diff mbox series

[V3,1/4] misc: vop: change the way of allocating vring and device page

Message ID 20201022050638.29641-2-sherry.sun@nxp.com
State New
Headers show
Series Change vring space from nomal memory to dma coherent memory | expand

Commit Message

Sherry Sun Oct. 22, 2020, 5:06 a.m. UTC 
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(-)

Comments

kernel test robot Oct. 22, 2020, 7:58 a.m. UTC | #1 
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
Christoph Hellwig Oct. 23, 2020, 9:25 a.m. UTC | #2 
>  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.
Sherry Sun Oct. 26, 2020, 2:54 a.m. UTC | #3 
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
diff mbox series

Patch

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;
 		}