Messages in this thread | | | Subject | Re: [PATCHv3 08/11] arm64: Check for selected granule support | From | "Suzuki K. Poulose" <> | Date | Thu, 15 Oct 2015 10:48:13 +0100 |
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On 14/10/15 22:13, Jeremy Linton wrote: > On 10/14/2015 06:20 AM, Suzuki K. Poulose wrote: > >> + * Checks if the selected granule size is supported by the CPU. >> + * If it doesn't park the CPU > > The problem is when you park the boot CPU. > > I think for EFI there is a slightly better error mechanism. This tweak will print an > error and return to the EFI boot manager rather than hanging the machine without any > notification. Now it prints: > > EFI stub: Booting Linux Kernel... > EFI stub: ERROR: 16K granule not supported by this machine > EFI stub: ERROR: Failed to relocate kernel > FS4:\>
Nice ! I will pick this up.
> > > Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> > --- > arch/arm64/kernel/efi-stub.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/arch/arm64/kernel/efi-stub.c b/arch/arm64/kernel/efi-stub.c > index 816120e..90fb868 100644 > --- a/arch/arm64/kernel/efi-stub.c > +++ b/arch/arm64/kernel/efi-stub.c > @@ -25,6 +25,20 @@ efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg, > unsigned long kernel_size, kernel_memsize = 0; > unsigned long nr_pages; > void *old_image_addr = (void *)*image_addr; > + u32 aa64mmfr0_el1; > + > +#ifdef CONFIG_ARM64_16K_PAGES
I would prefer to have it on for all page sizes and not just 16K, to be on a safer side
> + /* > + * check to see if this kernel image is > + * compatible with the current system > + */ > + asm volatile("mrs %0, ID_AA64MMFR0_EL1" : "=r" (aa64mmfr0_el1)); > + aa64mmfr0_el1 >>= ID_AA64MMFR0_TGRAN16_SHIFT; > + if ((aa64mmfr0_el1 & ID_AA64MMFR0_TGRAN4_ON) == 0) { > + pr_efi_err(sys_table_arg, "16K granule not supported by this machine\n"); > + return EFI_UNSUPPORTED; > + } > +#endif
Thanks Suzuki
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