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Message-ID: <20241220112214.2598872-12-ardb+git@google.com>
Date: Fri, 20 Dec 2024 12:22:18 +0100
From: Ard Biesheuvel <ardb+git@...gle.com>
To: linux-efi@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, Ard Biesheuvel <ardb@...nel.org>
Subject: [PATCH 3/7] efi/libstub: Simplify GOP handling code
From: Ard Biesheuvel <ardb@...nel.org>
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@...nel.org>
---
arch/x86/include/asm/efi.h | 3 ++
drivers/firmware/efi/libstub/efi-stub.c | 28 ++++------
drivers/firmware/efi/libstub/efistub.h | 7 +--
drivers/firmware/efi/libstub/gop.c | 57 +++++++-------------
drivers/firmware/efi/libstub/x86-stub.c | 17 +-----
5 files changed, 38 insertions(+), 74 deletions(-)
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 521aad70e41b..f227a70ac91f 100644
--- 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 382b54f40603..90e06a6b1a45 100644
--- 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 c321735eb237..a7c24f0a2e5e 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -314,7 +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 *, ...);
@@ -1083,8 +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 8eef63c48288..fce28488c76c 100644
--- 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,
+ (void **)&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 71173471faf6..53da6b5be739 100644
--- 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);
--
2.47.1.613.gc27f4b7a9f-goog
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