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Diffstat (limited to 'drivers/gpu/drm/v3d/v3d_mmu.c')
-rw-r--r--drivers/gpu/drm/v3d/v3d_mmu.c125
1 files changed, 125 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 000000000..5a4535329
--- /dev/null
+++ b/drivers/gpu/drm/v3d/v3d_mmu.c
@@ -0,0 +1,125 @@
+// 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->drm.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->drm.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->drm.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_ENABLE |
+ V3D_MMU_CTL_PT_INVALID_ABORT |
+ V3D_MMU_CTL_PT_INVALID_INT |
+ V3D_MMU_CTL_WRITE_VIOLATION_ABORT |
+ V3D_MMU_CTL_WRITE_VIOLATION_INT |
+ V3D_MMU_CTL_CAP_EXCEEDED_ABORT |
+ V3D_MMU_CTL_CAP_EXCEEDED_INT);
+ 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 drm_gem_shmem_object *shmem_obj = &bo->base;
+ struct v3d_dev *v3d = to_v3d_dev(shmem_obj->base.dev);
+ u32 page = bo->node.start;
+ u32 page_prot = V3D_PTE_WRITEABLE | V3D_PTE_VALID;
+ struct sg_dma_page_iter dma_iter;
+
+ for_each_sgtable_dma_page(shmem_obj->sgt, &dma_iter, 0) {
+ dma_addr_t dma_addr = sg_page_iter_dma_address(&dma_iter);
+ u32 page_address = dma_addr >> V3D_MMU_PAGE_SHIFT;
+ u32 pte = page_prot | page_address;
+ u32 i;
+
+ BUG_ON(page_address + (PAGE_SIZE >> V3D_MMU_PAGE_SHIFT) >=
+ BIT(24));
+ for (i = 0; i < PAGE_SIZE >> V3D_MMU_PAGE_SHIFT; i++)
+ v3d->pt[page++] = pte + i;
+ }
+
+ WARN_ON_ONCE(page - bo->node.start !=
+ shmem_obj->base.size >> V3D_MMU_PAGE_SHIFT);
+
+ if (v3d_mmu_flush_all(v3d))
+ dev_err(v3d->drm.dev, "MMU flush timeout\n");
+}
+
+void v3d_mmu_remove_ptes(struct v3d_bo *bo)
+{
+ struct v3d_dev *v3d = to_v3d_dev(bo->base.base.dev);
+ u32 npages = bo->base.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->drm.dev, "MMU flush timeout\n");
+}