Add corebootdrm, a DRM driver for coreboot framebuffers. The driver supports a pre-initialized framebuffer with various packed RGB formats. The driver code is fairly small and uses the same logic as the other sysfb drivers. Most of the implementation comes from existing sysfb helpers.
Until now, coreboot relied on simpledrm or simplefb for boot-up graphics output. Initialize the platform device for corebootdrm in the same place in framebuffer_probe(). With a later commit, the simple-framebuffer should be removed. v3: - comment on _HAS_LFB semantics (Tzung-Bi) - fix typo in commit description (Tzung-Bi) - comment on simple-framebuffer being obsolete for coreboot v2: - reimplement as platform driver - limit resources and mappings to known framebuffer memory; no page alignment - create corebootdrm device from coreboot framebuffer code Signed-off-by: Thomas Zimmermann <[email protected]> Acked-by: Julius Werner <[email protected]> --- drivers/firmware/google/Kconfig | 3 +- .../firmware/google/framebuffer-coreboot.c | 22 +- drivers/gpu/drm/sysfb/Kconfig | 16 + drivers/gpu/drm/sysfb/Makefile | 1 + drivers/gpu/drm/sysfb/corebootdrm.c | 412 ++++++++++++++++++ include/linux/coreboot.h | 8 + 6 files changed, 458 insertions(+), 4 deletions(-) create mode 100644 drivers/gpu/drm/sysfb/corebootdrm.c diff --git a/drivers/firmware/google/Kconfig b/drivers/firmware/google/Kconfig index 3ab3e089328b..b78c644fa253 100644 --- a/drivers/firmware/google/Kconfig +++ b/drivers/firmware/google/Kconfig @@ -63,7 +63,8 @@ config GOOGLE_FRAMEBUFFER_COREBOOT help This option enables the kernel to search for a framebuffer in the coreboot table. If found, it is registered with a platform - device of type simple-framebuffer. + device of type coreboot-framebuffer. Using the old device of + type simple-framebuffer is deprecated. config GOOGLE_MEMCONSOLE_COREBOOT tristate "Firmware Memory Console" diff --git a/drivers/firmware/google/framebuffer-coreboot.c b/drivers/firmware/google/framebuffer-coreboot.c index fab3f28655d3..2c63a9bd0dcb 100644 --- a/drivers/firmware/google/framebuffer-coreboot.c +++ b/drivers/firmware/google/framebuffer-coreboot.c @@ -76,22 +76,23 @@ static struct device *framebuffer_parent_dev(struct resource *res) return NULL; } -static const struct simplefb_format formats[] = SIMPLEFB_FORMATS; - static int framebuffer_probe(struct coreboot_device *dev) { - int i; struct lb_framebuffer *fb = &dev->framebuffer; struct device *parent; struct platform_device *pdev; struct resource res; int ret; +#if !IS_ENABLED(CONFIG_DRM_COREBOOTDRM) struct simplefb_platform_data pdata = { .width = fb->x_resolution, .height = fb->y_resolution, .stride = fb->bytes_per_line, .format = NULL, }; + int i; + static const struct simplefb_format formats[] = SIMPLEFB_FORMATS; +#endif /* * On coreboot systems, the advertised LB_TAG_FRAMEBUFFER entry @@ -118,6 +119,20 @@ static int framebuffer_probe(struct coreboot_device *dev) if (IS_ERR(parent)) return PTR_ERR(parent); +#if IS_ENABLED(CONFIG_DRM_COREBOOTDRM) + pdev = platform_device_register_resndata(parent, "coreboot-framebuffer", 0, + &res, 1, fb, fb->size); + if (IS_ERR(pdev)) { + pr_warn("coreboot: could not register framebuffer\n"); + ret = PTR_ERR(pdev); + goto out_put_device_parent; + } +#else + /* + * FIXME: Coreboot systems should use a driver that binds to + * coreboot-framebuffer devices. Remove support for + * simple-framebuffer at some