| Message ID | 1457588408-19309-9-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 18 March 2016 at 12:53, Matt Fleming <matt@codeblueprint.co.uk> wrote: > On Thu, 10 Mar, at 12:40:08PM, Ard Biesheuvel wrote: >> Unlike on arm64, where we can simply access the screen_info struct directly, >> ARM requires an intermediate step to get the information discovered by the >> GOP code in the UEFI stub into the screen_info struct. >> >> So retrieve the dedicated config table we invented for this purpose, and >> put its contents into the core kernel's copy of struct screen_info. >> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> >> --- >> arch/arm/kernel/efi.c | 24 ++++++++++++++++++++ >> drivers/firmware/efi/arm-init.c | 6 +++++ >> 2 files changed, 30 insertions(+) > > [...] > >> diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c >> index eca9b4f826ee..689bf65f8ddf 100644 >> --- a/drivers/firmware/efi/arm-init.c >> +++ b/drivers/firmware/efi/arm-init.c >> @@ -112,6 +112,12 @@ static int __init uefi_init(void) >> retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables, >> sizeof(efi_config_table_t), NULL); >> >> + if (IS_ENABLED(CONFIG_ARM)) { >> + extern void efi_find_screen_info(efi_config_table_t *, u32); >> + >> + efi_find_screen_info(config_tables, efi.systab->nr_tables); >> + } >> + >> early_memunmap(config_tables, table_size); >> out: >> early_memunmap(efi.systab, sizeof(efi_system_table_t)); > > It's unfortunate that this is the first example of putting > arch-specific things in arm-init.c. Is there anyway we can move it out > into arch/arm? > > If not, because efi_find_screen_info() uses all standard data types > and function calls, I wouldn't be opposed to just sticking this in > efi_config_parse_tables() like we do for EFI_PROPERTIES_TABLE. It's > certainly nice to have all config table code in one place. > > Also, it would save ARM the effort of looping over the config tables > twice. I'd actually prefer that, especially since -at some point- we may expose the stub-to-kernel interface as an ABI, for things like Xen dom0 that expose a 'sanitized' EFI environment, and don't boot the dom0 kernel via the stub. There, this config table would be the only way to populate screen_info, and the fact that arm64 *may* do it directly becomes an implementation detail of the stub. So in v2, I will rename the GUID to drop the ARMxx part, and move its handling into the generic code. -- Ard. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/arch/arm/kernel/efi.c b/arch/arm/kernel/efi.c index ff8a9d8acfac..8d1119259654 100644 --- a/arch/arm/kernel/efi.c +++ b/arch/arm/kernel/efi.c @@ -6,11 +6,35 @@ * published by the Free Software Foundation. */ +#define pr_fmt(fmt) "efi: " fmt + #include <linux/efi.h> +#include <linux/screen_info.h> #include <asm/efi.h> #include <asm/mach/map.h> #include <asm/mmu_context.h> +static const efi_guid_t __initconst si_tbl = LINUX_ARM32_SCREEN_INFO_TABLE_GUID; + +void __init efi_find_screen_info(efi_config_table_t *tbl, u32 num_tables) +{ + struct screen_info *si; + + while (num_tables--) { + if (efi_guidcmp(tbl->guid, si_tbl) == 0) { + si = early_memremap_ro(tbl->table, sizeof(*si)); + if (!si) { + pr_warn("Failed to remap screen_info config table\n"); + return; + } + screen_info = *si; + early_memunmap(si, sizeof(*si)); + break; + } + tbl++; + } +} + int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md) { struct map_desc desc = { diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c index eca9b4f826ee..689bf65f8ddf 100644 --- a/drivers/firmware/efi/arm-init.c +++ b/drivers/firmware/efi/arm-init.c @@ -112,6 +112,12 @@ static int __init uefi_init(void) retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sizeof(efi_config_table_t), NULL); + if (IS_ENABLED(CONFIG_ARM)) { + extern void efi_find_screen_info(efi_config_table_t *, u32); + + efi_find_screen_info(config_tables, efi.systab->nr_tables); + } + early_memunmap(config_tables, table_size); out: early_memunmap(efi.systab, sizeof(efi_system_table_t));
Unlike on arm64, where we can simply access the screen_info struct directly, ARM requires an intermediate step to get the information discovered by the GOP code in the UEFI stub into the screen_info struct. So retrieve the dedicated config table we invented for this purpose, and put its contents into the core kernel's copy of struct screen_info. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm/kernel/efi.c | 24 ++++++++++++++++++++ drivers/firmware/efi/arm-init.c | 6 +++++ 2 files changed, 30 insertions(+) -- 1.9.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel