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* [PATCH V3 0/4]  Change vring space from nomal memory to dma coherent memory
@ 2020-10-22  5:06 Sherry Sun
  2020-10-22  5:06 ` [PATCH V3 1/4] misc: vop: change the way of allocating vring and device page Sherry Sun
                   ` (3 more replies)
  0 siblings, 4 replies; 13+ messages in thread
From: Sherry Sun @ 2020-10-22  5:06 UTC (permalink / raw)
  To: hch, sudeep.dutt, ashutosh.dixit, arnd, gregkh, kishon,
	lorenzo.pieralisi
  Cc: linux-kernel, linux-pci, linux-imx

Changes in V3:
1. Change the device page allocation method of the Intel mic layer in Patch 1 to
align with the vring allocation. 
2. Move the vring physical address changes in mmap callback from Prach 3 to 1.
3. Use must_be_zero instead of directly deleting used_address_updated in
Patch 2 to avoid the influence of ABI change.
(I tried to use dma_mmap_coherent api in Patch 4 as Christoph suggested, but
 met some issues explained here https://lore.kernel.org/patchwork/patch/1313327/,
 so there is no change to Patch 4, and still can't find a better way than
 patch 3)

The original vop driver only supports dma coherent device, as it allocates and
maps vring by _get_free_pages and dma_map_single, but not use 
dma_sync_single_for_cpu/device to sync the updates of device_page/vring between
EP and RC, which will cause memory synchronization problem for device don't
support hardware dma coherent.

And allocate vrings use dma_alloc_coherent is a common way in kernel, as the
memory interacted between two systems should use consistent memory to avoid
caching effects. So here add noncoherent platform support for vop driver.
Also add some related dma changes to make sure noncoherent platform works
well.

Sherry Sun (4):
  misc: vop: change the way of allocating vring and device page
  misc: vop: do not allocate and reassign the used ring
  misc: vop: simply return the saved dma address instead of virt_to_phys
  misc: vop: mapping kernel memory to user space as noncached

 drivers/misc/mic/bus/vop_bus.h     |  2 +
 drivers/misc/mic/host/mic_boot.c   |  8 +++
 drivers/misc/mic/host/mic_main.c   | 15 ++----
 drivers/misc/mic/vop/vop_debugfs.c |  2 -
 drivers/misc/mic/vop/vop_main.c    | 48 +++--------------
 drivers/misc/mic/vop/vop_vringh.c  | 84 +++++++-----------------------
 include/uapi/linux/mic_common.h    |  5 +-
 7 files changed, 42 insertions(+), 122 deletions(-)

-- 
2.17.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH V3 1/4] misc: vop: change the way of allocating vring and device page
  2020-10-22  5:06 [PATCH V3 0/4] Change vring space from nomal memory to dma coherent memory Sherry Sun
@ 2020-10-22  5:06 ` Sherry Sun
  2020-10-22  7:58   ` kernel test robot
  2020-10-23  9:25   ` Christoph Hellwig
  2020-10-22  5:06 ` [PATCH V3 2/4] misc: vop: do not allocate and reassign the used ring Sherry Sun
                   ` (2 subsequent siblings)
  3 siblings, 2 replies; 13+ messages in thread
From: Sherry Sun @ 2020-10-22  5:06 UTC (permalink / raw)
  To: hch, sudeep.dutt, ashutosh.dixit, arnd, gregkh, kishon,
	lorenzo.pieralisi
  Cc: linux-kernel, linux-pci, linux-imx

Allocate vrings use dma_alloc_coherent is a common way in kernel. As the
memory interacted between two systems should use consistent memory to
avoid caching effects, same as device page memory.

The orginal way use __get_free_pages and dma_map_single to allocate and
map vring, but not use dma_sync_single_for_cpu/device api to sync the
changes of vring between EP and RC, which will cause memory
synchronization problem for those devices which don't support hardware
dma coherent.

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
---
 drivers/misc/mic/host/mic_main.c  | 15 +++--------
 drivers/misc/mic/vop/vop_vringh.c | 43 +++++++++----------------------
 2 files changed, 16 insertions(+), 42 deletions(-)

diff --git a/drivers/misc/mic/host/mic_main.c b/drivers/misc/mic/host/mic_main.c
index ea4608527ea0..ebacaa35cb47 100644
--- a/drivers/misc/mic/host/mic_main.c
+++ b/drivers/misc/mic/host/mic_main.c
@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/poll.h>
+#include <linux/dma-mapping.h>
 
 #include <linux/mic_common.h>
 #include "../common/mic_dev.h"
@@ -48,18 +49,11 @@ static struct ida g_mic_ida;
 /* Initialize the device page */
 static int mic_dp_init(struct mic_device *mdev)
 {
-	mdev->dp = kzalloc(MIC_DP_SIZE, GFP_KERNEL);
+	mdev->dp = dma_alloc_coherent(&mdev->pdev->dev, MIC_DP_SIZE,
+				      &mdev->dp_dma_addr, GFP_KERNEL);
 	if (!mdev->dp)
 		return -ENOMEM;
 
-	mdev->dp_dma_addr = mic_map_single(mdev,
-		mdev->dp, MIC_DP_SIZE);
-	if (mic_map_error(mdev->dp_dma_addr)) {
-		kfree(mdev->dp);
-		dev_err(&mdev->pdev->dev, "%s %d err %d\n",
-			__func__, __LINE__, -ENOMEM);
-		return -ENOMEM;
-	}
 	mdev->ops->write_spad(mdev, MIC_DPLO_SPAD, mdev->dp_dma_addr);
 	mdev->ops->write_spad(mdev, MIC_DPHI_SPAD, mdev->dp_dma_addr >> 32);
 	return 0;
@@ -68,8 +62,7 @@ static int mic_dp_init(struct mic_device *mdev)
 /* Uninitialize the device page */
 static void mic_dp_uninit(struct mic_device *mdev)
 {
-	mic_unmap_single(mdev, mdev->dp_dma_addr, MIC_DP_SIZE);
-	kfree(mdev->dp);
+	dma_free_coherent(&mdev->pdev->dev, MIC_DP_SIZE, mdev->dp, mdev->dp_dma_addr);
 }
 