point. + */ for (i = 0; i < ARRAY_SIZE(formats); ++i) { if (fb->bits_per_pixel == formats[i].bits_per_pixel && fb->red_mask_pos == formats[i].red.offset && @@ -142,6 +157,7 @@ static int framebuffer_probe(struct coreboot_device *dev) pr_warn("coreboot: could not register framebuffer\n"); goto out_put_device_parent; } +#endif ret = 0; diff --git a/drivers/gpu/drm/sysfb/Kconfig b/drivers/gpu/drm/sysfb/Kconfig index 9c9884c7efc6..2559ead6cf1f 100644 --- a/drivers/gpu/drm/sysfb/Kconfig +++ b/drivers/gpu/drm/sysfb/Kconfig @@ -7,6 +7,22 @@ config DRM_SYSFB_HELPER tristate depends on DRM +config DRM_COREBOOTDRM + tristate "Coreboot framebuffer driver" + depends on DRM && MMU + depends on GOOGLE_FRAMEBUFFER_COREBOOT + select APERTURE_HELPERS + select DRM_CLIENT_SELECTION + select DRM_GEM_SHMEM_HELPER + select DRM_KMS_HELPER + select DRM_SYSFB_HELPER + help + DRM driver for coreboot-provided framebuffers. + + This driver assumes that the display hardware has been initialized + by coreboot firmware before the kernel boots. Scanout buffer, size, + and display format must be provided via coreboot framebuffer device. + config DRM_EFIDRM tristate "EFI framebuffer driver" depends on DRM && MMU && EFI && (!SYSFB_SIMPLEFB || COMPILE_TEST) diff --git a/drivers/gpu/drm/sysfb/Makefile b/drivers/gpu/drm/sysfb/Makefile index a156c496413d..85c9087ab03d 100644 --- a/drivers/gpu/drm/sysfb/Makefile +++ b/drivers/gpu/drm/sysfb/Makefile @@ -6,6 +6,7 @@ drm_sysfb_helper-y := \ drm_sysfb_helper-$(CONFIG_SCREEN_INFO) += drm_sysfb_screen_info.o obj-$(CONFIG_DRM_SYSFB_HELPER) += drm_sysfb_helper.o +obj-$(CONFIG_DRM_COREBOOTDRM) += corebootdrm.o obj-$(CONFIG_DRM_EFIDRM) += efidrm.o obj-$(CONFIG_DRM_OFDRM) += ofdrm.o obj-$(CONFIG_DRM_SIMPLEDRM) += simpledrm.o diff --git a/drivers/gpu/drm/sysfb/corebootdrm.c b/drivers/gpu/drm/sysfb/corebootdrm.c new file mode 100644 index 000000000000..745318580a5d --- /dev/null +++ b/drivers/gpu/drm/sysfb/corebootdrm.c @@ -0,0 +1,412 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/aperture.h> +#include <linux/coreboot.h> +#include <linux/minmax.h> +#include <linux/platform_device.h> + +#include <drm/clients/drm_client_setup.h> +#include <drm/drm_atomic.h> +#include <drm/drm_atomic_state_helper.h> +#include <drm/drm_connector.h> +#include <drm/drm_damage_helper.h> +#include <drm/drm_device.h> +#include <drm/drm_drv.h> +#include <drm/drm_fbdev_shmem.h> +#include <drm/drm_framebuffer.h> +#include <drm/drm_gem_atomic_helper.h> +#include <drm/drm_gem_framebuffer_helper.h> +#include <drm/drm_gem_shmem_helper.h> +#include <drm/drm_managed.h> +#include <drm/drm_modeset_helper_vtables.h> +#include <drm/drm_print.h> +#include <drm/drm_probe_helper.h> + +#include "drm_sysfb_helper.h" + +#define DRIVER_NAME "corebootdrm" +#define DRIVER_DESC "DRM driver for Coreboot framebuffers" +#define DRIVER_MAJOR 1 +#define DRIVER_MINOR 0 + +static const struct drm_format_info * +corebootdrm_get_format_fb(struct drm_device *dev, const struct lb_framebuffer *fb) +{ + static const struct drm_sysfb_format formats[] = { + { PIXEL_FORMAT_XRGB1555, DRM_FORMAT_XRGB1555, }, + { PIXEL_FORMAT_RGB565, DRM_FORMAT_RGB565, }, + { PIXEL_FORMAT_RGB888, DRM_FORMAT_RGB888, }, + { PIXEL_FORMAT_XRGB8888, DRM_FORMAT_XRGB8888, }, + { PIXEL_FORMAT_XBGR8888, DRM_FORMAT_XBGR8888, }, + { PIXEL_FORMAT_XRGB2101010, DRM_FORMAT_XRGB2101010, }, + }; + const struct pixel_format pixel = { + .bits_per_pixel = fb->bits_per_pixel, + .indexed = false, + .alpha = { + .offset = 0, + .length = 0, + }, + .red = { + .offset = fb->red_mask_pos, + .length = fb->red_mask_size, + }, + .green = { + .offset = fb->green_mask_pos, + .length = fb->green_mask_size, + }, + .blue = { + .offset = fb->blue_mask_pos, + .length = fb->blue_mask_size, + }, + }; + + return drm_sysfb_get_format(dev, formats, ARRAY_SIZE(formats), &pixel); +} + +static int corebootdrm_get_width_fb(struct drm_device *dev, const struct lb_framebuffer *fb) +{ + return drm_sysfb_get_validated_int0(dev, "width", fb->x_resolution, INT_MAX); +} + +static int corebootdrm_get_height_fb(struct drm_device *dev, const struct lb_framebuffer *fb) +{ + return drm_sysfb_get_validated_int0(dev, "height", fb->y_resolution, INT_MAX); +} + +static int corebootdrm_get_pitch_fb(struct drm_device *dev, const struct drm_format_info *format, + unsigned int width, const struct lb_framebuffer *fb) +{ + u64 bytes_per_line = fb->bytes_per_line; + + if (!bytes_per_line) + bytes_per_line = drm_format_info_min_pitch(format, 0, width); + + return drm_sysfb_get_validated_int0(dev, "pitch", bytes_per_line, INT_MAX); +} + +static resource_size_t corebootdrm_get_size_fb(struct drm_device *dev, unsigned int height, + unsigned int pitch, + const struct lb_framebuffer *fb) +{ + resource_size_t size; + + if (check_mul_overflow(height, pitch, &size)) + return 0; + + return size; +} + +static phys_addr_t corebootdrm_get_address_fb(struct drm_device *dev, resource_size_t size, + const struct lb_framebuffer *fb) +{ + if (size > PHYS_ADDR_MAX) + return 0; + if (!fb->physical_address) + return 0; + if (fb->physical_address > (PHYS_ADDR_MAX - size)) + return 0; + + return fb->physical_address; +} + +/* + * Simple Framebuffer device + */ + +struct corebootdrm_device { + struct drm_sysfb_device sysfb; + + /* modesetting */ + u32 formats[DRM_SYSFB_PLANE_NFORMATS(1)]; + struct drm_plane primary_plane; + struct drm_crtc crtc; + struct drm_encoder encoder; + struct drm_connector connector; +}; + +/* + * Modesetting + */ + +static const u64 corebootdrm_primary_plane_format_modifiers[] = { + DRM_SYSFB_PLANE_FORMAT_MODIFIERS, +}; + +static const struct drm_plane_helper_funcs corebootdrm_primary_plane_helper_funcs = { + DRM_SYSFB_PLANE_HELPER_FUNCS, +}; + +static const struct drm_plane_funcs corebootdrm_primary_plane_funcs = { + DRM_SYSFB_PLANE_FUNCS, + .destroy = drm_plane_cleanup, +}; + +static const struct drm_crtc_helper_funcs corebootdrm_crtc_helper_funcs = { + DRM_SYSFB_CRTC_HELPER_FUNCS, +}; + +static const struct drm_crtc_funcs corebootdrm_crtc_funcs = { + DRM_SYSFB_CRTC_FUNCS, + .destroy = drm_crtc_cleanup, +}; + +static const struct drm_encoder_funcs corebootdrm_encoder_funcs = { + .destroy = drm_encoder_cleanup, +}; + +static const struct drm_connector_helper_funcs corebootdrm_connector_helper_funcs = { + DRM_SYSFB_CONNECTOR_HELPER_FUNCS, +}; + +static const struct drm_connector_funcs corebootdrm_connector_funcs = { + DRM_SYSFB_CONNECTOR_FUNCS, + .destroy = drm_connector_cleanup, +}; + +static const struct drm_mode_config_funcs corebootdrm_mode_config_funcs = { + DRM_SYSFB_MODE_CONFIG_FUNCS, +}; + +static int corebootdrm_mode_config_init(struct corebootdrm_device *cdev) +{ + struct drm_sysfb_device *sysfb = &cdev->sysfb; + struct drm_device *dev = &sysfb->dev; + const struct drm_format_info *format = sysfb->fb_format; + unsigned int width = sysfb->fb_mode.hdisplay; + unsigned