Currently, arm64, RISC-V and LoongArch rely on the fact that struct
screen_info can be accessed directly, due to the fact that the EFI stub
and the core kernel are part of the same image. This will change after a
future patch, so let's ensure that the screen_info handling is able to
deal with this, by adopting the arm32 approach of passing it as a
configuration table. While at it, switch to ACPI reclaim memory to hold
the screen_info data, which is more appropriate for this kind of
allocation.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/arm/include/asm/efi.h | 3 --
arch/arm/kernel/efi.c | 31 ++---------
arch/arm64/include/asm/efi.h | 6 ---
arch/loongarch/include/asm/efi.h | 9 ----
arch/loongarch/kernel/efi.c | 24 ++++++++-
arch/riscv/include/asm/efi.h | 6 ---
drivers/firmware/efi/efi-init.c | 21 ++++++--
drivers/firmware/efi/efi.c | 5 ++
drivers/firmware/efi/libstub/Makefile | 3 +-
drivers/firmware/efi/libstub/arm32-stub.c | 37 -------------
drivers/firmware/efi/libstub/efi-stub.c | 9 ++++
drivers/firmware/efi/libstub/efistub.h | 3 ++
drivers/firmware/efi/libstub/screen_info.c | 56 ++++++++++++++++++++
include/linux/efi.h | 2 +-
14 files changed, 121 insertions(+), 94 deletions(-)
diff --git a/arch/arm/include/asm/efi.h b/arch/arm/include/asm/efi.h
index 4bdd930167c0..b95241b1ca65 100644
--- a/arch/arm/include/asm/efi.h
+++ b/arch/arm/include/asm/efi.h
@@ -43,9 +43,6 @@ void efi_virtmap_unload(void);
/* arch specific definitions used by the stub code */
-struct screen_info *alloc_screen_info(void);
-void free_screen_info(struct screen_info *si);
-
/*
* A reasonable upper bound for the uncompressed kernel size is 32 MBytes,
* so we will reserve that amount of memory. We have no easy way to tell what
diff --git a/arch/arm/kernel/efi.c b/arch/arm/kernel/efi.c
index e50ad7eefc02..882104f43b3b 100644
--- a/arch/arm/kernel/efi.c
+++ b/arch/arm/kernel/efi.c
@@ -75,38 +75,13 @@ int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
return 0;
}
-static unsigned long __initdata screen_info_table = EFI_INVALID_TABLE_ADDR;
static unsigned long __initdata cpu_state_table = EFI_INVALID_TABLE_ADDR;
const efi_config_table_type_t efi_arch_tables[] __initconst = {
- {LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, &screen_info_table},
{LINUX_EFI_ARM_CPU_STATE_TABLE_GUID, &cpu_state_table},
{}
};
-static void __init load_screen_info_table(void)
-{
- struct screen_info *si;
-
- if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
- si = early_memremap_ro(screen_info_table, sizeof(*si));
- if (!si) {
- pr_err("Could not map screen_info config table\n");
- return;
- }
- screen_info = *si;
- early_memunmap(si, sizeof(*si));
-
- /* dummycon on ARM needs non-zero values for columns/lines */
- screen_info.orig_video_cols = 80;
- screen_info.orig_video_lines = 25;
-
- if (memblock_is_map_memory(screen_info.lfb_base))
- memblock_mark_nomap(screen_info.lfb_base,
- screen_info.lfb_size);
- }
-}
-
static void __init load_cpu_state_table(void)
{
if (cpu_state_table != EFI_INVALID_TABLE_ADDR) {
@@ -145,7 +120,11 @@ void __init arm_efi_init(void)
{
efi_init();
- load_screen_info_table();
+ if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI) {
+ /* dummycon on ARM needs non-zero values for columns/lines */
+ screen_info.orig_video_cols = 80;
+ screen_info.orig_video_lines = 25;
+ }
/* ARM does not permit early mappings to persist across paging_init() */
efi_memmap_unmap();
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index 439e2bc5d5d8..af35ad671754 100644
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -76,12 +76,6 @@ static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
}
-#define alloc_screen_info(x...) &screen_info
-
-static inline void free_screen_info(struct screen_info *si)
-{
-}
-
