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-rw-r--r--arch/arm/kernel/Makefile1
-rw-r--r--arch/arm/kernel/asm-offsets.c5
-rw-r--r--arch/arm/kernel/perf_event.c21
-rw-r--r--arch/arm/kernel/perf_event_cpu.c71
-rw-r--r--arch/arm/kernel/perf_event_v7.c525
-rw-r--r--arch/arm/kernel/process.c16
-rw-r--r--arch/arm/kernel/setup.c5
-rw-r--r--arch/arm/kernel/vdso.c337
8 files changed, 902 insertions, 79 deletions
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index b6544abe2f5e..ba5f83226011 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -75,6 +75,7 @@ obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o perf_event_cpu.o
CFLAGS_pj4-cp0.o := -marm
AFLAGS_iwmmxt.o := -Wa,-mcpu=iwmmxt
obj-$(CONFIG_ARM_CPU_TOPOLOGY) += topology.o
+obj-$(CONFIG_VDSO) += vdso.o
ifneq ($(CONFIG_ARCH_EBSA110),y)
obj-y += io.o
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index 2d2d6087b9b1..9147008f0d51 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -25,6 +25,7 @@
#include <asm/memory.h>
#include <asm/procinfo.h>
#include <asm/suspend.h>
+#include <asm/vdso_datapage.h>
#include <asm/hardware/cache-l2x0.h>
#include <linux/kbuild.h>
@@ -210,5 +211,9 @@ int main(void)
#endif
DEFINE(KVM_VTTBR, offsetof(struct kvm, arch.vttbr));
#endif
+ BLANK();
+#ifdef CONFIG_VDSO
+ DEFINE(VDSO_DATA_SIZE, sizeof(union vdso_data_store));
+#endif
return 0;
}
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 557e128e4df0..4a86a0133ac3 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -259,20 +259,29 @@ out:
}
static int
-validate_event(struct pmu_hw_events *hw_events,
- struct perf_event *event)
+validate_event(struct pmu *pmu, struct pmu_hw_events *hw_events,
+ struct perf_event *event)
{
- struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
+ struct arm_pmu *armpmu;
if (is_software_event(event))
return 1;
+ /*
+ * Reject groups spanning multiple HW PMUs (e.g. CPU + CCI). The
+ * core perf code won't check that the pmu->ctx == leader->ctx
+ * until after pmu->event_init(event).
+ */
+ if (event->pmu != pmu)
+ return 0;
+
if (event->state < PERF_EVENT_STATE_OFF)
return 1;
if (event->state == PERF_EVENT_STATE_OFF && !event->attr.enable_on_exec)
return 1;
+ armpmu = to_arm_pmu(event->pmu);
return armpmu->get_event_idx(hw_events, event) >= 0;
}
@@ -288,15 +297,15 @@ validate_group(struct perf_event *event)
*/
memset(&fake_pmu.used_mask, 0, sizeof(fake_pmu.used_mask));
- if (!validate_event(&fake_pmu, leader))
+ if (!validate_event(event->pmu, &fake_pmu, leader))
return -EINVAL;
list_for_each_entry(sibling, &leader->sibling_list, group_entry) {
- if (!validate_event(&fake_pmu, sibling))
+ if (!validate_event(event->pmu, &fake_pmu, sibling))
return -EINVAL;
}
- if (!validate_event(&fake_pmu, event))
+ if (!validate_event(event->pmu, &fake_pmu, event))
return -EINVAL;
return 0;
diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c
index 61b53c46edfa..91c7ba182dcd 100644
--- a/arch/arm/kernel/perf_event_cpu.c
+++ b/arch/arm/kernel/perf_event_cpu.c
@@ -92,11 +92,16 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
free_percpu_irq(irq, &hw_events->percpu_pmu);
} else {
for (i = 0; i < irqs; ++i) {
- if (!cpumask_test_and_clear_cpu(i, &cpu_pmu->active_irqs))
+ int cpu = i;
+
+ if (cpu_pmu->irq_affinity)
+ cpu = cpu_pmu->irq_affinity[i];
+
+ if (!cpumask_test_and_clear_cpu(cpu, &cpu_pmu->active_irqs))
continue;
irq = platform_get_irq(pmu_device, i);
if (irq >= 0)
- free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, i));
+ free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, cpu));
}
}
}
@@ -128,32 +133,37 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
on_each_cpu(cpu_pmu_enable_percpu_irq, &irq, 1);
} else {
for (i = 0; i < irqs; ++i) {
+ int cpu = i;
+
err = 0;
irq = platform_get_irq(pmu_device, i);
if (irq < 0)
continue;
+ if (cpu_pmu->irq_affinity)
+ cpu = cpu_pmu->irq_affinity[i];
+
/*
* If we have a single PMU interrupt that we can't shift,
* assume that we're running on a uniprocessor machine and
* continue. Otherwise, continue without this interrupt.
