From mboxrd@z Thu Jan 1 00:00:00 1970 From: sudeep.holla@arm.com (Sudeep Holla) Date: Fri, 27 Apr 2018 13:49:51 +0100 Subject: [PATCH v8 07/13] drivers: base cacheinfo: Add support for ACPI based firmware tables In-Reply-To: <48bd3299-a95a-8aa6-524d-b3aa01dd9ef2@arm.com> References: <20180425233121.13270-1-jeremy.linton@arm.com> <20180425233121.13270-8-jeremy.linton@arm.com> <48bd3299-a95a-8aa6-524d-b3aa01dd9ef2@arm.com> Message-ID: <14062628-d6bb-2e46-fd7c-edce814b5d22@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 26/04/18 19:57, Jeremy Linton wrote: > Hi, > > On 04/26/2018 06:05 AM, Sudeep Holla wrote: >> >> >> On 26/04/18 00:31, Jeremy Linton wrote: >>> Call ACPI cache parsing routines from base cacheinfo code if ACPI >>> is enable. Also stub out cache_setup_acpi() so that individual >>> architectures can enable ACPI topology parsing. >>> >> >> [...] >> >>> +#ifndef CONFIG_ACPI >>> +static inline int acpi_find_last_cache_level(unsigned int cpu) >>> +{ >>> +??? /* ACPI kernels should be built with PPTT support */ >> >> This sounds incorrect for x86. But I understand why you have it there. >> Does it makes sense to change above to .. ? >> >> #if !defined(CONFIG_ACPI) || (defined(CONFIG_ACPI) && >> !(CONFIG_ACPI_PPTT)) >> > I'm not sure what that buys us, if anything you want more non-users of > the function to be falling through to the function prototype rather than > the static inline. The only place any of this matters (as long as the > compiler/linker is tossing the static inline) is arm64 because its the > only arch making a call to acpi_find_last_cache_level(). ACPI_PPTT is > also only visible on arm64 at the moment due to being wrapped in a if > ARM64 in the Kconfig > Fair enough. > Put another way, I wouldn't expect an arch to have a 'user' visible > option to enable/disable parsing the PPTT. If an arch can handle > ACPI/PPTT topology then I would expect it to be fixed to the CONFIG_ACPI > state. What happens when acpi_find_last_cache_level() is called should > only be dependent on whether ACPI is enabled, the PPTT parser itself > will handle the cases of a missing table. Agreed. But technically that statement is still incorrect as x86 ACPI build need not have PPTT enabled. IMO you can reword it, but I will leave that to Rafael :) Other than that, it looks good. Acked-by: Sudeep Holla -- Regards, Sudeep