From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: Andrew Murray <andrew.murray@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
coresight@lists.linaro.org, Leo Yan <leo.yan@linaro.org>,
Sudeep Holla <sudeep.holla@arm.com>,
linux-arm-kernel@lists.infradead.org,
Mike Leach <mike.leach@linaro.org>
Subject: Re: [PATCH v3 5/6] coresight: etm4x: save/restore state across CPU low power states
Date: Mon, 15 Jul 2019 17:04:30 -0600 [thread overview]
Message-ID: <20190715230430.GA9613@xps15> (raw)
In-Reply-To: <20190711160114.634-6-andrew.murray@arm.com>
Hi Andrew,
Please see comments below.
On Thu, Jul 11, 2019 at 05:01:13PM +0100, Andrew Murray wrote:
> Some hardware will ignore bit TRCPDCR.PU which is used to signal
> to hardware that power should not be removed from the trace unit.
> Let's mitigate against this by conditionally saving and restoring
> the trace unit state when the CPU enters low power states.
>
> This patchset introduces a firmware property named
> 'arm,coresight-needs-save-restore' - when this is present the
> hardware state will be conditionally saved and restored.
>
> A module parameter 'pm_save_enable' is also introduced which can
> be configured to override the firmware property. This can be set
> to never allow save/restore, to conditionally allow it, or to
> do as the firmware indicates (default).
>
> The hardware state is only ever saved and restored when the claim
> tags indicate that coresight is in use.
>
> Signed-off-by: Andrew Murray <andrew.murray@arm.com>
> ---
> drivers/hwtracing/coresight/coresight-etm4x.c | 324 ++++++++++++++++++
> drivers/hwtracing/coresight/coresight-etm4x.h | 62 ++++
> drivers/hwtracing/coresight/coresight.c | 2 +-
> include/linux/coresight.h | 8 +
> 4 files changed, 395 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
> index d993359e2117..b0bd8158bf13 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
> @@ -18,6 +18,7 @@
> #include <linux/stat.h>
> #include <linux/clk.h>
> #include <linux/cpu.h>
> +#include <linux/cpu_pm.h>
> #include <linux/coresight.h>
> #include <linux/coresight-pmu.h>
> #include <linux/pm_wakeup.h>
> @@ -26,6 +27,7 @@
> #include <linux/uaccess.h>
> #include <linux/perf_event.h>
> #include <linux/pm_runtime.h>
> +#include <linux/property.h>
> #include <asm/sections.h>
> #include <asm/local.h>
> #include <asm/virt.h>
> @@ -37,6 +39,15 @@ static int boot_enable;
> module_param(boot_enable, int, 0444);
> MODULE_PARM_DESC(boot_enable, "Enable tracing on boot");
>
> +#define PARAM_PM_SAVE_NEVER 0 /* never save/restore state */
> +#define PARAM_PM_SAVE_ALWAYS 1 /* always save/restore state */
> +#define PARAM_PM_SAVE_FIRMWARE 2 /* only save/restore if firmware flag set */
> +
> +static int pm_save_enable = PARAM_PM_SAVE_FIRMWARE;
> +module_param(pm_save_enable, int, 0644);
> +MODULE_PARM_DESC(pm_save_enable,
> + "Save/restore state on power down: 0 = never, 1 = always, 2 = firmware");
> +
> /* The number of ETMv4 currently registered */
> static int etm4_count;
> static struct etmv4_drvdata *etmdrvdata[NR_CPUS];
> @@ -54,6 +65,14 @@ static void etm4_os_unlock(struct etmv4_drvdata *drvdata)
> isb();
> }
>
> +static void etm4_os_lock(struct etmv4_drvdata *drvdata)
> +{
> + /* Writing 0x1 to TRCOSLAR locks the trace registers */
> + writel_relaxed(0x1, drvdata->base + TRCOSLAR);
> + drvdata->os_unlock = false;
> + isb();
> +}
> +
> static bool etm4_arch_supported(u8 arch)
> {
> /* Mask out the minor version number */
