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authorSuzuki K Poulose <suzuki.poulose@arm.com>2019-08-29 23:28:31 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-09-03 23:01:16 +0300
commit8a4bc4f195044004520e38da7b8a52a76ccc9945 (patch)
treeaadd5ab4df9c571608199ba1f74fc1d2030b3256 /drivers/hwtracing
parentf52ff9b7d64953b9a1a03faaf797d23b5c1d10d0 (diff)
downloadlinux-8a4bc4f195044004520e38da7b8a52a76ccc9945.tar.xz
coresight: tmc-etr: Check if non-secure access is enabled
CoreSight TMC-ETR must have the non-secure invasive debug access enabled for use by self-hosted tracing. Without it, there is no point in enabling the ETR. So, let us check it in the TMC_AUTHSTATUS register and fail the probe if it is disabled. Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Link: https://lore.kernel.org/r/20190829202842.580-7-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/coresight/coresight-tmc.c12
-rw-r--r--drivers/hwtracing/coresight/coresight-tmc.h3
2 files changed, 15 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc.c b/drivers/hwtracing/coresight/coresight-tmc.c
index be37aff573b4..3055bf8e2236 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.c
+++ b/drivers/hwtracing/coresight/coresight-tmc.c
@@ -236,6 +236,7 @@ coresight_tmc_reg(ffcr, TMC_FFCR);
coresight_tmc_reg(mode, TMC_MODE);
coresight_tmc_reg(pscr, TMC_PSCR);
coresight_tmc_reg(axictl, TMC_AXICTL);
+coresight_tmc_reg(authstatus, TMC_AUTHSTATUS);
coresight_tmc_reg(devid, CORESIGHT_DEVID);
coresight_tmc_reg64(rrp, TMC_RRP, TMC_RRPHI);
coresight_tmc_reg64(rwp, TMC_RWP, TMC_RWPHI);
@@ -255,6 +256,7 @@ static struct attribute *coresight_tmc_mgmt_attrs[] = {
&dev_attr_devid.attr,
&dev_attr_dba.attr,
&dev_attr_axictl.attr,
+ &dev_attr_authstatus.attr,
NULL,
};
@@ -342,6 +344,13 @@ static inline bool tmc_etr_can_use_sg(struct device *dev)
return fwnode_property_present(dev->fwnode, "arm,scatter-gather");
}
+static inline bool tmc_etr_has_non_secure_access(struct tmc_drvdata *drvdata)
+{
+ u32 auth = readl_relaxed(drvdata->base + TMC_AUTHSTATUS);
+
+ return (auth & TMC_AUTH_NSID_MASK) == 0x3;
+}
+
/* Detect and initialise the capabilities of a TMC ETR */
static int tmc_etr_setup_caps(struct device *parent, u32 devid, void *dev_caps)
{
@@ -349,6 +358,9 @@ static int tmc_etr_setup_caps(struct device *parent, u32 devid, void *dev_caps)
u32 dma_mask = 0;
struct tmc_drvdata *drvdata = dev_get_drvdata(parent);
+ if (!tmc_etr_has_non_secure_access(drvdata))
+ return -EACCES;
+
/* Set the unadvertised capabilities */
tmc_etr_init_caps(drvdata, (u32)(unsigned long)dev_caps);
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 95d2e2747970..4c59f2a4ad0e 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -39,6 +39,7 @@
#define TMC_ITATBCTR2 0xef0
#define TMC_ITATBCTR1 0xef4
#define TMC_ITATBCTR0 0xef8
+#define TMC_AUTHSTATUS 0xfb8
/* register description */
/* TMC_CTL - 0x020 */
@@ -90,6 +91,8 @@
#define TMC_DEVID_AXIAW_SHIFT 17
#define TMC_DEVID_AXIAW_MASK 0x7f
+#define TMC_AUTH_NSID_MASK GENMASK(1, 0)
+
enum tmc_config_type {
TMC_CONFIG_TYPE_ETB,
TMC_CONFIG_TYPE_ETR,