* [PATCH 0/2] efi capsule loader fixes @ 2020-12-07 18:02 ` Ard Biesheuvel 0 siblings, 0 replies; 6+ messages in thread From: Ard Biesheuvel @ 2020-12-07 18:02 UTC (permalink / raw) To: linux-efi; +Cc: linux-arm-kernel, Ard Biesheuvel, Samer El-Haj-Mahmoud A couple of fixes for the EFI capsule loader. Patch #1 switches from kmap() to kmap_atomic(). Patch #2 adds cache maintenance of the scatter gather list entries passed to UpdateCapsule. Cc: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com> Ard Biesheuvel (2): efi: capsule: use atomic kmap for transient sglist mappings efi: capsule: clean scatter-gather entries from the D-cache arch/arm/include/asm/efi.h | 5 +++++ arch/arm64/include/asm/efi.h | 5 +++++ drivers/firmware/efi/capsule.c | 16 ++++++++++++++-- 3 files changed, 24 insertions(+), 2 deletions(-) -- 2.17.1 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 0/2] efi capsule loader fixes @ 2020-12-07 18:02 ` Ard Biesheuvel 0 siblings, 0 replies; 6+ messages in thread From: Ard Biesheuvel @ 2020-12-07 18:02 UTC (permalink / raw) To: linux-efi; +Cc: Samer El-Haj-Mahmoud, Ard Biesheuvel, linux-arm-kernel A couple of fixes for the EFI capsule loader. Patch #1 switches from kmap() to kmap_atomic(). Patch #2 adds cache maintenance of the scatter gather list entries passed to UpdateCapsule. Cc: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com> Ard Biesheuvel (2): efi: capsule: use atomic kmap for transient sglist mappings efi: capsule: clean scatter-gather entries from the D-cache arch/arm/include/asm/efi.h | 5 +++++ arch/arm64/include/asm/efi.h | 5 +++++ drivers/firmware/efi/capsule.c | 16 ++++++++++++++-- 3 files changed, 24 insertions(+), 2 deletions(-) -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 2/2] efi: capsule: clean scatter-gather entries from the D-cache 2020-12-07 18:02 ` Ard Biesheuvel @ 2020-12-07 18:02 ` Ard Biesheuvel -1 siblings, 0 replies; 6+ messages in thread From: Ard Biesheuvel @ 2020-12-07 18:02 UTC (permalink / raw) To: linux-efi; +Cc: linux-arm-kernel, Ard Biesheuvel, Samer El-Haj-Mahmoud The UEFI spec 2.9 has recently been updated to include a requirement that scatter-gather lists passed to UpdateCapsule() should be cleaned from the D-cache to ensure that they are visible to the CPU after a warm reboot before it enables the MMU. On ARM and arm64 systems, this implies a D-cache clean by virtual address to the point of coherency. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/arm/include/asm/efi.h | 5 +++++ arch/arm64/include/asm/efi.h | 5 +++++ drivers/firmware/efi/capsule.c | 12 ++++++++++++ 3 files changed, 22 insertions(+) diff --git a/arch/arm/include/asm/efi.h b/arch/arm/include/asm/efi.h index 3ee4f4381985..e9a06e164e06 100644 --- a/arch/arm/include/asm/efi.h +++ b/arch/arm/include/asm/efi.h @@ -93,4 +93,9 @@ struct efi_arm_entry_state { u32 sctlr_after_ebs; }; +static inline void efi_capsule_flush_cache_range(void *addr, int size) +{ + __cpuc_flush_dcache_area(addr, size); +} + #endif /* _ASM_ARM_EFI_H */ diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 973b14415271..00bd1e179d36 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -141,4 +141,9 @@ static inline void efi_set_pgd(struct mm_struct *mm) void efi_virtmap_load(void); void efi_virtmap_unload(void); +static inline void efi_capsule_flush_cache_range(void *addr, int size) +{ + __flush_dcache_area(addr, size); +} + #endif /* _ASM_EFI_H */ diff --git a/drivers/firmware/efi/capsule.c