diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dumb_buffers.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dumb_buffers.c | 171 |
1 files changed, 160 insertions, 11 deletions
diff --git a/drivers/gpu/drm/drm_dumb_buffers.c b/drivers/gpu/drm/drm_dumb_buffers.c index 70032bba1c97..e2b62e5fb891 100644 --- a/drivers/gpu/drm/drm_dumb_buffers.c +++ b/drivers/gpu/drm/drm_dumb_buffers.c @@ -25,8 +25,11 @@ #include <drm/drm_device.h> #include <drm/drm_drv.h> +#include <drm/drm_dumb_buffers.h> +#include <drm/drm_fourcc.h> #include <drm/drm_gem.h> #include <drm/drm_mode.h> +#include <drm/drm_print.h> #include "drm_crtc_internal.h" #include "drm_internal.h" @@ -57,6 +60,134 @@ * a hardware-specific ioctl to allocate suitable buffer objects. */ +static int drm_mode_align_dumb(struct drm_mode_create_dumb *args, + unsigned long hw_pitch_align, + unsigned long hw_size_align) +{ + u32 pitch = args->pitch; + u32 size; + + if (!pitch) + return -EINVAL; + + if (hw_pitch_align) + pitch = roundup(pitch, hw_pitch_align); + + if (!hw_size_align) + hw_size_align = PAGE_SIZE; + else if (!IS_ALIGNED(hw_size_align, PAGE_SIZE)) + return -EINVAL; /* TODO: handle this if necessary */ + + if (check_mul_overflow(args->height, pitch, &size)) + return -EINVAL; + size = ALIGN(size, hw_size_align); + if (!size) + return -EINVAL; + + args->pitch = pitch; + args->size = size; + + return 0; +} + +/** + * drm_mode_size_dumb - Calculates the scanline and buffer sizes for dumb buffers + * @dev: DRM device + * @args: Parameters for the dumb buffer + * @hw_pitch_align: Hardware scanline alignment in bytes + * @hw_size_align: Hardware buffer-size alignment in bytes + * + * The helper drm_mode_size_dumb() calculates the size of the buffer + * allocation and the scanline size for a dumb buffer. Callers have to + * set the buffers width, height and color mode in the argument @arg. + * The helper validates the correctness of the input and tests for + * possible overflows. If successful, it returns the dumb buffer's + * required scanline pitch and size in &args. + * + * The parameter @hw_pitch_align allows the driver to specifies an + * alignment for the scanline pitch, if the hardware requires any. The + * calculated pitch will be a multiple of the alignment. The parameter + * @hw_size_align allows to specify an alignment for buffer sizes. The + * provided alignment should represent requirements of the graphics + * hardware. drm_mode_size_dumb() handles GEM-related constraints + * automatically across all drivers and hardware. For example, the + * returned buffer size is always a multiple of PAGE_SIZE, which is + * required by mmap(). + * + * Returns: + * Zero on success, or a negative error code otherwise. + */ +int drm_mode_size_dumb(struct drm_device *dev, + struct drm_mode_create_dumb *args, + unsigned long hw_pitch_align, + unsigned long hw_size_align) +{ + u64 pitch = 0; + u32 fourcc; + + /* + * The scanline pitch depends on the buffer width and the color + * format. The latter is specified as a color-mode constant for + * which we first have to find the corresponding color format. + * + * Different color formats can have the same color-mode constant. + * For example XRGB8888 and BGRX8888 both have a color mode of 32. + * It is possible to use different formats for dumb-buffer allocation + * and rendering as long as all involved formats share the same + * color-mode constant. + */ + fourcc = drm_driver_color_mode_format(dev, args->bpp); + if (fourcc != DRM_FORMAT_INVALID) { + const struct drm_format_info *info = drm_format_info(fourcc); + + if (!info) + return -EINVAL; + pitch = drm_format_info_min_pitch(info, 0, args->width); + } else if (args->bpp) { + /* + * Some userspace throws in arbitrary values for bpp and + * relies on the kernel to figure it out. In this case we + * fall back to the old method of using bpp directly. The + * over-commitment of memory from the rounding is acceptable + * for compatibility with legacy userspace. We have a number + * of deprecated legacy values that are explicitly supported. + */ + switch (args->bpp) { + default: + drm_warn_once(dev, + "Unknown color mode %u; guessing buffer size.\n", + args->bpp); + fallthrough; + /* + * These constants represent various YUV formats supported by + * drm_gem_afbc_get_bpp(). + */ + case 12: // DRM_FORMAT_YUV420_8BIT + case 15: // DRM_FORMAT_YUV420_10BIT + case 30: // DRM_FORMAT_VUY101010 + fallthrough; + /* + * Used by Mesa and Gstreamer to allocate NV formats and others + * as RGB buffers. Technically, XRGB16161616F formats are RGB, + * but the dumb buffers are not supposed to be used for anything + * beyond 32 bits per pixels. + */ + case 10: // DRM_FORMAT_NV{15,20,30}, DRM_FORMAT_P010 + case 64: // DRM_FORMAT_{XRGB,XBGR,ARGB,ABGR}16161616F + pitch = args->width * DIV_ROUND_UP(args->bpp, SZ_8); + break; + } + } + + if (!pitch || pitch > U32_MAX) + return -EINVAL; + + args->pitch = pitch; + + return drm_mode_align_dumb(args, hw_pitch_align, hw_size_align); +} +EXPORT_SYMBOL(drm_mode_size_dumb); + int drm_mode_create_dumb(struct drm_device *dev, struct drm_mode_create_dumb *args, struct drm_file *file_priv) @@ -99,7 +230,30 @@ int drm_mode_create_dumb(struct drm_device *dev, int drm_mode_create_dumb_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { - return drm_mode_create_dumb(dev, data, file_priv); + struct drm_mode_create_dumb *args = data; + int err; + + err = drm_mode_create_dumb(dev, args, file_priv); + if (err) { + args->handle = 0; + args->pitch = 0; + args->size = 0; + } + return err; +} + +static int drm_mode_mmap_dumb(struct drm_device *dev, struct drm_mode_map_dumb *args, + struct drm_file *file_priv) +{ + if (!dev->driver->dumb_create) + return -ENOSYS; + + if (dev->driver->dumb_map_offset) + return dev->driver->dumb_map_offset(file_priv, dev, args->handle, + &args->offset); + else + return drm_gem_dumb_map_offset(file_priv, dev, args->handle, + &args->offset); } /** @@ -120,17 +274,12 @@ int drm_mode_mmap_dumb_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_mode_map_dumb *args = data; + int err; - if (!dev->driver->dumb_create) - return -ENOSYS; - - if (dev->driver->dumb_map_offset) - return dev->driver->dumb_map_offset(file_priv, dev, - args->handle, - &args->offset); - else - return drm_gem_dumb_map_offset(file_priv, dev, args->handle, - &args->offset); + err = drm_mode_mmap_dumb(dev, args, file_priv); + if (err) + args->offset = 0; + return err; } int drm_mode_destroy_dumb(struct drm_device *dev, u32 handle, |