> @@ -1085,6 +1104,303 @@ static void etm4_init_trace_id(struct etmv4_drvdata *drvdata)
> drvdata->trcid = coresight_get_trace_id(drvdata->cpu);
> }
>
> +#ifdef CONFIG_CPU_PM
> +static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
> +{
> + int i, ret = 0;
> + u32 control;
> + struct etmv4_save_state *state;
> + struct device *etm_dev = &drvdata->csdev->dev;
> +
> + /*
> + * As recommended by 3.4.1 ("The procedure when powering down the PE")
> + * of ARM IHI 0064D
> + */
> + dsb(sy);
> + isb();
> +
> + CS_UNLOCK(drvdata->base);
> +
> + /* Lock the OS lock to disable trace and external debugger access */
> + etm4_os_lock(drvdata);
> +
> + /* wait for TRCSTATR.PMSTABLE to go up */
> + if (coresight_timeout(drvdata->base, TRCSTATR,
> + TRCSTATR_PMSTABLE_BIT, 1)) {
> + dev_err(etm_dev,
> + "timeout while waiting for PM Stable Status\n");
> + etm4_os_unlock(drvdata);
> + ret = -EBUSY;
> + goto out;
> + }
> +
> + state = &drvdata->save_state;
> +
> + state->trcprgctlr = readl(drvdata->base + TRCPRGCTLR);
> + state->trcprocselr = readl(drvdata->base + TRCPROCSELR);
> + state->trcconfigr = readl(drvdata->base + TRCCONFIGR);
> + state->trcauxctlr = readl(drvdata->base + TRCAUXCTLR);
> + state->trceventctl0r = readl(drvdata->base + TRCEVENTCTL0R);
> + state->trceventctl1r = readl(drvdata->base + TRCEVENTCTL1R);
> + state->trcstallctlr = readl(drvdata->base + TRCSTALLCTLR);
> + state->trctsctlr = readl(drvdata->base + TRCTSCTLR);
> + state->trcsyncpr = readl(drvdata->base + TRCSYNCPR);
> + state->trcccctlr = readl(drvdata->base + TRCCCCTLR);
> + state->trcbbctlr = readl(drvdata->base + TRCBBCTLR);
> + state->trctraceidr = readl(drvdata->base + TRCTRACEIDR);
> + state->trcqctlr = readl(drvdata->base + TRCQCTLR);
> +
> + state->trcvictlr = readl(drvdata->base + TRCVICTLR);
> + state->trcviiectlr = readl(drvdata->base + TRCVIIECTLR);
> + state->trcvissctlr = readl(drvdata->base + TRCVISSCTLR);
> + state->trcvipcssctlr = readl(drvdata->base + TRCVIPCSSCTLR);
> + state->trcvdctlr = readl(drvdata->base + TRCVDCTLR);
> + state->trcvdsacctlr = readl(drvdata->base + TRCVDSACCTLR);
> + state->trcvdarcctlr = readl(drvdata->base + TRCVDARCCTLR);
> +
> + for (i = 0; i < drvdata->nrseqstate; i++)
> + state->trcseqevr[i] = readl(drvdata->base + TRCSEQEVRn(i));
> +
> + state->trcseqrstevr = readl(drvdata->base + TRCSEQRSTEVR);
> + state->trcseqstr = readl(drvdata->base + TRCSEQSTR);
> + state->trcextinselr = readl(drvdata->base + TRCEXTINSELR);
> +
> + for (i = 0; i < drvdata->nr_cntr; i++) {
> + state->trccntrldvr[i] = readl(drvdata->base + TRCCNTRLDVRn(i));
> + state->trccntctlr[i] = readl(drvdata->base + TRCCNTCTLRn(i));
> + state->trccntvr[i] = readl(drvdata->base + TRCCNTVRn(i));
> + }
> +
> + for (i = 0; i < drvdata->nr_resource * 2; i++)
> + state->trcrsctlr[i] = readl(drvdata->base + TRCRSCTLRn(i));
> +
> + for (i = 0; i < drvdata->nr_ss_cmp; i++) {
> + state->trcssccr[i] = readl(drvdata->base + TRCSSCCRn(i));
> + state->trcsscsr[i] = readl(drvdata->base + TRCSSCSRn(i));
> + state->trcsspcicr[i] = readl(drvdata->base + TRCSSPCICRn(i));
> + }
> +
> + for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) {
> + state->trcacvr[i] = readl(drvdata->base + TRCACVRn(i));
> + state->trcacatr[i] = readl(drvdata->base + TRCACATRn(i));
> + }
> +
> + /*
> + * Data trace stream is architecturally prohibited for A profile cores
> + * so we don't save (or later restore) trcdvcvr and trcdvcmr - As per
> + * section 1.3.4 ("Possible functional configurations of an ETMv4 trace
> + * unit") of ARM IHI 0064D.
