Revert "dmatest: append verify result to results"

This reverts commit d86b2f29.

The kernel log buffer is sufficient for collecting test results.  The
current logging OOMs the machine on long running tests, and usually only
the first error is relevant.  It is better to stop on error and parse
the kernel output.  If output volume becomes an issue we can always
investigate using trace messages.

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Documentation/dmatest.txt

@@ -76,7 +76,5 @@ The message format is unified across the different types of errors. A number in
 the parens represents additional information, e.g. error code, error counter,
 or status.
 
-Comparison between buffers is stored to the dedicated structure.
-
-Note that the verify result is now accessible only via file 'results' in the
-debugfs.
+Note that the buffer comparison is done in the old way, i.e. data is not
+collected and just printed out.

drivers/dma/dmatest.c

@@ -98,20 +98,6 @@ enum dmatest_error_type {
 	DMATEST_ET_DMA_ERROR,
 	DMATEST_ET_DMA_IN_PROGRESS,
 	DMATEST_ET_VERIFY,
-	DMATEST_ET_VERIFY_BUF,
-};
-
-struct dmatest_verify_buffer {
-	unsigned int	index;
-	u8		expected;
-	u8		actual;
-};
-
-struct dmatest_verify_result {
-	unsigned int			error_count;
-	struct dmatest_verify_buffer	data[MAX_ERROR_COUNT];
-	u8				pattern;
-	bool				is_srcbuf;
 };
 
 struct dmatest_thread_result {
@@ -126,7 +112,6 @@ struct dmatest_thread_result {
 		dma_cookie_t		cookie;
 		enum dma_status		status;
 		int			error;
-		struct dmatest_verify_result	*vr;
 	};
 };
 
@@ -262,9 +247,31 @@ static void dmatest_init_dsts(u8 **bufs, unsigned int start, unsigned int len,
 	}
 }
 
-static unsigned int dmatest_verify(struct dmatest_verify_result *vr, u8 **bufs,
-		unsigned int start, unsigned int end, unsigned int counter,
-		u8 pattern, bool is_srcbuf)
+static void dmatest_mismatch(u8 actual, u8 pattern, unsigned int index,
+		unsigned int counter, bool is_srcbuf)
+{
+	u8		diff = actual ^ pattern;
+	u8		expected = pattern | (~counter & PATTERN_COUNT_MASK);
+	const char	*thread_name = current->comm;
+
+	if (is_srcbuf)
+		pr_warn("%s: srcbuf[0x%x] overwritten! Expected %02x, got %02x\n",
+			thread_name, index, expected, actual);
+	else if ((pattern & PATTERN_COPY)
+			&& (diff & (PATTERN_COPY | PATTERN_OVERWRITE)))
+		pr_warn("%s: dstbuf[0x%x] not copied! Expected %02x, got %02x\n",
+			thread_name, index, expected, actual);
+	else if (diff & PATTERN_SRC)
+		pr_warn("%s: dstbuf[0x%x] was copied! Expected %02x, got %02x\n",
+			thread_name, index, expected, actual);
+	else
+		pr_warn("%s: dstbuf[0x%x] mismatch! Expected %02x, got %02x\n",
+			thread_name, index, expected, actual);
+}
+
+static unsigned int dmatest_verify(u8 **bufs, unsigned int start,
+		unsigned int end, unsigned int counter, u8 pattern,
+		bool is_srcbuf)
 {
 	unsigned int i;
 	unsigned int error_count = 0;
@@ -272,7 +279,6 @@ static unsigned int dmatest_verify(struct dmatest_verify_result *vr, u8 **bufs,
 	u8 expected;
 	u8 *buf;
 	unsigned int counter_orig = counter;
-	struct dmatest_verify_buffer *vb;
 
