[PATCH v2 5/6] drm/panfrost: Implement generic DRM object RSS reporting function
Adrián Larumbe
adrian.larumbe at collabora.com
Fri Sep 1 00:03:23 UTC 2023
On 30.08.2023 12:52, Boris Brezillon wrote:
>On Thu, 24 Aug 2023 02:34:48 +0100
>Adrián Larumbe <adrian.larumbe at collabora.com> wrote:
>
>> BO's RSS is updated every time new pages are allocated and mapped for the
>> object, either in its entirety at creation time for non-heap buffers, or
>> else on demand for heap buffers at GPU page fault's IRQ handler.
>>
>> Same calculations had to be done for imported PRIME objects, since backing
>> storage for it might have already been allocated by the exporting driver.
>>
>> Signed-off-by: Adrián Larumbe <adrian.larumbe at collabora.com>
>> ---
>> drivers/gpu/drm/panfrost/panfrost_gem.c | 22 ++++++++++++++++++++++
>> drivers/gpu/drm/panfrost/panfrost_gem.h | 5 +++++
>> drivers/gpu/drm/panfrost/panfrost_mmu.c | 16 +++++++++++-----
>> 3 files changed, 38 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
>> index aea16b0e4dda..c6bd1f16a6d4 100644
>> --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
>> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
>> @@ -206,6 +206,17 @@ static enum drm_gem_object_status panfrost_gem_status(struct drm_gem_object *obj
>>
>> return res;
>> }
>> +
>> +size_t panfrost_gem_rss(struct drm_gem_object *obj)
>> +{
>> + struct panfrost_gem_object *bo = to_panfrost_bo(obj);
>> +
>> + if (!bo->base.pages)
>> + return 0;
>> +
>> + return bo->rss_size;
>> +}
>> +
>> static const struct drm_gem_object_funcs panfrost_gem_funcs = {
>> .free = panfrost_gem_free_object,
>> .open = panfrost_gem_open,
>> @@ -218,6 +229,7 @@ static const struct drm_gem_object_funcs panfrost_gem_funcs = {
>> .vunmap = drm_gem_shmem_object_vunmap,
>> .mmap = drm_gem_shmem_object_mmap,
>> .status = panfrost_gem_status,
>> + .rss = panfrost_gem_rss,
>> .vm_ops = &drm_gem_shmem_vm_ops,
>> };
>>
>> @@ -274,13 +286,23 @@ panfrost_gem_prime_import_sg_table(struct drm_device *dev,
>> {
>> struct drm_gem_object *obj;
>> struct panfrost_gem_object *bo;
>> + struct scatterlist *sgl;
>> + unsigned int count;
>> + size_t total = 0;
>>
>> obj = drm_gem_shmem_prime_import_sg_table(dev, attach, sgt);
>> if (IS_ERR(obj))
>> return ERR_CAST(obj);
>>
>> + for_each_sgtable_dma_sg(sgt, sgl, count) {
>> + size_t len = sg_dma_len(sgl);
>> +
>> + total += len;
>> + }
>
>Why not simply have bo->rss_size = obj->size here? Not sure I see a
>reason to not trust dma_buf?
Can PRIME-imported BO's ever be heap objects?
