[PATCH v2 4/5] arm64: cpufeature: Test 'matches' pointer to find the end of the list
From: james.morse@arm.com (James Morse)
Date: 2016-02-05 14:58:49
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
CPU feature code uses the desc field as a test to find the end of the list, this means every entry must have a description. This generates noise for entries in the list that aren't really features, but combinations of them. e.g.
CPU features: detected feature: Privileged Access Never CPU features: detected feature: PAN and not UAO
These combination features are needed for corner cases with alternatives, where cpu features interact. Change all walkers of the arm64_features[] and arm64_hwcaps[] lists to test 'matches' not 'desc', and only print 'desc' if it is non-NULL. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by : Suzuki K Poulose [off-list ref] --- arch/arm64/kernel/cpufeature.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 06bdcd019bd6..c717c3d78f5e 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -754,7 +754,7 @@ static void __init setup_cpu_hwcaps(void) int i; const struct arm64_cpu_capabilities *hwcaps = arm64_hwcaps; - for (i = 0; hwcaps[i].desc; i++) + for (i = 0; hwcaps[i].matches; i++) if (hwcaps[i].matches(&hwcaps[i])) cap_set_hwcap(&hwcaps[i]); }
@@ -764,11 +764,11 @@ void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps, { int i; - for (i = 0; caps[i].desc; i++) { + for (i = 0; caps[i].matches; i++) { if (!caps[i].matches(&caps[i])) continue; - if (!cpus_have_cap(caps[i].capability)) + if (!cpus_have_cap(caps[i].capability) && caps[i].desc) pr_info("%s %s\n", info, caps[i].desc); cpus_set_cap(caps[i].capability); }
@@ -783,7 +783,7 @@ enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps) { int i; - for (i = 0; caps[i].desc; i++) + for (i = 0; caps[i].matches; i++) if (caps[i].enable && cpus_have_cap(caps[i].capability)) on_each_cpu(caps[i].enable, NULL, true); }
@@ -890,7 +890,7 @@ void verify_local_cpu_capabilities(void) return; caps = arm64_features; - for (i = 0; caps[i].desc; i++) { + for (i = 0; caps[i].matches; i++) { if (!cpus_have_cap(caps[i].capability) || !caps[i].sys_reg) continue; /*
@@ -903,7 +903,7 @@ void verify_local_cpu_capabilities(void) caps[i].enable(NULL); } - for (i = 0, caps = arm64_hwcaps; caps[i].desc; i++) { + for (i = 0, caps = arm64_hwcaps; caps[i].matches; i++) { if (!cpus_have_hwcap(&caps[i])) continue; if (!feature_matches(__raw_read_system_reg(caps[i].sys_reg), &caps[i]))
--
2.6.2