 	for (; (buf = *bufs); bufs++) {
 		counter = counter_orig;
@@ -280,12 +286,9 @@ static unsigned int dmatest_verify(struct dmatest_verify_result *vr, u8 **bufs,
 			actual = buf[i];
 			expected = pattern | (~counter & PATTERN_COUNT_MASK);
 			if (actual != expected) {
-				if (error_count < MAX_ERROR_COUNT && vr) {
-					vb = &vr->data[error_count];
-					vb->index = i;
-					vb->expected = expected;
-					vb->actual = actual;
-				}
+				if (error_count < MAX_ERROR_COUNT)
+					dmatest_mismatch(actual, pattern, i,
+							 counter, is_srcbuf);
 				error_count++;
 			}
 			counter++;
@@ -293,7 +296,7 @@ static unsigned int dmatest_verify(struct dmatest_verify_result *vr, u8 **bufs,
 	}
 
 	if (error_count > MAX_ERROR_COUNT)
-		pr_warning("%s: %u errors suppressed\n",
+		pr_warn("%s: %u errors suppressed\n",
 			current->comm, error_count - MAX_ERROR_COUNT);
 
 	return error_count;
@@ -334,30 +337,6 @@ static unsigned int min_odd(unsigned int x, unsigned int y)
 	return val % 2 ? val : val - 1;
 }
 
-static char *verify_result_get_one(struct dmatest_verify_result *vr,
-		unsigned int i)
-{
-	struct dmatest_verify_buffer *vb = &vr->data[i];
-	u8 diff = vb->actual ^ vr->pattern;
-	static char buf[512];
-	char *msg;
-
-	if (vr->is_srcbuf)
-		msg = "srcbuf overwritten!";
-	else if ((vr->pattern & PATTERN_COPY)
-			&& (diff & (PATTERN_COPY | PATTERN_OVERWRITE)))
-		msg = "dstbuf not copied!";
-	else if (diff & PATTERN_SRC)
-		msg = "dstbuf was copied!";
-	else
-		msg = "dstbuf mismatch!";
-
-	snprintf(buf, sizeof(buf) - 1, "%s [0x%x] Expected %02x, got %02x", msg,
-		 vb->index, vb->expected, vb->actual);
-
-	return buf;
-}
-
 static char *thread_result_get(const char *name,
 		struct dmatest_thread_result *tr)
 {
@@ -373,7 +352,6 @@ static char *thread_result_get(const char *name,
 		[DMATEST_ET_DMA_IN_PROGRESS]	=
 			"got completion callback (DMA_IN_PROGRESS)",
 		[DMATEST_ET_VERIFY]		= "errors",
-		[DMATEST_ET_VERIFY_BUF]		= "verify errors",
 	};
 	static char buf[512];
 
@@ -415,51 +393,6 @@ static int thread_result_add(struct dmatest_info *info,
 	return 0;
 }
 
-static unsigned int verify_result_add(struct dmatest_info *info,
-		struct dmatest_result *r, unsigned int n,
-		unsigned int src_off, unsigned int dst_off, unsigned int len,
-		u8 **bufs, int whence, unsigned int counter, u8 pattern,
-		bool is_srcbuf)
-{
-	struct dmatest_verify_result *vr;
-	unsigned int error_count;
-	unsigned int buf_off = is_srcbuf ? src_off : dst_off;
-	unsigned int start, end;
-
-	if (whence < 0) {
-		start = 0;
-		end = buf_off;
-	} else if (whence > 0) {
-		start = buf_off + len;
-		end = info->params.buf_size;
-	} else {
-		start = buf_off;
-		end = buf_off + len;
-	}
-
-	vr = kmalloc(sizeof(*vr), GFP_KERNEL);
-	if (!vr) {
-		pr_warn("dmatest: No memory to store verify result\n");
-		return dmatest_verify(NULL, bufs, start, end, counter, pattern,
-				      is_srcbuf);
-	}
-
-	vr->pattern = pattern;
-	vr->is_srcbuf = is_srcbuf;
-
-	error_count = dmatest_verify(vr, bufs, start, end, counter, pattern,
-				     is_srcbuf);
-	if (error_count) {
-		vr->error_count = error_count;
-		thread_result_add(info, r, DMATEST_ET_VERIFY_BUF, n, src_off,
-				  dst_off, len, (unsigned long)vr);
-		return error_count;
-	}
-
-	kfree(vr);
-	return 0;
-}
-
 static void result_free(struct dmatest_info *info, const char *name)
 {
 	struct dmatest_result *r, *_r;
@@ -472,8 +405,6 @@ static void result_free(struct dmatest_info *info, const char *name)
 			continue;
 
