efi/libstub: gop: Add support for reading EDID

Add support for EFI_EDID_DISCOVERED_PROTOCOL and EFI_EDID_ACTIVE_PROTOCOL
as defined in UEFI 2.8, sec 12.9. Define GUIDs and data structures in the
rsp header files.

In the GOP setup function, read the EDID of the primary GOP device. First
try EFI_EDID_ACTIVE_PROTOCOL, which supports user-specified EDID data. Or
else try EFI_EDID_DISCOVERED_PROTOCOL, which returns the display device's
native EDID. If no EDID could be retrieved, clear the storage.

Rename efi_setup_gop() to efi_setup_graphics() to reflect the changes
Let callers pass an optional instance of struct edid_data, if they are
interested.

While screen_info and edid_info come from the same device handle, they
should be considered indendent data. The former refers to the graphics
mode, the latter refers to the display device. GOP devices might not
provide both.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index 874f63b4a3830ca84ee027e5515359f9b1fd48b7..9cb814c5ba1bd71bda99f1ec3c5b2bf0eeb2a571 100644 (file)
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -56,7 +56,7 @@ static struct screen_info *setup_graphics(void)
 {
        struct screen_info *si, tmp = {};
 
-       if (efi_setup_gop(&tmp) != EFI_SUCCESS)
+       if (efi_setup_graphics(&tmp, NULL) != EFI_SUCCESS)
                return NULL;
 
        si = alloc_screen_info();

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index f5ba032863a9c995e7cdd5c928f4733de0126766..b2fb0c3fa7217db3f47b73aa385e59fc68326dc4 100644 (file)
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -34,6 +34,9 @@
 #define EFI_ALLOC_LIMIT                ULONG_MAX
 #endif
 
+struct edid_info;
+struct screen_info;
+
 extern bool efi_no5lvl;
 extern bool efi_nochunk;
 extern bool efi_nokaslr;
@@ -578,6 +581,32 @@ union efi_graphics_output_protocol {
        } mixed_mode;
 };
 
+typedef union efi_edid_discovered_protocol efi_edid_discovered_protocol_t;
+
+union efi_edid_discovered_protocol {
+       struct {
+               u32 size_of_edid;
+               u8 *edid;
+       };
+       struct {
+               u32 size_of_edid;
+               u32 edid;
+       } mixed_mode;
+};
+
+typedef union efi_edid_active_protocol efi_edid_active_protocol_t;
+
+union efi_edid_active_protocol {
+       struct {
+               u32 size_of_edid;
+               u8 *edid;
+       };
+       struct {
+               u32 size_of_edid;
+               u32 edid;
+       } mixed_mode;
+};
+
 typedef union {
        struct {
                u32                     revision;
@@ -1085,7 +1114,7 @@ efi_status_t efi_parse_options(char const *cmdline);
 
 void efi_parse_option_graphics(char *option);
 
-efi_status_t efi_setup_gop(struct screen_info *si);
+efi_status_t efi_setup_graphics(struct screen_info *si, struct edid_info *edid);
 
 efi_status_t handle_cmdline_files(efi_loaded_image_t *image,
                                  const efi_char16_t *optstr,

diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c
index 02459ef0f18caf49e6be11246c2853ce3c8efe6e..72d74436a7a4417e46219203411c1b5c3727edc1 100644 (file)
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -12,6 +12,7 @@
 #include <linux/string.h>
 #include <asm/efi.h>
 #include <asm/setup.h>
+#include <video/edid.h>
 
 #include "efistub.h"
 
@@ -413,6 +414,14 @@ static void setup_screen_info(struct screen_info *si, const efi_graphics_output_
        si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;
 }
 
+static void setup_edid_info(struct edid_info *edid, u32 gop_size_of_edid, u8 *gop_edid)
+{
+       if (!gop_edid || gop_size_of_edid < 128)
+               memset(edid->dummy, 0, sizeof(edid->dummy));
+       else
+               memcpy(edid->dummy, gop_edid, min(gop_size_of_edid, sizeof(edid->dummy)));
+}
+
 static efi_handle_t find_handle_with_primary_gop(unsigned long num, const efi_handle_t handles[],
                                                 efi_graphics_output_protocol_t **found_gop)
 {
@@ -469,7 +478,7 @@ static efi_handle_t find_handle_with_primary_gop(unsigned long num, const efi_ha
        return first_gop_handle;
 }
 
