Re: [PATCH] perf/arm-cmn: Fix port detection for CMN-700

From: Ilkka Koskinen
Date: Tue Apr 04 2023 - 02:12:40 EST


Hi Robin,

On Mon, 3 Apr 2023, Robin Murphy wrote:
On 2023-04-03 12:50, Robin Murphy wrote:
When the "extra device ports" configuration was first added, the
additional mxp_device_port_connect_info registers were added around the
existing mxp_mesh_port_connect_info registers. What I missed about
CMN-700 is that it shuffled them around to remove this discontinuity.
As such, tweak the definitions and factor out a helper for reading these
registers so we can deal with this discrepancy easily, which does at
least allow nicely tidying up the callsites. With this we can then also
do the nice thing and skip accesses completely rather than relying on
RES0 behaviour where we know the extra registers aren't defined.

Fixes: 23760a014417 ("perf/arm-cmn: Add CMN-700 support")
Reported-by: Jing Zhang <renyu.zj@xxxxxxxxxxxxxxxxx>
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
---
drivers/perf/arm-cmn.c | 55 ++++++++++++++++++++++--------------------
1 file changed, 29 insertions(+), 26 deletions(-)

diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
index c9689861be3f..367d41c5d983 100644
--- a/drivers/perf/arm-cmn.c
+++ b/drivers/perf/arm-cmn.c
@@ -57,14 +57,12 @@
#define CMN_INFO_REQ_VC_NUM GENMASK_ULL(1, 0)
/* XPs also have some local topology info which has uses too */
-#define CMN_MXP__CONNECT_INFO_P0 0x0008
-#define CMN_MXP__CONNECT_INFO_P1 0x0010
-#define CMN_MXP__CONNECT_INFO_P2 0x0028
-#define CMN_MXP__CONNECT_INFO_P3 0x0030
-#define CMN_MXP__CONNECT_INFO_P4 0x0038
-#define CMN_MXP__CONNECT_INFO_P5 0x0040
+#define CMN_MXP__CONNECT_INFO(p) (0x0008 + 8 * (p))
#define CMN__CONNECT_INFO_DEVICE_TYPE GENMASK_ULL(4, 0)
+#define CMN_MAX_PORTS 6
+#define CI700_CONNECT_INFO_P2_5_OFFSET 0x20

...which of course should be 0x10 for the way the code below ended up, sigh. I'll wait for any further review before resending.

Cheers,
Robin.

I quickly checked cmn650, cmn700, ci700 TRMs and the change looks good to me. I also tested the patch briefly on cmn650 and it was working fine just like I expected.

Cheers, Ilkka

+
/* PMU registers occupy the 3rd 4KB page of each node's region */
#define CMN_PMU_OFFSET 0x2000
@@ -396,6 +394,25 @@ static struct arm_cmn_node *arm_cmn_node(const struct arm_cmn *cmn,
return NULL;
}
+static u32 arm_cmn_device_connect_info(const struct arm_cmn *cmn,
+ const struct arm_cmn_node *xp, int port)
+{
+ int offset = CMN_MXP__CONNECT_INFO(port);
+
+ if (port >= 2) {
+ if (cmn->model & (CMN600 | CMN650))
+ return 0;
+ /*
+ * CI-700 may have extra ports, but still has the
+ * mesh_port_connect_info registers in the way.
+ */
+ if (cmn->model == CI700)
+ offset += CI700_CONNECT_INFO_P2_5_OFFSET;
+ }
+
+ return readl_relaxed(xp->pmu_base - CMN_PMU_OFFSET + offset);
+}
+
static struct dentry *arm_cmn_debugfs;
#ifdef CONFIG_DEBUG_FS
@@ -469,7 +486,7 @@ static int arm_cmn_map_show(struct seq_file *s, void *data)
y = cmn->mesh_y;
while (y--) {
int xp_base = cmn->mesh_x * y;
- u8 port[6][CMN_MAX_DIMENSION];
+ u8 port[CMN_MAX_PORTS][CMN_MAX_DIMENSION];
for (x = 0; x < cmn->mesh_x; x++)
seq_puts(s, "--------+");
@@ -477,14 +494,9 @@ static int arm_cmn_map_show(struct seq_file *s, void *data)
seq_printf(s, "\n%d |", y);
for (x = 0; x < cmn->mesh_x; x++) {
struct arm_cmn_node *xp = cmn->xps + xp_base + x;
- void __iomem *base = xp->pmu_base - CMN_PMU_OFFSET;
- port[0][x] = readl_relaxed(base + CMN_MXP__CONNECT_INFO_P0);
- port[1][x] = readl_relaxed(base + CMN_MXP__CONNECT_INFO_P1);
- port[2][x] = readl_relaxed(base + CMN_MXP__CONNECT_INFO_P2);
- port[3][x] = readl_relaxed(base + CMN_MXP__CONNECT_INFO_P3);
- port[4][x] = readl_relaxed(base + CMN_MXP__CONNECT_INFO_P4);
- port[5][x] = readl_relaxed(base + CMN_MXP__CONNECT_INFO_P5);
+ for (p = 0; p < CMN_MAX_PORTS; p++)
+ port[p][x] = arm_cmn_device_connect_info(cmn, xp, p);
seq_printf(s, " XP #%-2d |", xp_base + x);
}
@@ -2083,18 +2095,9 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
* from this, since in that case we will see at least one XP
* with port 2 connected, for the HN-D.
*/
- if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P0))
- xp_ports |= BIT(0);
- if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P1))
- xp_ports |= BIT(1);
- if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P2))
- xp_ports |= BIT(2);
- if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P3))
- xp_ports |= BIT(3);
- if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P4))
- xp_ports |= BIT(4);
- if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P5))
- xp_ports |= BIT(5);
+ for (int p = 0; p < CMN_MAX_PORTS; p++)
+ if (arm_cmn_device_connect_info(cmn, xp, p))
+ xp_ports |= BIT(p);
if (cmn->multi_dtm && (xp_ports & 0xc))
arm_cmn_init_dtm(dtm++, xp, 1);

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