int height = sysfb->fb_mode.vdisplay; + struct drm_plane *primary_plane; + struct drm_crtc *crtc; + struct drm_encoder *encoder; + struct drm_connector *connector; + size_t nformats; + int ret; + + ret = drmm_mode_config_init(dev); + if (ret) + return ret; + + dev->mode_config.min_width = width; + dev->mode_config.max_width = max_t(unsigned int, width, DRM_SHADOW_PLANE_MAX_WIDTH); + dev->mode_config.min_height = height; + dev->mode_config.max_height = max_t(unsigned int, height, DRM_SHADOW_PLANE_MAX_HEIGHT); + dev->mode_config.funcs = &corebootdrm_mode_config_funcs; + dev->mode_config.preferred_depth = format->depth; + + /* Primary plane */ + + nformats = drm_sysfb_build_fourcc_list(dev, &format->format, 1, + cdev->formats, ARRAY_SIZE(cdev->formats)); + + primary_plane = &cdev->primary_plane; + ret = drm_universal_plane_init(dev, primary_plane, 0, &corebootdrm_primary_plane_funcs, + cdev->formats, nformats, + corebootdrm_primary_plane_format_modifiers, + DRM_PLANE_TYPE_PRIMARY, NULL); + if (ret) + return ret; + drm_plane_helper_add(primary_plane, &corebootdrm_primary_plane_helper_funcs); + drm_plane_enable_fb_damage_clips(primary_plane); + + /* CRTC */ + + crtc = &cdev->crtc; + ret = drm_crtc_init_with_planes(dev, crtc, primary_plane, NULL, + &corebootdrm_crtc_funcs, NULL); + if (ret) + return ret; + drm_crtc_helper_add(crtc, &corebootdrm_crtc_helper_funcs); + + /* Encoder */ + + encoder = &cdev->encoder; + ret = drm_encoder_init(dev, encoder, &corebootdrm_encoder_funcs, + DRM_MODE_ENCODER_NONE, NULL); + if (ret) + return ret; + encoder->possible_crtcs = drm_crtc_mask(crtc); + + /* Connector */ + + connector = &cdev->connector; + ret = drm_connector_init(dev, connector, &corebootdrm_connector_funcs, + DRM_MODE_CONNECTOR_Unknown); + if (ret) + return ret; + drm_connector_helper_add(connector, &corebootdrm_connector_helper_funcs); + drm_connector_set_panel_orientation_with_quirk(connector, + DRM_MODE_PANEL_ORIENTATION_UNKNOWN, + width, height); + + ret = drm_connector_attach_encoder(connector, encoder); + if (ret) + return ret; + + return 0; +} + +/* + * DRM driver + */ + +DEFINE_DRM_GEM_FOPS(corebootdrm_fops); + +static struct drm_driver corebootdrm_drm_driver = { + DRM_GEM_SHMEM_DRIVER_OPS, + DRM_FBDEV_SHMEM_DRIVER_OPS, + .name = DRIVER_NAME, + .desc = DRIVER_DESC, + .major = DRIVER_MAJOR, + .minor = DRIVER_MINOR, + .driver_features = DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET, + .fops = &corebootdrm_fops, +}; + +/* + * Coreboot driver + */ + +static int corebootdrm_probe(struct platform_device *pdev) +{ + const struct lb_framebuffer *fb = dev_get_platdata(&pdev->dev); + struct corebootdrm_device *cdev; + struct drm_sysfb_device *sysfb; + struct drm_device *dev; + const struct drm_format_info *format; + int width, height, pitch; + resource_size_t size; + phys_addr_t address; + struct resource *res, *mem = NULL; + struct resource aperture; + void __iomem *screen_base; + int ret; + + cdev = devm_drm_dev_alloc(&pdev->dev, &corebootdrm_drm_driver, + struct corebootdrm_device, sysfb.dev); + if (IS_ERR(cdev)) + return PTR_ERR(cdev); + platform_set_drvdata(pdev, cdev); + + sysfb = &cdev->sysfb; + dev = &sysfb->dev; + + if (!fb) { + drm_err(dev, "coreboot framebuffer not found\n"); + return -EINVAL; + } else if (!LB_FRAMEBUFFER_HAS_LFB(fb)) { + drm_err(dev, "coreboot framebuffer entry too small\n"); + return -EINVAL; + } + + /* + * Hardware