Re: [PATCH 02/19] drm/i915/perf: Add OA formats for DG2

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 06/09/2022 22:46, Umesh Nerlige Ramappa wrote:
On Tue, Sep 06, 2022 at 10:35:16PM +0300, Lionel Landwerlin wrote:
On 23/08/2022 23:41, Umesh Nerlige Ramappa wrote:
Add new OA formats for DG2. Some of the newer OA formats are not
multples of 64 bytes and are not powers of 2. For those formats, adjust
hw_tail accordingly when checking for new reports.

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramampa@xxxxxxxxx>

Apart from the coding style issue :


Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxx>


---
 drivers/gpu/drm/i915/i915_perf.c | 63 ++++++++++++++++++++------------
 include/uapi/drm/i915_drm.h      |  6 +++
 2 files changed, 46 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 735244a3aedd..c8331b549d31 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -306,7 +306,8 @@ static u32 i915_oa_max_sample_rate = 100000;
 /* XXX: beware if future OA HW adds new report formats that the current   * code assumes all reports have a power-of-two size and ~(size - 1) can
- * be used as a mask to align the OA tail pointer.
+ * be used as a mask to align the OA tail pointer. In some of the
+ * formats, R is used to denote reserved field.
  */
 static const struct i915_oa_format oa_formats[I915_OA_FORMAT_MAX] = {
     [I915_OA_FORMAT_A13]        = { 0, 64 },
@@ -320,6 +321,10 @@ static const struct i915_oa_format oa_formats[I915_OA_FORMAT_MAX] = {
     [I915_OA_FORMAT_A12]            = { 0, 64 },
     [I915_OA_FORMAT_A12_B8_C8]        = { 2, 128 },
     [I915_OA_FORMAT_A32u40_A4u32_B8_C8] = { 5, 256 },
+    [I915_OAR_FORMAT_A32u40_A4u32_B8_C8]    = { 5, 256 },
+    [I915_OA_FORMAT_A24u40_A14u32_B8_C8]    = { 5, 256 },
+    [I915_OAR_FORMAT_A36u64_B8_C8]        = { 1, 384 },
+    [I915_OA_FORMAT_A38u64_R2u64_B8_C8]    = { 1, 448 },
 };
 #define SAMPLE_OA_REPORT      (1<<0)
@@ -467,6 +472,7 @@ static bool oa_buffer_check_unlocked(struct i915_perf_stream *stream)
     bool pollin;
     u32 hw_tail;
     u64 now;
+    u32 partial_report_size;
     /* We have to consider the (unlikely) possibility that read() errors       * could result in an OA buffer reset which might reset the head and @@ -476,10 +482,16 @@ static bool oa_buffer_check_unlocked(struct i915_perf_stream *stream)
     hw_tail = stream->perf->ops.oa_hw_tail_read(stream);
-    /* The tail pointer increases in 64 byte increments,
-     * not in report_size steps...
+    /* The tail pointer increases in 64 byte increments, whereas report
+     * sizes need not be integral multiples or 64 or powers of 2.
+     * Compute potentially partially landed report in the OA buffer
      */
-    hw_tail &= ~(report_size - 1);
+    partial_report_size = OA_TAKEN(hw_tail, stream->oa_buffer.tail);
+    partial_report_size %= report_size;
+
+    /* Subtract partial amount off the tail */
+    hw_tail = gtt_offset + ((hw_tail - partial_report_size) &
+                (stream->oa_buffer.vma->size - 1));
     now = ktime_get_mono_fast_ns();
@@ -601,6 +613,8 @@ static int append_oa_sample(struct i915_perf_stream *stream,
 {
     int report_size = stream->oa_buffer.format_size;
     struct drm_i915_perf_record_header header;
+    int report_size_partial;
+    u8 *oa_buf_end;
     header.type = DRM_I915_PERF_RECORD_SAMPLE;
     header.pad = 0;
@@ -614,7 +628,19 @@ static int append_oa_sample(struct i915_perf_stream *stream,
         return -EFAULT;
     buf += sizeof(header);
-    if (copy_to_user(buf, report, report_size))
+    oa_buf_end = stream->oa_buffer.vaddr +
+             stream->oa_buffer.vma->size;
+    report_size_partial = oa_buf_end - report;
+
+    if (report_size_partial < report_size) {
+        if(copy_to_user(buf, report, report_size_partial))
+            return -EFAULT;
+        buf += report_size_partial;
+
+        if(copy_to_user(buf, stream->oa_buffer.vaddr,
+                report_size - report_size_partial))
+            return -EFAULT;

I think the coding style requires you to use if () not if()


Will fix.