-efi_status_t efi_setup_gop(struct screen_info *si)
+efi_status_t efi_setup_graphics(struct screen_info *si, struct edid_info *edid)
 {
        efi_handle_t *handles __free(efi_pool) = NULL;
        efi_handle_t handle;
@@ -494,5 +503,30 @@ efi_status_t efi_setup_gop(struct screen_info *si)
        if (si)
                setup_screen_info(si, gop);
 
+       /* Display EDID for primary GOP */
+       if (edid) {
+               efi_edid_discovered_protocol_t *discovered_edid;
+               efi_edid_active_protocol_t *active_edid;
+               u32 gop_size_of_edid = 0;
+               u8 *gop_edid = NULL;
+
+               status = efi_bs_call(handle_protocol, handle, &EFI_EDID_ACTIVE_PROTOCOL_GUID,
+                                    (void **)&active_edid);
+               if (status == EFI_SUCCESS) {
+                       gop_size_of_edid = active_edid->size_of_edid;
+                       gop_edid = active_edid->edid;
+               } else {
+                       status = efi_bs_call(handle_protocol, handle,
+                                            &EFI_EDID_DISCOVERED_PROTOCOL_GUID,
+                                            (void **)&discovered_edid);
+                       if (status == EFI_SUCCESS) {
+                               gop_size_of_edid = discovered_edid->size_of_edid;
+                               gop_edid = discovered_edid->edid;
+                       }
+               }
+
+               setup_edid_info(edid, gop_size_of_edid, gop_edid);
+       }
+
        return EFI_SUCCESS;
 }

diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index dd9e19c31dd7c5e8a069228882187e9ee6c4493c..6e51cca72684112bd2823251e93c7d68dbd164e7 100644 (file)
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -488,7 +488,7 @@ static void setup_graphics(struct boot_params *boot_params)
 {
        struct screen_info *si = memset(&boot_params->screen_info, 0, sizeof(*si));
 
-       efi_setup_gop(si);
+       efi_setup_graphics(si, NULL);
 }
 
 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)

diff --git a/include/linux/efi.h b/include/linux/efi.h
index 60e994096e208053ce210c499e3bb70bf4d3784c..a01f3fe20dab5b0e1d8ca90af4a9913ab7f615f3 100644 (file)
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -373,6 +373,8 @@ void efi_native_runtime_setup(void);
 #define EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID  EFI_GUID(0x8b843e20, 0x8132, 0x4852,  0x90, 0xcc, 0x55, 0x1a, 0x4e, 0x4a, 0x7f, 0x1c)
 #define EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL_GUID        EFI_GUID(0x05c99a21, 0xc70f, 0x4ad2,  0x8a, 0x5f, 0x35, 0xdf, 0x33, 0x43, 0xf5, 0x1e)
 #define EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID      EFI_GUID(0x9042a9de, 0x23dc, 0x4a38,  0x96, 0xfb, 0x7a, 0xde, 0xd0, 0x80, 0x51, 0x6a)
+#define EFI_EDID_DISCOVERED_PROTOCOL_GUID      EFI_GUID(0x1c0c34f6, 0xd380, 0x41fa,  0xa0, 0x49, 0x8a, 0xd0, 0x6c, 0x1a, 0x66, 0xaa)
+#define EFI_EDID_ACTIVE_PROTOCOL_GUID          EFI_GUID(0xbd8c1056, 0x9f36, 0x44ec,  0x92, 0xa8, 0xa6, 0x33, 0x7f, 0x81, 0x79, 0x86)
 #define EFI_PCI_IO_PROTOCOL_GUID               EFI_GUID(0x4cf5b200, 0x68b8, 0x4ca5,  0x9e, 0xec, 0xb2, 0x3e, 0x3f, 0x50, 0x02, 0x9a)
 #define EFI_FILE_INFO_ID                       EFI_GUID(0x09576e92, 0x6d3f, 0x11d2,  0x8e, 0x39, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b)
 #define EFI_SYSTEM_RESOURCE_TABLE_GUID         EFI_GUID(0xb122a263, 0x3661, 0x4f68,  0x99, 0x29, 0x78, 0xf8, 0xb0, 0xd6, 0x21, 0x80)