Messages in this thread | | | Subject | Re: [PATCH v2 16/22] arm64/debug: Make use of the system wide safe value | From | "Suzuki K. Poulose" <> | Date | Thu, 8 Oct 2015 16:57:56 +0100 |
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On 08/10/15 16:08, Catalin Marinas wrote: > On Thu, Oct 08, 2015 at 12:56:28PM +0100, Suzuki K. Poulose wrote: >> On 08/10/15 12:11, Catalin Marinas wrote: >>> On Mon, Oct 05, 2015 at 06:02:05PM +0100, Suzuki K. Poulose wrote: >>>> @@ -137,13 +138,17 @@ extern struct pmu perf_ops_bp; >>>> /* Determine number of BRP registers available. */ >>>> static inline int get_num_brps(void) >>>> { >>>> - return ((read_cpuid(ID_AA64DFR0_EL1) >> 12) & 0xf) + 1; >>>> + return 1 + >>>> + cpuid_feature_extract_field(read_system_reg(SYS_ID_AA64DFR0_EL1), >>>> + ID_AA64DFR0_BRPS_SHIFT); >>>> } >>> >>> cpuid_feature_extract_field() is fine but we should we bother with >>> read_system_reg vs just read_cpuid? >>> Similar question for patch 17/22. >> >> Well, we would have already TAINTed the kernel, if these fields are different. >> It is just the matter of, whether we want to provide the safer value on a tainted >> kernel or not. I am open to suggestions. > > Ah, sorry, I mixed read_system_reg() with read_cpu_sysreg(). I think we
Oh, ok. I think we should rename it as you suggest below to avoid the confusion.
> need to rename the latter as it gets confusing. Maybe something like > read_native_sys_reg() or __raw_read_system_reg(). >
Thanks Suzuki
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