> + */
> +
> + for (i = 0; i < drvdata->numcidc; i++)
> + state->trccidcvr[i] = readl(drvdata->base + TRCCIDCVRn(i));
> +
> + for (i = 0; i < drvdata->numvmidc; i++)
> + state->trcvmidcvr[i] = readl(drvdata->base + TRCVMIDCVRn(i));
> +
> + state->trccidcctlr0 = readl(drvdata->base + TRCCIDCCTLR0);
> + state->trccidcctlr1 = readl(drvdata->base + TRCCIDCCTLR1);
> +
> + state->trcvmidcctlr0 = readl(drvdata->base + TRCVMIDCCTLR0);
> + state->trcvmidcctlr0 = readl(drvdata->base + TRCVMIDCCTLR1);
> +
> + state->trcclaimset = readl(drvdata->base + TRCCLAIMCLR);
> +
> + /* wait for TRCSTATR.IDLE to go up */
> + if (coresight_timeout(drvdata->base, TRCSTATR, TRCSTATR_IDLE_BIT, 1)) {
> + dev_err(etm_dev,
> + "timeout while waiting for Idle Trace Status\n");
> + etm4_os_unlock(drvdata);
> + ret = -EBUSY;
> + goto out;
> + }
> +
> + drvdata->state_needs_restore = true;
> +
> + /*
> + * Power can be removed from the trace unit now. We do this to
> + * potentially save power on systems that respect the TRCPDCR_PU
> + * despite requesting software to save/restore state.
> + */
> + control = readl_relaxed(drvdata->base + TRCPDCR);
> + control &= ~TRCPDCR_PU;
> + writel_relaxed(control, drvdata->base + TRCPDCR);
> +
> +out:
> + CS_LOCK(drvdata->base);
> + return ret;
> +}
> +
> +static void etm4_cpu_restore(struct etmv4_drvdata *drvdata)
> +{
> + int i;
> + struct etmv4_save_state *state;
> +
> + state = &drvdata->save_state;
> +
> + CS_UNLOCK(drvdata->base);
> +
> + writel_relaxed(state->trcclaimset, drvdata->base + TRCCLAIMSET);
> +
> + writel_relaxed(state->trcprgctlr, drvdata->base + TRCPRGCTLR);
> + writel_relaxed(state->trcprocselr, drvdata->base + TRCPROCSELR);
> + writel_relaxed(state->trcconfigr, drvdata->base + TRCCONFIGR);
> + writel_relaxed(state->trcauxctlr, drvdata->base + TRCAUXCTLR);
> + writel_relaxed(state->trceventctl0r, drvdata->base + TRCEVENTCTL0R);
> + writel_relaxed(state->trceventctl1r, drvdata->base + TRCEVENTCTL1R);
> + writel_relaxed(state->trcstallctlr, drvdata->base + TRCSTALLCTLR);
> + writel_relaxed(state->trctsctlr, drvdata->base + TRCTSCTLR);
> + writel_relaxed(state->trcsyncpr, drvdata->base + TRCSYNCPR);
> + writel_relaxed(state->trcccctlr, drvdata->base + TRCCCCTLR);
> + writel_relaxed(state->trcbbctlr, drvdata->base + TRCBBCTLR);
> + writel_relaxed(state->trctraceidr, drvdata->base + TRCTRACEIDR);
> + writel_relaxed(state->trcqctlr, drvdata->base + TRCQCTLR);
> +
> + writel_relaxed(state->trcvictlr, drvdata->base + TRCVICTLR);
> + writel_relaxed(state->trcviiectlr, drvdata->base + TRCVIIECTLR);
> + writel_relaxed(state->trcvissctlr, drvdata->base + TRCVISSCTLR);
> + writel_relaxed(state->trcvipcssctlr, drvdata->base + TRCVIPCSSCTLR);
> + writel_relaxed(state->trcvdctlr, drvdata->base + TRCVDCTLR);
> + writel_relaxed(state->trcvdsacctlr, drvdata->base + TRCVDSACCTLR);
> + writel_relaxed(state->trcvdarcctlr, drvdata->base + TRCVDARCCTLR);
> +
> + for (i = 0; i < drvdata->nrseqstate; i++)
> + writel_relaxed(state->trcseqevr[i],
> + drvdata->base + TRCSEQEVRn(i));
> +
> + writel_relaxed(state->trcseqrstevr, drvdata->base + TRCSEQRSTEVR);
> + writel_relaxed(state->trcseqstr, drvdata->base + TRCSEQSTR);
> + writel_relaxed(state->trcextinselr, drvdata->base + TRCEXTINSELR);
> +
> + for (i = 0; i < drvdata->nr_cntr; i++) {