#define EFI_ALLOC_ALIGN SZ_64K
/*
diff --git a/arch/loongarch/include/asm/efi.h b/arch/loongarch/include/asm/efi.h
index 174567b00ddb..60d6a170c18d 100644
--- a/arch/loongarch/include/asm/efi.h
+++ b/arch/loongarch/include/asm/efi.h
@@ -19,15 +19,6 @@ void efifb_setup_from_dmi(struct screen_info *si, const char *opt);
#define EFI_ALLOC_ALIGN SZ_64K
#define EFI_RT_VIRTUAL_OFFSET CSR_DMW0_BASE
-static inline struct screen_info *alloc_screen_info(void)
-{
- return &screen_info;
-}
-
-static inline void free_screen_info(struct screen_info *si)
-{
-}
-
static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
{
return ULONG_MAX;
diff --git a/arch/loongarch/kernel/efi.c b/arch/loongarch/kernel/efi.c
index a31329971133..d75ce73e8ff8 100644
--- a/arch/loongarch/kernel/efi.c
+++ b/arch/loongarch/kernel/efi.c
@@ -52,6 +52,27 @@ void __init efi_runtime_init(void)
set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
}
+unsigned long __initdata screen_info_table = EFI_INVALID_TABLE_ADDR;
+
+static void __init init_screen_info(void)
+{
+ struct screen_info *si;
+
+ if (screen_info_table == EFI_INVALID_TABLE_ADDR)
+ return;
+
+ si = early_memremap(screen_info_table, sizeof(*si));
+ if (!si) {
+ pr_err("Could not map screen_info config table\n");
+ return;
+ }
+ screen_info = *si;
+ memset(si, 0, sizeof(*si));
+ early_memunmap(si, sizeof(*si));
+
+ memblock_reserve(screen_info.lfb_base, screen_info.lfb_size);
+}
+
void __init efi_init(void)
{
int size;
@@ -80,8 +101,7 @@ void __init efi_init(void)
set_bit(EFI_CONFIG_TABLES, &efi.flags);
- if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI)
- memblock_reserve(screen_info.lfb_base, screen_info.lfb_size);
+ init_screen_info();
if (boot_memmap == EFI_INVALID_TABLE_ADDR)
return;
diff --git a/arch/riscv/include/asm/efi.h b/arch/riscv/include/asm/efi.h
index f74879a8f1ea..d0570936cb8c 100644
--- a/arch/riscv/include/asm/efi.h
+++ b/arch/riscv/include/asm/efi.h
@@ -31,12 +31,6 @@ static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
return ULONG_MAX;
}
-#define alloc_screen_info(x...) (&screen_info)
-
-static inline void free_screen_info(struct screen_info *si)
-{
-}
-
void efi_virtmap_load(void);
void efi_virtmap_unload(void);
diff --git a/drivers/firmware/efi/efi-init.c b/drivers/firmware/efi/efi-init.c
index 2fd770b499a3..1639159493e3 100644
--- a/drivers/firmware/efi/efi-init.c
+++ b/drivers/firmware/efi/efi-init.c
@@ -22,6 +22,8 @@
#include <asm/efi.h>
+unsigned long __initdata screen_info_table = EFI_INVALID_TABLE_ADDR;
+
static int __init is_memory(efi_memory_desc_t *md)
{
if (md->attribute & (EFI_MEMORY_WB|EFI_MEMORY_WT|EFI_MEMORY_WC))
@@ -55,9 +57,22 @@ extern __weak const efi_config_table_type_t efi_arch_tables[];
static void __init init_screen_info(void)
{
- if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
- memblock_is_map_memory(screen_info.lfb_base))
- memblock_mark_nomap(screen_info.lfb_base, screen_info.lfb_size);
+ struct screen_info *si;
+
+ if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
+ si = early_memremap(screen_info_table, sizeof(*si));
+ if (!si) {
+ pr_err("Could not map screen_info config table\n");
+ return;
+ }
+ screen_info = *si;
+ memset(si, 0, sizeof(*si));
+ early_memunmap(si, sizeof(*si));
+
+ if (memblock_is_map_memory(screen_info.lfb_base))
+ memblock_mark_nomap(screen_info.lfb_base,
+ screen_info.lfb_size);
+ }
}
static int __init uefi_init(u64 efi_system_table)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 9624735f1575..84a3e52fe888 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -58,6 +58,8 @@ static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR;
static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR;
static unsigned long __initdata initrd = EFI_INVALID_TABLE_ADDR;
