linux-kernel - [PATCH v4 15/15] dmaengine: Revert "cookie bypass for out of order completion"

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Date:   Wed, 22 Jun 2022 12:37:53 -0700
From:   Ben Walker <benjamin.walker@...el.com>
To:     vkoul@...nel.org
Cc:     dmaengine@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v4 15/15] dmaengine: Revert "cookie bypass for out of order completion"

This reverts commit 47ec7f09bc107720905c96bc37771e4ed1ff0aed.

This is no longer necessary now that all assumptions about the order of
completions have been removed from the dmaengine client API.

Signed-off-by: Ben Walker <benjamin.walker@...el.com>
---
 .../driver-api/dmaengine/provider.rst         | 19 -------------------
 drivers/dma/dmatest.c                         | 11 +----------
 drivers/dma/idxd/dma.c                        |  1 -
 include/linux/dmaengine.h                     |  2 --
 4 files changed, 1 insertion(+), 32 deletions(-)

diff --git a/Documentation/driver-api/dmaengine/provider.rst b/Documentation/driver-api/dmaengine/provider.rst
index db019ec492b58..8565241270a62 100644
--- a/Documentation/driver-api/dmaengine/provider.rst
+++ b/Documentation/driver-api/dmaengine/provider.rst
@@ -268,22 +268,6 @@ Currently, the types available are:
     want to transfer a portion of uncompressed data directly to the
     display to print it
 
-- DMA_COMPLETION_NO_ORDER
-
-  - The device does not support in order completion.
-
-  - The driver should return DMA_OUT_OF_ORDER for device_tx_status if
-    the device is setting this capability.
-
-  - All cookie tracking and checking API should be treated as invalid if
-    the device exports this capability.
-
-  - At this point, this is incompatible with polling option for dmatest.
-
-  - If this cap is set, the user is recommended to provide an unique
-    identifier for each descriptor sent to the DMA device in order to
-    properly track the completion.
-
 - DMA_REPEAT
 
   - The device supports repeated transfers. A repeated transfer, indicated by
@@ -467,9 +451,6 @@ supported.
   - In the case of a cyclic transfer, it should only take into
     account the total size of the cyclic buffer.
 
-  - Should return DMA_OUT_OF_ORDER if the device does not support in order
-    completion and is completing the operation out of order.
-
   - This function can be called in an interrupt context.
 
 - device_config
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index 3ee47a72bf9d7..d34e7a9b63d89 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -845,10 +845,7 @@ static int dmatest_func(void *data)
 			result("test timed out", total_tests, src->off, dst->off,
 			       len, 0);
 			goto error_unmap_continue;
-		} else if (status != DMA_COMPLETE &&
-			   !(dma_has_cap(DMA_COMPLETION_NO_ORDER,
-					 dev->cap_mask) &&
-			     status == DMA_OUT_OF_ORDER)) {
+		} else if (status != DMA_COMPLETE) {
 			result(status == DMA_ERROR ?
 			       "completion error status" :
 			       "completion busy status", total_tests, src->off,
@@ -1027,12 +1024,6 @@ static int dmatest_add_channel(struct dmatest_info *info,
 	dtc->chan = chan;
 	INIT_LIST_HEAD(&dtc->threads);
 
-	if (dma_has_cap(DMA_COMPLETION_NO_ORDER, dma_dev->cap_mask) &&
-	    info->params.polled) {
-		info->params.polled = false;
-		pr_warn("DMA_COMPLETION_NO_ORDER, polled disabled\n");
-	}
-
 	if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask)) {
 		if (dmatest == 0) {
 			cnt = dmatest_add_threads(info, dtc, DMA_MEMCPY);
diff --git a/drivers/dma/idxd/dma.c b/drivers/dma/idxd/dma.c
index dda5342d273f4..49e863abd50cd 100644
--- a/drivers/dma/idxd/dma.c
+++ b/drivers/dma/idxd/dma.c
@@ -297,7 +297,6 @@ int idxd_register_dma_device(struct idxd_device *idxd)
 
 	dma_cap_set(DMA_INTERRUPT, dma->cap_mask);
 	dma_cap_set(DMA_PRIVATE, dma->cap_mask);
-	dma_cap_set(DMA_COMPLETION_NO_ORDER, dma->cap_mask);
 	dma->device_release = idxd_dma_release;
 
 	dma->device_prep_dma_interrupt = idxd_dma_prep_interrupt;
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index e3e5311b6bb64..136c7afbcc385 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -39,7 +39,6 @@ enum dma_status {
 	DMA_IN_PROGRESS,
 	DMA_PAUSED,
 	DMA_ERROR,
-	DMA_OUT_OF_ORDER,
 };
 
 /**
@@ -63,7 +62,6 @@ enum dma_transaction_type {
 	DMA_SLAVE,
 	DMA_CYCLIC,
 	DMA_INTERLEAVE,
-	DMA_COMPLETION_NO_ORDER,
 	DMA_REPEAT,
 	DMA_LOAD_EOT,
 /* last transaction type for creation of the capabilities mask */
-- 
2.35.1