Just a suggestion : you could make this code deal with the partial bit as the main bit of the function :


oa_buf_end = stream->oa_buffer.vaddr +
         stream->oa_buffer.vma->size;

report_size_partial = oa_buf_end - report;

if (copy_to_user(buf, report, report_size_partial))
    return -EFAULT;
buf += report_size_partial;

This ^ may not work because append_oa_sample is appending exactly one report to the user buffer, whereas the above may append more than one.

Thanks,
Umesh


Ah I see, thanks for pointing this out.

-Lionel




if (report_size_partial < report_size &&
   copy_to_user(buf, stream->oa_buffer.vaddr,
        report_size - report_size_partial))
    return -EFAULT;
buf += report_size - report_size_partial;


+    } else if (copy_to_user(buf, report, report_size))
         return -EFAULT;
     (*offset) += header.size;
@@ -684,8 +710,8 @@ static int gen8_append_oa_reports(struct i915_perf_stream *stream,
      * all a power of two).
      */
     if (drm_WARN_ONCE(&uncore->i915->drm,
-              head > OA_BUFFER_SIZE || head % report_size ||
-              tail > OA_BUFFER_SIZE || tail % report_size,
+              head > stream->oa_buffer.vma->size ||
+              tail > stream->oa_buffer.vma->size,
               "Inconsistent OA buffer pointers: head = %u, tail = %u\n",
               head, tail))
         return -EIO;
@@ -699,22 +725,6 @@ static int gen8_append_oa_reports(struct i915_perf_stream *stream,
         u32 ctx_id;
         u32 reason;
-        /*
-         * All the report sizes factor neatly into the buffer
-         * size so we never expect to see a report split
-         * between the beginning and end of the buffer.
-         *
-         * Given the initial alignment check a misalignment
-         * here would imply a driver bug that would result
-         * in an overrun.
-         */
-        if (drm_WARN_ON(&uncore->i915->drm,
-                (OA_BUFFER_SIZE - head) < report_size)) {
-            drm_err(&uncore->i915->drm,
-                "Spurious OA head ptr: non-integral report offset\n");
-            break;
-        }
-
         /*
          * The reason field includes flags identifying what
          * triggered this specific report (mostly timer
@@ -4513,6 +4523,13 @@ static void oa_init_supported_formats(struct i915_perf *perf)
         oa_format_add(perf, I915_OA_FORMAT_C4_B8);
         break;
+    case INTEL_DG2:
+        oa_format_add(perf, I915_OAR_FORMAT_A32u40_A4u32_B8_C8);
+        oa_format_add(perf, I915_OA_FORMAT_A24u40_A14u32_B8_C8);
+        oa_format_add(perf, I915_OAR_FORMAT_A36u64_B8_C8);
+        oa_format_add(perf, I915_OA_FORMAT_A38u64_R2u64_B8_C8);
+        break;
+
     default:
         MISSING_CASE(platform);
     }
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 520ad2691a99..d20d723925b5 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -2650,6 +2650,12 @@ enum drm_i915_oa_format {
     I915_OA_FORMAT_A12_B8_C8,
     I915_OA_FORMAT_A32u40_A4u32_B8_C8,
+    /* DG2 */
+    I915_OAR_FORMAT_A32u40_A4u32_B8_C8,
+    I915_OA_FORMAT_A24u40_A14u32_B8_C8,
+    I915_OAR_FORMAT_A36u64_B8_C8,
+    I915_OA_FORMAT_A38u64_R2u64_B8_C8,
+
     I915_OA_FORMAT_MAX        /* non-ABI */
 };






[Index of Archives]     [AMD Graphics]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux