[PATCH 0/5] CCN fixes for 4.8

[PATCH 0/5] CCN fixes for 4.8

[Pawel Moll]

Greetings, Arnd, Olof, Kevin,

This is a small set of various CCN driver fixes I accumulated over the
last few weeks.

I'll send a pull request later, probably next week, that will also
include Mark's patches he sent out yesterday.

Pawel Moll (5):
  bus: arm-ccn: Fix PMU handling of MN
  bus: arm-ccn: Do not attempt to configure XPs for cycle counter
  bus: arm-ccn: Fix XP watchpoint settings bitmask
  bus: arm-ccn: Correct required arguments for XP PMU events
  bus: arm-ccn: Add missing event attribute exclusions for host/guest

 drivers/bus/arm-ccn.c | 42 +++++++++++++++++++++++++++++++++---------
 1 file changed, 33 insertions(+), 9 deletions(-)

-- 
2.7.4

[PATCH 1/5] bus: arm-ccn: Fix PMU handling of MN

[Pawel Moll]

The "Miscellaneous Node" fell through cracks of node initialisation,
as its ID is shared with HN-I.

This patch treats MN as a special case (which it is), adding separate
validation check for it and pre-defining the node ID in relevant events
descriptions. That way one can simply run:

	# perf stat -a -e ccn/mn_ecbarrier/ <workload>

Additionally, direction in the MN pseudo-events XP watchpoint
definitions is corrected to be "TX" (1) as they are defined from the
crosspoint point of view (thus barriers are transmitted from XP to MN).

Cc: stable at vger.kernel.org # 3.17+
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
---
 drivers/bus/arm-ccn.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
index 97a9185..a11b9bb 100644
--- a/drivers/bus/arm-ccn.c
+++ b/drivers/bus/arm-ccn.c
@@ -187,6 +187,7 @@ struct arm_ccn {
 	struct arm_ccn_component *xp;
 
 	struct arm_ccn_dt dt;
+	int mn_id;
 };
 
 static DEFINE_MUTEX(arm_ccn_mutex);
@@ -328,6 +329,7 @@ struct arm_ccn_pmu_event {
 static ssize_t arm_ccn_pmu_event_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
+	struct arm_ccn *ccn = pmu_to_arm_ccn(dev_get_drvdata(dev));
 	struct arm_ccn_pmu_event *event = container_of(attr,
 			struct arm_ccn_pmu_event, attr);
 	ssize_t res;
@@ -354,6 +356,9 @@ static ssize_t arm_ccn_pmu_event_show(struct device *dev,
 			res += snprintf(buf + res, PAGE_SIZE - res,
 					",cmp_l=?,cmp_h=?,mask=?");
 		break;
+	case CCN_TYPE_MN:
+		res += snprintf(buf + res, PAGE_SIZE - res, ",node=%d", ccn->mn_id);
+		break;
 	default:
 		res += snprintf(buf + res, PAGE_SIZE - res, ",node=?");
 		break;
@@ -383,9 +388,9 @@ static umode_t arm_ccn_pmu_events_is_visible(struct kobject *kobj,
 }
 
 static struct arm_ccn_pmu_event arm_ccn_pmu_events[] = {
-	CCN_EVENT_MN(eobarrier, "dir=0,vc=0,cmp_h=0x1c00", CCN_IDX_MASK_OPCODE),
-	CCN_EVENT_MN(ecbarrier, "dir=0,vc=0,cmp_h=0x1e00", CCN_IDX_MASK_OPCODE),
-	CCN_EVENT_MN(dvmop, "dir=0,vc=0,cmp_h=0x2800", CCN_IDX_MASK_OPCODE),
+	CCN_EVENT_MN(eobarrier, "dir=1,vc=0,cmp_h=0x1c00", CCN_IDX_MASK_OPCODE),
+	CCN_EVENT_MN(ecbarrier, "dir=1,vc=0,cmp_h=0x1e00", CCN_IDX_MASK_OPCODE),
+	CCN_EVENT_MN(dvmop, "dir=1,vc=0,cmp_h=0x2800", CCN_IDX_MASK_OPCODE),
 	CCN_EVENT_HNI(txdatflits, "dir=1,vc=3", CCN_IDX_MASK_ANY),
 	CCN_EVENT_HNI(rxdatflits, "dir=0,vc=3", CCN_IDX_MASK_ANY),
 	CCN_EVENT_HNI(txreqflits, "dir=1,vc=0", CCN_IDX_MASK_ANY),
@@ -759,6 +764,12 @@ static int arm_ccn_pmu_event_init(struct perf_event *event)
 