*/
- if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) {
+ if (irq_set_affinity(irq, cpumask_of(cpu)) && irqs > 1) {
pr_warn("unable to set irq affinity (irq=%d, cpu=%u)\n",
- irq, i);
+ irq, cpu);
continue;
}
err = request_irq(irq, handler,
IRQF_NOBALANCING | IRQF_NO_THREAD, "arm-pmu",
- per_cpu_ptr(&hw_events->percpu_pmu, i));
+ per_cpu_ptr(&hw_events->percpu_pmu, cpu));
if (err) {
pr_err("unable to request IRQ%d for ARM PMU counters\n",
irq);
return err;
}
- cpumask_set_cpu(i, &cpu_pmu->active_irqs);
+ cpumask_set_cpu(cpu, &cpu_pmu->active_irqs);
}
}
@@ -243,6 +253,8 @@ static const struct of_device_id cpu_pmu_of_device_ids[] = {
{.compatible = "arm,arm1176-pmu", .data = armv6_1176_pmu_init},
{.compatible = "arm,arm1136-pmu", .data = armv6_1136_pmu_init},
{.compatible = "qcom,krait-pmu", .data = krait_pmu_init},
+ {.compatible = "qcom,scorpion-pmu", .data = scorpion_pmu_init},
+ {.compatible = "qcom,scorpion-mp-pmu", .data = scorpion_mp_pmu_init},
{},
};
@@ -289,6 +301,48 @@ static int probe_current_pmu(struct arm_pmu *pmu)
return ret;
}
+static int of_pmu_irq_cfg(struct platform_device *pdev)
+{
+ int i;
+ int *irqs = kcalloc(pdev->num_resources, sizeof(*irqs), GFP_KERNEL);
+
+ if (!irqs)
+ return -ENOMEM;
+
+ for (i = 0; i < pdev->num_resources; ++i) {
+ struct device_node *dn;
+ int cpu;
+
+ dn = of_parse_phandle(pdev->dev.of_node, "interrupt-affinity",
+ i);
+ if (!dn) {
+ pr_warn("Failed to parse %s/interrupt-affinity[%d]\n",
+ of_node_full_name(dn), i);
+ break;
+ }
+
+ for_each_possible_cpu(cpu)
+ if (arch_find_n_match_cpu_physical_id(dn, cpu, NULL))
+ break;
+
+ of_node_put(dn);
+ if (cpu >= nr_cpu_ids) {
+ pr_warn("Failed to find logical CPU for %s\n",
+ dn->name);
+ break;
+ }
+
+ irqs[i] = cpu;
+ }
+
+ if (i == pdev->num_resources)
+ cpu_pmu->irq_affinity = irqs;
+ else
+ kfree(irqs);
+
+ return 0;
+}
+
static int cpu_pmu_device_probe(struct platform_device *pdev)
{
const struct of_device_id *of_id;
@@ -313,7 +367,10 @@ static int cpu_pmu_device_probe(struct platform_device *pdev)
if (node && (of_id = of_match_node(cpu_pmu_of_device_ids, pdev->dev.of_node))) {
init_fn = of_id->data;
- ret = init_fn(pmu);
+
+ ret = of_pmu_irq_cfg(pdev);
+ if (!ret)
+ ret = init_fn(pmu);
} else {
ret = probe_current_pmu(pmu);
}
diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c
index 8993770c47de..f4207a4dcb01 100644
--- a/arch/arm/kernel/perf_event_v7.c
+++ b/arch/arm/kernel/perf_event_v7.c
@@ -140,6 +140,23 @@ enum krait_perf_types {
KRAIT_PERFCTR_L1_DTLB_ACCESS = 0x12210,
};
+/* ARMv7 Scorpion specific event types */
+enum scorpion_perf_types {
+ SCORPION_LPM0_GROUP0 = 0x4c,
+ SCORPION_LPM1_GROUP0 = 0x50,
+ SCORPION_LPM2_GROUP0 = 0x54,
+ SCORPION_L2LPM_GROUP0 = 0x58,
+ SCORPION_VLPM_GROUP0 = 0x5c,
+
+ SCORPION_ICACHE_ACCESS = 0x10053,
+ SCORPION_ICACHE_MISS = 0x10052,
+
+ SCORPION_DTLB_ACCESS = 0x12013,
+ SCORPION_DTLB_MISS = 0x12012,
+
+ SCORPION_ITLB_MISS = 0x12021,
+};
+
/*
* Cortex-A8 HW events mapping
*
@@ -482,6 +499,49 @@ static const unsigned krait_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
};
/*
+ * Scorpion HW events mapping
+ */
+static const unsigned scorpion_perf_map[PERF_COUNT_HW_MAX] = {
+ PERF_MAP_ALL_UNSUPPORTED,
+ [PERF_COUNT_HW_CPU_CYCLES] = ARMV7_PERFCTR_CPU_CYCLES,
+ [PERF_COUNT_HW_INSTRUCTIONS] = ARMV7_PERFCTR_INSTR_EXECUTED,
+ [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = ARMV7_PERFCTR_PC_WRITE,
+ [PERF_COUNT_HW_BRANCH_MISSES] = ARMV7_PERFCTR_PC_BRANCH_MIS_PRED,
+ [PERF_COUNT_HW_BUS_CYCLES] = ARMV7_PERFCTR_CLOCK_CYCLES,
+};
+
+static const unsigned scorpion_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
+ [PERF_COUNT_HW_CACHE_OP_MAX]
+ [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
+ PERF_CACHE_MAP_ALL_UNSUPPORTED,
+ /*
+ * The performance counters don't differentiate between read and write
+ * accesses/misses so this isn't strictly correct, but it's the best we
+ * can do. Writes and reads get combined.
+ */
+ [C(L1D)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV7_PERFCTR_L1_DCACHE_ACCESS,
+ [C(L1D)][C(OP_READ)][C(RESULT_MISS)] = ARMV7_PERFCTR_L1_DCACHE_REFILL,
+ [C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV7_PERFCTR_L1_DCACHE_ACCESS,
+ [C(L1D)][C(OP_WRITE)][C(RESULT_MISS)] = ARMV7_PERFCTR_L1_DCACHE_REFILL,
+ [C(L1I)][C(OP_READ)][C(RESULT_ACCESS)] = SCORPION_ICACHE_ACCESS,
+ [C(L1I)][C(OP_READ)][C(RESULT_MISS)] = SCORPION_ICACHE_MISS,
+ /*
+ * Only ITLB misses and DTLB refills are supported. If users want the
+ * DTLB refills misses a raw counter must be used.