>> +
>> bo = to_panfrost_bo(obj);
>> bo->noexec = true;
>> + bo->rss_size = total;
>>
>> return obj;
>> }
>> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
>> index e06f7ceb8f73..e2a7c46403c7 100644
>> --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
>> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
>> @@ -36,6 +36,11 @@ struct panfrost_gem_object {
>> */
>> atomic_t gpu_usecount;
>>
>> + /*
>> + * Object chunk size currently mapped onto physical memory
>> + */
>> + size_t rss_size;
>> +
>> bool noexec :1;
>> bool is_heap :1;
>> bool is_purgable :1;
>> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
>> index c0123d09f699..e03a5a9da06f 100644
>> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
>> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
>> @@ -285,17 +285,19 @@ static void panfrost_mmu_flush_range(struct panfrost_device *pfdev,
>> pm_runtime_put_autosuspend(pfdev->dev);
>> }
>>
>> -static int mmu_map_sg(struct panfrost_device *pfdev, struct panfrost_mmu *mmu,
>> +static size_t mmu_map_sg(struct panfrost_device *pfdev, struct panfrost_mmu *mmu,
>> u64 iova, int prot, struct sg_table *sgt)
>> {
>> unsigned int count;
>> struct scatterlist *sgl;
>> struct io_pgtable_ops *ops = mmu->pgtbl_ops;
>> u64 start_iova = iova;
>> + size_t total = 0;
>>
>> for_each_sgtable_dma_sg(sgt, sgl, count) {
>> unsigned long paddr = sg_dma_address(sgl);
>> size_t len = sg_dma_len(sgl);
>> + total += len;
>>
>> dev_dbg(pfdev->dev, "map: as=%d, iova=%llx, paddr=%lx, len=%zx", mmu->as, iova, paddr, len);
>>
>> @@ -315,7 +317,7 @@ static int mmu_map_sg(struct panfrost_device *pfdev, struct panfrost_mmu *mmu,
>>
>> panfrost_mmu_flush_range(pfdev, mmu, start_iova, iova - start_iova);
>>
>> - return 0;
>> + return total;
>> }
>>
>> int panfrost_mmu_map(struct panfrost_gem_mapping *mapping)
>> @@ -326,6 +328,7 @@ int panfrost_mmu_map(struct panfrost_gem_mapping *mapping)
>> struct panfrost_device *pfdev = to_panfrost_device(obj->dev);
>> struct sg_table *sgt;
>> int prot = IOMMU_READ | IOMMU_WRITE;
>> + size_t mapped_size;
>>
>> if (WARN_ON(mapping->active))
>> return 0;
>> @@ -337,9 +340,10 @@ int panfrost_mmu_map(struct panfrost_gem_mapping *mapping)
>> if (WARN_ON(IS_ERR(sgt)))
>> return PTR_ERR(sgt);
>>
>> - mmu_map_sg(pfdev, mapping->mmu, mapping->mmnode.start << PAGE_SHIFT,
>> + mapped_size = mmu_map_sg(pfdev, mapping->mmu, mapping->mmnode.start << PAGE_SHIFT,
>> prot, sgt);
>> mapping->active = true;
>> + bo->rss_size += mapped_size;
>
>Actually, the GEM might be resident even before panfrost_mmu_map() is
>called: as soon as drm_gem_shmem_get_pages[_locked]() is called, it's
>resident (might get evicted after that point though). That means any
>mmap coming from userspace will make the buffer resident too. I know
>we're automatically mapping GEMs to the GPU VM in panfrost_gem_open(),
>so it makes no difference, but I think I'd prefer if we keep ->rss_size
>for heap BOs only (we probably want to rename it heap_rss_size) and
>then have
>
>
> if (bo->is_heap)
> return bo->heap_rss_size;
> else if (bo->base.pages)
> return bo->base.base.size;
> else
> return 0;
>
>in panfrost_gem_rss().
>
>>
>> return 0;
>> }
>> @@ -447,6 +451,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
>> pgoff_t page_offset;
>> struct sg_table *sgt;
>> struct page **pages;
>> + size_t mapped_size;
>>
>> bomapping = addr_to_mapping(pfdev, as, addr);
>> if (!bomapping)
>> @@ -518,10 +523,11 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
>> if (ret)
>> goto err_map;
>>
>> - mmu_map_sg(pfdev, bomapping->mmu, addr,
>> - IOMMU_WRITE | IOMMU_READ | IOMMU_NOEXEC, sgt);
>> + mapped_size = mmu_map_sg(pfdev, bomapping->mmu, addr,
>> + IOMMU_WRITE | IOMMU_READ | IOMMU_NOEXEC, sgt);
>>
>> bomapping->active = true;
>> + bo->rss_size += mapped_size;
>>
>> dev_dbg(pfdev->dev, "mapped page fault @ AS%d %llx", as, addr);
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