> + writel_relaxed(state->trccntrldvr[i],
> + drvdata->base + TRCCNTRLDVRn(i));
> + writel_relaxed(state->trccntctlr[i],
> + drvdata->base + TRCCNTCTLRn(i));
> + writel_relaxed(state->trccntvr[i],
> + drvdata->base + TRCCNTVRn(i));
> + }
> +
> + for (i = 0; i < drvdata->nr_resource * 2; i++)
> + writel_relaxed(state->trcrsctlr[i],
> + drvdata->base + TRCRSCTLRn(i));
> +
> + for (i = 0; i < drvdata->nr_ss_cmp; i++) {
> + writel_relaxed(state->trcssccr[i],
> + drvdata->base + TRCSSCCRn(i));
> + writel_relaxed(state->trcsscsr[i],
> + drvdata->base + TRCSSCSRn(i));
> + writel_relaxed(state->trcsspcicr[i],
> + drvdata->base + TRCSSPCICRn(i));
> + }
> +
> + for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) {
> + writel_relaxed(state->trcacvr[i],
> + drvdata->base + TRCACVRn(i));
> + writel_relaxed(state->trcacatr[i],
> + drvdata->base + TRCACATRn(i));
> + }
> +
> + for (i = 0; i < drvdata->numcidc; i++)
> + writel_relaxed(state->trccidcvr[i],
> + drvdata->base + TRCCIDCVRn(i));
> +
> + for (i = 0; i < drvdata->numvmidc; i++)
> + writel_relaxed(state->trcvmidcvr[i],
> + drvdata->base + TRCVMIDCVRn(i));
> +
> + writel_relaxed(state->trccidcctlr0, drvdata->base + TRCCIDCCTLR0);
> + writel_relaxed(state->trccidcctlr1, drvdata->base + TRCCIDCCTLR1);
> +
> + writel_relaxed(state->trcvmidcctlr0, drvdata->base + TRCVMIDCCTLR0);
> + writel_relaxed(state->trcvmidcctlr0, drvdata->base + TRCVMIDCCTLR1);
> +
> + writel_relaxed(state->trcclaimset, drvdata->base + TRCCLAIMSET);
> +
> + drvdata->state_needs_restore = false;
> +
> + /*
> + * Request to keep the trace unit powered and also
> + * emulation of powerdown
> + */
> + writel_relaxed(readl_relaxed(drvdata->base + TRCPDCR) | TRCPDCR_PU,
> + drvdata->base + TRCPDCR);
> +
> + /*
> + * As recommended by section 4.3.7 ("Synchronization when using the
> + * memory-mapped interface") of ARM IHI 0064D
> + */
> + dsb(sy);
> + isb();
> +
> + /* Unlock the OS lock to re-enable trace and external debug access */
> + etm4_os_unlock(drvdata);
> + CS_LOCK(drvdata->base);
> +}
> +
> +static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd,
> + void *v)
> +{
> + struct etmv4_drvdata *drvdata;
> + unsigned int cpu = smp_processor_id();
> +
> + if (!etmdrvdata[cpu])
> + return 0;
> +
> + drvdata = etmdrvdata[cpu];
> +
> + if (pm_save_enable == PARAM_PM_SAVE_NEVER ||
> + (pm_save_enable == PARAM_PM_SAVE_FIRMWARE &&
> + !drvdata->pm_save_enable))
> + return NOTIFY_OK;
> +
> + if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id()))
> + return NOTIFY_BAD;
> +
> + switch (cmd) {
> + case CPU_PM_ENTER:
> + /* save the state if coresight is in use */
> + if (coresight_is_claimed_any(drvdata->base))
> + if (etm4_cpu_save(drvdata))
> + return NOTIFY_BAD;
> + break;
> + case CPU_PM_EXIT:
> + case CPU_PM_ENTER_FAILED:
> + /* trcclaimset is set when there is state to restore */
> + if (drvdata->state_needs_restore)
> + etm4_cpu_restore(drvdata);
> + break;
> + default:
> + return NOTIFY_DONE;
> + }
> +
> + return NOTIFY_OK;
> +}
> +
> +static struct notifier_block etm4_cpu_pm_nb = {
> + .notifier_call = etm4_cpu_pm_notify,
> +};
> +
> +static int etm4_cpu_pm_register(void)
> +{
> + return cpu_pm_register_notifier(&etm4_cpu_pm_nb);
> +}
> +
> +static void etm4_cpu_pm_unregister(void)
> +{
> + cpu_pm_unregister_notifier(&etm4_cpu_pm_nb);