+ */
+ [C(DTLB)][C(OP_READ)][C(RESULT_ACCESS)] = SCORPION_DTLB_ACCESS,
+ [C(DTLB)][C(OP_READ)][C(RESULT_MISS)] = SCORPION_DTLB_MISS,
+ [C(DTLB)][C(OP_WRITE)][C(RESULT_ACCESS)] = SCORPION_DTLB_ACCESS,
+ [C(DTLB)][C(OP_WRITE)][C(RESULT_MISS)] = SCORPION_DTLB_MISS,
+ [C(ITLB)][C(OP_READ)][C(RESULT_MISS)] = SCORPION_ITLB_MISS,
+ [C(ITLB)][C(OP_WRITE)][C(RESULT_MISS)] = SCORPION_ITLB_MISS,
+ [C(BPU)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV7_PERFCTR_PC_BRANCH_PRED,
+ [C(BPU)][C(OP_READ)][C(RESULT_MISS)] = ARMV7_PERFCTR_PC_BRANCH_MIS_PRED,
+ [C(BPU)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV7_PERFCTR_PC_BRANCH_PRED,
+ [C(BPU)][C(OP_WRITE)][C(RESULT_MISS)] = ARMV7_PERFCTR_PC_BRANCH_MIS_PRED,
+};
+
+/*
* Perf Events' indices
*/
#define ARMV7_IDX_CYCLE_COUNTER 0
@@ -976,6 +1036,12 @@ static int krait_map_event_no_branch(struct perf_event *event)
&krait_perf_cache_map, 0xFFFFF);
}
+static int scorpion_map_event(struct perf_event *event)
+{
+ return armpmu_map_event(event, &scorpion_perf_map,
+ &scorpion_perf_cache_map, 0xFFFFF);
+}
+
static void armv7pmu_init(struct arm_pmu *cpu_pmu)
{
cpu_pmu->handle_irq = armv7pmu_handle_irq;
@@ -1103,6 +1169,12 @@ static int armv7_a17_pmu_init(struct arm_pmu *cpu_pmu)
#define KRAIT_EVENT_MASK (KRAIT_EVENT | VENUM_EVENT)
#define PMRESRn_EN BIT(31)
+#define EVENT_REGION(event) (((event) >> 12) & 0xf) /* R */
+#define EVENT_GROUP(event) ((event) & 0xf) /* G */
+#define EVENT_CODE(event) (((event) >> 4) & 0xff) /* CC */
+#define EVENT_VENUM(event) (!!(event & VENUM_EVENT)) /* N=2 */
+#define EVENT_CPU(event) (!!(event & KRAIT_EVENT)) /* N=1 */
+
static u32 krait_read_pmresrn(int n)
{
u32 val;
@@ -1141,19 +1213,19 @@ static void krait_write_pmresrn(int n, u32 val)
}
}
-static u32 krait_read_vpmresr0(void)
+static u32 venum_read_pmresr(void)
{
u32 val;
asm volatile("mrc p10, 7, %0, c11, c0, 0" : "=r" (val));
return val;
}
-static void krait_write_vpmresr0(u32 val)
+static void venum_write_pmresr(u32 val)
{
asm volatile("mcr p10, 7, %0, c11, c0, 0" : : "r" (val));
}
-static void krait_pre_vpmresr0(u32 *venum_orig_val, u32 *fp_orig_val)
+static void venum_pre_pmresr(u32 *venum_orig_val, u32 *fp_orig_val)
{
u32 venum_new_val;
u32 fp_new_val;
@@ -1170,7 +1242,7 @@ static void krait_pre_vpmresr0(u32 *venum_orig_val, u32 *fp_orig_val)
fmxr(FPEXC, fp_new_val);
}
-static void krait_post_vpmresr0(u32 venum_orig_val, u32 fp_orig_val)
+static void venum_post_pmresr(u32 venum_orig_val, u32 fp_orig_val)
{
BUG_ON(preemptible());
/* Restore FPEXC */
@@ -1193,16 +1265,11 @@ static void krait_evt_setup(int idx, u32 config_base)
u32 val;
u32 mask;
u32 vval, fval;
- unsigned int region;
- unsigned int group;
- unsigned int code;
+ unsigned int region = EVENT_REGION(config_base);
+ unsigned int group = EVENT_GROUP(config_base);
+ unsigned int code = EVENT_CODE(config_base);
unsigned int group_shift;
- bool venum_event;
-
- venum_event = !!(config_base & VENUM_EVENT);
- region = (config_base >> 12) & 0xf;
- code = (config_base >> 4) & 0xff;
- group = (config_base >> 0) & 0xf;
+ bool venum_event = EVENT_VENUM(config_base);
group_shift = group * 8;
mask = 0xff << group_shift;
@@ -1217,16 +1284,14 @@ static void krait_evt_setup(int idx, u32 config_base)
val |= config_base & (ARMV7_EXCLUDE_USER | ARMV7_EXCLUDE_PL1);
armv7_pmnc_write_evtsel(idx, val);
- asm volatile("mcr p15, 0, %0, c9, c15, 0" : : "r" (0));
-
if (venum_event) {
- krait_pre_vpmresr0(&vval, &fval);
- val = krait_read_vpmresr0();
+ venum_pre_pmresr(&vval, &fval);
+ val = venum_read_pmresr();
val &= ~mask;
val |= code << group_shift;
val |= PMRESRn_EN;
- krait_write_vpmresr0(val);
- krait_post_vpmresr0(vval, fval);
+ venum_write_pmresr(val);
+ venum_post_pmresr(vval, fval);
} else {
val = krait_read_pmresrn(region);
val &= ~mask;
@@ -1236,7 +1301,7 @@ static void krait_evt_setup(int idx, u32 config_base)
}
}
-static u32 krait_clear_pmresrn_group(u32 val, int group)
+static u32 clear_pmresrn_group(u32 val, int group)
{
u32 mask;
int group_shift;
@@ -1256,23 +1321,19 @@ static void krait_clearpmu(u32 config_base)
{
u32 val;
u32 vval, fval;
- unsigned int region;
- unsigned int group;
- bool venum_event;
-
- venum_event = !!(config_base & VENUM_EVENT);
- region = (config_base >> 12) & 0xf;
- group = (config_base >> 0) & 0xf;
+ unsigned int region = EVENT_REGION(config_base);
+ unsigned int group = EVENT_GROUP(config_base);
+ bool venum_event = EVENT_VENUM(config_base);
if (venum_event) {
- krait_pre_vpmresr0(&vval, &fval);
