efi/libstub: Simplify GOP handling code

Use the LocateHandleBuffer() API and a __free() function to simplify the
logic that allocates a handle buffer to iterate over all GOP protocols
in the EFI database.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 521aad70e41b9d718d61c53034ade8fedd2aeef8..f227a70ac91f04eb8f50430c034c9fd9d866010a 100644 (file)
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -250,6 +250,9 @@ static inline u32 efi64_convert_status(efi_status_t status)
 #define __efi64_argmap_allocate_pool(type, size, buffer)               \
        ((type), (size), efi64_zero_upper(buffer))
 
+#define __efi64_argmap_locate_handle_buffer(type, proto, key, num, buf)        \
+       ((type), (proto), (key), efi64_zero_upper(num), efi64_zero_upper(buf))
+
 #define __efi64_argmap_create_event(type, tpl, f, c, event)            \
        ((type), (tpl), (f), (c), efi64_zero_upper(event))
 

diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index 382b54f40603bfd449342b97b190c897217569a3..90e06a6b1a45e0b1e28bc5caebf99da667a84e61 100644 (file)
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -10,6 +10,7 @@
  */
 
 #include <linux/efi.h>
+#include <linux/screen_info.h>
 #include <asm/efi.h>
 
 #include "efistub.h"
@@ -53,25 +54,16 @@ void __weak free_screen_info(struct screen_info *si)
 
 static struct screen_info *setup_graphics(void)
 {
-       efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
-       efi_status_t status;
-       unsigned long size;
-       void **gop_handle = NULL;
-       struct screen_info *si = NULL;
+       struct screen_info *si, tmp = {};
 
-       size = 0;
-       status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-                            &gop_proto, NULL, &size, gop_handle);
-       if (status == EFI_BUFFER_TOO_SMALL) {
-               si = alloc_screen_info();
-               if (!si)
-                       return NULL;
-               status = efi_setup_gop(si, &gop_proto, size);
-               if (status != EFI_SUCCESS) {
-                       free_screen_info(si);
-                       return NULL;
-               }
-       }
+       if (efi_setup_gop(&tmp) != EFI_SUCCESS)
+               return NULL;
+
+       si = alloc_screen_info();
+       if (!si)
+               return NULL;
+
+       *si = tmp;
        return si;
 }
 

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 55553038b8507101c75a8341544ab2c50a128a89..d96d4494070df094306588d6293ed6ade322a424 100644 (file)
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -4,6 +4,7 @@
 #define _DRIVERS_FIRMWARE_EFI_EFISTUB_H
 
 #include <linux/compiler.h>
+#include <linux/cleanup.h>
 #include <linux/efi.h>
 #include <linux/kernel.h>
 #include <linux/kern_levels.h>
@@ -313,7 +314,9 @@ union efi_boot_services {
                void *close_protocol;
                void *open_protocol_information;
                void *protocols_per_handle;
-               void *locate_handle_buffer;
+               efi_status_t (__efiapi *locate_handle_buffer)(int, efi_guid_t *,
+                                                             void *, unsigned long *,
+                                                             efi_handle_t **);
                efi_status_t (__efiapi *locate_protocol)(efi_guid_t *, void *,
                                                         void **);
                efi_status_t (__efiapi *install_multiple_protocol_interfaces)(efi_handle_t *, ...);
@@ -1052,6 +1055,7 @@ void efi_puts(const char *str);
 __printf(1, 2) int efi_printk(char const *fmt, ...);
 
 void efi_free(unsigned long size, unsigned long addr);
+DEFINE_FREE(efi_pool, void *, if (_T) efi_bs_call(free_pool, _T));
 
 void efi_apply_loadoptions_quirk(const void **load_options, u32 *load_options_size);
 
@@ -1081,8 +1085,7 @@ 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_guid_t *proto,
-                          unsigned long size);
+efi_status_t efi_setup_gop(struct screen_info *si);
 
 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 8eef63c48288daa6706a995c735767a6d743532d..a4b3d18f91da82b8958f97ac371080c0600c2db8 100644 (file)
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -461,25 +461,25 @@ setup_pixel_info(struct screen_info *si, u32 pixels_per_scan_line,
        }
 }
 