> +}
> +#else
> +static int etm4_cpu_pm_register(void) { return 0; }
> +static void etm4_cpu_pm_unregister(void) { }
> +#endif
> +
> +static inline bool etm4_needs_save_restore(struct device *dev)
> +{
> + return fwnode_property_present(dev->fwnode,
> + "arm,coresight-needs-save-restore");
> +}
> +
> static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
> {
> int ret;
> @@ -1101,6 +1417,8 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
>
> dev_set_drvdata(dev, drvdata);
>
> + drvdata->pm_save_enable = etm4_needs_save_restore(dev);
> +
> /* Validity for the resource is already checked by the AMBA core */
> base = devm_ioremap_resource(dev, res);
> if (IS_ERR(base))
> @@ -1132,6 +1450,10 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
> if (ret < 0)
> goto err_arch_supported;
> hp_online = ret;
> +
> + ret = etm4_cpu_pm_register();
> + if (ret)
> + goto err_arch_supported;
> }
>
> cpus_read_unlock();
> @@ -1182,6 +1504,8 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
>
> err_arch_supported:
> if (--etm4_count == 0) {
> + etm4_cpu_pm_unregister();
> +
> cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
> if (hp_online)
> cpuhp_remove_state_nocalls(hp_online);
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
> index 4523f10ddd0f..c31634c64f87 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.h
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
> @@ -175,6 +175,7 @@
> ETM_MODE_EXCL_USER)
>
> #define TRCSTATR_IDLE_BIT 0
> +#define TRCSTATR_PMSTABLE_BIT 1
> #define ETM_DEFAULT_ADDR_COMP 0
>
> /* PowerDown Control Register bits */
> @@ -281,6 +282,63 @@ struct etmv4_config {
> u32 ext_inp;
> };
>
> +/**
> + * struct etm4_save_state - state to be preserved when ETM is without power
> + */
> +struct etmv4_save_state {
> + u32 trcprgctlr;
> + u32 trcprocselr;
> + u32 trcconfigr;
> + u32 trcauxctlr;
> + u32 trceventctl0r;
> + u32 trceventctl1r;
> + u32 trcstallctlr;
> + u32 trctsctlr;
> + u32 trcsyncpr;
> + u32 trcccctlr;
> + u32 trcbbctlr;
> + u32 trctraceidr;
> + u32 trcqctlr;
> +
> + u32 trcvictlr;
> + u32 trcviiectlr;
> + u32 trcvissctlr;
> + u32 trcvipcssctlr;
> + u32 trcvdctlr;
> + u32 trcvdsacctlr;
> + u32 trcvdarcctlr;
> +
> + u32 trcseqevr[ETM_MAX_SEQ_STATES];
> + u32 trcseqrstevr;
> + u32 trcseqstr;
> + u32 trcextinselr;
> + u32 trccntrldvr[ETMv4_MAX_CNTR];
> + u32 trccntctlr[ETMv4_MAX_CNTR];
> + u32 trccntvr[ETMv4_MAX_CNTR];
> +
> + u32 trcrsctlr[ETM_MAX_RES_SEL * 2];
> +
> + u32 trcssccr[ETM_MAX_SS_CMP];
> + u32 trcsscsr[ETM_MAX_SS_CMP];
> + u32 trcsspcicr[ETM_MAX_SS_CMP];
> +
> + u64 trcacvr[ETM_MAX_SINGLE_ADDR_CMP];
> + u64 trcacatr[ETM_MAX_SINGLE_ADDR_CMP];
> + u64 trccidcvr[ETMv4_MAX_CTXID_CMP];
> + u32 trcvmidcvr[ETM_MAX_VMID_CMP];
> + u32 trccidcctlr0;
> + u32 trccidcctlr1;
> + u32 trcvmidcctlr0;
> + u32 trcvmidcctlr1;
> +
> + u32 trcclaimset;
> +
> + u32 cntr_val[ETMv4_MAX_CNTR];
> + u32 seq_state;
> + u32 vinst_ctrl;
> + u32 ss_status[ETM_MAX_SS_CMP];
> +};
> +
> /**
> * struct etm4_drvdata - specifics associated to an ETM component
> * @base: Memory mapped base address for this component.
> @@ -336,6 +394,7 @@ struct etmv4_config {
> * @atbtrig: If the implementation can support ATB triggers
> * @lpoverride: If the implementation can support low-power state over.
> * @config: structure holding configuration parameters.
> + * @save_state: State to be preserved across power loss
> */
> struct etmv4_drvdata {
> void __iomem *base;
> @@ -367,6 +426,7 @@ struct etmv4_drvdata {
> u8 q_support;
> bool sticky_enable;
> bool boot_enable;
> + bool pm_save_enable;
Please document - otherwise we have to guess what this is for.
> bool os_unlock;
> bool instrp0;
> bool trcbb;
> @@ -381,6 +441,8 @@ struct etmv4_drvdata {
> bool atbtrig;
> bool lpoverride;
> struct etmv4_config config;
> + struct etmv4_save_state save_state;
> + bool state_needs_restore;
Same as above.
Did you get a chance to test your code on something else than Juno? I gave it a
spin on my dragonboard and I can't get the kernel to finish booting - my board
resets just after the ETMv4 have initialized. I'll try to debug this futher tomorrow.
Thanks,
Mathieu
> };
>
> /* Address comparator access types */
> diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
> index 86d1fc2c1bd4..aba71a5a025f 100644
> --- a/drivers/hwtracing/coresight/coresight.c
> +++ b/drivers/hwtracing/coresight/coresight.c
> @@ -140,7 +140,7 @@ static inline bool coresight_is_claimed_self_hosted(void __iomem *base)
> return coresight_read_claim_tags(base) == CORESIGHT_CLAIM_SELF_HOSTED;
> }
>
> -static inline bool coresight_is_claimed_any(void __iomem *base)
> +bool coresight_is_claimed_any(void __iomem *base)
> {
> return coresight_read_claim_tags(base) != 0;
> }
> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> index a2b68823717b..c3a875dffe65 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -285,6 +285,9 @@ extern void coresight_disclaim_device(void __iomem *base);
> extern void coresight_disclaim_device_unlocked(void __iomem *base);
> extern char *coresight_alloc_device_name(struct coresight_dev_list *devs,
> struct device *dev);
> +
> +extern bool coresight_is_claimed_any(void __iomem *base);
> +
> #else
> static inline struct coresight_device *
> coresight_register(struct coresight_desc *desc) { return NULL; }
> @@ -307,6 +310,11 @@ static inline int coresight_claim_device(void __iomem *base)
> static inline void coresight_disclaim_device(void __iomem *base) {}
> static inline void coresight_disclaim_device_unlocked(void __iomem *base) {}
>
> +static inline bool coresight_is_claimed_any(void __iomem *base)
> +{
> + return false;
> +}
> +
> #endif
>
> extern int coresight_get_cpu(struct device *dev);
> --
> 2.21.0
>
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next prev parent reply other threads:[~2019-07-15 23:04 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-11 16:01 [PATCH v3 0/6] coresight: etm4x: save/restore ETMv4 context across CPU low power states Andrew Murray
2019-07-11 16:01 ` [PATCH v3 1/6] coresight: etm4x: remove superfluous setting of os_unlock Andrew Murray
2019-07-11 16:01 ` [PATCH v3 2/6] coresight: etm4x: use explicit barriers on enable/disable Andrew Murray
2019-07-11 16:01 ` [PATCH v3 3/6] coresight: etm4x: use module_param instead of module_param_named Andrew Murray
2019-07-11 16:01 ` [PATCH v3 4/6] coresight: etm4x: improve clarity of etm4_os_unlock comment Andrew Murray
2019-07-11 16:01 ` [PATCH v3 5/6] coresight: etm4x: save/restore state across CPU low power states Andrew Murray
2019-07-12 15:00 ` [PATCH] coresight: etm4x: lazily allocate memory for save_state Andrew Murray
2019-07-22 20:32 ` Mathieu Poirier
2019-07-23 9:05 ` Suzuki K Poulose
2019-07-26 11:24 ` Andrew Murray
2019-07-30 10:15 ` Suzuki K Poulose
2019-07-15 14:22 ` [PATCH v3 5/6] coresight: etm4x: save/restore state across CPU low power states Mike Leach
2019-07-16 11:50 ` Andrew Murray
2019-07-16 14:43 ` Mike Leach
2019-07-15 23:04 ` Mathieu Poirier [this message]
2019-07-16 11:52 ` Andrew Murray
2019-07-11 16:01 ` [PATCH v3 6/6] dt-bindings: arm: coresight: Add support for coresight-needs-save-restore Andrew Murray
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