- val = krait_read_vpmresr0();
- val = krait_clear_pmresrn_group(val, group);
- krait_write_vpmresr0(val);
- krait_post_vpmresr0(vval, fval);
+ venum_pre_pmresr(&vval, &fval);
+ val = venum_read_pmresr();
+ val = clear_pmresrn_group(val, group);
+ venum_write_pmresr(val);
+ venum_post_pmresr(vval, fval);
} else {
val = krait_read_pmresrn(region);
- val = krait_clear_pmresrn_group(val, group);
+ val = clear_pmresrn_group(val, group);
krait_write_pmresrn(region, val);
}
}
@@ -1342,6 +1403,8 @@ static void krait_pmu_enable_event(struct perf_event *event)
static void krait_pmu_reset(void *info)
{
u32 vval, fval;
+ struct arm_pmu *cpu_pmu = info;
+ u32 idx, nb_cnt = cpu_pmu->num_events;
armv7pmu_reset(info);
@@ -1350,9 +1413,16 @@ static void krait_pmu_reset(void *info)
krait_write_pmresrn(1, 0);
krait_write_pmresrn(2, 0);
- krait_pre_vpmresr0(&vval, &fval);
- krait_write_vpmresr0(0);
- krait_post_vpmresr0(vval, fval);
+ venum_pre_pmresr(&vval, &fval);
+ venum_write_pmresr(0);
+ venum_post_pmresr(vval, fval);
+
+ /* Reset PMxEVNCTCR to sane default */
+ for (idx = ARMV7_IDX_CYCLE_COUNTER; idx < nb_cnt; ++idx) {
+ armv7_pmnc_select_counter(idx);
+ asm volatile("mcr p15, 0, %0, c9, c15, 0" : : "r" (0));
+ }
+
}
static int krait_event_to_bit(struct perf_event *event, unsigned int region,
@@ -1386,26 +1456,18 @@ static int krait_pmu_get_event_idx(struct pmu_hw_events *cpuc,
{
int idx;
int bit = -1;
- unsigned int prefix;
- unsigned int region;
- unsigned int code;
- unsigned int group;
- bool krait_event;
struct hw_perf_event *hwc = &event->hw;
+ unsigned int region = EVENT_REGION(hwc->config_base);
+ unsigned int code = EVENT_CODE(hwc->config_base);
+ unsigned int group = EVENT_GROUP(hwc->config_base);
+ bool venum_event = EVENT_VENUM(hwc->config_base);
+ bool krait_event = EVENT_CPU(hwc->config_base);
- region = (hwc->config_base >> 12) & 0xf;
- code = (hwc->config_base >> 4) & 0xff;
- group = (hwc->config_base >> 0) & 0xf;
- krait_event = !!(hwc->config_base & KRAIT_EVENT_MASK);
-
- if (krait_event) {
+ if (venum_event || krait_event) {
/* Ignore invalid events */
if (group > 3 || region > 2)
return -EINVAL;
- prefix = hwc->config_base & KRAIT_EVENT_MASK;
- if (prefix != KRAIT_EVENT && prefix != VENUM_EVENT)
- return -EINVAL;
- if (prefix == VENUM_EVENT && (code & 0xe0))
+ if (venum_event && (code & 0xe0))
return -EINVAL;
bit = krait_event_to_bit(event, region, group);
@@ -1425,15 +1487,12 @@ static void krait_pmu_clear_event_idx(struct pmu_hw_events *cpuc,
{
int bit;
struct hw_perf_event *hwc = &event->hw;
- unsigned int region;
- unsigned int group;
- bool krait_event;
+ unsigned int region = EVENT_REGION(hwc->config_base);
+ unsigned int group = EVENT_GROUP(hwc->config_base);
+ bool venum_event = EVENT_VENUM(hwc->config_base);
+ bool krait_event = EVENT_CPU(hwc->config_base);
- region = (hwc->config_base >> 12) & 0xf;
- group = (hwc->config_base >> 0) & 0xf;
- krait_event = !!(hwc->config_base & KRAIT_EVENT_MASK);
-
- if (krait_event) {
+ if (venum_event || krait_event) {
bit = krait_event_to_bit(event, region, group);
clear_bit(bit, cpuc->used_mask);
}
@@ -1458,6 +1517,344 @@ static int krait_pmu_init(struct arm_pmu *cpu_pmu)
cpu_pmu->clear_event_idx = krait_pmu_clear_event_idx;
return 0;
}
+
+/*
+ * Scorpion Local Performance Monitor Register (LPMn)
+ *
+ * 31 30 24 16 8 0
+ * +--------------------------------+
+ * LPM0 | EN | CC | CC | CC | CC | N = 1, R = 0
+ * +--------------------------------+
+ * LPM1 | EN | CC | CC | CC | CC | N = 1, R = 1
+ * +--------------------------------+
+ * LPM2 | EN | CC | CC | CC | CC | N = 1, R = 2
+ * +--------------------------------+
+ * L2LPM | EN | CC | CC | CC | CC | N = 1, R = 3
+ * +--------------------------------+
+ * VLPM | EN | CC | CC | CC | CC | N = 2, R = ?
+ * +--------------------------------+
+ * EN | G=3 | G=2 | G=1 | G=0
+ *
+ *
+ * Event Encoding:
+ *
+ * hwc->config_base = 0xNRCCG
+ *
+ * N = prefix, 1 for Scorpion CPU (LPMn/L2LPM), 2 for Venum VFP (VLPM)
+ * R = region register
+ * CC = class of events the group G is choosing from
+ * G = group or particular event
+ *
+ * Example: 0x12021 is a Scorpion CPU event in LPM2's group 1 with code 2
+ *
+ * A region (R) corresponds to a piece of the CPU (execution unit, instruction
+ * unit, etc.) while the event code (CC) corresponds to a particular class of
+ * events (interrupts for example). An event code is broken down into
+ * groups (G) that can be mapped into the PMU (irq, fiqs, and irq+fiqs for
+ * example).