 /**
diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c
index 7014ffe88632..2cc3c22482b5 100644
--- a/drivers/misc/mic/vop/vop_vringh.c
+++ b/drivers/misc/mic/vop/vop_vringh.c
@@ -298,9 +298,8 @@ static int vop_virtio_add_device(struct vop_vdev *vdev,
 		mutex_init(&vvr->vr_mutex);
 		vr_size = PAGE_ALIGN(round_up(vring_size(num, MIC_VIRTIO_RING_ALIGN), 4) +
 			sizeof(struct _mic_vring_info));
-		vr->va = (void *)
-			__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-					 get_order(vr_size));
+		vr->va = dma_alloc_coherent(vop_dev(vdev), vr_size, &vr_addr,
+					    GFP_KERNEL);
 		if (!vr->va) {
 			ret = -ENOMEM;
 			dev_err(vop_dev(vdev), "%s %d err %d\n",
@@ -310,15 +309,6 @@ static int vop_virtio_add_device(struct vop_vdev *vdev,
 		vr->len = vr_size;
 		vr->info = vr->va + round_up(vring_size(num, MIC_VIRTIO_RING_ALIGN), 4);
 		vr->info->magic = cpu_to_le32(MIC_MAGIC + vdev->virtio_id + i);
-		vr_addr = dma_map_single(&vpdev->dev, vr->va, vr_size,
-					 DMA_BIDIRECTIONAL);
-		if (dma_mapping_error(&vpdev->dev, vr_addr)) {
-			free_pages((unsigned long)vr->va, get_order(vr_size));
-			ret = -ENOMEM;
-			dev_err(vop_dev(vdev), "%s %d err %d\n",
-				__func__, __LINE__, ret);
-			goto err;
-		}
 		vqconfig[i].address = cpu_to_le64(vr_addr);
 
 		vring_init(&vr->vr, num, vr->va, MIC_VIRTIO_RING_ALIGN);
@@ -339,11 +329,8 @@ static int vop_virtio_add_device(struct vop_vdev *vdev,
 		dev_dbg(&vpdev->dev,
 			"%s %d index %d va %p info %p vr_size 0x%x\n",
 			__func__, __LINE__, i, vr->va, vr->info, vr_size);
-		vvr->buf = (void *)__get_free_pages(GFP_KERNEL,
-					get_order(VOP_INT_DMA_BUF_SIZE));
-		vvr->buf_da = dma_map_single(&vpdev->dev,
-					  vvr->buf, VOP_INT_DMA_BUF_SIZE,
-					  DMA_BIDIRECTIONAL);
+		vvr->buf = dma_alloc_coherent(vop_dev(vdev), VOP_INT_DMA_BUF_SIZE,
+					      &vvr->buf_da, GFP_KERNEL);
 	}
 
 	snprintf(irqname, sizeof(irqname), "vop%dvirtio%d", vpdev->index,
@@ -382,10 +369,8 @@ static int vop_virtio_add_device(struct vop_vdev *vdev,
 	for (j = 0; j < i; j++) {
 		struct vop_vringh *vvr = &vdev->vvr[j];
 
-		dma_unmap_single(&vpdev->dev, le64_to_cpu(vqconfig[j].address),
-				 vvr->vring.len, DMA_BIDIRECTIONAL);
-		free_pages((unsigned long)vvr->vring.va,
-			   get_order(vvr->vring.len));
+		dma_free_coherent(vop_dev(vdev), vvr->vring.len, vvr->vring.va,
+				  le64_to_cpu(vqconfig[j].address));
 	}
 	return ret;
 }
@@ -433,17 +418,12 @@ static void vop_virtio_del_device(struct vop_vdev *vdev)
 	for (i = 0; i < vdev->dd->num_vq; i++) {
 		struct vop_vringh *vvr = &vdev->vvr[i];
 
-		dma_unmap_single(&vpdev->dev,
-				 vvr->buf_da, VOP_INT_DMA_BUF_SIZE,
-				 DMA_BIDIRECTIONAL);
-		free_pages((unsigned long)vvr->buf,
-			   get_order(VOP_INT_DMA_BUF_SIZE));
+		dma_free_coherent(vop_dev(vdev), VOP_INT_DMA_BUF_SIZE,
+				  vvr->buf, vvr->buf_da);
 		vringh_kiov_cleanup(&vvr->riov);
 		vringh_kiov_cleanup(&vvr->wiov);
-		dma_unmap_single(&vpdev->dev, le64_to_cpu(vqconfig[i].address),
-				 vvr->vring.len, DMA_BIDIRECTIONAL);
-		free_pages((unsigned long)vvr->vring.va,
-			   get_order(vvr->vring.len));
+		dma_free_coherent(vop_dev(vdev), vvr->vring.len, vvr->vring.va,
+				  le64_to_cpu(vqconfig[i].address));
 	}
 	/*
 	 * Order the type update with previous stores. This write barrier
@@ -1047,6 +1027,7 @@ vop_query_offset(struct vop_vdev *vdev, unsigned long offset,
 		 unsigned long *size, unsigned long *pa)
 {
 	struct vop_device *vpdev = vdev->vpdev;
+	struct mic_vqconfig *vqconfig = mic_vq_config(vdev->dd);
 	unsigned long start = MIC_DP_SIZE;
 	int i;
 
@@ -1068,7 +1049,7 @@ vop_query_offset(struct vop_vdev *vdev, unsigned long offset,
 		struct vop_vringh *vvr = &vdev->vvr[i];
 
 		if (offset == start) {
-			*pa = virt_to_phys(vvr->vring.va);
+			*pa = vqconfig[i].address;
 			*size = vvr->vring.len;
 			return 0;
 		}
-- 
2.17.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH V3 2/4] misc: vop: do not allocate and reassign the used ring
  2020-10-22  5:06 [PATCH V3 0/4] Change vring space from nomal memory to dma coherent memory Sherry Sun
  2020-10-22  5:06 ` [PATCH V3 1/4] misc: vop: change the way of allocating vring and device page Sherry Sun
@ 2020-10-22  5:06 ` Sherry Sun
  2020-10-22  8:53   ` kernel test robot
  2020-10-23  9:26   ` Christoph Hellwig
  2020-10-22  5:06 ` [PATCH V3 3/4] misc: vop: simply return the saved dma address instead of virt_to_phys Sherry Sun
  2020-10-22  5:06 ` [PATCH V3 4/4] misc: vop: mapping kernel memory to user space as noncached Sherry Sun
  3 siblings, 2 replies; 13+ messages in thread
From: Sherry Sun @ 2020-10-22  5:06 UTC (permalink / raw)
  To: hch, sudeep.dutt, ashutosh.dixit, arnd, gregkh, kishon,
	lorenzo.pieralisi
  Cc: linux-kernel, linux-pci, linux-imx

We don't need to allocate and reassign the used ring here and remove the
used_address_updated flag.Since RC has allocated the entire vring,
including the used ring. Simply add the corresponding offset can get the
used ring address.

