Hi, On 13/12/2018 15:03, Julien Thierry wrote: > > Argh, not as simple as I had expected. > > Turns out include/linux/efi.h does not include asm/efi.h (including it > at the beginning of the file breaks the build because asm/efi.h misses > the efi type definitions. > > So a thing like: > > #ifndef efi_get_irqflags > #define efi_get_irqflags(flags) local_save_flags(flags) > #endif > > in include/linux/efi.h cannot be overridden. > > Either I would need to introduce the definitions arm, arm64 and x86 (I > don't think there are other arch supporting EFI right now) or I'll need > to come up with another solution. >
Would the following patch be acceptable for the EFI generic side? If it is, I'll add it to the next iteration of this series. Thanks, Julien --> >From 7acaa8e17142263addafb18ae10bd5d2d49cfb39 Mon Sep 17 00:00:00 2001 From: Julien Thierry <[email protected]> Date: Fri, 14 Dec 2018 14:20:13 +0000 Subject: [RFC] efi: Let architectures decide the flags that should be saved/restored Currently, irqflags are saved before calling runtime services and checked for mismatch on return. Add a config option to let architectures define a set of flags to be checked and (if needed) restored when coming back from runtime services. This allows to use check flags that are not necesarly related to irqflags. Signed-off-by: Julien Thierry <[email protected]> --- arch/Kconfig | 8 ++++++++ drivers/firmware/efi/runtime-wrappers.c | 4 ++-- include/linux/efi.h | 12 ++++++++++-- 3 files changed, 20 insertions(+), 4 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig index e1e540f..cbec325 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -695,6 +695,14 @@ config HAVE_ARCH_HASH file which provides platform-specific implementations of some functions in <linux/hash.h> or fs/namei.c. +config HAVE_GENERIC_EFI_FLAGS + bool + default n + help + Architecture defines a set of flags that EFI runtime services + should take care to restore when returning to the OS. + If this is not set, the set of flags defaults to the arch irqflags. + config ISA_BUS_API def_bool ISA diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c index 8903b9c..6dafa04 100644 --- a/drivers/firmware/efi/runtime-wrappers.c +++ b/drivers/firmware/efi/runtime-wrappers.c @@ -93,7 +93,7 @@ void efi_call_virt_check_flags(unsigned long flags, const char *call) { unsigned long cur_flags, mismatch; - local_save_flags(cur_flags); + efi_save_flags(cur_flags); mismatch = flags ^ cur_flags; if (!WARN_ON_ONCE(mismatch & ARCH_EFI_IRQ_FLAGS_MASK)) @@ -102,7 +102,7 @@ void efi_call_virt_check_flags(unsigned long flags, const char *call) add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_NOW_UNRELIABLE); pr_err_ratelimited(FW_BUG "IRQ flags corrupted (0x%08lx=>0x%08lx) by EFI %s\n", flags, cur_flags, call); - local_irq_restore(flags); + efi_restore_flags(flags); } /* diff --git a/include/linux/efi.h b/include/linux/efi.h index 100ce4a..41c110a 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1594,6 +1594,14 @@ enum efi_secureboot_mode { void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table); +#ifdef CONFIG_HAVE_GENERIC_EFI_FLAGS +#define efi_save_flags(state_flags) arch_efi_save_flags(state_flags) +#define efi_restore_flags(state_flags) arch_efi_restore_flags(state_flags) +#else +#define efi_save_flags(state_flags) local_save_flags(state_flags) +#define efi_restore_flags(state_flags) local_irq_restore(state_flags) +#endif + /* * Arch code can implement the following three template macros, avoiding * reptition for the void/non-void return cases of {__,}efi_call_virt(): @@ -1621,7 +1629,7 @@ enum efi_secureboot_mode { \ arch_efi_call_virt_setup(); \ \ - local_save_flags(__flags); \ + efi_save_flags(__flags); \ __s = arch_efi_call_virt(p, f, args); \ efi_call_virt_check_flags(__flags, __stringify(f)); \ \ @@ -1636,7 +1644,7 @@ enum efi_secureboot_mode { \ arch_efi_call_virt_setup(); \ \ - local_save_flags(__flags); \ + efi_save_flags(__flags); \ arch_efi_call_virt(p, f, args); \ efi_call_virt_check_flags(__flags, __stringify(f)); \ \ -- 1.9.1 -- Julien Thierry