+ */
+
+static u32 scorpion_read_pmresrn(int n)
+{
+ u32 val;
+
+ switch (n) {
+ case 0:
+ asm volatile("mrc p15, 0, %0, c15, c0, 0" : "=r" (val));
+ break;
+ case 1:
+ asm volatile("mrc p15, 1, %0, c15, c0, 0" : "=r" (val));
+ break;
+ case 2:
+ asm volatile("mrc p15, 2, %0, c15, c0, 0" : "=r" (val));
+ break;
+ case 3:
+ asm volatile("mrc p15, 3, %0, c15, c2, 0" : "=r" (val));
+ break;
+ default:
+ BUG(); /* Should be validated in scorpion_pmu_get_event_idx() */
+ }
+
+ return val;
+}
+
+static void scorpion_write_pmresrn(int n, u32 val)
+{
+ switch (n) {
+ case 0:
+ asm volatile("mcr p15, 0, %0, c15, c0, 0" : : "r" (val));
+ break;
+ case 1:
+ asm volatile("mcr p15, 1, %0, c15, c0, 0" : : "r" (val));
+ break;
+ case 2:
+ asm volatile("mcr p15, 2, %0, c15, c0, 0" : : "r" (val));
+ break;
+ case 3:
+ asm volatile("mcr p15, 3, %0, c15, c2, 0" : : "r" (val));
+ break;
+ default:
+ BUG(); /* Should be validated in scorpion_pmu_get_event_idx() */
+ }
+}
+
+static u32 scorpion_get_pmresrn_event(unsigned int region)
+{
+ static const u32 pmresrn_table[] = { SCORPION_LPM0_GROUP0,
+ SCORPION_LPM1_GROUP0,
+ SCORPION_LPM2_GROUP0,
+ SCORPION_L2LPM_GROUP0 };
+ return pmresrn_table[region];
+}
+
+static void scorpion_evt_setup(int idx, u32 config_base)
+{
+ u32 val;
+ u32 mask;
+ u32 vval, fval;
+ unsigned int region = EVENT_REGION(config_base);
+ unsigned int group = EVENT_GROUP(config_base);
+ unsigned int code = EVENT_CODE(config_base);
+ unsigned int group_shift;
+ bool venum_event = EVENT_VENUM(config_base);
+
+ group_shift = group * 8;
+ mask = 0xff << group_shift;
+
+ /* Configure evtsel for the region and group */
+ if (venum_event)
+ val = SCORPION_VLPM_GROUP0;
+ else
+ val = scorpion_get_pmresrn_event(region);
+ val += group;
+ /* Mix in mode-exclusion bits */
+ val |= config_base & (ARMV7_EXCLUDE_USER | ARMV7_EXCLUDE_PL1);
+ armv7_pmnc_write_evtsel(idx, val);
+
+ asm volatile("mcr p15, 0, %0, c9, c15, 0" : : "r" (0));
+
+ if (venum_event) {
+ venum_pre_pmresr(&vval, &fval);
+ val = venum_read_pmresr();
+ val &= ~mask;
+ val |= code << group_shift;
+ val |= PMRESRn_EN;
+ venum_write_pmresr(val);
+ venum_post_pmresr(vval, fval);
+ } else {
+ val = scorpion_read_pmresrn(region);
+ val &= ~mask;
+ val |= code << group_shift;
+ val |= PMRESRn_EN;
+ scorpion_write_pmresrn(region, val);
+ }
+}
+
+static void scorpion_clearpmu(u32 config_base)
+{
+ u32 val;
+ u32 vval, fval;
+ unsigned int region = EVENT_REGION(config_base);
+ unsigned int group = EVENT_GROUP(config_base);
+ bool venum_event = EVENT_VENUM(config_base);
+
+ if (venum_event) {
+ venum_pre_pmresr(&vval, &fval);
+ val = venum_read_pmresr();
+ val = clear_pmresrn_group(val, group);
+ venum_write_pmresr(val);
+ venum_post_pmresr(vval, fval);
+ } else {
+ val = scorpion_read_pmresrn(region);
+ val = clear_pmresrn_group(val, group);
+ scorpion_write_pmresrn(region, val);
+ }
+}
+
+static void scorpion_pmu_disable_event(struct perf_event *event)
+{
+ unsigned long flags;
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
+ struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
+ struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
+
+ /* Disable counter and interrupt */
+ raw_spin_lock_irqsave(&events->pmu_lock, flags);
+
+ /* Disable counter */
+ armv7_pmnc_disable_counter(idx);
+
+ /*
+ * Clear pmresr code (if destined for PMNx counters)
+ */
+ if (hwc->config_base & KRAIT_EVENT_MASK)
+ scorpion_clearpmu(hwc->config_base);
+
+ /* Disable interrupt for this counter */
+ armv7_pmnc_disable_intens(idx);
+
+ raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
+}
+
+static void scorpion_pmu_enable_event(struct perf_event *event)
+{
+ unsigned long flags;
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
+ struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
+ struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
+
+ /*
+ * Enable counter and interrupt, and set the counter to count
+ * the event that we're interested in.
+ */
+ raw_spin_lock_irqsave(&events->pmu_lock, flags);
+
+ /* Disable counter */
+ armv7_pmnc_disable_counter(idx);
+
+ /*
+ * Set event (if destined for PMNx counters)
+ * We don't set the event for the cycle counter because we
+ * don't have the ability to perform event filtering.
+ */
+ if (hwc->config_base & KRAIT_EVENT_MASK)
+ scorpion_evt_setup(idx, hwc->config_base);
+ else if (idx != ARMV7_IDX_CYCLE_COUNTER)
+ armv7_pmnc_write_evtsel(idx, hwc->config_base);
+
+ /* Enable interrupt for this counter */
+ armv7_pmnc_enable_intens(idx);
+
+ /* Enable counter */
+ armv7_pmnc_enable_counter(idx);
+
+ raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
+}
+
+static void scorpion_pmu_reset(void *info)
+{
+ u32 vval, fval;
+ struct arm_pmu *cpu_pmu = info;
+ u32 idx, nb_cnt = cpu_pmu->num_events;
+
+ armv7pmu_reset(info);
+
+ /* Clear all pmresrs */
+ scorpion_write_pmresrn(0, 0);
+ scorpion_write_pmresrn(1, 0);
+ scorpion_write_pmresrn(2, 0);
+ scorpion_write_pmresrn(3, 0);
+
+ venum_pre_pmresr(&vval, &fval);
+ venum_write_pmresr(0);
+ venum_post_pmresr(vval, fval);
+
+ /* Reset PMxEVNCTCR to sane default */
+ for (idx = ARMV7_IDX_CYCLE_COUNTER; idx < nb_cnt; ++idx) {
+ armv7_pmnc_select_counter(idx);
+ asm volatile("mcr p15, 0, %0, c9, c15, 0" : : "r" (0));
+ }
+}
+
+static int scorpion_event_to_bit(struct perf_event *event, unsigned int region,
+ unsigned int group)
+{
+ int bit;
+ struct hw_perf_event *hwc = &event->hw;
+ struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
+
+ if (hwc->config_base & VENUM_EVENT)
+ bit = SCORPION_VLPM_GROUP0;
+ else
+ bit = scorpion_get_pmresrn_event(region);
+ bit -= scorpion_get_pmresrn_event(0);
+ bit += group;
+ /*
+ * Lower bits are reserved for use by the counters (see
+ * armv7pmu_get_event_idx() for more info)
+ */
+ bit += ARMV7_IDX_COUNTER_LAST(cpu_pmu) + 1;
+
+ return bit;
+}
+
+/*
+ * We check for column exclusion constraints here.
+ * Two events cant use the same group within a pmresr register.
+ */
+static int scorpion_pmu_get_event_idx(struct pmu_hw_events *cpuc,
+ struct perf_event *event)
+{
+ int idx;
+ int bit = -1;
+ struct hw_perf_event *hwc = &event->hw;
+ unsigned int region = EVENT_REGION(hwc->config_base);
+ unsigned int group = EVENT_GROUP(hwc->config_base);
+ bool venum_event = EVENT_VENUM(hwc->config_base);
+ bool scorpion_event = EVENT_CPU(hwc->config_base);
+
+ if (venum_event || scorpion_event) {
+ /* Ignore invalid events */
+ if (group > 3 || region > 3)
+ return -EINVAL;
+
+ bit = scorpion_event_to_bit(event, region, group);
+ if (test_and_set_bit(bit, cpuc->used_mask))
+ return -EAGAIN;
+ }
+
+ idx = armv7pmu_get_event_idx(cpuc, event);
+ if (idx < 0 && bit >= 0)
+ clear_bit(bit, cpuc->used_mask);
+
+ return idx;
+}
+
+static void scorpion_pmu_clear_event_idx(struct pmu_hw_events *cpuc,
+ struct perf_event *event)
+{
+ int bit;
+ struct hw_perf_event *hwc = &event->hw;
+ unsigned int region = EVENT_REGION(hwc->config_base);
+ unsigned int group = EVENT_GROUP(hwc->config_base);
+ bool venum_event = EVENT_VENUM(hwc->config_base);
+ bool scorpion_event = EVENT_CPU(hwc->config_base);
+
+ if (venum_event || scorpion_event) {
+ bit = scorpion_event_to_bit(event, region, group);
+ clear_bit(bit, cpuc->used_mask);
+ }
+}
+
+static int scorpion_pmu_init(struct arm_pmu *cpu_pmu)
+{
+ armv7pmu_init(cpu_pmu);
+ cpu_pmu->name = "armv7_scorpion";
+ cpu_pmu->map_event = scorpion_map_event;
+ cpu_pmu->num_events = armv7_read_num_pmnc_events();
+ cpu_pmu->reset = scorpion_pmu_reset;
+ cpu_pmu->enable = scorpion_pmu_enable_event;
+ cpu_pmu->disable = scorpion_pmu_disable_event;
+ cpu_pmu->get_event_idx = scorpion_pmu_get_event_idx;
+ cpu_pmu->clear_event_idx = scorpion_pmu_clear_event_idx;
+ return 0;
+}
+
+static int scorpion_mp_pmu_init(struct arm_pmu *cpu_pmu)
+{
+ armv7pmu_init(cpu_pmu);
+ cpu_pmu->name = "armv7_scorpion_mp";
+ cpu_pmu->map_event = scorpion_map_event;
+ cpu_pmu->num_events = armv7_read_num_pmnc_events();
+ cpu_pmu->reset = scorpion_pmu_reset;
+ cpu_pmu->enable = scorpion_pmu_enable_event;
+ cpu_pmu->disable = scorpion_pmu_disable_event;
+ cpu_pmu->get_event_idx = scorpion_pmu_get_event_idx;
+ cpu_pmu->clear_event_idx = scorpion_pmu_clear_event_idx;
+ return 0;
+}
#else
static inline int armv7_a8_pmu_init(struct arm_pmu *cpu_pmu)
{
@@ -1498,4 +1895,14 @@ static inline int krait_pmu_init(struct arm_pmu *cpu_pmu)
{
return -ENODEV;
}
+
+static inline int scorpion_pmu_init(struct arm_pmu *cpu_pmu)
+{
+ return -ENODEV;
+}
+
+static inline int scorpion_mp_pmu_init(struct arm_pmu *cpu_pmu)
+{
+ return -ENODEV;
+}
#endif /* CONFIG_CPU_V7 */
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index f810a6cc3790..f192a2a41719 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -334,7 +334,7 @@ const char *arch_vma_name(struct vm_area_struct *vma)
}
/* If possible, provide a placement hint at a random offset from the
- * stack for the signal page.
+ * stack for the sigpage and vdso pages.
