diff options
Diffstat (limited to 'drivers/gpu/drm/v3d/v3d_mmu.c')
| -rw-r--r-- | drivers/gpu/drm/v3d/v3d_mmu.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/drivers/gpu/drm/v3d/v3d_mmu.c b/drivers/gpu/drm/v3d/v3d_mmu.c new file mode 100644 index 000000000000..b00f97c31b70 --- /dev/null +++ b/drivers/gpu/drm/v3d/v3d_mmu.c @@ -0,0 +1,122 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* Copyright (C) 2017-2018 Broadcom */ + +/** + * DOC: Broadcom V3D MMU + * + * The V3D 3.x hardware (compared to VC4) now includes an MMU. It has + * a single level of page tables for the V3D's 4GB address space to + * map to AXI bus addresses, thus it could need up to 4MB of + * physically contiguous memory to store the PTEs. + * + * Because the 4MB of contiguous memory for page tables is precious, + * and switching between them is expensive, we load all BOs into the + * same 4GB address space. + * + * To protect clients from each other, we should use the GMP to + * quickly mask out (at 128kb granularity) what pages are available to + * each client. This is not yet implemented. + */ + +#include "v3d_drv.h" +#include "v3d_regs.h" + +#define V3D_MMU_PAGE_SHIFT 12 + +/* Note: All PTEs for the 1MB superpage must be filled with the + * superpage bit set. + */ +#define V3D_PTE_SUPERPAGE BIT(31) +#define V3D_PTE_WRITEABLE BIT(29) +#define V3D_PTE_VALID BIT(28) + +static int v3d_mmu_flush_all(struct v3d_dev *v3d) +{ + int ret; + + /* Make sure that another flush isn't already running when we + * start this one. + */ + ret = wait_for(!(V3D_READ(V3D_MMU_CTL) & + V3D_MMU_CTL_TLB_CLEARING), 100); + if (ret) + dev_err(v3d->dev, "TLB clear wait idle pre-wait failed\n"); + + V3D_WRITE(V3D_MMU_CTL, V3D_READ(V3D_MMU_CTL) | + V3D_MMU_CTL_TLB_CLEAR); + + V3D_WRITE(V3D_MMUC_CONTROL, + V3D_MMUC_CONTROL_FLUSH | + V3D_MMUC_CONTROL_ENABLE); + + ret = wait_for(!(V3D_READ(V3D_MMU_CTL) & + V3D_MMU_CTL_TLB_CLEARING), 100); + if (ret) { + dev_err(v3d->dev, "TLB clear wait idle failed\n"); + return ret; + } + + ret = wait_for(!(V3D_READ(V3D_MMUC_CONTROL) & + V3D_MMUC_CONTROL_FLUSHING), 100); + if (ret) + dev_err(v3d->dev, "MMUC flush wait idle failed\n"); + + return ret; +} + +int v3d_mmu_set_page_table(struct v3d_dev *v3d) +{ + V3D_WRITE(V3D_MMU_PT_PA_BASE, v3d->pt_paddr >> V3D_MMU_PAGE_SHIFT); + V3D_WRITE(V3D_MMU_CTL, + V3D_MMU_CTL_ENABLE | + V3D_MMU_CTL_PT_INVALID | + V3D_MMU_CTL_PT_INVALID_ABORT | + V3D_MMU_CTL_WRITE_VIOLATION_ABORT | + V3D_MMU_CTL_CAP_EXCEEDED_ABORT); + V3D_WRITE(V3D_MMU_ILLEGAL_ADDR, + (v3d->mmu_scratch_paddr >> V3D_MMU_PAGE_SHIFT) | + V3D_MMU_ILLEGAL_ADDR_ENABLE); + V3D_WRITE(V3D_MMUC_CONTROL, V3D_MMUC_CONTROL_ENABLE); + + return v3d_mmu_flush_all(v3d); +} + +void v3d_mmu_insert_ptes(struct v3d_bo *bo) +{ + struct v3d_dev *v3d = to_v3d_dev(bo->base.dev); + u32 page = bo->node.start; + u32 page_prot = V3D_PTE_WRITEABLE | V3D_PTE_VALID; + unsigned int count; + struct scatterlist *sgl; + + for_each_sg(bo->sgt->sgl, sgl, bo->sgt->nents, count) { + u32 page_address = sg_dma_address(sgl) >> V3D_MMU_PAGE_SHIFT; + u32 pte = page_prot | page_address; + u32 i; + + BUG_ON(page_address + (sg_dma_len(sgl) >> V3D_MMU_PAGE_SHIFT) >= + BIT(24)); + + for (i = 0; i < sg_dma_len(sgl) >> V3D_MMU_PAGE_SHIFT; i++) + v3d->pt[page++] = pte + i; + } + + WARN_ON_ONCE(page - bo->node.start != + bo->base.size >> V3D_MMU_PAGE_SHIFT); + + if (v3d_mmu_flush_all(v3d)) + dev_err(v3d->dev, "MMU flush timeout\n"); +} + +void v3d_mmu_remove_ptes(struct v3d_bo *bo) +{ + struct v3d_dev *v3d = to_v3d_dev(bo->base.dev); + u32 npages = bo->base.size >> V3D_MMU_PAGE_SHIFT; + u32 page; + + for (page = bo->node.start; page < bo->node.start + npages; page++) + v3d->pt[page] = 0; + + if (v3d_mmu_flush_all(v3d)) + dev_err(v3d->dev, "MMU flush timeout\n"); +} |