Messages in this thread | | | Subject | Re: [PATCH v3 2/5] arm64: Work around Falkor erratum 1003 | From | Christopher Covington <> | Date | Tue, 24 Jan 2017 09:54:44 -0500 |
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Hi Catalin,
On 01/11/2017 01:06 PM, Catalin Marinas wrote: > Some minor comments below, nothing fundamental (as long as you say the > new sequence doesn't have the speculative TLB load problem I mentioned > on a previous version).
This workaround is documented as providing functional correctness for both explicit and speculative memory accesses.
>> diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S >> index 32682be..9ee46df 100644 >> --- a/arch/arm64/mm/proc.S >> +++ b/arch/arm64/mm/proc.S >> @@ -23,6 +23,7 @@ >> #include <asm/assembler.h> >> #include <asm/asm-offsets.h> >> #include <asm/hwcap.h> >> +#include <asm/mmu_context.h> >> #include <asm/pgtable.h> >> #include <asm/pgtable-hwdef.h> >> #include <asm/cpufeature.h> >> @@ -140,6 +141,18 @@ ENDPROC(cpu_do_resume) >> ENTRY(cpu_do_switch_mm) >> mmid x1, x1 // get mm->context.id >> bfi x0, x1, #48, #16 // set the ASID >> +#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1003 >> +alternative_if ARM64_WORKAROUND_QCOM_FALKOR_E1003 >> + mrs x2, ttbr0_el1 >> + mov x3, #FALKOR_RESERVED_ASID >> + bfi x2, x3, #48, #16 // reserved ASID + old BADDR >> + msr ttbr0_el1, x2 >> + isb >> + bfi x2, x0, #0, #48 // reserved ASID + new BADDR >> + msr ttbr0_el1, x2 >> + isb >> +alternative_else_nop_endif >> +#endif >> msr ttbr0_el1, x0 // set TTBR0 >> isb >> post_ttbr0_update_workaround > > Please move the above hunk to a pre_ttbr0_update_workaround macro for > consistency with post_ttbr0_update_workaround.
How should I deal with inputs to the macro?
A) Use no input parameters and hard code x0 usage B) Use a macro input parameter for the new TTBR value (x0) C) Something else
Thanks, Cov
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