*/
static unsigned long sigpage_addr(const struct mm_struct *mm,
unsigned int npages)
@@ -378,6 +378,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
+ unsigned long npages;
unsigned long addr;
unsigned long hint;
int ret = 0;
@@ -387,9 +388,12 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
if (!signal_page)
return -ENOMEM;
+ npages = 1; /* for sigpage */
+ npages += vdso_total_pages;
+
down_write(&mm->mmap_sem);
- hint = sigpage_addr(mm, 1);
- addr = get_unmapped_area(NULL, hint, PAGE_SIZE, 0, 0);
+ hint = sigpage_addr(mm, npages);
+ addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0);
if (IS_ERR_VALUE(addr)) {
ret = addr;
goto up_fail;
@@ -406,6 +410,12 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
mm->context.sigpage = addr;
+ /* Unlike the sigpage, failure to install the vdso is unlikely
+ * to be fatal to the process, so no error check needed
+ * here.
+ */
+ arm_install_vdso(mm, addr + PAGE_SIZE);
+
up_fail:
up_write(&mm->mmap_sem);
return ret;
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 910bb1796946..6c777e908a24 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -246,12 +246,9 @@ static int __get_cpu_architecture(void)
if (cpu_arch)
cpu_arch += CPU_ARCH_ARMv3;
} else if ((read_cpuid_id() & 0x000f0000) == 0x000f0000) {
- unsigned int mmfr0;
-
/* Revised CPUID format. Read the Memory Model Feature
* Register 0 and check for VMSAv7 or PMSAv7 */
- asm("mrc p15, 0, %0, c0, c1, 4"
- : "=r" (mmfr0));
+ unsigned int mmfr0 = read_cpuid_ext(CPUID_EXT_MMFR0);
if ((mmfr0 & 0x0000000f) >= 0x00000003 ||
(mmfr0 & 0x000000f0) >= 0x00000030)
cpu_arch = CPU_ARCH_ARMv7;
diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
new file mode 100644
index 000000000000..0d31d3ccab81
--- /dev/null
+++ b/arch/arm/kernel/vdso.c
@@ -0,0 +1,337 @@
+/*
+ * Adapted from arm64 version.
+ *
+ * Copyright (C) 2012 ARM Limited
+ * Copyright (C) 2015 Mentor Graphics Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/elf.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/of.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/timekeeper_internal.h>
+#include <linux/vmalloc.h>
+#include <asm/arch_timer.h>
+#include <asm/barrier.h>
+#include <asm/cacheflush.h>
+#include <asm/page.h>
+#include <asm/vdso.h>
+#include <asm/vdso_datapage.h>
+#include <clocksource/arm_arch_timer.h>
+
+#define MAX_SYMNAME 64
+
+static struct page **vdso_text_pagelist;
+
+/* Total number of pages needed for the data and text portions of the VDSO. */
+unsigned int vdso_total_pages __read_mostly;
+
+/*
+ * The VDSO data page.
+ */
+static union vdso_data_store vdso_data_store __page_aligned_data;
+static struct vdso_data *vdso_data = &vdso_data_store.data;
+
+static struct page *vdso_data_page;
+static struct vm_special_mapping vdso_data_mapping = {
+ .name = "[vvar]",
+ .pages = &vdso_data_page,
+};
+
+static struct vm_special_mapping vdso_text_mapping = {
+ .name = "[vdso]",
+};
+
+struct elfinfo {
+ Elf32_Ehdr *hdr; /* ptr to ELF */
+ Elf32_Sym *dynsym; /* ptr to .dynsym section */
+ unsigned long dynsymsize; /* size of .dynsym section */
+ char *dynstr; /* ptr to .dynstr section */
+};
+
+/* Cached result of boot-time check for whether the arch timer exists,
+ * and if so, whether the virtual counter is useable.
+ */
+static bool cntvct_ok __read_mostly;
+
+static bool __init cntvct_functional(void)
+{
+ struct device_node *np;
+ bool ret = false;
+
+ if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
+ goto out;
+
+ /* The arm_arch_timer core should export
+ * arch_timer_use_virtual or similar so we don't have to do
+ * this.
+ */
+ np = of_find_compatible_node(NULL, NULL, "arm,armv7-timer");
+ if (!np)
+ goto out_put;
+
+ if (of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
+ goto out_put;
+
+ ret = true;
+
+out_put:
+ of_node_put(np);
+out:
+ return ret;
+}
+
+static void * __init find_section(Elf32_Ehdr *ehdr, const char *name,
+ unsigned long *size)
+{
+ Elf32_Shdr *sechdrs;
+ unsigned int i;
+ char *secnames;
+
+ /* Grab section headers and strings so we can tell who is who */
+ sechdrs = (void *)ehdr + ehdr->e_shoff;
+ secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
+
+ /* Find the section they want */
+ for (i = 1; i < ehdr->e_shnum; i++) {
+ if (strcmp(secnames + sechdrs[i].sh_name, name) == 0) {
+ if (size)
+ *size = sechdrs[i].sh_size;
+ return (void *)ehdr + sechdrs[i].sh_offset;
+ }
+ }
+
+ if (size)
+ *size = 0;
+ return NULL;
+}
+
+static Elf32_Sym * __init find_symbol(struct elfinfo *lib, const char *symname)
+{
+ unsigned int i;
+
+ for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
+ char name[MAX_SYMNAME], *c;
+
+ if (lib->dynsym[i].st_name == 0)
+ continue;
+ strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
+ MAX_SYMNAME);
+ c = strchr(name, '@');
+ if (c)
+ *c = 0;
+ if (strcmp(symname, name) == 0)
+ return &lib->dynsym[i];
+ }
+ return NULL;
+}
+
+static void __init vdso_nullpatch_one(struct elfinfo *lib, const char *symname)
+{
+ Elf32_Sym *sym;
+
+ sym = find_symbol(lib, symname);
+ if (!sym)
+ return;
+
+ sym->st_name = 0;
+}
+
+static void __init patch_vdso(void *ehdr)
+{
+ struct elfinfo einfo;
+
+ einfo = (struct elfinfo) {
+ .hdr = ehdr,
+ };
+
+ einfo.dynsym = find_section(einfo.hdr, ".dynsym", &einfo.dynsymsize);
+ einfo.dynstr = find_section(einfo.hdr, ".dynstr", NULL);
+
+ /* If the virtual counter is absent or non-functional we don't
+ * want programs to incur the slight additional overhead of
+ * dispatching through the VDSO only to fall back to syscalls.
