diff options
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-trbe.c | 69 |
1 files changed, 68 insertions, 1 deletions
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index cdbb134892f6..fdd60ff4fb3d 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -16,6 +16,8 @@ #define pr_fmt(fmt) DRVNAME ": " fmt #include <asm/barrier.h> +#include <asm/cpufeature.h> + #include "coresight-self-hosted-trace.h" #include "coresight-trbe.h" @@ -68,6 +70,34 @@ struct trbe_buf { }; /* + * TRBE erratum list + * + * The errata are defined in arm64 generic cpu_errata framework. + * Since the errata work arounds could be applied individually + * to the affected CPUs inside the TRBE driver, we need to know if + * a given CPU is affected by the erratum. Unlike the other erratum + * work arounds, TRBE driver needs to check multiple times during + * a trace session. Thus we need a quicker access to per-CPU + * errata and not issue costly this_cpu_has_cap() everytime. + * We keep a set of the affected errata in trbe_cpudata, per TRBE. + * + * We rely on the corresponding cpucaps to be defined for a given + * TRBE erratum. We map the given cpucap into a TRBE internal number + * to make the tracking of the errata lean. + * + * This helps in : + * - Not duplicating the detection logic + * - Streamlined detection of erratum across the system + */ + +static int trbe_errata_cpucaps[] = { + -1, /* Sentinel, must be the last entry */ +}; + +/* The total number of listed errata in trbe_errata_cpucaps */ +#define TRBE_ERRATA_MAX (ARRAY_SIZE(trbe_errata_cpucaps) - 1) + +/* * struct trbe_cpudata: TRBE instance specific data * @trbe_flag - TRBE dirty/access flag support * @trbe_hw_align - Actual TRBE alignment required for TRBPTR_EL1. @@ -75,6 +105,7 @@ struct trbe_buf { * @cpu - CPU this TRBE belongs to. * @mode - Mode of current operation. (perf/disabled) * @drvdata - TRBE specific drvdata + * @errata - Bit map for the errata on this TRBE. */ struct trbe_cpudata { bool trbe_flag; @@ -84,6 +115,7 @@ struct trbe_cpudata { enum cs_mode mode; struct trbe_buf *buf; struct trbe_drvdata *drvdata; + DECLARE_BITMAP(errata, TRBE_ERRATA_MAX); }; struct trbe_drvdata { @@ -96,6 +128,25 @@ struct trbe_drvdata { struct platform_device *pdev; }; +static void trbe_check_errata(struct trbe_cpudata *cpudata) +{ + int i; + + for (i = 0; i < TRBE_ERRATA_MAX; i++) { + int cap = trbe_errata_cpucaps[i]; + + if (WARN_ON_ONCE(cap < 0)) + return; + if (this_cpu_has_cap(cap)) + set_bit(i, cpudata->errata); + } +} + +static inline bool trbe_has_erratum(struct trbe_cpudata *cpudata, int i) +{ + return (i < TRBE_ERRATA_MAX) && test_bit(i, cpudata->errata); +} + static int trbe_alloc_node(struct perf_event *event) { if (event->cpu == -1) @@ -956,6 +1007,9 @@ cpu_clear: cpumask_clear_cpu(cpu, &drvdata->supported_cpus); } +/* + * Must be called with preemption disabled, for trbe_check_errata(). + */ static void arm_trbe_probe_cpu(void *info) { struct trbe_drvdata *drvdata = info; @@ -983,6 +1037,12 @@ static void arm_trbe_probe_cpu(void *info) goto cpu_clear; } + /* + * Run the TRBE erratum checks, now that we know + * this instance is about to be registered. + */ + trbe_check_errata(cpudata); + cpudata->trbe_align = cpudata->trbe_hw_align; cpudata->trbe_flag = get_trbe_flag_update(trbidr); cpudata->cpu = cpu; @@ -1038,6 +1098,13 @@ static int arm_trbe_remove_coresight(struct trbe_drvdata *drvdata) return 0; } +static void arm_trbe_probe_hotplugged_cpu(struct trbe_drvdata *drvdata) +{ + preempt_disable(); + arm_trbe_probe_cpu(drvdata); + preempt_enable(); +} + static int arm_trbe_cpu_startup(unsigned int cpu, struct hlist_node *node) { struct trbe_drvdata *drvdata = hlist_entry_safe(node, struct trbe_drvdata, hotplug_node); @@ -1049,7 +1116,7 @@ static int arm_trbe_cpu_startup(unsigned int cpu, struct hlist_node *node) * initialize it now. */ if (!coresight_get_percpu_sink(cpu)) { - arm_trbe_probe_cpu(drvdata); + arm_trbe_probe_hotplugged_cpu(drvdata); if (cpumask_test_cpu(cpu, &drvdata->supported_cpus)) arm_trbe_register_coresight_cpu(drvdata, cpu); if (cpumask_test_cpu(cpu, &drvdata->supported_cpus)) |