mmc: mmc_test: Pass different sg lists for non-blocking requests

Supply a separate sg list for each of the request in non-blocking
IO test cases where two requests will be issued at same time.

Otherwise, sg memory may get unmapped when a request is done while
same memory is being accessed by controller from the other request,
and it leads to iommu errors with below call stack:

	__arm_lpae_unmap+0x2e0/0x478
	arm_lpae_unmap+0x54/0x70
	arm_smmu_unmap+0x64/0xa4
	__iommu_unmap+0xb8/0x1f0
	iommu_unmap_fast+0x38/0x48
	__iommu_dma_unmap+0x88/0x108
	iommu_dma_unmap_sg+0x90/0xa4
	sdhci_post_req+0x5c/0x78
	mmc_test_start_areq+0x10c/0x120 [mmc_test]
	mmc_test_area_io_seq+0x150/0x264 [mmc_test]
	mmc_test_rw_multiple+0x174/0x1c0 [mmc_test]
	mmc_test_rw_multiple_sg_len+0x44/0x6c [mmc_test]
	mmc_test_profile_sglen_wr_nonblock_perf+0x6c/0x94 [mmc_test]
	mtf_test_write+0x238/0x3cc [mmc_test]

Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/1582714668-17247-1-git-send-email-vbadigan@codeaurora.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/core/mmc_test.c

@@ -71,6 +71,7 @@ struct mmc_test_mem {
  * @sg_len: length of currently mapped scatterlist @sg
  * @mem: allocated memory
  * @sg: scatterlist
+ * @sg_areq: scatterlist for non-blocking request
  */
 struct mmc_test_area {
 	unsigned long max_sz;
@@ -82,6 +83,7 @@ struct mmc_test_area {
 	unsigned int sg_len;
 	struct mmc_test_mem *mem;
 	struct scatterlist *sg;
+	struct scatterlist *sg_areq;
 };
 
 /**
@@ -836,14 +838,16 @@ static int mmc_test_start_areq(struct mmc_test_card *test,
 }
 
 static int mmc_test_nonblock_transfer(struct mmc_test_card *test,
-				      struct scatterlist *sg, unsigned sg_len,
-				      unsigned dev_addr, unsigned blocks,
-				      unsigned blksz, int write, int count)
+				      unsigned int dev_addr, int write,
+				      int count)
 {
 	struct mmc_test_req *rq1, *rq2;
 	struct mmc_request *mrq, *prev_mrq;
 	int i;
 	int ret = RESULT_OK;
+	struct mmc_test_area *t = &test->area;
+	struct scatterlist *sg = t->sg;
+	struct scatterlist *sg_areq = t->sg_areq;
 
 	rq1 = mmc_test_req_alloc();
 	rq2 = mmc_test_req_alloc();
@@ -857,8 +861,8 @@ static int mmc_test_nonblock_transfer(struct mmc_test_card *test,
 
 	for (i = 0; i < count; i++) {
 		mmc_test_req_reset(container_of(mrq, struct mmc_test_req, mrq));
-		mmc_test_prepare_mrq(test, mrq, sg, sg_len, dev_addr, blocks,
-				     blksz, write);
+		mmc_test_prepare_mrq(test, mrq, sg, t->sg_len, dev_addr,
+				     t->blocks, 512, write);
 		ret = mmc_test_start_areq(test, mrq, prev_mrq);
 		if (ret)
 			goto err;
@@ -867,7 +871,8 @@ static int mmc_test_nonblock_transfer(struct mmc_test_card *test,
 			prev_mrq = &rq2->mrq;
 
 		swap(mrq, prev_mrq);
-		dev_addr += blocks;
+		swap(sg, sg_areq);
+		dev_addr += t->blocks;
 	}
 
 	ret = mmc_test_start_areq(test, NULL, prev_mrq);
@@ -1396,10 +1401,11 @@ static int mmc_test_no_highmem(struct mmc_test_card *test)
  * Map sz bytes so that it can be transferred.
  */
 static int mmc_test_area_map(struct mmc_test_card *test, unsigned long sz,
-			     int max_scatter, int min_sg_len)
+			     int max_scatter, int min_sg_len, bool nonblock)
 {
 	struct mmc_test_area *t = &test->area;
 	int err;
+	unsigned int sg_len = 0;
 
 	t->blocks = sz >> 9;
 