 	/* Validate node/xp vs topology */
 	switch (type) {
+	case CCN_TYPE_MN:
+		if (node_xp != ccn->mn_id) {
+			dev_warn(ccn->dev, "Invalid MN ID %d!\n", node_xp);
+			return -EINVAL;
+		}
+		break;
 	case CCN_TYPE_XP:
 		if (node_xp >= ccn->num_xps) {
 			dev_warn(ccn->dev, "Invalid XP ID %d!\n", node_xp);
@@ -1361,6 +1372,8 @@ static int arm_ccn_init_nodes(struct arm_ccn *ccn, int region,
 
 	switch (type) {
 	case CCN_TYPE_MN:
+		ccn->mn_id = id;
+		return 0;
 	case CCN_TYPE_DT:
 		return 0;
 	case CCN_TYPE_XP:
-- 
2.7.4

[PATCH 2/5] bus: arm-ccn: Do not attempt to configure XPs for cycle counter

[Pawel Moll]

Fuzzing the CCN perf driver revealed a small but definitely dangerous
mistake in the event setup code. When a cycle counter is requested, the
driver should not reconfigure the events bus at all, otherwise it will
corrupt (in most but the simplest cases) its configuration and may end
up accessing XP array out of its bounds.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Cc: stable at vger.kernel.org # 3.17+
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
---
 drivers/bus/arm-ccn.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
index a11b9bb..9bbb0ab 100644
--- a/drivers/bus/arm-ccn.c
+++ b/drivers/bus/arm-ccn.c
@@ -897,6 +897,10 @@ static void arm_ccn_pmu_xp_dt_config(struct perf_event *event, int enable)
 	struct arm_ccn_component *xp;
 	u32 val, dt_cfg;
 
+	/* Nothing to do for cycle counter */
+	if (hw->idx == CCN_IDX_PMU_CYCLE_COUNTER)
+		return;
+
 	if (CCN_CONFIG_TYPE(event->attr.config) == CCN_TYPE_XP)
 		xp = &ccn->xp[CCN_CONFIG_XP(event->attr.config)];
 	else
-- 
2.7.4

[PATCH 3/5] bus: arm-ccn: Fix XP watchpoint settings bitmask

[Pawel Moll]

The code setting XP watchpoint comparator and mask registers should, in
order to be fully compliant with specification, zero one or more most
significant bits of each field. In both L cases it means zeroing bit 63.
The bitmask doing this was wrong, though, zeroing bit 60 instead.
Fortunately, due to a lucky coincidence, this turned out to be fairly
innocent with the existing hardware.

Fixed now.

Cc: stable at vger.kernel.org # 3.17+
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
---
 drivers/bus/arm-ccn.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
index 9bbb0ab..647a27b 100644
--- a/drivers/bus/arm-ccn.c
+++ b/drivers/bus/arm-ccn.c
@@ -1003,7 +1003,7 @@ static void arm_ccn_pmu_xp_watchpoint_config(struct perf_event *event)
 
 	/* Comparison values */
 	writel(cmp_l & 0xffffffff, source->base + CCN_XP_DT_CMP_VAL_L(wp));
-	writel((cmp_l >> 32) & 0xefffffff,
+	writel((cmp_l >> 32) & 0x7fffffff,
 			source->base + CCN_XP_DT_CMP_VAL_L(wp) + 4);
 	writel(cmp_h & 0xffffffff, source->base + CCN_XP_DT_CMP_VAL_H(wp));
 	writel((cmp_h >> 32) & 0x0fffffff,
@@ -1011,7 +1011,7 @@ static void arm_ccn_pmu_xp_watchpoint_config(struct perf_event *event)
 