+extern unsigned long screen_info_table;
+
struct mm_struct efi_mm = {
.mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, efi_mm.mmap_lock),
.mm_users = ATOMIC_INIT(2),
@@ -544,6 +546,9 @@ static const efi_config_table_type_t common_tables[] __initconst = {
#endif
#ifdef CONFIG_EFI_COCO_SECRET
{LINUX_EFI_COCO_SECRET_AREA_GUID, &efi.coco_secret, "CocoSecret" },
+#endif
+#ifdef CONFIG_EFI_GENERIC_STUB
+ {LINUX_EFI_SCREEN_INFO_TABLE_GUID, &screen_info_table },
#endif
{},
};
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index cb600c7a14de..53304e9c6778 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -77,7 +77,8 @@ lib-$(CONFIG_EFI_PARAMS_FROM_FDT) += fdt.o \
$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
$(call if_changed_rule,cc_o_c)
-lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o string.o intrinsics.o systable.o
+lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o string.o intrinsics.o systable.o \
+ screen_info.o
lib-$(CONFIG_ARM) += arm32-stub.o
lib-$(CONFIG_ARM64) += arm64-stub.o arm64-entry.o
diff --git a/drivers/firmware/efi/libstub/arm32-stub.c b/drivers/firmware/efi/libstub/arm32-stub.c
index 0131e3aaa605..1073dd947516 100644
--- a/drivers/firmware/efi/libstub/arm32-stub.c
+++ b/drivers/firmware/efi/libstub/arm32-stub.c
@@ -76,43 +76,6 @@ void efi_handle_post_ebs_state(void)
&efi_entry_state->sctlr_after_ebs);
}
-static efi_guid_t screen_info_guid = LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID;
-
-struct screen_info *alloc_screen_info(void)
-{
- struct screen_info *si;
- efi_status_t status;
-
- /*
- * Unlike on arm64, where we can directly fill out the screen_info
- * structure from the stub, we need to allocate a buffer to hold
- * its contents while we hand over to the kernel proper from the
- * decompressor.
- */
- status = efi_bs_call(allocate_pool, EFI_RUNTIME_SERVICES_DATA,
- sizeof(*si), (void **)&si);
-
- if (status != EFI_SUCCESS)
- return NULL;
-
- status = efi_bs_call(install_configuration_table,
- &screen_info_guid, si);
- if (status == EFI_SUCCESS)
- return si;
-
- efi_bs_call(free_pool, si);
- return NULL;
-}
-
-void free_screen_info(struct screen_info *si)
-{
- if (!si)
- return;
-
- efi_bs_call(install_configuration_table, &screen_info_guid, NULL);
- efi_bs_call(free_pool, si);
-}
-
efi_status_t handle_kernel_image(unsigned long *image_addr,
unsigned long *image_size,
unsigned long *reserve_addr,
diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index b55d1009d4c8..8521dc09c6ae 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -47,6 +47,15 @@
static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;
static bool flat_va_mapping = (EFI_RT_VIRTUAL_OFFSET != 0);
+struct screen_info * __weak alloc_screen_info(void)
+{
+ return &screen_info;
+}
+
+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;
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 313647b1c196..215186a29ab9 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -1027,4 +1027,7 @@ efi_enable_reset_attack_mitigation(void) { }
void efi_retrieve_tpm2_eventlog(void);
+struct screen_info *alloc_screen_info(void);
+void free_screen_info(struct screen_info *si);
+
#endif
diff --git a/drivers/firmware/efi/libstub/screen_info.c b/drivers/firmware/efi/libstub/screen_info.c
new file mode 100644
index 000000000000..8e76a8b384ba
--- /dev/null
+++ b/drivers/firmware/efi/libstub/screen_info.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/efi.h>
+#include <asm/efi.h>
+
+#include "efistub.h"
+
+/*
+ * There are two ways of populating the core kernel's struct screen_info via the stub:
+ * - using a configuration table, like below, which relies on the EFI init code
+ * to locate the table and copy the contents;
+ * - by linking directly to the core kernel's copy of the global symbol.
+ *
+ * The latter is preferred because it makes the EFIFB earlycon available very
+ * early, but it only works if the EFI stub is part of the core kernel image
+ * itself. The zboot decompressor can only use the configuration table
+ * approach.
+ *
+ * In order to support both methods from the same build of the EFI stub
+ * library, provide this dummy global definition of struct screen_info. If it
+ * is required to satisfy a link dependency, it means we need to override the
+ * __weak alloc and free methods with the ones below, and those will be pulled
+ * in as well.
+ */
+struct screen_info screen_info;
+
+static efi_guid_t screen_info_guid = LINUX_EFI_SCREEN_INFO_TABLE_GUID;
+
+struct screen_info *alloc_screen_info(void)
+{
+ struct screen_info *si;
+ efi_status_t status;
+
+ status = efi_bs_call(allocate_pool, EFI_ACPI_RECLAIM_MEMORY,
+ sizeof(*si), (void **)&si);
+
+ if (status != EFI_SUCCESS)
+ return NULL;
+
+ status = efi_bs_call(install_configuration_table,
+ &screen_info_guid, si);
+ if (status == EFI_SUCCESS)
+ return si;
+
+ efi_bs_call(free_pool, si);
+ return NULL;
+}
+
+void free_screen_info(struct screen_info *si)
+{
+ if (!si)
+ return;
+
+ efi_bs_call(install_configuration_table, &screen_info_guid, NULL);
+ efi_bs_call(free_pool, si);
+}
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 256e70e42114..ca3278077670 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -404,7 +404,7 @@ void efi_native_runtime_setup(void);
* structure that was populated by the stub based on the GOP protocol instance
* associated with ConOut
*/
-#define LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID EFI_GUID(0xe03fc20a, 0x85dc, 0x406e, 0xb9, 0x0e, 0x4a, 0xb5, 0x02, 0x37, 0x1d, 0x95)
+#define LINUX_EFI_SCREEN_INFO_TABLE_GUID EFI_GUID(0xe03fc20a, 0x85dc, 0x406e, 0xb9, 0x0e, 0x4a, 0xb5, 0x02, 0x37, 0x1d, 0x95)
#define LINUX_EFI_ARM_CPU_STATE_TABLE_GUID EFI_GUID(0xef79e4aa, 0x3c3d, 0x4989, 0xb9, 0x02, 0x07, 0xa9, 0x43, 0xe5, 0x50, 0xd2)
#define LINUX_EFI_LOADER_ENTRY_GUID EFI_GUID(0x4a67b082, 0x0a4c, 0x41cf, 0xb6, 0xc7, 0x44, 0x0b, 0x29, 0xbb, 0x8c, 0x4f)
#define LINUX_EFI_RANDOM_SEED_TABLE_GUID EFI_GUID(0x1ce1e5bc, 0x7ceb, 0x42f2, 0x81, 0xe5, 0x8a, 0xad, 0xf1, 0x80, 0xf5, 0x7b)
--
2.35.1