If following the orginal way to reassign the used ring, will encounter a
problem. When host finished with descriptor, it will update the used
ring with putused_kern api, if reassign used ring at EP side, used
ring will be io device memory for RC, use memcpy in putused_kern will
cause kernel panic.

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
---
 drivers/misc/mic/vop/vop_debugfs.c |  2 --
 drivers/misc/mic/vop/vop_main.c    | 48 ++++--------------------------
 drivers/misc/mic/vop/vop_vringh.c  | 31 -------------------
 include/uapi/linux/mic_common.h    |  5 ++--
 4 files changed, 8 insertions(+), 78 deletions(-)

diff --git a/drivers/misc/mic/vop/vop_debugfs.c b/drivers/misc/mic/vop/vop_debugfs.c
index 9d4f175f4dd1..05eca4a98585 100644
--- a/drivers/misc/mic/vop/vop_debugfs.c
+++ b/drivers/misc/mic/vop/vop_debugfs.c
@@ -79,8 +79,6 @@ static int vop_dp_show(struct seq_file *s, void *pos)
 		seq_printf(s, "Vdev reset %d\n", dc->vdev_reset);
 		seq_printf(s, "Guest Ack %d ", dc->guest_ack);
 		seq_printf(s, "Host ack %d\n", dc->host_ack);
-		seq_printf(s, "Used address updated %d ",
-			   dc->used_address_updated);
 		seq_printf(s, "Vdev 0x%llx\n", dc->vdev);
 		seq_printf(s, "c2h doorbell %d ", dc->c2h_vdev_db);
 		seq_printf(s, "h2c doorbell %d\n", dc->h2c_vdev_db);
diff --git a/drivers/misc/mic/vop/vop_main.c b/drivers/misc/mic/vop/vop_main.c
index 714b94f42d38..1ccc94dfd6ac 100644
--- a/drivers/misc/mic/vop/vop_main.c
+++ b/drivers/misc/mic/vop/vop_main.c
@@ -250,10 +250,6 @@ static void vop_del_vq(struct virtqueue *vq, int n)
 	struct _vop_vdev *vdev = to_vopvdev(vq->vdev);
 	struct vop_device *vpdev = vdev->vpdev;
 
-	dma_unmap_single(&vpdev->dev, vdev->used[n],
-			 vdev->used_size[n], DMA_BIDIRECTIONAL);
-	free_pages((unsigned long)vdev->used_virt[n],
-		   get_order(vdev->used_size[n]));
 	vring_del_virtqueue(vq);
 	vpdev->hw_ops->unmap(vpdev, vdev->vr[n]);
 	vdev->vr[n] = NULL;
@@ -340,8 +336,8 @@ static struct virtqueue *vop_find_vq(struct virtio_device *dev,
 	vdev->used_size[index] = PAGE_ALIGN(sizeof(__u16) * 3 +
 					     sizeof(struct vring_used_elem) *
 					     le16_to_cpu(config.num));
-	used = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-					get_order(vdev->used_size[index]));
+	used = va + PAGE_ALIGN(sizeof(struct vring_desc) * le16_to_cpu(config.num) +
+			       sizeof(__u16) * (3 + le16_to_cpu(config.num)));
 	vdev->used_virt[index] = used;
 	if (!used) {
 		err = -ENOMEM;
@@ -355,27 +351,15 @@ static struct virtqueue *vop_find_vq(struct virtio_device *dev,
 			       name, used);
 	if (!vq) {
 		err = -ENOMEM;
-		goto free_used;
+		goto unmap;
 	}
 
-	vdev->used[index] = dma_map_single(&vpdev->dev, used,
-					    vdev->used_size[index],
-					    DMA_BIDIRECTIONAL);
-	if (dma_mapping_error(&vpdev->dev, vdev->used[index])) {
-		err = -ENOMEM;
-		dev_err(_vop_dev(vdev), "%s %d err %d\n",
-			__func__, __LINE__, err);
-		goto del_vq;
-	}
+	vdev->used[index] = config.address + PAGE_ALIGN(sizeof(struct vring_desc) * le16_to_cpu(config.num) +
+			    sizeof(__u16) * (3 + le16_to_cpu(config.num)));
 	writeq(vdev->used[index], &vqconfig->used_address);
 
 	vq->priv = vdev;
 	return vq;
-del_vq:
-	vring_del_virtqueue(vq);
-free_used:
-	free_pages((unsigned long)used,
-		   get_order(vdev->used_size[index]));
 unmap:
 	vpdev->hw_ops->unmap(vpdev, vdev->vr[index]);
 	return ERR_PTR(err);
@@ -388,9 +372,7 @@ static int vop_find_vqs(struct virtio_device *dev, unsigned nvqs,
 			struct irq_affinity *desc)
 {
 	struct _vop_vdev *vdev = to_vopvdev(dev);
-	struct vop_device *vpdev = vdev->vpdev;
-	struct mic_device_ctrl __iomem *dc = vdev->dc;
-	int i, err, retry, queue_idx = 0;
+	int i, err, queue_idx = 0;
 
 	/* We must have this many virtqueues. */
 	if (nvqs > ioread8(&vdev->desc->num_vq))
@@ -412,24 +394,6 @@ static int vop_find_vqs(struct virtio_device *dev, unsigned nvqs,
 		}
 	}
 
-	iowrite8(1, &dc->used_address_updated);
-	/*
-	 * Send an interrupt to the host to inform it that used
-	 * rings have been re-assigned.
-	 */
-	vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db);
-	for (retry = 100; --retry;) {
-		if (!ioread8(&dc->used_address_updated))
-			break;
-		msleep(100);
-	}
-
-	dev_dbg(_vop_dev(vdev), "%s: retry: %d\n", __func__, retry);
-	if (!retry) {
-		err = -ENODEV;
-		goto error;
-	}
-
 	return 0;
 error:
 	vop_del_vqs(dev);
diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c
index 2cc3c22482b5..cc928d45af5a 100644
--- a/drivers/misc/mic/vop/vop_vringh.c
+++ b/drivers/misc/mic/vop/vop_vringh.c
@@ -53,33 +53,6 @@ static void _vop_notify(struct vringh *vrh)
 		vpdev->hw_ops->send_intr(vpdev, db);
 }
 
