From 3bcc5209ba6af1019487b54b30fc226ecf79193d Mon Sep 17 00:00:00 2001 From: Karol Wachowski Date: Sat, 28 Oct 2023 17:59:34 +0200 Subject: accel/ivpu: Make DMA allocations for MMU600 write combined Previously using dma_alloc_wc() API we created cache coherent (mapped as write-back) mappings. Because we disable MMU600 snooping it was required to do costly page walk and cache flushes after each page table modification. With write-combined buffers it's possible to do a single write memory barrier to flush write-combined buffer to memory which simplifies the driver and significantly reduce time of map/unmap operations. Mapping time of 255 MB is reduced from 2.5 ms to 500 us. Signed-off-by: Karol Wachowski Reviewed-by: Stanislaw Gruszka Reviewed-by: Jeffrey Hugo Signed-off-by: Stanislaw Gruszka Link: https://patchwork.freedesktop.org/patch/msgid/20231028155936.1183342-7-stanislaw.gruszka@linux.intel.com --- drivers/accel/ivpu/ivpu_mmu_context.c | 115 +++++++++++++++++++--------------- 1 file changed, 63 insertions(+), 52 deletions(-) (limited to 'drivers/accel/ivpu') diff --git a/drivers/accel/ivpu/ivpu_mmu_context.c b/drivers/accel/ivpu/ivpu_mmu_context.c index 0c8c65351919..7d8005bc78d2 100644 --- a/drivers/accel/ivpu/ivpu_mmu_context.c +++ b/drivers/accel/ivpu/ivpu_mmu_context.c @@ -5,6 +5,9 @@ #include #include +#include + +#include #include "ivpu_drv.h" #include "ivpu_hw.h" @@ -38,12 +41,57 @@ #define IVPU_MMU_ENTRY_MAPPED (IVPU_MMU_ENTRY_FLAG_AF | IVPU_MMU_ENTRY_FLAG_USER | \ IVPU_MMU_ENTRY_FLAG_NG | IVPU_MMU_ENTRY_VALID) +static void *ivpu_pgtable_alloc_page(struct ivpu_device *vdev, dma_addr_t *dma) +{ + dma_addr_t dma_addr; + struct page *page; + void *cpu; + + page = alloc_page(GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO); + if (!page) + return NULL; + + set_pages_array_wc(&page, 1); + + dma_addr = dma_map_page(vdev->drm.dev, page, 0, PAGE_SIZE, DMA_BIDIRECTIONAL); + if (dma_mapping_error(vdev->drm.dev, dma_addr)) + goto err_free_page; + + cpu = vmap(&page, 1, VM_MAP, pgprot_writecombine(PAGE_KERNEL)); + if (!cpu) + goto err_dma_unmap_page; + + + *dma = dma_addr; + return cpu; + +err_dma_unmap_page: + dma_unmap_page(vdev->drm.dev, dma_addr, PAGE_SIZE, DMA_BIDIRECTIONAL); + +err_free_page: + put_page(page); + return NULL; +} + +static void ivpu_pgtable_free_page(struct ivpu_device *vdev, u64 *cpu_addr, dma_addr_t dma_addr) +{ + struct page *page; + + if (cpu_addr) { + page = vmalloc_to_page(cpu_addr); + vunmap(cpu_addr); + dma_unmap_page(vdev->drm.dev, dma_addr & ~IVPU_MMU_ENTRY_FLAGS_MASK, PAGE_SIZE, + DMA_BIDIRECTIONAL); + set_pages_array_wb(&page, 1); + put_page(page); + } +} + static int