Messages in this thread | | | Subject | Re: [PATCH 3/3] x86/platform/UV: use efi_runtime_sem to serialise BIOS calls | From | Bhupesh Sharma <> | Date | Thu, 10 Jan 2019 12:43:38 +0530 |
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Hi Hedi,
Thanks for the patchset.
I will give this a go on my sgi-uv300 machine and come back with more detailed inputs, but I wanted to ask about the hang/panic you mentioned in the cover letter when efi_scratch gets clobbered. Can you describe the same (for e.g. how to reproduce this).
Nitpicks below:
On 01/09/2019 04:15 PM, Hedi Berriche wrote: > Calls into UV firmware must be protected against concurrency, use the > now visible efi_runtime_sem lock to serialise them. > > Signed-off-by: Hedi Berriche <hedi.berriche@hpe.com> > Reviewed-by: Russ Anderson <rja@hpe.com> > Reviewed-by: Mike Travis <mike.travis@hpe.com> > Reviewed-by: Dimitri Sivanich <sivanich@hpe.com> > Reviewed-by: Steve Wahl <steve.wahl@hpe.com> > --- > arch/x86/include/asm/uv/bios.h | 3 ++- > arch/x86/platform/uv/bios_uv.c | 25 ++++++++++++++++++++++--- > 2 files changed, 24 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/include/asm/uv/bios.h b/arch/x86/include/asm/uv/bios.h > index 4eee646544b2..33e94aa0b1ff 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 */ > diff --git a/arch/x86/platform/uv/bios_uv.c b/arch/x86/platform/uv/bios_uv.c > index cd05af157763..92f960798e20 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) > +s64 __uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, > + u64 a4, u64 a5)
Can we make this static?
> { > struct uv_systab *tab = uv_systab; > s64 ret; > @@ -44,13 +45,26 @@ s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5) > * If EFI_OLD_MEMMAP is set, we need to fall back to using our old EFI > * callback method, which uses efi_call() directly, with the kernel page tables: > */ > - if (unlikely(test_bit(EFI_OLD_MEMMAP, &efi.flags))) > + if (unlikely(efi_enabled(EFI_OLD_MEMMAP))) > ret = efi_call((void *)__va(tab->function), (u64)which, a1, a2, a3, a4, a5); > else > ret = efi_call_virt_pointer(tab, function, (u64)which, a1, a2, a3, a4, 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_runtime_sem)) > + return BIOS_STATUS_ABORT; > + > + ret = __uv_bios_call(which, a1, a2, a3, a4, a5); > + up(&efi_runtime_sem); > + > + 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_runtime_sem)) > + 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_runtime_sem); > + > return ret; > } >
Thanks, Bhupesh
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