-static void vop_virtio_init_post(struct vop_vdev *vdev)
-{
-	struct mic_vqconfig *vqconfig = mic_vq_config(vdev->dd);
-	struct vop_device *vpdev = vdev->vpdev;
-	int i, used_size;
-
-	for (i = 0; i < vdev->dd->num_vq; i++) {
-		used_size = PAGE_ALIGN(sizeof(u16) * 3 +
-				sizeof(struct vring_used_elem) *
-				le16_to_cpu(vqconfig->num));
-		if (!le64_to_cpu(vqconfig[i].used_address)) {
-			dev_warn(vop_dev(vdev), "used_address zero??\n");
-			continue;
-		}
-		vdev->vvr[i].vrh.vring.used =
-			(void __force *)vpdev->hw_ops->remap(
-			vpdev,
-			le64_to_cpu(vqconfig[i].used_address),
-			used_size);
-	}
-
-	vdev->dc->used_address_updated = 0;
-
-	dev_info(vop_dev(vdev), "%s: device type %d LINKUP\n",
-		 __func__, vdev->virtio_id);
-}
-
 static inline void vop_virtio_device_reset(struct vop_vdev *vdev)
 {
 	int i;
@@ -130,9 +103,6 @@ static void vop_bh_handler(struct work_struct *work)
 	struct vop_vdev *vdev = container_of(work, struct vop_vdev,
 			virtio_bh_work);
 
-	if (vdev->dc->used_address_updated)
-		vop_virtio_init_post(vdev);
-
 	if (vdev->dc->vdev_reset)
 		vop_virtio_device_reset(vdev);
 
@@ -250,7 +220,6 @@ static void vop_init_device_ctrl(struct vop_vdev *vdev,
 	dc->guest_ack = 0;
 	dc->vdev_reset = 0;
 	dc->host_ack = 0;
-	dc->used_address_updated = 0;
 	dc->c2h_vdev_db = -1;
 	dc->h2c_vdev_db = -1;
 	vdev->dc = dc;
diff --git a/include/uapi/linux/mic_common.h b/include/uapi/linux/mic_common.h
index 504e523f702c..fe660d486b20 100644
--- a/include/uapi/linux/mic_common.h
+++ b/include/uapi/linux/mic_common.h
@@ -56,8 +56,7 @@ struct mic_device_desc {
  * @vdev_reset: Set to 1 by guest to indicate virtio device has been reset.
  * @guest_ack: Set to 1 by guest to ack a command.
  * @host_ack: Set to 1 by host to ack a command.
- * @used_address_updated: Set to 1 by guest when the used address should be
- * updated.
+ * @must_be_zero: Reserved because this bit is no longer needed.
  * @c2h_vdev_db: The doorbell number to be used by guest. Set by host.
  * @h2c_vdev_db: The doorbell number to be used by host. Set by guest.
  */
@@ -67,7 +66,7 @@ struct mic_device_ctrl {
 	__u8 vdev_reset;
 	__u8 guest_ack;
 	__u8 host_ack;
-	__u8 used_address_updated;
+	__u8 must_be_zero;
 	__s8 c2h_vdev_db;
 	__s8 h2c_vdev_db;
 } __attribute__ ((aligned(8)));
-- 
2.17.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH V3 3/4] misc: vop: simply return the saved dma address instead of virt_to_phys
  2020-10-22  5:06 [PATCH V3 0/4] Change vring space from nomal memory to dma coherent memory Sherry Sun
  2020-10-22  5:06 ` [PATCH V3 1/4] misc: vop: change the way of allocating vring and device page Sherry Sun
  2020-10-22  5:06 ` [PATCH V3 2/4] misc: vop: do not allocate and reassign the used ring Sherry Sun
@ 2020-10-22  5:06 ` Sherry Sun
  2020-10-22  5:06 ` [PATCH V3 4/4] misc: vop: mapping kernel memory to user space as noncached Sherry Sun
  3 siblings, 0 replies; 13+ messages in thread
From: Sherry Sun @ 2020-10-22  5:06 UTC (permalink / raw)
  To: hch, sudeep.dutt, ashutosh.dixit, arnd, gregkh, kishon,
	lorenzo.pieralisi
  Cc: linux-kernel, linux-pci, linux-imx

The device page and vring should use consistent memory which are
allocated by dma_alloc_coherent api, when user space wants to get its
physical address, virt_to_phys cannot be used, should simply return the
saved device page dma address by get_dp_dma callback and the vring dma
address saved in mic_vqconfig.

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
---
 drivers/misc/mic/bus/vop_bus.h    | 2 ++
 drivers/misc/mic/host/mic_boot.c  | 8 ++++++++
 drivers/misc/mic/vop/vop_vringh.c | 8 +++++++-
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/mic/bus/vop_bus.h b/drivers/misc/mic/bus/vop_bus.h
index 4fa02808c1e2..d891eacae358 100644
--- a/drivers/misc/mic/bus/vop_bus.h
+++ b/drivers/misc/mic/bus/vop_bus.h
@@ -75,6 +75,7 @@ struct vop_driver {
  *                 node to add/remove/configure virtio devices.
  * @get_dp: Get access to the virtio device page used by the self
  *          node to add/remove/configure virtio devices.
+ * @get_dp_dma: Get dma address of the virtio device page.
  * @send_intr: Send an interrupt to the peer node on a specified doorbell.
  * @remap: Map a buffer with the specified DMA address and length.
  * @unmap: Unmap a buffer previously mapped.
@@ -92,6 +93,7 @@ struct vop_hw_ops {
 	void (*ack_interrupt)(struct vop_device *vpdev, int num);
 	void __iomem * (*get_remote_dp)(struct vop_device *vpdev);
 	void * (*get_dp)(struct vop_device *vpdev);
+	dma_addr_t (*get_dp_dma)(struct vop_device *vpdev);
 	void (*send_intr)(struct vop_device *vpdev, int db);
 	void __iomem * (*remap)(struct vop_device *vpdev,
 				  dma_addr_t pa, size_t len);
diff --git a/drivers/misc/mic/host/mic_boot.c b/drivers/misc/mic/host/mic_boot.c
index 8cb85b8b3e19..9591bf609f57 100644
--- a/drivers/misc/mic/host/mic_boot.c
+++ b/drivers/misc/mic/host/mic_boot.c
@@ -89,6 +89,13 @@ static void *__mic_get_dp(struct vop_device *vpdev)
 	return mdev->dp;
 }
 
+static dma_addr_t __mic_get_dp_dma(struct vop_device *vpdev)
+{
+	struct mic_device *mdev = vpdev_to_mdev(&vpdev->dev);
+
+	return mdev->dp_dma_addr;
+}
+
 static void __iomem *__mic_get_remote_dp(struct vop_device *vpdev)
 {
 	return NULL;
@@ -120,6 +127,7 @@ static struct vop_hw_ops vop_hw_ops = {
 	.ack_interrupt = __mic_ack_interrupt,
 	.next_db = __mic_next_db,
 	.get_dp = __mic_get_dp,
+	.get_dp_dma = __mic_get_dp_dma,
 	.get_remote_dp = __mic_get_remote_dp,
 	.send_intr = __mic_send_intr,
 	.remap = __mic_ioremap,
diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c
index cc928d45af5a..b5612183dcb8 100644
--- a/drivers/misc/mic/vop/vop_vringh.c
+++ b/drivers/misc/mic/vop/vop_vringh.c
@@ -1009,7 +1009,13 @@ vop_query_offset(struct vop_vdev *vdev, unsigned long offset,
 	 * ....
 	 */
 	if (!offset) {
-		*pa = virt_to_phys(vpdev->hw_ops->get_dp(vpdev));
+		if (vpdev->hw_ops->get_dp_dma)
+			*pa = vpdev->hw_ops->get_dp_dma(vpdev);
+		else {
+			dev_err(vop_dev(vdev), "can't get device page physical address\n");
+			return -EINVAL;
+		}
+
 		*size = MIC_DP_SIZE;
 		return 0;
 	}
-- 
2.17.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH V3 4/4] misc: vop: mapping kernel memory to user space as noncached
  2020-10-22  5:06 [PATCH V3 0/4] Change vring space from nomal memory to dma coherent memory Sherry Sun
                   ` (2 preceding siblings ...)
  2020-10-22  5:06 ` [PATCH V3 3/4] misc: vop: simply return the saved dma address instead of virt_to_phys Sherry Sun
@ 2020-10-22  5:06 ` Sherry Sun
  2020-10-23  9:28   ` Christoph Hellwig
  3 siblings, 1 reply; 13+ messages in thread
From: Sherry Sun @ 2020-10-22  5:06 UTC (permalink / raw)
  To: hch, sudeep.dutt, ashutosh.dixit, arnd, gregkh, kishon,
	lorenzo.pieralisi
  Cc: linux-kernel, linux-pci, linux-imx

Mapping kernel space memory to user space as noncached, since user space
need check the updates of avail_idx and device page flags timely.

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
---
 drivers/misc/mic/vop/vop_vringh.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c
index b5612183dcb8..b75c2b713a3b 100644
--- a/drivers/misc/mic/vop/vop_vringh.c
+++ b/drivers/misc/mic/vop/vop_vringh.c
@@ -1058,7 +1058,7 @@ static int vop_mmap(struct file *f, struct vm_area_struct *vma)
 		}
 		err = remap_pfn_range(vma, vma->vm_start + offset,
 				      pa >> PAGE_SHIFT, size,
-				      vma->vm_page_prot);
+				      pgprot_noncached(vma->vm_page_prot));
 		if (err)
 			goto ret;
 		size_rem -= size;
-- 
2.17.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH V3 1/4] misc: vop: change the way of allocating vring and device page
  2020-10-22  5:06 ` [PATCH V3 1/4] misc: vop: change the way of allocating vring and device page Sherry Sun
@ 2020-10-22  7:58   ` kernel test robot
  2020-10-23  9:25   ` Christoph Hellwig
  1 sibling, 0 replies; 13+ messages in thread
From: kernel test robot @ 2020-10-22  7:58 UTC (permalink / raw)
  To: Sherry Sun, hch, sudeep.dutt, ashutosh.dixit, arnd, gregkh,
	kishon, lorenzo.pieralisi
  Cc: kbuild-all, linux-kernel, linux-pci, linux-imx


[-- Attachment #1: Type: text/plain, Size: 3037 bytes --]

Hi Sherry,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on soc/for-next linus/master v5.9 next-20201022]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Sherry-Sun/Change-vring-space-from-nomal-memory-to-dma-coherent-memory/20201022-131008
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git f3277cbfba763cd2826396521b9296de67cf1bbc
config: i386-randconfig-s002-20201022 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.3-dirty
        # https://github.com/0day-ci/linux/commit/6851e84ec2f16ab12b04b2a5bf61b05465d450e6
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Sherry-Sun/Change-vring-space-from-nomal-memory-to-dma-coherent-memory/20201022-131008
        git checkout 6851e84ec2f16ab12b04b2a5bf61b05465d450e6
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=i386 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


"sparse warnings: (new ones prefixed by >>)"
>> drivers/misc/mic/vop/vop_vringh.c:1052:29: sparse: sparse: incorrect type in assignment (different base types) @@     expected unsigned long @@     got restricted __le64 [usertype] address @@
>> drivers/misc/mic/vop/vop_vringh.c:1052:29: sparse:     expected unsigned long
>> drivers/misc/mic/vop/vop_vringh.c:1052:29: sparse:     got restricted __le64 [usertype] address

vim +1052 drivers/misc/mic/vop/vop_vringh.c

  1024	
  1025	static inline int
  1026	vop_query_offset(struct vop_vdev *vdev, unsigned long offset,
  1027			 unsigned long *size, unsigned long *pa)
  1028	{
  1029		struct vop_device *vpdev = vdev->vpdev;
  1030		struct mic_vqconfig *vqconfig = mic_vq_config(vdev->dd);
  1031		unsigned long start = MIC_DP_SIZE;
  1032		int i;
  1033	
  1034		/*
  1035		 * MMAP interface is as follows:
  1036		 * offset				region
  1037		 * 0x0					virtio device_page
  1038		 * 0x1000				first vring
  1039		 * 0x1000 + size of 1st vring		second vring
  1040		 * ....
  1041		 */
  1042		if (!offset) {
  1043			*pa = virt_to_phys(vpdev->hw_ops->get_dp(vpdev));
  1044			*size = MIC_DP_SIZE;
  1045			return 0;
  1046		}
  1047	
  1048		for (i = 0; i < vdev->dd->num_vq; i++) {
  1049			struct vop_vringh *vvr = &vdev->vvr[i];
  1050	
  1051			if (offset == start) {
> 1052				*pa = vqconfig[i].address;
  1053				*size = vvr->vring.len;
  1054				return 0;
  1055			}
  1056			start += vvr->vring.len;
  1057		}
  1058		return -1;
  1059	}
  1060	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 36245 bytes --]