 	/* Mask */
 	writel(mask_l & 0xffffffff, source->base + CCN_XP_DT_CMP_MASK_L(wp));
-	writel((mask_l >> 32) & 0xefffffff,
+	writel((mask_l >> 32) & 0x7fffffff,
 			source->base + CCN_XP_DT_CMP_MASK_L(wp) + 4);
 	writel(mask_h & 0xffffffff, source->base + CCN_XP_DT_CMP_MASK_H(wp));
 	writel((mask_h >> 32) & 0x0fffffff,
-- 
2.7.4

[PATCH 4/5] bus: arm-ccn: Correct required arguments for XP PMU events

[Pawel Moll]

XP can provide events from two sources: watchpoints, observing traffic
on device ports and PMU looking at internal buses.

Unfortunately the sysfs definition of the PMU events was requiring
port number (instead of bus number) and direction (the buses are
unidirectional), as these fields were shared with the watchpoint event.

Although it does not introduce a major problem (port can be used as
bus alias and direction is simply ignored for XP PMU events), it's
better to fix it now, before external tools start depending on this
behaviour.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
---
 drivers/bus/arm-ccn.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
index 647a27b..e7c2321 100644
--- a/drivers/bus/arm-ccn.c
+++ b/drivers/bus/arm-ccn.c
@@ -213,6 +213,7 @@ static int arm_ccn_node_to_xp_port(int node)
 #define CCN_CONFIG_TYPE(_config)	(((_config) >> 8) & 0xff)
 #define CCN_CONFIG_EVENT(_config)	(((_config) >> 16) & 0xff)
 #define CCN_CONFIG_PORT(_config)	(((_config) >> 24) & 0x3)
+#define CCN_CONFIG_BUS(_config)		(((_config) >> 24) & 0x3)
 #define CCN_CONFIG_VC(_config)		(((_config) >> 26) & 0x7)
 #define CCN_CONFIG_DIR(_config)		(((_config) >> 29) & 0x1)
 #define CCN_CONFIG_MASK(_config)	(((_config) >> 30) & 0xf)
@@ -242,6 +243,7 @@ static CCN_FORMAT_ATTR(xp, "config:0-7");
 static CCN_FORMAT_ATTR(type, "config:8-15");
 static CCN_FORMAT_ATTR(event, "config:16-23");
 static CCN_FORMAT_ATTR(port, "config:24-25");
+static CCN_FORMAT_ATTR(bus, "config:24-25");
 static CCN_FORMAT_ATTR(vc, "config:26-28");
 static CCN_FORMAT_ATTR(dir, "config:29-29");
 static CCN_FORMAT_ATTR(mask, "config:30-33");
@@ -351,10 +353,14 @@ static ssize_t arm_ccn_pmu_event_show(struct device *dev,
 		break;
 	case CCN_TYPE_XP:
 		res += snprintf(buf + res, PAGE_SIZE - res,
-				",xp=?,port=?,vc=?,dir=?");
+				",xp=?,vc=?");
 		if (event->event == CCN_EVENT_WATCHPOINT)
 			res += snprintf(buf + res, PAGE_SIZE - res,
-					",cmp_l=?,cmp_h=?,mask=?");
+					",port=?,dir=?,cmp_l=?,cmp_h=?,mask=?");
+		else
+			res += snprintf(buf + res, PAGE_SIZE - res,
+					",bus=?");
+
 		break;
 	case CCN_TYPE_MN:
 		res += snprintf(buf + res, PAGE_SIZE - res, ",node=%d", ccn->mn_id);
@@ -1029,7 +1035,7 @@ static void arm_ccn_pmu_xp_event_config(struct perf_event *event)
 	hw->event_base = CCN_XP_DT_CONFIG__DT_CFG__XP_PMU_EVENT(hw->config_base);
 
 	id = (CCN_CONFIG_VC(event->attr.config) << 4) |
-			(CCN_CONFIG_PORT(event->attr.config) << 3) |
+			(CCN_CONFIG_BUS(event->attr.config) << 3) |
 			(CCN_CONFIG_EVENT(event->attr.config) << 0);
 
 	val = readl(source->base + CCN_XP_PMU_EVENT_SEL);
-- 
2.7.4

[PATCH 5/5] bus: arm-ccn: Add missing event attribute exclusions for host/guest

[Pawel Moll]