ivpu_mmu_pgtable_init(struct ivpu_device *vdev, struct ivpu_mmu_pgtable *pgtable) { dma_addr_t pgd_dma; - pgtable->pgd_dma_ptr = dma_alloc_coherent(vdev->drm.dev, IVPU_MMU_PGTABLE_SIZE, &pgd_dma, - GFP_KERNEL); + pgtable->pgd_dma_ptr = ivpu_pgtable_alloc_page(vdev, &pgd_dma); if (!pgtable->pgd_dma_ptr) return -ENOMEM; @@ -52,13 +100,6 @@ static int ivpu_mmu_pgtable_init(struct ivpu_device *vdev, struct ivpu_mmu_pgtab return 0; } -static void ivpu_mmu_pgtable_free(struct ivpu_device *vdev, u64 *cpu_addr, dma_addr_t dma_addr) -{ - if (cpu_addr) - dma_free_coherent(vdev->drm.dev, IVPU_MMU_PGTABLE_SIZE, cpu_addr, - dma_addr & ~IVPU_MMU_ENTRY_FLAGS_MASK); -} - static void ivpu_mmu_pgtables_free(struct ivpu_device *vdev, struct ivpu_mmu_pgtable *pgtable) { int pgd_idx, pud_idx, pmd_idx; @@ -83,19 +124,19 @@ static void ivpu_mmu_pgtables_free(struct ivpu_device *vdev, struct ivpu_mmu_pgt pte_dma_ptr = pgtable->pte_ptrs[pgd_idx][pud_idx][pmd_idx]; pte_dma = pgtable->pmd_ptrs[pgd_idx][pud_idx][pmd_idx]; - ivpu_mmu_pgtable_free(vdev, pte_dma_ptr, pte_dma); + ivpu_pgtable_free_page(vdev, pte_dma_ptr, pte_dma); } kfree(pgtable->pte_ptrs[pgd_idx][pud_idx]); - ivpu_mmu_pgtable_free(vdev, pmd_dma_ptr, pmd_dma); + ivpu_pgtable_free_page(vdev, pmd_dma_ptr, pmd_dma); } kfree(pgtable->pmd_ptrs[pgd_idx]); kfree(pgtable->pte_ptrs[pgd_idx]); - ivpu_mmu_pgtable_free(vdev, pud_dma_ptr, pud_dma); + ivpu_pgtable_free_page(vdev, pud_dma_ptr, pud_dma); } - ivpu_mmu_pgtable_free(vdev, pgtable->pgd_dma_ptr, pgtable->pgd_dma); + ivpu_pgtable_free_page(vdev, pgtable->pgd_dma_ptr, pgtable->pgd_dma); } static u64* @@ -107,7 +148,7 @@ ivpu_mmu_ensure_pud(struct ivpu_device *vdev, struct ivpu_mmu_pgtable *pgtable, if (pud_dma_ptr) return pud_dma_ptr; - pud_dma_ptr = dma_alloc_wc(vdev->drm.dev, IVPU_MMU_PGTABLE_SIZE, &pud_dma, GFP_KERNEL); + pud_dma_ptr = ivpu_pgtable_alloc_page(vdev, &pud_dma); if (!pud_dma_ptr) return NULL; @@ -130,7 +171,7 @@ err_free_pmd_ptrs: kfree(pgtable->pmd_ptrs[pgd_idx]); err_free_pud_dma_ptr: - ivpu_mmu_pgtable_free(vdev, pud_dma_ptr, pud_dma); + ivpu_pgtable_free_page(vdev, pud_dma_ptr, pud_dma); return NULL; } @@ -144,7 +185,7 @@ ivpu_mmu_ensure_pmd(struct ivpu_device *vdev, struct ivpu_mmu_pgtable *pgtable, if (pmd_dma_ptr) return pmd_dma_ptr; - pmd_dma_ptr = dma_alloc_wc(vdev->drm.dev, IVPU_MMU_PGTABLE_SIZE, &pmd_dma, GFP_KERNEL); + pmd_dma_ptr = ivpu_pgtable_alloc_page(vdev, &pmd_dma); if (!pmd_dma_ptr) return NULL; @@ -159,7 +200,7 @@ ivpu_mmu_ensure_pmd(struct ivpu_device *vdev, struct ivpu_mmu_pgtable *pgtable, return pmd_dma_ptr; err_free_pmd_dma_ptr: - ivpu_mmu_pgtable_free(vdev, pmd_dma_ptr, pmd_dma); + ivpu_pgtable_free_page(vdev, pmd_dma_ptr, pmd_dma); return