 		list_for_each_entry_safe(tr, _tr, &r->results, node) {
-			if (tr->type == DMATEST_ET_VERIFY_BUF)
-				kfree(tr->vr);
 			list_del(&tr->node);
 			kfree(tr);
 		}
@@ -755,26 +686,25 @@ static int dmatest_func(void *data)
 		error_count = 0;
 
 		pr_debug("%s: verifying source buffer...\n", thread_name);
-		error_count += verify_result_add(info, result, total_tests,
-				src_off, dst_off, len, thread->srcs, -1,
+		error_count += dmatest_verify(thread->srcs, 0, src_off,
 				0, PATTERN_SRC, true);
-		error_count += verify_result_add(info, result, total_tests,
-				src_off, dst_off, len, thread->srcs, 0,
-				src_off, PATTERN_SRC | PATTERN_COPY, true);
-		error_count += verify_result_add(info, result, total_tests,
-				src_off, dst_off, len, thread->srcs, 1,
-				src_off + len, PATTERN_SRC, true);
-
-		pr_debug("%s: verifying dest buffer...\n", thread_name);
-		error_count += verify_result_add(info, result, total_tests,
-				src_off, dst_off, len, thread->dsts, -1,
+		error_count += dmatest_verify(thread->srcs, src_off,
+				src_off + len, src_off,
+				PATTERN_SRC | PATTERN_COPY, true);
+		error_count += dmatest_verify(thread->srcs, src_off + len,
+				params->buf_size, src_off + len,
+				PATTERN_SRC, true);
+
+		pr_debug("%s: verifying dest buffer...\n",
+				thread->task->comm);
+		error_count += dmatest_verify(thread->dsts, 0, dst_off,
 				0, PATTERN_DST, false);
-		error_count += verify_result_add(info, result, total_tests,
-				src_off, dst_off, len, thread->dsts, 0,
-				src_off, PATTERN_SRC | PATTERN_COPY, false);
-		error_count += verify_result_add(info, result, total_tests,
-				src_off, dst_off, len, thread->dsts, 1,
-				dst_off + len, PATTERN_DST, false);
+		error_count += dmatest_verify(thread->dsts, dst_off,
+				dst_off + len, src_off,
+				PATTERN_SRC | PATTERN_COPY, false);
+		error_count += dmatest_verify(thread->dsts, dst_off + len,
+				params->buf_size, dst_off + len,
+				PATTERN_DST, false);
 
 		if (error_count) {
 			thread_result_add(info, result, DMATEST_ET_VERIFY,
@@ -1099,20 +1029,12 @@ static int dtf_results_show(struct seq_file *sf, void *data)
 	struct dmatest_info *info = sf->private;
 	struct dmatest_result *result;
 	struct dmatest_thread_result *tr;
-	unsigned int i;
 
 	mutex_lock(&info->results_lock);
 	list_for_each_entry(result, &info->results, node) {
-		list_for_each_entry(tr, &result->results, node) {
+		list_for_each_entry(tr, &result->results, node)
 			seq_printf(sf, "%s\n",
 				thread_result_get(result->name, tr));
-			if (tr->type == DMATEST_ET_VERIFY_BUF) {
-				for (i = 0; i < tr->vr->error_count; i++) {
-					seq_printf(sf, "\t%s\n",
-						verify_result_get_one(tr->vr, i));
-				}
-			}
-		}
 	}
 
 	mutex_unlock(&info->results_lock);