+ */
+ if (!cntvct_ok) {
+ vdso_nullpatch_one(&einfo, "__vdso_gettimeofday");
+ vdso_nullpatch_one(&einfo, "__vdso_clock_gettime");
+ }
+}
+
+static int __init vdso_init(void)
+{
+ unsigned int text_pages;
+ int i;
+
+ if (memcmp(&vdso_start, "\177ELF", 4)) {
+ pr_err("VDSO is not a valid ELF object!\n");
+ return -ENOEXEC;
+ }
+
+ text_pages = (&vdso_end - &vdso_start) >> PAGE_SHIFT;
+ pr_debug("vdso: %i text pages at base %p\n", text_pages, &vdso_start);
+
+ /* Allocate the VDSO text pagelist */
+ vdso_text_pagelist = kcalloc(text_pages, sizeof(struct page *),
+ GFP_KERNEL);
+ if (vdso_text_pagelist == NULL)
+ return -ENOMEM;
+
+ /* Grab the VDSO data page. */
+ vdso_data_page = virt_to_page(vdso_data);
+
+ /* Grab the VDSO text pages. */
+ for (i = 0; i < text_pages; i++) {
+ struct page *page;
+
+ page = virt_to_page(&vdso_start + i * PAGE_SIZE);
+ vdso_text_pagelist[i] = page;
+ }
+
+ vdso_text_mapping.pages = vdso_text_pagelist;
+
+ vdso_total_pages = 1; /* for the data/vvar page */
+ vdso_total_pages += text_pages;
+
+ cntvct_ok = cntvct_functional();
+
+ patch_vdso(&vdso_start);
+
+ return 0;
+}
+arch_initcall(vdso_init);
+
+static int install_vvar(struct mm_struct *mm, unsigned long addr)
+{
+ struct vm_area_struct *vma;
+
+ vma = _install_special_mapping(mm, addr, PAGE_SIZE,
+ VM_READ | VM_MAYREAD,
+ &vdso_data_mapping);
+
+ return IS_ERR(vma) ? PTR_ERR(vma) : 0;
+}
+
+/* assumes mmap_sem is write-locked */
+void arm_install_vdso(struct mm_struct *mm, unsigned long addr)
+{
+ struct vm_area_struct *vma;
+ unsigned long len;
+
+ mm->context.vdso = 0;
+
+ if (vdso_text_pagelist == NULL)
+ return;
+
+ if (install_vvar(mm, addr))
+ return;
+
+ /* Account for vvar page. */
+ addr += PAGE_SIZE;
+ len = (vdso_total_pages - 1) << PAGE_SHIFT;
+
+ vma = _install_special_mapping(mm, addr, len,
+ VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
+ &vdso_text_mapping);
+
+ if (!IS_ERR(vma))
+ mm->context.vdso = addr;
+}
+
+static void vdso_write_begin(struct vdso_data *vdata)
+{
+ ++vdso_data->seq_count;
+ smp_wmb(); /* Pairs with smp_rmb in vdso_read_retry */
+}
+
+static void vdso_write_end(struct vdso_data *vdata)
+{
+ smp_wmb(); /* Pairs with smp_rmb in vdso_read_begin */
+ ++vdso_data->seq_count;
+}
+
+static bool tk_is_cntvct(const struct timekeeper *tk)
+{
+ if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
+ return false;
+
+ if (strcmp(tk->tkr.clock->name, "arch_sys_counter") != 0)
+ return false;
+
+ return true;
+}
+
+/**
+ * update_vsyscall - update the vdso data page
+ *
+ * Increment the sequence counter, making it odd, indicating to
+ * userspace that an update is in progress. Update the fields used
+ * for coarse clocks and, if the architected system timer is in use,
+ * the fields used for high precision clocks. Increment the sequence
+ * counter again, making it even, indicating to userspace that the
+ * update is finished.
+ *
+ * Userspace is expected to sample seq_count before reading any other
+ * fields from the data page. If seq_count is odd, userspace is
+ * expected to wait until it becomes even. After copying data from
+ * the page, userspace must sample seq_count again; if it has changed
+ * from its previous value, userspace must retry the whole sequence.
+ *
+ * Calls to update_vsyscall are serialized by the timekeeping core.
+ */
+void update_vsyscall(struct timekeeper *tk)
+{
+ struct timespec xtime_coarse;
+ struct timespec64 *wtm = &tk->wall_to_monotonic;
+
+ if (!cntvct_ok) {
+ /* The entry points have been zeroed, so there is no
+ * point in updating the data page.
+ */
+ return;
+ }
+
+ vdso_write_begin(vdso_data);
+
+ xtime_coarse = __current_kernel_time();
+ vdso_data->tk_is_cntvct = tk_is_cntvct(tk);
+ vdso_data->xtime_coarse_sec = xtime_coarse.tv_sec;
+ vdso_data->xtime_coarse_nsec = xtime_coarse.tv_nsec;
+ vdso_data->wtm_clock_sec = wtm->tv_sec;
+ vdso_data->wtm_clock_nsec = wtm->tv_nsec;
+
+ if (vdso_data->tk_is_cntvct) {
+ vdso_data->cs_cycle_last = tk->tkr.cycle_last;
+ vdso_data->xtime_clock_sec = tk->xtime_sec;
+ vdso_data->xtime_clock_snsec = tk->tkr.xtime_nsec;
+ vdso_data->cs_mult = tk->tkr.mult;
+ vdso_data->cs_shift = tk->tkr.shift;
+ vdso_data->cs_mask = tk->tkr.mask;
+ }
+
+ vdso_write_end(vdso_data);
+
+ flush_dcache_page(virt_to_page(vdso_data));
+}
+
+void update_vsyscall_tz(void)
+{
+ vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
+ vdso_data->tz_dsttime = sys_tz.tz_dsttime;
+ flush_dcache_page(virt_to_page(vdso_data));
+}