NULL; } @@ -173,7 +214,7 @@ ivpu_mmu_ensure_pte(struct ivpu_device *vdev, struct ivpu_mmu_pgtable *pgtable, if (pte_dma_ptr) return pte_dma_ptr; - pte_dma_ptr = dma_alloc_wc(vdev->drm.dev, IVPU_MMU_PGTABLE_SIZE, &pte_dma, GFP_KERNEL); + pte_dma_ptr = ivpu_pgtable_alloc_page(vdev, &pte_dma); if (!pte_dma_ptr) return NULL; @@ -248,38 +289,6 @@ static void ivpu_mmu_context_unmap_page(struct ivpu_mmu_context *ctx, u64 vpu_ad ctx->pgtable.pte_ptrs[pgd_idx][pud_idx][pmd_idx][pte_idx] = IVPU_MMU_ENTRY_INVALID; } -static void -ivpu_mmu_context_flush_page_tables(struct ivpu_mmu_context *ctx, u64 vpu_addr, size_t size) -{ - struct ivpu_mmu_pgtable *pgtable = &ctx->pgtable; - u64 end_addr = vpu_addr + size; - - /* Align to PMD entry (2 MB) */ - vpu_addr &= ~(IVPU_MMU_PTE_MAP_SIZE - 1); - - while (vpu_addr < end_addr) { - int pgd_idx = FIELD_GET(IVPU_MMU_PGD_INDEX_MASK, vpu_addr); - u64 pud_end = (pgd_idx + 1) * (u64)IVPU_MMU_PUD_MAP_SIZE; - - while (vpu_addr < end_addr && vpu_addr < pud_end) { - int pud_idx = FIELD_GET(IVPU_MMU_PUD_INDEX_MASK, vpu_addr); - u64 pmd_end = (pud_idx + 1) * (u64)IVPU_MMU_PMD_MAP_SIZE; - - while (vpu_addr < end_addr && vpu_addr < pmd_end) { - int pmd_idx = FIELD_GET(IVPU_MMU_PMD_INDEX_MASK, vpu_addr); - - clflush_cache_range(pgtable->pte_ptrs[pgd_idx][pud_idx][pmd_idx], - IVPU_MMU_PGTABLE_SIZE); - vpu_addr += IVPU_MMU_PTE_MAP_SIZE; - } - clflush_cache_range(pgtable->pmd_ptrs[pgd_idx][pud_idx], - IVPU_MMU_PGTABLE_SIZE); - } - clflush_cache_range(pgtable->pud_ptrs[pgd_idx], IVPU_MMU_PGTABLE_SIZE); - } - clflush_cache_range(pgtable->pgd_dma_ptr, IVPU_MMU_PGTABLE_SIZE); -} - static int ivpu_mmu_context_map_pages(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx, u64 vpu_addr, dma_addr_t dma_addr, size_t size, u64 prot) @@ -352,10 +361,11 @@ ivpu_mmu_context_map_sgt(struct ivpu_device *vdev, struct ivpu_mmu_context *ctx, mutex_unlock(&ctx->lock); return ret; } - ivpu_mmu_context_flush_page_tables(ctx, vpu_addr, size); vpu_addr += size; } + /* Ensure page table modifications are flushed from wc buffers to memory */ + wmb(); mutex_unlock(&ctx->lock); ret = ivpu_mmu_invalidate_tlb(vdev, ctx->id); @@ -381,10 +391,11 @@ ivpu_mmu_context_unmap_sgt(struct ivpu_device *vdev, struct ivpu_mmu_context *ct size_t size = sg_dma_len(sg) + sg->offset; ivpu_mmu_context_unmap_pages(ctx, vpu_addr, size); - ivpu_mmu_context_flush_page_tables(ctx, vpu_addr, size); vpu_addr += size; } + /* Ensure page table modifications are flushed from wc buffers to memory */ + wmb(); mutex_unlock(&ctx->lock); ret = ivpu_mmu_invalidate_tlb(vdev, ctx->id); 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