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH V3 2/4] misc: vop: do not allocate and reassign the used ring
  2020-10-22  5:06 ` [PATCH V3 2/4] misc: vop: do not allocate and reassign the used ring Sherry Sun
@ 2020-10-22  8:53   ` kernel test robot
  2020-10-23  9:26   ` Christoph Hellwig
  1 sibling, 0 replies; 13+ messages in thread
From: kernel test robot @ 2020-10-22  8:53 UTC (permalink / raw)
  To: Sherry Sun, hch, sudeep.dutt, ashutosh.dixit, arnd, gregkh,
	kishon, lorenzo.pieralisi
  Cc: kbuild-all, linux-kernel, linux-pci, linux-imx


[-- Attachment #1: Type: text/plain, Size: 4976 bytes --]

Hi Sherry,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on soc/for-next linus/master v5.9 next-20201022]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Sherry-Sun/Change-vring-space-from-nomal-memory-to-dma-coherent-memory/20201022-131008
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git f3277cbfba763cd2826396521b9296de67cf1bbc
config: i386-randconfig-s002-20201022 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.3-dirty
        # https://github.com/0day-ci/linux/commit/6ae9d6d36b63c7bb8170f4c0409470d8e7101880
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Sherry-Sun/Change-vring-space-from-nomal-memory-to-dma-coherent-memory/20201022-131008
        git checkout 6ae9d6d36b63c7bb8170f4c0409470d8e7101880
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=i386 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


"sparse warnings: (new ones prefixed by >>)"
>> drivers/misc/mic/vop/vop_main.c:339:14: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected void *used @@     got void [noderef] __iomem * @@
>> drivers/misc/mic/vop/vop_main.c:339:14: sparse:     expected void *used
>> drivers/misc/mic/vop/vop_main.c:339:14: sparse:     got void [noderef] __iomem *
>> drivers/misc/mic/vop/vop_main.c:357:35: sparse: sparse: restricted __le64 degrades to integer

vim +339 drivers/misc/mic/vop/vop_main.c

   289	
   290	/*
   291	 * This routine will assign vring's allocated in host/io memory. Code in
   292	 * virtio_ring.c however continues to access this io memory as if it were local
   293	 * memory without io accessors.
   294	 */
   295	static struct virtqueue *vop_find_vq(struct virtio_device *dev,
   296					     unsigned index,
   297					     void (*callback)(struct virtqueue *vq),
   298					     const char *name, bool ctx)
   299	{
   300		struct _vop_vdev *vdev = to_vopvdev(dev);
   301		struct vop_device *vpdev = vdev->vpdev;
   302		struct mic_vqconfig __iomem *vqconfig;
   303		struct mic_vqconfig config;
   304		struct virtqueue *vq;
   305		void __iomem *va;
   306		struct _mic_vring_info __iomem *info;
   307		void *used;
   308		int vr_size, _vr_size, err, magic;
   309		u8 type = ioread8(&vdev->desc->type);
   310	
   311		if (index >= ioread8(&vdev->desc->num_vq))
   312			return ERR_PTR(-ENOENT);
   313	
   314		if (!name)
   315			return ERR_PTR(-ENOENT);
   316	
   317		/* First assign the vring's allocated in host memory */
   318		vqconfig = _vop_vq_config(vdev->desc) + index;
   319		memcpy_fromio(&config, vqconfig, sizeof(config));
   320		_vr_size = round_up(vring_size(le16_to_cpu(config.num), MIC_VIRTIO_RING_ALIGN), 4);
   321		vr_size = PAGE_ALIGN(_vr_size + sizeof(struct _mic_vring_info));
   322		va = vpdev->hw_ops->remap(vpdev, le64_to_cpu(config.address), vr_size);
   323		if (!va)
   324			return ERR_PTR(-ENOMEM);
   325		vdev->vr[index] = va;
   326		memset_io(va, 0x0, _vr_size);
   327	
   328		info = va + _vr_size;
   329		magic = ioread32(&info->magic);
   330	
   331		if (WARN(magic != MIC_MAGIC + type + index, "magic mismatch")) {
   332			err = -EIO;
   333			goto unmap;
   334		}
   335	
   336		vdev->used_size[index] = PAGE_ALIGN(sizeof(__u16) * 3 +
   337						     sizeof(struct vring_used_elem) *
   338						     le16_to_cpu(config.num));
 > 339		used = va + PAGE_ALIGN(sizeof(struct vring_desc) * le16_to_cpu(config.num) +
   340				       sizeof(__u16) * (3 + le16_to_cpu(config.num)));
   341		vdev->used_virt[index] = used;
   342		if (!used) {
   343			err = -ENOMEM;
   344			dev_err(_vop_dev(vdev), "%s %d err %d\n",
   345				__func__, __LINE__, err);
   346			goto unmap;
   347		}
   348	
   349		vq = vop_new_virtqueue(index, le16_to_cpu(config.num), dev, ctx,
   350				       (void __force *)va, vop_notify, callback,
   351				       name, used);
   352		if (!vq) {
   353			err = -ENOMEM;
   354			goto unmap;
   355		}
   356	
 > 357		vdev->used[index] = config.address + PAGE_ALIGN(sizeof(struct vring_desc) * le16_to_cpu(config.num) +
   358				    sizeof(__u16) * (3 + le16_to_cpu(config.num)));
   359		writeq(vdev->used[index], &vqconfig->used_address);
   360	
   361		vq->priv = vdev;
   362		return vq;
   363	unmap:
   364		vpdev->hw_ops->unmap(vpdev, vdev->vr[index]);
   365		return ERR_PTR(err);
   366	}
   367	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 36245 bytes --]

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH V3 1/4] misc: vop: change the way of allocating vring and device page
  2020-10-22  5:06 ` [PATCH V3 1/4] misc: vop: change the way of allocating vring and device page Sherry Sun
  2020-10-22  7:58   ` kernel test robot
@ 2020-10-23  9:25   ` Christoph Hellwig
  2020-10-26  2:54     ` Sherry Sun
  1 sibling, 1 reply; 13+ messages in thread
From: Christoph Hellwig @ 2020-10-23  9:25 UTC (permalink / raw)
  To: Sherry Sun
  Cc: hch, sudeep.dutt, ashutosh.dixit, arnd, gregkh, kishon,
	lorenzo.pieralisi, linux-kernel, linux-pci, linux-imx