settings + */ + + format = corebootdrm_get_format_fb(dev, fb); + if (!format) + return -EINVAL; + width = corebootdrm_get_width_fb(dev, fb); + if (width < 0) + return width; + height = corebootdrm_get_height_fb(dev, fb); + if (height < 0) + return height; + pitch = corebootdrm_get_pitch_fb(dev, format, width, fb); + if (pitch < 0) + return pitch; + size = corebootdrm_get_size_fb(dev, height, pitch, fb); + if (!size) + return -EINVAL; + address = corebootdrm_get_address_fb(dev, size, fb); + if (!address) + return -EINVAL; + + sysfb->fb_mode = drm_sysfb_mode(width, height, 0, 0); + sysfb->fb_format = format; + sysfb->fb_pitch = pitch; + + drm_dbg(dev, "display mode={" DRM_MODE_FMT "}\n", DRM_MODE_ARG(&sysfb->fb_mode)); + drm_dbg(dev, "framebuffer format=%p4cc, size=%dx%d, pitch=%d byte\n", + &format->format, width, height, pitch); + + /* + * Memory management + */ + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + drm_err(dev, "memory resource not found\n"); + return -EINVAL; + } + + mem = devm_request_mem_region(&pdev->dev, res->start, resource_size(res), + dev->driver->name); + if (!mem) { + drm_warn(dev, "could not acquire memory resource at %pr\n", res); + /* + * We cannot make this fatal. Sometimes this comes from magic + * spaces our resource handlers simply don't know about. Use + * the memory resource as-is and try to map that instead. + */ + mem = res; + } + + drm_dbg(dev, "using memory resource at %pr\n", mem); + + aperture = DEFINE_RES_MEM(address, size); + if (!resource_contains(mem, &aperture)) { + drm_err(dev, "framebuffer aperture at invalid memory range %pr\n", &aperture); + return -EINVAL; + } + + ret = devm_aperture_acquire_for_platform_device(pdev, address, size); + if (ret) { + drm_err(dev, "could not acquire framebuffer aperture: %d\n", ret); + return ret; + } + + screen_base = devm_ioremap_wc(&pdev->dev, address, size); + if (!screen_base) + return -ENOMEM; + + iosys_map_set_vaddr_iomem(&sysfb->fb_addr, screen_base); + + /* + * DRM mode setting and registration + */ + + ret = corebootdrm_mode_config_init(cdev); + if (ret) + return ret; + + drm_mode_config_reset(dev); + + ret = drm_dev_register(dev, 0); + if (ret) + return ret; + + drm_client_setup(dev, sysfb->fb_format); + + return 0; +} + +static void corebootdrm_remove(struct platform_device *pdev) +{ + struct corebootdrm_device *cdev = platform_get_drvdata(pdev); + struct drm_device *dev = &cdev->sysfb.dev; + + drm_dev_unplug(dev); +} + +static struct platform_driver corebootdrm_platform_driver = { + .driver = { + .name = "coreboot-framebuffer", + }, + .probe = corebootdrm_probe, + .remove = corebootdrm_remove, +}; + +module_platform_driver(corebootdrm_platform_driver); + +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); diff --git a/include/linux/coreboot.h b/include/linux/coreboot.h index 5746b99a070d..b51665165f9f 100644 --- a/include/linux/coreboot.h +++ b/include/linux/coreboot.h @@ -14,6 +14,7 @@ #include <linux/compiler_attributes.h> #include <linux/types.h> +#include <linux/stddef.h> typedef __aligned(4) u64 cb_u64; @@ -66,4 +67,11 @@ struct lb_framebuffer { u8 reserved_mask_size; }; +/* + * True if the coreboot-provided data is large enough to hold information + * on the linear framebuffer. False otherwise. + */ +#define LB_FRAMEBUFFER_HAS_LFB(__fb) \ + ((__fb)->size >= offsetofend(struct lb_framebuffer, reserved_mask_size)) + #endif /* _LINUX_COREBOOT_H */ -- 2.52.0
