From: suzuki.poulose@arm.com (Suzuki K Poulose)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4 06/22] arm64: capabilities: Unify the verification
Date: Tue, 13 Mar 2018 11:51:04 +0000 [thread overview]
Message-ID: <20180313115120.17256-7-suzuki.poulose@arm.com> (raw)
In-Reply-To: <20180313115120.17256-1-suzuki.poulose@arm.com>
Now that each capability describes how to treat the conflicts
of CPU cap state vs System wide cap state, we can unify the
verification logic to a single place.
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
arch/arm64/kernel/cpufeature.c | 91 +++++++++++++++++++++++++++---------------
1 file changed, 58 insertions(+), 33 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 5adacd39eb02..d671db5012c6 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1298,6 +1298,58 @@ enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps)
}
}
+/*
+ * Run through the list of capabilities to check for conflicts.
+ * If the system has already detected a capability, take necessary
+ * action on this CPU.
+ *
+ * Returns "false" on conflicts.
+ */
+static bool
+__verify_local_cpu_caps(const struct arm64_cpu_capabilities *caps_list)
+{
+ bool cpu_has_cap, system_has_cap;
+ const struct arm64_cpu_capabilities *caps;
+
+ for (caps = caps_list; caps->matches; caps++) {
+ cpu_has_cap = __this_cpu_has_cap(caps_list, caps->capability);
+ system_has_cap = cpus_have_cap(caps->capability);
+
+ if (system_has_cap) {
+ /*
+ * Check if the new CPU misses an advertised feature,
+ * which is not safe to miss.
+ */
+ if (!cpu_has_cap && !cpucap_late_cpu_optional(caps))
+ break;
+ /*
+ * We have to issue cpu_enable() irrespective of
+ * whether the CPU has it or not, as it is enabeld
+ * system wide. It is upto the call back to take
+ * appropriate action on this CPU.
+ */
+ if (caps->cpu_enable)
+ caps->cpu_enable(caps);
+ } else {
+ /*
+ * Check if the CPU has this capability if it isn't
+ * safe to have when the system doesn't.
+ */
+ if (cpu_has_cap && !cpucap_late_cpu_permitted(caps))
+ break;
+ }
+ }
+
+ if (caps->matches) {
+ pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",
+ smp_processor_id(), caps->capability,
+ caps->desc, system_has_cap, cpu_has_cap);
+ return false;
+ }
+
+ return true;
+}
+
/*
* Check for CPU features that are used in early boot
* based on the Boot CPU value.
@@ -1320,25 +1372,10 @@ verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
}
}
-static void
-verify_local_cpu_features(const struct arm64_cpu_capabilities *caps_list)
+static void verify_local_cpu_features(void)
{
- const struct arm64_cpu_capabilities *caps = caps_list;
- for (; caps->matches; caps++) {
- if (!cpus_have_cap(caps->capability))
- continue;
- /*
- * If the new CPU misses an advertised feature, we cannot proceed
- * further, park the cpu.
- */
- if (!__this_cpu_has_cap(caps_list, caps->capability)) {
- pr_crit("CPU%d: missing feature: %s\n",
- smp_processor_id(), caps->desc);
- cpu_die_early();
- }
- if (caps->cpu_enable)
- caps->cpu_enable(caps);
- }
+ if (!__verify_local_cpu_caps(arm64_features))
+ cpu_die_early();
}
static void verify_sve_features(void)
@@ -1365,20 +1402,8 @@ static void verify_sve_features(void)
*/
static void verify_local_cpu_errata_workarounds(void)
{
- const struct arm64_cpu_capabilities *caps = arm64_errata;
-
- for (; caps->matches; caps++) {
- if (cpus_have_cap(caps->capability)) {
- if (caps->cpu_enable)
- caps->cpu_enable(caps);
- } else if (caps->matches(caps, SCOPE_LOCAL_CPU)) {
- pr_crit("CPU%d: Requires work around for %s, not detected"
- " at boot time\n",
- smp_processor_id(),
- caps->desc ? : "an erratum");
- cpu_die_early();
- }
- }
+ if (!__verify_local_cpu_caps(arm64_errata))
+ cpu_die_early();
}
static void update_cpu_errata_workarounds(void)
@@ -1402,7 +1427,7 @@ static void __init enable_errata_workarounds(void)
static void verify_local_cpu_capabilities(void)
{
verify_local_cpu_errata_workarounds();
- verify_local_cpu_features(arm64_features);
+ verify_local_cpu_features();
verify_local_elf_hwcaps(arm64_elf_hwcaps);
if (system_supports_32bit_el0())
--
2.14.3
next prev parent reply other threads:[~2018-03-13 11:51 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-13 11:50 [PATCH v4 00/22] arm64: Rework cpu capabilities handling Suzuki K Poulose
2018-03-13 11:50 ` [PATCH v4 01/22] arm64: capabilities: Update prototype for enable call back Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 02/22] arm64: capabilities: Move errata work around check on boot CPU Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 03/22] arm64: capabilities: Move errata processing code Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 04/22] arm64: capabilities: Prepare for fine grained capabilities Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 05/22] arm64: capabilities: Add flags to handle the conflicts on late CPU Suzuki K Poulose
2018-03-13 11:51 ` Suzuki K Poulose [this message]
2018-03-13 11:51 ` [PATCH v4 07/22] arm64: capabilities: Filter the entries based on a given mask Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 08/22] arm64: capabilities: Prepare for grouping features and errata work arounds Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 09/22] arm64: capabilities: Split the processing of " Suzuki K Poulose
2018-03-22 16:44 ` Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 10/22] arm64: capabilities: Allow features based on local CPU scope Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 11/22] arm64: capabilities: Group handling of features and errata workarounds Suzuki K Poulose
2018-03-21 15:07 ` Dave Martin
2018-03-13 11:51 ` [PATCH v4 12/22] arm64: capabilities: Introduce weak features based on local CPU Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 13/22] arm64: capabilities: Restrict KPTI detection to boot-time CPUs Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 14/22] arm64: capabilities: Add support for features enabled early Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 15/22] arm64: capabilities: Change scope of VHE to Boot CPU feature Suzuki K Poulose
2018-03-21 15:18 ` Dave Martin
2018-03-13 11:51 ` [PATCH v4 16/22] arm64: capabilities: Clean up midr range helpers Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 17/22] arm64: Add helpers for checking CPU MIDR against a range Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 18/22] arm64: capabilities: Add support for checks based on a list of MIDRs Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 19/22] arm64: capabilities: Handle shared entries Suzuki K Poulose
2018-03-22 16:43 ` Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 20/22] arm64: Add MIDR encoding for Arm Cortex-A55 and Cortex-A35 Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 21/22] arm64: Delay enabling hardware DBM feature Suzuki K Poulose
2018-03-21 15:22 ` Dave Martin
2018-03-13 11:51 ` [PATCH v4 22/22] arm64: Add work around for Arm Cortex-A55 Erratum 1024718 Suzuki K Poulose
2018-03-21 15:31 ` Dave Martin
2018-03-22 16:42 ` Suzuki K Poulose
2018-03-26 11:53 ` [PATCH v4 00/22] arm64: Rework cpu capabilities handling Will Deacon
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