>  static int mic_dp_init(struct mic_device *mdev)
>  {
> -	mdev->dp = kzalloc(MIC_DP_SIZE, GFP_KERNEL);
> +	mdev->dp = dma_alloc_coherent(&mdev->pdev->dev, MIC_DP_SIZE,
> +				      &mdev->dp_dma_addr, GFP_KERNEL);
>  	if (!mdev->dp)
>  		return -ENOMEM;
>  
> -	mdev->dp_dma_addr = mic_map_single(mdev,
> -		mdev->dp, MIC_DP_SIZE);
> -	if (mic_map_error(mdev->dp_dma_addr)) {
> -		kfree(mdev->dp);
> -		dev_err(&mdev->pdev->dev, "%s %d err %d\n",
> -			__func__, __LINE__, -ENOMEM);
> -		return -ENOMEM;
> -	}
>  	mdev->ops->write_spad(mdev, MIC_DPLO_SPAD, mdev->dp_dma_addr);
>  	mdev->ops->write_spad(mdev, MIC_DPHI_SPAD, mdev->dp_dma_addr >> 32);
>  	return 0;
> @@ -68,8 +62,7 @@ static int mic_dp_init(struct mic_device *mdev)
>  /* Uninitialize the device page */
>  static void mic_dp_uninit(struct mic_device *mdev)
>  {
> -	mic_unmap_single(mdev, mdev->dp_dma_addr, MIC_DP_SIZE);
> -	kfree(mdev->dp);
> +	dma_free_coherent(&mdev->pdev->dev, MIC_DP_SIZE, mdev->dp, mdev->dp_dma_addr);
>  }

This adds an over 80 char line.  Also please just kill mic_dp_init and
mic_dp_uninit and inline those into the callers.

> +		vvr->buf = dma_alloc_coherent(vop_dev(vdev), VOP_INT_DMA_BUF_SIZE,
> +					      &vvr->buf_da, GFP_KERNEL);

Another overly long line.

> @@ -1068,7 +1049,7 @@ vop_query_offset(struct vop_vdev *vdev, unsigned long offset,
>  		struct vop_vringh *vvr = &vdev->vvr[i];
>  
>  		if (offset == start) {
> -			*pa = virt_to_phys(vvr->vring.va);
> +			*pa = vqconfig[i].address;

vqconfig[i].address is a __le64, so this needs an endian swap.

But more importantly the caller of vop_query_offset, vop_mmap, uses
remap_pfn_range and pa.  You cannot mix remap_pfn_range with DMA
coherent allocations, it can only be mmaped using dma_mmap_coherent.

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH V3 2/4] misc: vop: do not allocate and reassign the used ring
  2020-10-22  5:06 ` [PATCH V3 2/4] misc: vop: do not allocate and reassign the used ring Sherry Sun
  2020-10-22  8:53   ` kernel test robot
@ 2020-10-23  9:26   ` Christoph Hellwig
  2020-10-26  3:04     ` Sherry Sun
  1 sibling, 1 reply; 13+ messages in thread
From: Christoph Hellwig @ 2020-10-23  9:26 UTC (permalink / raw)
  To: Sherry Sun
  Cc: hch, sudeep.dutt, ashutosh.dixit, arnd, gregkh, kishon,
	lorenzo.pieralisi, linux-kernel, linux-pci, linux-imx

On Thu, Oct 22, 2020 at 01:06:36PM +0800, Sherry Sun wrote:
> We don't need to allocate and reassign the used ring here and remove the
> used_address_updated flag.Since RC has allocated the entire vring,
> including the used ring. Simply add the corresponding offset can get the
> used ring address.

Someone needs to verify this vs the existing intel implementations.

> -	used = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
> -					get_order(vdev->used_size[index]));
> +	used = va + PAGE_ALIGN(sizeof(struct vring_desc) * le16_to_cpu(config.num) +

This adds an over 80 char line.

> +	vdev->used[index] = config.address + PAGE_ALIGN(sizeof(struct vring_desc) * le16_to_cpu(config.num) +

Again.


^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH V3 4/4] misc: vop: mapping kernel memory to user space as noncached
  2020-10-22  5:06 ` [PATCH V3 4/4] misc: vop: mapping kernel memory to user space as noncached Sherry Sun
@ 2020-10-23  9:28   ` Christoph Hellwig
  0 siblings, 0 replies; 13+ messages in thread
From: Christoph Hellwig @ 2020-10-23  9:28 UTC (permalink / raw)
  To: Sherry Sun
  Cc: hch, sudeep.dutt, ashutosh.dixit, arnd, gregkh, kishon,
	lorenzo.pieralisi, linux-kernel, linux-pci, linux-imx

On Thu, Oct 22, 2020 at 01:06:38PM +0800, Sherry Sun wrote:
> Mapping kernel space memory to user space as noncached, since user space
> need check the updates of avail_idx and device page flags timely.
> 
> Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
> Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
> ---
>  drivers/misc/mic/vop/vop_vringh.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c
> index b5612183dcb8..b75c2b713a3b 100644
> --- a/drivers/misc/mic/vop/vop_vringh.c
> +++ b/drivers/misc/mic/vop/vop_vringh.c
> @@ -1058,7 +1058,7 @@ static int vop_mmap(struct file *f, struct vm_area_struct *vma)
>  		}
>  		err = remap_pfn_range(vma, vma->vm_start + offset,
>  				      pa >> PAGE_SHIFT, size,
> -				      vma->vm_page_prot);
> +				      pgprot_noncached(vma->vm_page_prot));

Again, memory allocated using dma_alloc_coherent can only be mapped
using dma_mmap_coherent, which will use the right attributes for the
mapping, which often are cached.

^ permalink raw reply	[flat|nested] 13+ messages in thread

* RE: [PATCH V3 1/4] misc: vop: change the way of allocating vring and device page
  2020-10-23  9:25   ` Christoph Hellwig
@ 2020-10-26  2:54     ` Sherry Sun
  0 siblings, 0 replies; 13+ messages in thread
From: Sherry Sun @ 2020-10-26  2:54 UTC (permalink / raw)
  To: Christoph Hellwig
  Cc: sudeep.dutt, ashutosh.dixit, arnd, gregkh, kishon,
	lorenzo.pieralisi, linux-kernel, linux-pci, dl-linux-imx

