttm)
>> +{
>> + ttm->dma_address = kvmalloc_array(ttm->ttm.num_pages,
>> + sizeof(*ttm->dma_address),
>> + GFP_KERNEL | __GFP_ZERO);
>> + if (!ttm->dma_address)
>> + return -ENOMEM;
>> + return 0;
>> +}
>> +
>> #ifdef CONFIG_X86
>> static inline int ttm_tt_set_page_caching(struct page *p,
>> enum ttm_caching_state c_old, @@ -227,8
>> +237,8 @@ void ttm_tt_destroy(struct ttm_tt *ttm)
>> ttm->func->destroy(ttm);
>> }
>> -int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
>> - unsigned long size, uint32_t page_flags)
>> +void ttm_tt_init_fields(struct ttm_tt *ttm, struct ttm_bo_device
>> +*bdev,
>> + unsigned long size, uint32_t page_flags)
>> {
>> ttm->bdev = bdev;
>> ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; @@
>> -236,6 +246,12 @@ int ttm_tt_init(struct ttm_tt *ttm, struct
>> ttm_bo_device *bdev,
>> ttm->page_flags = page_flags;
>> ttm->state = tt_unpopulated;
>> ttm->swap_storage = NULL;
>> +}
>> +
>> +int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
>> + unsigned long size, uint32_t page_flags) {
>> + ttm_tt_init_fields(ttm, bdev, size, page_flags);
>> if (ttm_tt_alloc_page_directory(ttm)) {
>> ttm_tt_destroy(ttm);
>> @@ -258,12 +274,7 @@ int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma,
>> struct ttm_bo_device *bdev,
>> {
>> struct ttm_tt *ttm = &ttm_dma->ttm;
>> - ttm->bdev = bdev;
>> - ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
>> - ttm->caching_state = tt_cached;
>> - ttm->page_flags = page_flags;
>> - ttm->state = tt_unpopulated;
>> - ttm->swap_storage = NULL;
>> + ttm_tt_init_fields(ttm, bdev, size, page_flags);
>> INIT_LIST_HEAD(&ttm_dma->pages_list);
>> if (ttm_dma_tt_alloc_page_directory(ttm_dma)) { @@ -275,11
>> +286,36 @@ int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct
>> ttm_bo_device *bdev,
>> }
>> EXPORT_SYMBOL(ttm_dma_tt_init);
>> +int ttm_sg_tt_init(struct ttm_dma_tt *ttm_dma, struct
>> ttm_bo_device *bdev,
>> + unsigned long size, uint32_t page_flags) {
>> + struct ttm_tt *ttm = &ttm_dma->ttm;
>> + int ret;
>> +
>> + ttm_tt_init_fields(ttm, bdev, size, page_flags);
>> +
>> + INIT_LIST_HEAD(&ttm_dma->pages_list);
>> + if (page_flags & TTM_PAGE_FLAG_SG)
>> + ret = ttm_sg_tt_alloc_page_directory(ttm_dma);
>> + else
>> + ret = ttm_dma_tt_alloc_page_directory(ttm_dma);
>> + if (ret) {
>> + ttm_tt_destroy(ttm);
>> + pr_err("Failed allocating page table\n");
>> + return -ENOMEM;
>> + }
>> + return 0;
>> +}
>> +EXPORT_SYMBOL(ttm_sg_tt_init);
>> +
>> void ttm_dma_tt_fini(struct ttm_dma_tt *ttm_dma)
>> {
>> struct ttm_tt *ttm = &ttm_dma->ttm;
>> - kvfree(ttm->pages);
>> + if (ttm->pages)
>> + kvfree(ttm->pages);
>> + else
>> + kvfree(ttm_dma->dma_address);
>> ttm->pages = NULL;
>> ttm_dma->dma_address = NULL;
>> }
>> diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h
>> index 9c78556b488e..1cf316a4257c 100644
>> --- a/include/drm/ttm/ttm_tt.h
>> +++ b/include/drm/ttm/ttm_tt.h
>> @@ -163,6 +163,8 @@ int ttm_tt_init(struct ttm_tt *ttm, struct
>> ttm_bo_device *bdev,
>> unsigned long size, uint32_t page_flags);
>> int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct
>> ttm_bo_device *bdev,
>> unsigned long size, uint32_t page_flags);
>> +int ttm_sg_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device
>> *bdev,
>> + unsigned long size, uint32_t page_flags);
>> /**
>> * ttm_tt_fini
>
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