CCN PMUs have no knowledge into VM-related origins of the memory
traffic, therefore can't handle requests for host-only or guest-only
events. Add appropriate exclusions (they should have been there from
the beginning).

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
---
 drivers/bus/arm-ccn.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
index e7c2321..f2e099b 100644
--- a/drivers/bus/arm-ccn.c
+++ b/drivers/bus/arm-ccn.c
@@ -744,7 +744,8 @@ static int arm_ccn_pmu_event_init(struct perf_event *event)
 
 	if (has_branch_stack(event) || event->attr.exclude_user ||
 			event->attr.exclude_kernel || event->attr.exclude_hv ||
-			event->attr.exclude_idle) {
+			event->attr.exclude_idle || event->attr.exclude_host ||
+			event->attr.exclude_guest) {
 		dev_warn(ccn->dev, "Can't exclude execution levels!\n");
 		return -EOPNOTSUPP;
 	}
-- 
2.7.4

[PATCH 0/5] CCN fixes for 4.8

[Arnd Bergmann]

On Friday, August 12, 2016 5:25:51 PM CEST Pawel Moll wrote:
> Greetings, Arnd, Olof, Kevin,
> 
> This is a small set of various CCN driver fixes I accumulated over the
> last few weeks.
> 
> I'll send a pull request later, probably next week, that will also
> include Mark's patches he sent out yesterday.
> 

This seems to have gotten lost, I picked it up into the fixes branch now.

Sorry for the delay.

	Arnd

[PATCH 0/5] CCN fixes for 4.8

[Pawel Moll]

On Fri, 2016-09-02 at 16:01 +0200, Arnd Bergmann wrote:
> On Friday, August 12, 2016 5:25:51 PM CEST Pawel Moll wrote:
> > 
> > Greetings, Arnd, Olof, Kevin,
> > 
> > This is a small set of various CCN driver fixes I accumulated over
> > the
> > last few weeks.
> > 
> > I'll send a pull request later, probably next week, that will also
> > include Mark's patches he sent out yesterday.
> > 
> This seems to have gotten lost, I picked it up into the fixes branch
> now.
> 
> Sorry for the delay.

Cool, no problem - thanks!. Just want to make sure you pulled the
latest version, as described in the v2 request:

http://www.spinics.net/lists/arm-kernel/msg526595.html

Cheers!

Pawe?

[PATCH 0/5] CCN fixes for 4.8

[Arnd Bergmann]

On Friday, September 2, 2016 3:07:46 PM CEST Pawel Moll wrote:
> On Fri, 2016-09-02 at 16:01 +0200, Arnd Bergmann wrote:
> > On Friday, August 12, 2016 5:25:51 PM CEST Pawel Moll wrote:
> > > 
> > > Greetings, Arnd, Olof, Kevin,
> > > 
> > > This is a small set of various CCN driver fixes I accumulated over
> > > the
> > > last few weeks.
> > > 
> > > I'll send a pull request later, probably next week, that will also
> > > include Mark's patches he sent out yesterday.
> > > 
> > This seems to have gotten lost, I picked it up into the fixes branch
> > now.
> > 
> > Sorry for the delay.
> 
> Cool, no problem - thanks!. Just want to make sure you pulled the
> latest version, as described in the v2 request:
> 
> http://www.spinics.net/lists/arm-kernel/msg526595.html
> 

I took the wrong one and applied the patches from the original
series manually.

I fixed it up now, thanks a lot for the heads-up!

	Arnd