Hi Christoph,

> 
> >  static int mic_dp_init(struct mic_device *mdev)  {
> > -	mdev->dp = kzalloc(MIC_DP_SIZE, GFP_KERNEL);
> > +	mdev->dp = dma_alloc_coherent(&mdev->pdev->dev, MIC_DP_SIZE,
> > +				      &mdev->dp_dma_addr, GFP_KERNEL);
> >  	if (!mdev->dp)
> >  		return -ENOMEM;
> >
> > -	mdev->dp_dma_addr = mic_map_single(mdev,
> > -		mdev->dp, MIC_DP_SIZE);
> > -	if (mic_map_error(mdev->dp_dma_addr)) {
> > -		kfree(mdev->dp);
> > -		dev_err(&mdev->pdev->dev, "%s %d err %d\n",
> > -			__func__, __LINE__, -ENOMEM);
> > -		return -ENOMEM;
> > -	}
> >  	mdev->ops->write_spad(mdev, MIC_DPLO_SPAD, mdev-
> >dp_dma_addr);
> >  	mdev->ops->write_spad(mdev, MIC_DPHI_SPAD, mdev-
> >dp_dma_addr >> 32);
> >  	return 0;
> > @@ -68,8 +62,7 @@ static int mic_dp_init(struct mic_device *mdev)
> >  /* Uninitialize the device page */
> >  static void mic_dp_uninit(struct mic_device *mdev)  {
> > -	mic_unmap_single(mdev, mdev->dp_dma_addr, MIC_DP_SIZE);
> > -	kfree(mdev->dp);
> > +	dma_free_coherent(&mdev->pdev->dev, MIC_DP_SIZE, mdev->dp,
> > +mdev->dp_dma_addr);
> >  }
> 
> This adds an over 80 char line.  Also please just kill mic_dp_init and
> mic_dp_uninit and inline those into the callers.

Okay, will fix them.
> 
> > +		vvr->buf = dma_alloc_coherent(vop_dev(vdev),
> VOP_INT_DMA_BUF_SIZE,
> > +					      &vvr->buf_da, GFP_KERNEL);
> 
> Another overly long line.
> 
> > @@ -1068,7 +1049,7 @@ vop_query_offset(struct vop_vdev *vdev,
> unsigned long offset,
> >  		struct vop_vringh *vvr = &vdev->vvr[i];
> >
> >  		if (offset == start) {
> > -			*pa = virt_to_phys(vvr->vring.va);
> > +			*pa = vqconfig[i].address;
> 
> vqconfig[i].address is a __le64, so this needs an endian swap.
> 
> But more importantly the caller of vop_query_offset, vop_mmap, uses
> remap_pfn_range and pa.  You cannot mix remap_pfn_range with DMA
> coherent allocations, it can only be mmaped using dma_mmap_coherent.

Will change to use dma_mmap_coherent in V4.

Best regards
Sherry 

^ permalink raw reply	[flat|nested] 13+ messages in thread

* RE: [PATCH V3 2/4] misc: vop: do not allocate and reassign the used ring
  2020-10-23  9:26   ` Christoph Hellwig
@ 2020-10-26  3:04     ` Sherry Sun
  2020-10-27  6:28       ` gregkh
  0 siblings, 1 reply; 13+ messages in thread
From: Sherry Sun @ 2020-10-26  3:04 UTC (permalink / raw)
  To: Christoph Hellwig, gregkh
  Cc: sudeep.dutt, ashutosh.dixit, arnd, kishon, lorenzo.pieralisi,
	linux-kernel, linux-pci, dl-linux-imx

Hi Greg & Christoph,

> Subject: Re: [PATCH V3 2/4] misc: vop: do not allocate and reassign the used
> ring
> 
> On Thu, Oct 22, 2020 at 01:06:36PM +0800, Sherry Sun wrote:
> > We don't need to allocate and reassign the used ring here and remove
> > the used_address_updated flag.Since RC has allocated the entire vring,
> > including the used ring. Simply add the corresponding offset can get
> > the used ring address.
> 
> Someone needs to verify this vs the existing intel implementations.

Hi Greg, @gregkh@linuxfoundation.org, sorry I don't have the Intel MIC devices so cannot test it, do you know anyone who can help test this patch changes on the Intel MIC platform? Thanks.

> 
> > -	used = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
> > -					get_order(vdev->used_size[index]));
> > +	used = va + PAGE_ALIGN(sizeof(struct vring_desc) *
> > +le16_to_cpu(config.num) +
> 
> This adds an over 80 char line.

Hi Christoph, will fix it in V4, thanks.

> 
> > +	vdev->used[index] = config.address + PAGE_ALIGN(sizeof(struct
> > +vring_desc) * le16_to_cpu(config.num) +
> 
> Again.

Best regards
Sherry

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH V3 2/4] misc: vop: do not allocate and reassign the used ring
  2020-10-26  3:04     ` Sherry Sun
@ 2020-10-27  6:28       ` gregkh
  0 siblings, 0 replies; 13+ messages in thread
From: gregkh @ 2020-10-27  6:28 UTC (permalink / raw)
  To: Sherry Sun
  Cc: Christoph Hellwig, sudeep.dutt, ashutosh.dixit, arnd, kishon,
	lorenzo.pieralisi, linux-kernel, linux-pci, dl-linux-imx

On Mon, Oct 26, 2020 at 03:04:45AM +0000, Sherry Sun wrote:
> Hi Greg & Christoph,
> 
> > Subject: Re: [PATCH V3 2/4] misc: vop: do not allocate and reassign the used
> > ring
> > 
> > On Thu, Oct 22, 2020 at 01:06:36PM +0800, Sherry Sun wrote:
> > > We don't need to allocate and reassign the used ring here and remove
> > > the used_address_updated flag.Since RC has allocated the entire vring,
> > > including the used ring. Simply add the corresponding offset can get
> > > the used ring address.
> > 
> > Someone needs to verify this vs the existing intel implementations.
> 
> Hi Greg, @gregkh@linuxfoundation.org, sorry I don't have the Intel MIC devices so cannot test it, do you know anyone who can help test this patch changes on the Intel MIC platform? Thanks.

Why not ask the authors/maintainers of that code?

greg k-h

^ permalink raw reply	[flat|nested] 13+ messages in thread

end of thread, back to index

Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-22  5:06 [PATCH V3 0/4] Change vring space from nomal memory to dma coherent memory Sherry Sun
2020-10-22  5:06 ` [PATCH V3 1/4] misc: vop: change the way of allocating vring and device page Sherry Sun
2020-10-22  7:58   ` kernel test robot
2020-10-23  9:25   ` Christoph Hellwig
2020-10-26  2:54     ` Sherry Sun
2020-10-22  5:06 ` [PATCH V3 2/4] misc: vop: do not allocate and reassign the used ring Sherry Sun
2020-10-22  8:53   ` kernel test robot
2020-10-23  9:26   ` Christoph Hellwig
2020-10-26  3:04     ` Sherry Sun
2020-10-27  6:28       ` gregkh
2020-10-22  5:06 ` [PATCH V3 3/4] misc: vop: simply return the saved dma address instead of virt_to_phys Sherry Sun
2020-10-22  5:06 ` [PATCH V3 4/4] misc: vop: mapping kernel memory to user space as noncached Sherry Sun
2020-10-23  9:28   ` Christoph Hellwig

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