aarch64 has no vendor_id in /proc/cpuinfo, so detect_vendor() returns 0 and arch_supports_noncont_cat() falls through to "return false". L3_NONCONT_CAT spuriously fails on every ARM MPAM platform.
Define ARCH_ARM, short-circuite detect_vendor() to it on aarch64, and add it to the AMD/Hygon alwasy-supports early-out in arch_support_noncont_cat(). aarch64 has many implementers (ARM 0x41, NVIDIA 0x43, etc...) but MPAM mandates non-contiguous CPBM uniformly, so per-implementer bits is not needed here. Signed-off-by: Richard Cheng <[email protected]> --- tools/testing/selftests/resctrl/cat_test.c | 9 +++++++-- tools/testing/selftests/resctrl/resctrl.h | 1 + tools/testing/selftests/resctrl/resctrl_tests.c | 11 +++++++++++ 3 files changed, 19 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c index f00b622c1460..37ca70523ed2 100644 --- a/tools/testing/selftests/resctrl/cat_test.c +++ b/tools/testing/selftests/resctrl/cat_test.c @@ -292,8 +292,13 @@ static bool arch_supports_noncont_cat(const struct resctrl_test *test) { unsigned int vendor_id = get_vendor(); - /* AMD and Hygon always support non-contiguous CBM. */ - if (vendor_id == ARCH_AMD || vendor_id == ARCH_HYGON) + /* + * AMD and Hygon always support non-contiguous CBM. ARM/MPAM + * defines MPAMCFG_CPBM as a bitmap with no contiguity constraint + * per ARM DDI 0598. + */ + if (vendor_id == ARCH_AMD || vendor_id == ARCH_HYGON || + vendor_id == ARCH_ARM) return true; #if defined(__i386__) || defined(__x86_64__) /* arch */ diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h index afe635b6e48d..670e5b128b4d 100644 --- a/tools/testing/selftests/resctrl/resctrl.h +++ b/tools/testing/selftests/resctrl/resctrl.h @@ -40,6 +40,7 @@ #define ARCH_INTEL BIT(0) #define ARCH_AMD BIT(1) #define ARCH_HYGON BIT(2) +#define ARCH_ARM BIT(3) #define END_OF_TESTS 1 diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c index dbcd5eea9fbc..b97d3541fcb2 100644 --- a/tools/testing/selftests/resctrl/resctrl_tests.c +++ b/tools/testing/selftests/resctrl/resctrl_tests.c @@ -34,6 +34,17 @@ static unsigned int detect_vendor(void) if (initialized) return vendor_id; +#if defined(__aarch64__) + /* + * aarch64 has no userspace vendor_id in /proc/cpuinfo. MPAM-capable + * ARM implementations follow ARM DDI 0598; treat all aarch64 builds + * as a single vendor for the purposes of resctrl selftests. + */ + vendor_id = ARCH_ARM; + initialized = true; + return vendor_id; +#endif + inf = fopen("/proc/cpuinfo", "r"); if (!inf) { vendor_id = 0; -- 2.43.0
