On 2019-12-17 12:28, Jonathan Kim wrote:
The DF routines to arm xGMI performance will attempt to re-arm both on
performance monitoring start and read on initial failure to arm.
Signed-off-by: Jonathan Kim <Jonathan.Kim@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/df_v3_6.c | 153 ++++++++++++++++++++-------
1 file changed, 117 insertions(+), 36 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/df_v3_6.c b/drivers/gpu/drm/amd/amdgpu/df_v3_6.c
index 4043ebcea5de..af445054305f 100644
--- a/drivers/gpu/drm/amd/amdgpu/df_v3_6.c
+++ b/drivers/gpu/drm/amd/amdgpu/df_v3_6.c
@@ -162,25 +162,45 @@ static void df_v3_6_perfmon_rreg(struct amdgpu_device *adev,
}
/*
- * df_v3_6_perfmon_wreg - write to perfmon lo and hi
- *
- * required to be atomic. no mmio method provided so subsequent reads after
- * data writes cannot occur to preserve data fabrics finite state machine.
+ * retry arming counters every 100 usecs within 1 millisecond interval.
+ * if retry fails after time out, return error.
*/
-static void df_v3_6_perfmon_wreg(struct amdgpu_device *adev, uint32_t lo_addr,
- uint32_t lo_val, uint32_t hi_addr, uint32_t hi_val)
+#define ARM_RETRY_USEC_TIMEOUT 1000
+#define ARM_RETRY_USEC_INTERVAL 100
+static int df_v3_6_perfmon_arm_with_retry(struct amdgpu_device *adev,
+ uint32_t lo_addr, uint32_t lo_val,
+ uint32_t hi_addr, uint32_t hi_val)
{
unsigned long flags, address, data;
+ uint32_t lo_val_rb, hi_val_rb;
+ int countdown = ARM_RETRY_USEC_TIMEOUT;
address = adev->nbio.funcs->get_pcie_index_offset(adev);
data = adev->nbio.funcs->get_pcie_data_offset(adev);
spin_lock_irqsave(&adev->pcie_idx_lock, flags);
- WREG32(address, lo_addr);
- WREG32(data, lo_val);
- WREG32(address, hi_addr);
- WREG32(data, hi_val);
+
+ while (countdown) {
+ WREG32(address, lo_addr);
+ WREG32(data, lo_val);
+ WREG32(address, hi_addr);
+ WREG32(data, hi_val);
+
+ WREG32(address, lo_addr);
+ lo_val_rb = RREG32(data);
+ WREG32(address, hi_addr);
+ hi_val_rb = RREG32(data);
+
+ if (lo_val == lo_val_rb && hi_val == hi_val_rb)
+ break;
+
+ countdown -= ARM_RETRY_USEC_INTERVAL;
+ udelay(ARM_RETRY_USEC_INTERVAL);
+ }
+
spin_unlock_irqrestore(&adev->pcie_idx_lock, flags);
I don't think it's a good idea to hold the spin lock for the entire
duration of this retry loop. Maybe put that inside the loop and release
the lock while waiting in udelay.
+
+ return countdown > 0 ? 0 : -ETIME;
}
/* get the number of df counters available */
@@ -334,20 +354,20 @@ static void df_v3_6_pmc_get_addr(struct amdgpu_device *adev,
switch (target_cntr) {
case 0:
- *lo_base_addr = is_ctrl ? smnPerfMonCtlLo0 : smnPerfMonCtrLo0;
- *hi_base_addr = is_ctrl ? smnPerfMonCtlHi0 : smnPerfMonCtrHi0;
+ *lo_base_addr = is_ctrl ? smnPerfMonCtlLo4 : smnPerfMonCtrLo4;
+ *hi_base_addr = is_ctrl ? smnPerfMonCtlHi4 : smnPerfMonCtrHi4;
break;
case 1:
- *lo_base_addr = is_ctrl ? smnPerfMonCtlLo1 : smnPerfMonCtrLo1;
- *hi_base_addr = is_ctrl ? smnPerfMonCtlHi1 : smnPerfMonCtrHi1;
+ *lo_base_addr = is_ctrl ? smnPerfMonCtlLo5 : smnPerfMonCtrLo5;
+ *hi_base_addr = is_ctrl ? smnPerfMonCtlHi5 : smnPerfMonCtrHi5;
break;
case 2:
- *lo_base_addr = is_ctrl ? smnPerfMonCtlLo2 : smnPerfMonCtrLo2;
- *hi_base_addr = is_ctrl ? smnPerfMonCtlHi2 : smnPerfMonCtrHi2;
+ *lo_base_addr = is_ctrl ? smnPerfMonCtlLo6 : smnPerfMonCtrLo6;
+ *hi_base_addr = is_ctrl ? smnPerfMonCtlHi6 : smnPerfMonCtrHi6;
break;
case 3:
- *lo_base_addr = is_ctrl ? smnPerfMonCtlLo3 : smnPerfMonCtrLo3;
- *hi_base_addr = is_ctrl ? smnPerfMonCtlHi3 : smnPerfMonCtrHi3;
+ *lo_base_addr = is_ctrl ? smnPerfMonCtlLo7 : smnPerfMonCtrLo7;
+ *hi_base_addr = is_ctrl ? smnPerfMonCtlHi7 : smnPerfMonCtrHi7;
break;
}
@@ -422,6 +442,42 @@ static int df_v3_6_pmc_add_cntr(struct amdgpu_device *adev,
return -ENOSPC;
}
+#define DEFERRED_ARM_MASK (1 << 31)
+static int df_v3_6_pmc_defer_cntr(struct amdgpu_device *adev,
+ uint64_t config, int err)
Consider renaming this function. I found its usage confusing because
it's used to defer arming as well as clearing the deferred flag. Maybe
df_v3_6_pmc_set_deferred. The "err" parameter could be named "defer" to
better indicate its meaning and maybe make it bool, since that's what's
returned by the counterpart df_v3_6_pmc_is_deferred.
+{
+ int target_cntr;
+
+ target_cntr = df_v3_6_pmc_config_2_cntr(adev, config);
+
+ if (target_cntr < 0)
+ return -EINVAL;
+
+ if (err)
+ adev->df_perfmon_config_assign_mask[target_cntr] |=
+ DEFERRED_ARM_MASK;
+ else
+ adev->df_perfmon_config_assign_mask[target_cntr] &=
+ ~DEFERRED_ARM_MASK;
+
+ return 0;
+}
+
+static bool df_v3_6_pmc_is_deferred(struct amdgpu_device *adev,
+ uint64_t config)
+{
+ int target_cntr;
+
+ target_cntr = df_v3_6_pmc_config_2_cntr(adev, config);
+
+ if (target_cntr < 0)
+ return -EINVAL;
+
+ return (adev->df_perfmon_config_assign_mask[target_cntr]
+ & DEFERRED_ARM_MASK);
+
+}
+
/* release performance counter */
static void df_v3_6_pmc_release_cntr(struct amdgpu_device *adev,
uint64_t config)
@@ -433,7 +489,7 @@ static void df_v3_6_pmc_release_cntr(struct amdgpu_device *adev,
}
-static void df_v3_6_reset_perfmon_cntr(struct amdgpu_device *adev,
+static int df_v3_6_reset_perfmon_cntr(struct amdgpu_device *adev,
uint64_t config)
{
uint32_t lo_base_addr, hi_base_addr;
@@ -442,38 +498,54 @@ static void df_v3_6_reset_perfmon_cntr(struct amdgpu_device *adev,
&hi_base_addr);
if ((lo_base_addr == 0) || (hi_base_addr == 0))
- return;
+ return -EINVAL;
- df_v3_6_perfmon_wreg(adev, lo_base_addr, 0, hi_base_addr, 0);
+ return df_v3_6_perfmon_arm_with_retry(adev, lo_base_addr, 0,
+ hi_base_addr, 0);
}
static int df_v3_6_pmc_start(struct amdgpu_device *adev, uint64_t config,
int is_enable)
{
uint32_t lo_base_addr, hi_base_addr, lo_val, hi_val;
- int ret = 0;
+ int err = 0, ret = 0;
switch (adev->asic_type) {
case CHIP_VEGA20:
-
- df_v3_6_reset_perfmon_cntr(adev, config);
-
if (is_enable) {
ret = df_v3_6_pmc_add_cntr(adev, config);
- } else {
- ret = df_v3_6_pmc_get_ctrl_settings(adev,
+ return ret;
This could be one line
return df_v3_6_pmc_get_cntr(adev, config);
+ }
+
+ err = df_v3_6_reset_perfmon_cntr(adev, config);
+
+ ret = df_v3_6_pmc_defer_cntr(adev, config, err);
This is confusing. This looks like you're always deferring, but in fact
this is conditional based on err. See my suggesting about renaming the
function above.
