linux/drivers/gpu/drm/v3d/v3d_mmu.c

// 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"

/* Note: All PTEs for the 1MB superpage must be filled with the
 * superpage bit set.
 */
#define V3D_PTE_SUPERPAGE …
#define V3D_PTE_WRITEABLE …
#define V3D_PTE_VALID …

static int v3d_mmu_flush_all(struct v3d_dev *v3d)
{ … }

int v3d_mmu_set_page_table(struct v3d_dev *v3d)
{ … }

void v3d_mmu_insert_ptes(struct v3d_bo *bo)
{ … }

void v3d_mmu_remove_ptes(struct v3d_bo *bo)
{ … }