[PATCH 6/7] remoteproc: remove the hardcoded vring alignment

[Ohad Ben-Cohen]

Remove the hardcoded vring alignment of 4096 bytes,
and instead utilize tha vring alignment as specified in
the resource table.

This is needed for remote processors that have rigid
memory requirement, and which have found the alignment of
4096 bytes to be excessively big.

Signed-off-by: Ohad Ben-Cohen <ohad at wizery.com>
Cc: Brian Swetland <swetland at google.com>
Cc: Iliyan Malchev <malchev at google.com>
Cc: Arnd Bergmann <arnd at arndb.de>
Cc: Grant Likely <grant.likely at secretlab.ca>
Cc: Rusty Russell <rusty at rustcorp.com.au>
Cc: Mark Grosen <mgrosen at ti.com>
Cc: John Williams <john.williams at petalogix.com>
Cc: Michal Simek <monstr at monstr.eu>
Cc: Loic PALLARDY <loic.pallardy at stericsson.com>
Cc: Ludovic BARRE <ludovic.barre at stericsson.com>
Cc: Omar Ramirez Luna <omar.luna at linaro.org>
Cc: Guzman Lugo Fernando <fernando.lugo at ti.com>
Cc: Anna Suman <s-anna at ti.com>
Cc: Clark Rob <rob at ti.com>
Cc: Stephen Boyd <sboyd at codeaurora.org>
Cc: Saravana Kannan <skannan at codeaurora.org>
Cc: David Brown <davidb at codeaurora.org>
Cc: Kieran Bingham <kieranbingham at gmail.com>
Cc: Tony Lindgren <tony at atomide.com>
---
 drivers/remoteproc/remoteproc_core.c   |   12 +++++++-----
 drivers/remoteproc/remoteproc_virtio.c |    2 +-
 include/linux/remoteproc.h             |    9 ++-------
 3 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index ca02f12..9be5dad 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -298,14 +298,15 @@ __rproc_handle_vring(struct rproc_vdev *rvdev, struct fw_rsc_vdev *rsc, int i)
 		return -EINVAL;
 	}
 
-	/* the firmware must provide the expected queue size */
-	if (!vring->num) {
-		dev_err(dev, "invalid qsz (%d)\n", vring->num);
+	/* verify queue size and vring alignment are sane */
+	if (!vring->num || !vring->align) {
+		dev_err(dev, "invalid qsz (%d) or alignment (%d)\n",
+						vring->num, vring->align);
 		return -EINVAL;
 	}
 
 	/* actual size of vring (in bytes) */
-	size = PAGE_ALIGN(vring_size(vring->num, AMP_VRING_ALIGN));
+	size = PAGE_ALIGN(vring_size(vring->num, vring->align));
 
 	if (!idr_pre_get(&rproc->notifyids, GFP_KERNEL)) {
 		dev_err(dev, "idr_pre_get failed\n");
@@ -340,6 +341,7 @@ __rproc_handle_vring(struct rproc_vdev *rvdev, struct fw_rsc_vdev *rsc, int i)
 					dma, size, notifyid);
 
 	rvdev->vring[i].len = vring->num;
+	rvdev->vring[i].align = vring->align;
 	rvdev->vring[i].va = va;
 	rvdev->vring[i].dma = dma;
 	rvdev->vring[i].notifyid = notifyid;
@@ -354,7 +356,7 @@ static void __rproc_free_vrings(struct rproc_vdev *rvdev, int i)
 
 	for (i--; i > 0; i--) {
 		struct rproc_vring *rvring = &rvdev->vring[i];
-		int size = PAGE_ALIGN(vring_size(rvring->len, AMP_VRING_ALIGN));
+		int size = PAGE_ALIGN(vring_size(rvring->len, rvring->align));
 
 		dma_free_coherent(rproc->dev, size, rvring->va, rvring->dma);
 		idr_remove(&rproc->notifyids, rvring->notifyid);
diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
index 0700410..ecf6121 100644
--- a/drivers/remoteproc/remoteproc_virtio.c
+++ b/drivers/remoteproc/remoteproc_virtio.c
@@ -99,7 +99,7 @@ static struct virtqueue *rp_find_vq(struct virtio_device *vdev,
 	 * Create the new vq, and tell virtio we're not interested in
 	 * the 'weak' smp barriers, since we're talking with a real device.
 	 */
-	vq = vring_new_virtqueue(len, AMP_VRING_ALIGN, vdev, false, addr,
+	vq = vring_new_virtqueue(len, rvring->align, vdev, false, addr,
 					rproc_virtio_notify, callback, name);
 	if (!vq) {
 		dev_err(rproc->dev, "vring_new_virtqueue %s failed\n", name);
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 7750d8a..f1ffabb 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -43,13 +43,6 @@
 #include <linux/completion.h>
 #include <linux/idr.h>
 
-/*
- * The alignment between the consumer and producer parts of the vring.
- * Note: this is part of the "wire" protocol. If you change this, you need
- * to update your peers too.
- */
-#define AMP_VRING_ALIGN	(4096)
-
 /**
  * struct resource_table - firmware resource table header
  * @ver: version number
@@ -423,6 +416,7 @@ struct rproc {
  * @dma: dma address
  * @len: length, in bytes
  * @da: device address
+ * @align: vring alignment
  * @notifyid: rproc-specific unique vring index
  * @rvdev: remote vdev
  * @vq: the virtqueue of this vring
@@ -432,6 +426,7 @@ struct rproc_vring {
 	dma_addr_t dma;
 	int len;
 	u32 da;
+	u32 align;
 	int notifyid;
 	struct rproc_vdev *rvdev;
 	struct virtqueue *vq;
-- 
1.7.5.4