Commit-ID: f331e766c4be33f4338574f3c9f7f77e98ab4571 Gitweb: https://git.kernel.org/tip/f331e766c4be33f4338574f3c9f7f77e98ab4571 Author: Hedi Berriche <hedi.berriche@xxxxxxx> AuthorDate: Wed, 13 Feb 2019 19:34:13 +0000 Committer: Borislav Petkov <bp@xxxxxxx> CommitDate: Fri, 15 Feb 2019 15:19:56 +0100 x86/platform/UV: Use efi_runtime_lock to serialise BIOS calls Calls into UV firmware must be protected against concurrency, expose the efi_runtime_lock to the UV platform, and use it to serialise UV BIOS calls. Signed-off-by: Hedi Berriche <hedi.berriche@xxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> Reviewed-by: Russ Anderson <rja@xxxxxxx> Reviewed-by: Dimitri Sivanich <sivanich@xxxxxxx> Reviewed-by: Mike Travis <mike.travis@xxxxxxx> Cc: Andy Shevchenko <andy@xxxxxxxxxxxxx> Cc: Bhupesh Sharma <bhsharma@xxxxxxxxxx> Cc: Darren Hart <dvhart@xxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: linux-efi <linux-efi@xxxxxxxxxxxxxxx> Cc: platform-driver-x86@xxxxxxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx # v4.9+ Cc: Steve Wahl <steve.wahl@xxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: x86-ml <x86@xxxxxxxxxx> Link: https://lkml.kernel.org/r/20190213193413.25560-5-hedi.berriche@xxxxxxx --- arch/x86/include/asm/uv/bios.h | 8 +++++++- arch/x86/platform/uv/bios_uv.c | 23 +++++++++++++++++++++-- drivers/firmware/efi/runtime-wrappers.c | 7 +++++++ 3 files changed, 35 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/uv/bios.h b/arch/x86/include/asm/uv/bios.h index e652a7cc6186..3f697a9e3f59 100644 --- a/arch/x86/include/asm/uv/bios.h +++ b/arch/x86/include/asm/uv/bios.h @@ -48,7 +48,8 @@ enum { BIOS_STATUS_SUCCESS = 0, BIOS_STATUS_UNIMPLEMENTED = -ENOSYS, BIOS_STATUS_EINVAL = -EINVAL, - BIOS_STATUS_UNAVAIL = -EBUSY + BIOS_STATUS_UNAVAIL = -EBUSY, + BIOS_STATUS_ABORT = -EINTR, }; /* Address map parameters */ @@ -167,4 +168,9 @@ extern long system_serial_number; extern struct kobject *sgi_uv_kobj; /* /sys/firmware/sgi_uv */ +/* + * EFI runtime lock; cf. firmware/efi/runtime-wrappers.c for details + */ +extern struct semaphore __efi_uv_runtime_lock; + #endif /* _ASM_X86_UV_BIOS_H */ diff --git a/arch/x86/platform/uv/bios_uv.c b/arch/x86/platform/uv/bios_uv.c index 4a6a5a26c582..eb33432f2f24 100644 --- a/arch/x86/platform/uv/bios_uv.c +++ b/arch/x86/platform/uv/bios_uv.c @@ -29,7 +29,8 @@ struct uv_systab *uv_systab; -s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5) +static s64 __uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, + u64 a4, u64 a5) { struct uv_systab *tab = uv_systab; s64 ret; @@ -51,6 +52,19 @@ s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5) return ret; } + +s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5) +{ + s64 ret; + + if (down_interruptible(&__efi_uv_runtime_lock)) + return BIOS_STATUS_ABORT; + + ret = __uv_bios_call(which, a1, a2, a3, a4, a5); + up(&__efi_uv_runtime_lock); + + return ret; +} EXPORT_SYMBOL_GPL(uv_bios_call); s64 uv_bios_call_irqsave(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, @@ -59,10 +73,15 @@ s64 uv_bios_call_irqsave(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, unsigned long bios_flags; s64 ret; + if (down_interruptible(&__efi_uv_runtime_lock)) + return BIOS_STATUS_ABORT; + local_irq_save(bios_flags); - ret = uv_bios_call(which, a1, a2, a3, a4, a5); + ret = __uv_bios_call(which, a1, a2, a3, a4, a5); local_irq_restore(bios_flags); + up(&__efi_uv_runtime_lock); + return ret; } diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c index 8903b9ccfc2b..e2abfdb5cee6 100644 --- a/drivers/firmware/efi/runtime-wrappers.c +++ b/drivers/firmware/efi/runtime-wrappers.c @@ -146,6 +146,13 @@ void efi_call_virt_check_flags(unsigned long flags, const char *call) */ static DEFINE_SEMAPHORE(efi_runtime_lock); +/* + * Expose the EFI runtime lock to the UV platform + */ +#ifdef CONFIG_X86_UV +extern struct semaphore __efi_uv_runtime_lock __alias(efi_runtime_lock); +#endif + /* * Calls the appropriate efi_runtime_service() with the appropriate * arguments.
