zircon/kernel/dev/udisplay/udisplay.cc

// Copyright 2016 The Fuchsia Authors
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#include <assert.h>
#include <lib/crashlog.h>
#include <lib/debuglog.h>
#include <lib/gfxconsole.h>
#include <lib/io.h>
#include <platform.h>
#include <stdlib.h>
#include <string.h>
#include <trace.h>
#include <zircon/boot/crash-reason.h>

#include <dev/udisplay.h>
#include <ktl/move.h>
#include <platform/crashlog.h>
#include <vm/vm_address_region.h>
#include <vm/vm_aspace.h>
#include <vm/vm_object.h>

#include <ktl/enforce.h>

#define LOCAL_TRACE 0

constexpr uint kFramebufferArchMmuFlags = ARCH_MMU_FLAG_PERM_READ | ARCH_MMU_FLAG_PERM_WRITE;

struct udisplay_info {
  void* framebuffer_virt;
  size_t framebuffer_size;
  display_info info;
  fbl::RefPtr<VmMapping> framebuffer_vmo_mapping;
};

static struct udisplay_info g_udisplay = {};

zx_status_t udisplay_init(void) { return ZX_OK; }

void udisplay_clear_framebuffer_vmo() {
  if (g_udisplay.framebuffer_vmo_mapping) {
    g_udisplay.framebuffer_size = 0;
    g_udisplay.framebuffer_virt = 0;
    g_udisplay.framebuffer_vmo_mapping->Destroy();
    g_udisplay.framebuffer_vmo_mapping = nullptr;
  }
}

zx_status_t udisplay_set_framebuffer(fbl::RefPtr<VmObject> vmo) {
  udisplay_clear_framebuffer_vmo();

  const size_t size = vmo->size();
  zx::result<VmAddressRegion::MapResult> mapping_result =
      VmAspace::kernel_aspace()->RootVmar()->CreateVmMapping(
          0 /* ignored */, size, 0 /* align pow2 */, 0 /* vmar flags */, ktl::move(vmo), 0,
          kFramebufferArchMmuFlags, "framebuffer_vmo");
  if (mapping_result.is_error()) {
    return mapping_result.status_value();
  }

  zx_status_t status = mapping_result->mapping->MapRange(0, size, true);
  if (status != ZX_OK) {
    mapping_result->mapping->Destroy();
    return status;
  }

  g_udisplay.framebuffer_virt = reinterpret_cast<void*>(mapping_result->base);

  g_udisplay.framebuffer_size = size;
  g_udisplay.framebuffer_vmo_mapping = mapping_result->mapping;
  return ZX_OK;
}

zx_status_t udisplay_set_display_info(display_info* display) {
  memcpy(&g_udisplay.info, display, sizeof(display_info));
  return ZX_OK;
}

zx_status_t udisplay_bind_gfxconsole(void) {
  if (g_udisplay.framebuffer_virt == 0)
    return ZX_ERR_NOT_FOUND;

  // bind the display to the gfxconsole
  g_udisplay.info.framebuffer = g_udisplay.framebuffer_virt;
  g_udisplay.info.flags = DISPLAY_FLAG_NEEDS_CACHE_FLUSH | DISPLAY_FLAG_CRASH_FRAMEBUFFER;
  gfxconsole_bind_display(&g_udisplay.info, nullptr);

  return ZX_OK;
}