+
+ if (err || ret)
+ return ret;
+
+ ret = df_v3_6_pmc_get_ctrl_settings(adev,
config,
&lo_base_addr,
&hi_base_addr,
&lo_val,
&hi_val);
- if (ret)
- return ret;
+ if (ret)
+ return ret;
- df_v3_6_perfmon_wreg(adev, lo_base_addr, lo_val,
- hi_base_addr, hi_val);
- }
+ /*
+ * if arm with retries fail, mark reserved counter high bit to
+ * indicate that event arm has failed. retry will occur
+ * during pmc_count in this case.
You're explaining the implementation of df_v3_6_pmc_defer_cntr rather
than the abstract interface. That's more confusing than helpful.
+ */
+ err = df_v3_6_perfmon_arm_with_retry(adev,
+ lo_base_addr,
+ lo_val,
+ hi_base_addr,
+ hi_val);
+
+ ret = df_v3_6_pmc_defer_cntr(adev, config, err);
break;
default:
@@ -501,7 +573,7 @@ static int df_v3_6_pmc_stop(struct amdgpu_device *adev, uint64_t config,
if (ret)
return ret;
- df_v3_6_perfmon_wreg(adev, lo_base_addr, 0, hi_base_addr, 0);
+ df_v3_6_reset_perfmon_cntr(adev, config);
Is this guaranteed to succeed? If not, we should check the return value.
if (is_disable)
df_v3_6_pmc_release_cntr(adev, config);
@@ -518,18 +590,28 @@ static void df_v3_6_pmc_get_count(struct amdgpu_device *adev,
uint64_t config,
uint64_t *count)
{
- uint32_t lo_base_addr, hi_base_addr, lo_val, hi_val;
+ uint32_t lo_base_addr, hi_base_addr, lo_val = 0, hi_val = 0;
+ int rearm_err = 0;
*count = 0;
switch (adev->asic_type) {
case CHIP_VEGA20:
-
df_v3_6_pmc_get_read_settings(adev, config, &lo_base_addr,
&hi_base_addr);
if ((lo_base_addr == 0) || (hi_base_addr == 0))
return;
+ /* rearm the counter or throw away count value on failure */
+ if (df_v3_6_pmc_is_deferred(adev, config)) {
+ rearm_err = df_v3_6_perfmon_arm_with_retry(
+ adev, lo_base_addr, lo_val,
+ hi_base_addr, hi_val);
Is it a good idea to retry here? I believe this is called under a
spin-lock. The get_count should usually be fast. Is it worth retrying
and potentially delaying the entire perf framework for a millisecond?
Regards,
Felix
+ }
+
+ if (rearm_err)
+ return;
+
df_v3_6_perfmon_rreg(adev, lo_base_addr, &lo_val,
hi_base_addr, &hi_val);
@@ -542,7 +624,6 @@ static void df_v3_6_pmc_get_count(struct amdgpu_device *adev,
config, lo_base_addr, hi_base_addr, lo_val, hi_val);
break;
-
default:
break;
}
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