@@ -1411,6 +1417,22 @@ static int mmc_test_area_map(struct mmc_test_card *test, unsigned long sz,
 		err = mmc_test_map_sg(t->mem, sz, t->sg, 1, t->max_segs,
 				      t->max_seg_sz, &t->sg_len, min_sg_len);
 	}
+
+	if (err || !nonblock)
+		goto err;
+
+	if (max_scatter) {
+		err = mmc_test_map_sg_max_scatter(t->mem, sz, t->sg_areq,
+						  t->max_segs, t->max_seg_sz,
+						  &sg_len);
+	} else {
+		err = mmc_test_map_sg(t->mem, sz, t->sg_areq, 1, t->max_segs,
+				      t->max_seg_sz, &sg_len, min_sg_len);
+	}
+	if (!err && sg_len != t->sg_len)
+		err = -EINVAL;
+
+err:
 	if (err)
 		pr_info("%s: Failed to map sg list\n",
 		       mmc_hostname(test->card->host));
@@ -1440,7 +1462,6 @@ static int mmc_test_area_io_seq(struct mmc_test_card *test, unsigned long sz,
 	struct timespec64 ts1, ts2;
 	int ret = 0;
 	int i;
-	struct mmc_test_area *t = &test->area;
 
 	/*
 	 * In the case of a maximally scattered transfer, the maximum transfer
@@ -1458,15 +1479,14 @@ static int mmc_test_area_io_seq(struct mmc_test_card *test, unsigned long sz,
 			sz = max_tfr;
 	}
 
-	ret = mmc_test_area_map(test, sz, max_scatter, min_sg_len);
+	ret = mmc_test_area_map(test, sz, max_scatter, min_sg_len, nonblock);
 	if (ret)
 		return ret;
 
 	if (timed)
 		ktime_get_ts64(&ts1);
 	if (nonblock)
-		ret = mmc_test_nonblock_transfer(test, t->sg, t->sg_len,
-				 dev_addr, t->blocks, 512, write, count);
+		ret = mmc_test_nonblock_transfer(test, dev_addr, write, count);
 	else
 		for (i = 0; i < count && ret == 0; i++) {
 			ret = mmc_test_area_transfer(test, dev_addr, write);
@@ -1525,6 +1545,7 @@ static int mmc_test_area_cleanup(struct mmc_test_card *test)
 	struct mmc_test_area *t = &test->area;
 
 	kfree(t->sg);
+	kfree(t->sg_areq);
 	mmc_test_free_mem(t->mem);
 
 	return 0;
@@ -1584,6 +1605,13 @@ static int mmc_test_area_init(struct mmc_test_card *test, int erase, int fill)
 		goto out_free;
 	}
 
+	t->sg_areq = kmalloc_array(t->max_segs, sizeof(*t->sg_areq),
+				   GFP_KERNEL);
+	if (!t->sg_areq) {
+		ret = -ENOMEM;
+		goto out_free;
+	}
+
 	t->dev_addr = mmc_test_capacity(test->card) / 2;
 	t->dev_addr -= t->dev_addr % (t->max_sz >> 9);
 
@@ -2468,7 +2496,7 @@ static int __mmc_test_cmds_during_tfr(struct mmc_test_card *test,
 	if (!(test->card->host->caps & MMC_CAP_CMD_DURING_TFR))
 		return RESULT_UNSUP_HOST;
 
-	ret = mmc_test_area_map(test, sz, 0, 0);
+	ret = mmc_test_area_map(test, sz, 0, 0, use_areq);
 	if (ret)
 		return ret;