b/drivers/firmware/efi/capsule.c index 43f6fe7bfe80..768430293669 100644 --- a/drivers/firmware/efi/capsule.c +++ b/drivers/firmware/efi/capsule.c @@ -12,6 +12,7 @@ #include <linux/highmem.h> #include <linux/efi.h> #include <linux/vmalloc.h> +#include <asm/efi.h> #include <asm/io.h> typedef struct { @@ -265,6 +266,17 @@ int efi_capsule_update(efi_capsule_header_t *capsule, phys_addr_t *pages) else sglist[j].data = page_to_phys(sg_pages[i + 1]); +#if defined(CONFIG_ARM) || defined(CONFIG_ARM64) + /* + * At runtime, the firmware has no way to find out where the + * sglist elements are mapped, if they are mapped in the first + * place. Therefore, on architectures that can only perform + * cache maintenance by virtual address, the firmware is unable + * to perform this maintenance, and so it is up to the OS to do + * it instead. + */ + efi_capsule_flush_cache_range(sglist, PAGE_SIZE); +#endif kunmap_atomic(sglist); } -- 2.17.1 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] efi: capsule: clean scatter-gather entries from the D-cache @ 2020-12-07 18:02 ` Ard Biesheuvel 0 siblings, 0 replies; 6+ messages in thread From: Ard Biesheuvel @ 2020-12-07 18:02 UTC (permalink / raw) To: linux-efi; +Cc: Samer El-Haj-Mahmoud, Ard Biesheuvel, linux-arm-kernel The UEFI spec 2.9 has recently been updated to include a requirement that scatter-gather lists passed to UpdateCapsule() should be cleaned from the D-cache to ensure that they are visible to the CPU after a warm reboot before it enables the MMU. On ARM and arm64 systems, this implies a D-cache clean by virtual address to the point of coherency. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/arm/include/asm/efi.h | 5 +++++ arch/arm64/include/asm/efi.h | 5 +++++ drivers/firmware/efi/capsule.c | 12 ++++++++++++ 3 files changed, 22 insertions(+) diff --git a/arch/arm/include/asm/efi.h b/arch/arm/include/asm/efi.h index 3ee4f4381985..e9a06e164e06 100644 --- a/arch/arm/include/asm/efi.h +++ b/arch/arm/include/asm/efi.h @@ -93,4 +93,9 @@ struct efi_arm_entry_state { u32 sctlr_after_ebs; }; +static inline void efi_capsule_flush_cache_range(void *addr, int size) +{ + __cpuc_flush_dcache_area(addr, size); +} + #endif /* _ASM_ARM_EFI_H */ diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 973b14415271..00bd1e179d36 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -141,4 +141,9 @@ static inline void efi_set_pgd(struct mm_struct *mm) void efi_virtmap_load(void); void efi_virtmap_unload(void); +static inline void efi_capsule_flush_cache_range(void *addr, int size) +{ + __flush_dcache_area(addr, size); +} + #endif /* _ASM_EFI_H */ diff --git a/drivers/firmware/efi/capsule.c b/drivers/firmware/efi/capsule.c index 43f6fe7bfe80..768430293669 100644 --- a/drivers/firmware/efi/capsule.c +++ b/drivers/firmware/efi/capsule.c @@ -12,6 +12,7 @@ #include <linux/highmem.h> #include <linux/efi.h> #include <linux/vmalloc.h> +#include <asm/efi.h> #include <asm/io.h> typedef struct { @@ -265,6 +266,17 @@ int efi_capsule_update(efi_capsule_header_t *capsule, phys_addr_t *pages) else sglist[j].data = page_to_phys(sg_pages[i + 1]); +#if defined(CONFIG_ARM) || defined(CONFIG_ARM64) + /* + * At runtime, the firmware has no way to find out where the + * sglist elements are mapped, if they are mapped in the first + * place. Therefore, on architectures that can only perform + * cache maintenance by virtual address, the firmware is unable + * to perform this maintenance, and so it is up to the OS to do + * it instead. + */ + efi_capsule_flush_cache_range(sglist, PAGE_SIZE); +#endif kunmap_atomic(sglist); } -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 1/2] efi: capsule: use atomic kmap for transient sglist mappings 2020-12-07 18:02 ` Ard Biesheuvel @ 2020-12-07 18:02 ` Ard Biesheuvel -1 siblings, 0 replies; 6+ messages in thread From: Ard Biesheuvel @ 2020-12-07 18:02 UTC (permalink / raw) To: linux-efi; +Cc: linux-arm-kernel, Ard Biesheuvel, Samer El-Haj-Mahmoud Don't use the heavy-weight kmap() API to create short-lived mappings of the scatter-gather list entries that are released as soon as the entries are written. Instead, use kmap_atomic(), which is more suited to this purpose. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- drivers/firmware/efi/capsule.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/efi/capsule.c b/drivers/firmware/efi/capsule.c index 598b7800d14e..43f6fe7bfe80 100644 --- a/drivers/firmware/efi/capsule.c +++ b/drivers/firmware/efi/capsule.c @@ -244,7 +244,7 @@ int efi_capsule_update(efi_capsule_header_t *capsule, phys_addr_t *pages) for (i = 0; i < sg_count; i++) { efi_capsule_block_desc_t *sglist; - sglist = kmap(sg_pages[i]); + sglist = kmap_atomic(sg_pages[i]); for (j = 0; j < SGLIST_PER_PAGE && count > 0; j++) { u64 sz = min_t(u64, imagesize, @@ -265,7 +265,7 @@ int efi_capsule_update(efi_capsule_header_t *capsule, phys_addr_t *pages) else sglist[j].data = page_to_phys(sg_pages[i + 1]); - kunmap(sg_pages[i]); + kunmap_atomic(sglist); } mutex_lock(&capsule_mutex); -- 2.17.1 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 1/2] efi: capsule: use atomic kmap for transient sglist mappings @ 2020-12-07 18:02 ` Ard Biesheuvel 0 siblings, 0 replies; 6+ messages in thread From: Ard Biesheuvel @ 2020-12-07 18:02 UTC (permalink / raw) To: linux-efi; +Cc: Samer El-Haj-Mahmoud, Ard Biesheuvel, linux-arm-kernel Don't use the heavy-weight kmap() API to create short-lived mappings of the scatter-gather list entries that are released as soon as the entries are written. Instead, use kmap_atomic(), which is more suited to this purpose. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- drivers/firmware/efi/capsule.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/efi/capsule.c b/drivers/firmware/efi/capsule.c index 598b7800d14e..43f6fe7bfe80 100644 --- a/drivers/firmware/efi/capsule.c +++ b/drivers/firmware/efi/capsule.c @@ -244,7 +244,7 @@ int efi_capsule_update(efi_capsule_header_t *capsule, phys_addr_t *pages) for (i = 0; i < sg_count; i++) { efi_capsule_block_desc_t *sglist; - sglist = kmap(sg_pages[i]); + sglist = kmap_atomic(sg_pages[i]); for (j = 0; j < SGLIST_PER_PAGE && count > 0; j++) { u64 sz = min_t(u64, imagesize, @@ -265,7 +265,7 @@ int efi_capsule_update(efi_capsule_header_t *capsule, phys_addr_t *pages) else sglist[j].data = page_to_phys(sg_pages[i + 1]); - kunmap(sg_pages[i]); + kunmap_atomic(sglist); } mutex_lock(&capsule_mutex); -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-12-07 18:03 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2020-12-07 18:02 [PATCH 0/2] efi capsule loader fixes Ard Biesheuvel 2020-12-07 18:02 ` Ard Biesheuvel 2020-12-07 18:02 ` [PATCH 2/2] efi: capsule: clean scatter-gather entries from the D-cache Ard Biesheuvel 2020-12-07 18:02 ` Ard Biesheuvel 2020-12-07 18:02 ` [PATCH 1/2] efi: capsule: use atomic kmap for transient sglist mappings Ard Biesheuvel 2020-12-07 18:02 ` Ard Biesheuvel
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.