-static efi_graphics_output_protocol_t *
-find_gop(efi_guid_t *proto, unsigned long size, void **handles)
+static efi_graphics_output_protocol_t *find_gop(unsigned long num,
+                                               const efi_handle_t handles[])
 {
        efi_graphics_output_protocol_t *first_gop;
        efi_handle_t h;
 
        first_gop = NULL;
 
-       for_each_efi_handle(h, handles, efi_get_handle_num(size)) {
+       for_each_efi_handle(h, handles, num) {
                efi_status_t status;
 
                efi_graphics_output_protocol_t *gop;
                efi_graphics_output_protocol_mode_t *mode;
                efi_graphics_output_mode_info_t *info;
-
-               efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID;
                void *dummy = NULL;
 
-               status = efi_bs_call(handle_protocol, h, proto, (void **)&gop);
+               status = efi_bs_call(handle_protocol, h,
+                                    &EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID,
+                                    (void **)&gop);
                if (status != EFI_SUCCESS)
                        continue;
 
@@ -499,7 +499,8 @@ find_gop(efi_guid_t *proto, unsigned long size, void **handles)
                 * Once we've found a GOP supporting ConOut,
                 * don't bother looking any further.
                 */
-               status = efi_bs_call(handle_protocol, h, &conout_proto, &dummy);
+               status = efi_bs_call(handle_protocol, h,
+                                    &EFI_CONSOLE_OUT_DEVICE_GUID, &dummy);
                if (status == EFI_SUCCESS)
                        return gop;
 
@@ -510,16 +511,22 @@ find_gop(efi_guid_t *proto, unsigned long size, void **handles)
        return first_gop;
 }
 
-static efi_status_t setup_gop(struct screen_info *si, efi_guid_t *proto,
-                             unsigned long size, void **handles)
+efi_status_t efi_setup_gop(struct screen_info *si)
 {
-       efi_graphics_output_protocol_t *gop;
+       efi_handle_t *handles __free(efi_pool) = NULL;
        efi_graphics_output_protocol_mode_t *mode;
        efi_graphics_output_mode_info_t *info;
+       efi_graphics_output_protocol_t *gop;
+       efi_status_t status;
+       unsigned long num;
 
-       gop = find_gop(proto, size, handles);
+       status = efi_bs_call(locate_handle_buffer, EFI_LOCATE_BY_PROTOCOL,
+                             &EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID, NULL, &num,
+                             &handles);
+       if (status != EFI_SUCCESS)
+               return status;
 
-       /* Did we find any GOPs? */
+       gop = find_gop(num, handles);
        if (!gop)
                return EFI_NOT_FOUND;
 
@@ -551,29 +558,3 @@ static efi_status_t setup_gop(struct screen_info *si, efi_guid_t *proto,
 
        return EFI_SUCCESS;
 }
-
-/*
- * See if we have Graphics Output Protocol
- */
-efi_status_t efi_setup_gop(struct screen_info *si, efi_guid_t *proto,
-                          unsigned long size)
-{
-       efi_status_t status;
-       void **gop_handle = NULL;
-
-       status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
-                            (void **)&gop_handle);
-       if (status != EFI_SUCCESS)
-               return status;
-
-       status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, proto, NULL,
-                            &size, gop_handle);
-       if (status != EFI_SUCCESS)
-               goto free_handle;
-
-       status = setup_gop(si, proto, size, gop_handle);
-
-free_handle:
-       efi_bs_call(free_pool, gop_handle);
-       return status;
-}

diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 71173471faf6c96d3a2184eae0e4741c9ffb9e76..53da6b5be739807ff0b1b17a69365ba9e37e18cd 100644 (file)
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -406,24 +406,11 @@ static void setup_quirks(struct boot_params *boot_params)
 
 static void setup_graphics(struct boot_params *boot_params)
 {
-       efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
-       struct screen_info *si;
-       efi_status_t status;
-       unsigned long size;
-       void **gop_handle = NULL;
-
-       si = &boot_params->screen_info;
-       memset(si, 0, sizeof(*si));
-
-       size = 0;
-       status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-                            &graphics_proto, NULL, &size, gop_handle);
-       if (status == EFI_BUFFER_TOO_SMALL)
-               status = efi_setup_gop(si, &graphics_proto, size);
+       struct screen_info *si = memset(&boot_params->screen_info, 0, sizeof(*si));
 
+       efi_setup_gop(si);
 }
 
-
 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
 {
        efi_bs_call(exit, handle, status, 0, NULL);