Re: [PATCH] forcedeth: switch from 'pci_' to 'dma_' API

Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> · Mon, 23 Aug 2021 06:33:10 +0200

Le 23/08/2021 à 04:39, Zhu Yanjun a écrit :
On Sun, Aug 22, 2021 at 3:09 PM Christophe JAILLET
<christophe.jaillet@xxxxxxxxxx> wrote:

The wrappers in include/linux/pci-dma-compat.h should go away.

The patch has been generated with the coccinelle script below.

It has been hand modified to use 'dma_set_mask_and_coherent()' instead of
'pci_set_dma_mask()/pci_set_consistent_dma_mask()' when applicable.
This is less verbose.

It has been compile tested.


@@
@@
-    PCI_DMA_BIDIRECTIONAL
+    DMA_BIDIRECTIONAL

@@
@@
-    PCI_DMA_TODEVICE
+    DMA_TO_DEVICE

@@
@@
-    PCI_DMA_FROMDEVICE
+    DMA_FROM_DEVICE

@@
@@
-    PCI_DMA_NONE
+    DMA_NONE

@@
expression e1, e2, e3;
@@
-    pci_alloc_consistent(e1, e2, e3)
+    dma_alloc_coherent(&e1->dev, e2, e3, GFP_)

@@
expression e1, e2, e3;
@@
-    pci_zalloc_consistent(e1, e2, e3)
+    dma_alloc_coherent(&e1->dev, e2, e3, GFP_)

@@
expression e1, e2, e3, e4;
@@
-    pci_free_consistent(e1, e2, e3, e4)
+    dma_free_coherent(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_map_single(e1, e2, e3, e4)
+    dma_map_single(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_unmap_single(e1, e2, e3, e4)
+    dma_unmap_single(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4, e5;
@@
-    pci_map_page(e1, e2, e3, e4, e5)
+    dma_map_page(&e1->dev, e2, e3, e4, e5)

@@
expression e1, e2, e3, e4;
@@
-    pci_unmap_page(e1, e2, e3, e4)
+    dma_unmap_page(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_map_sg(e1, e2, e3, e4)
+    dma_map_sg(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_unmap_sg(e1, e2, e3, e4)
+    dma_unmap_sg(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_dma_sync_single_for_cpu(e1, e2, e3, e4)
+    dma_sync_single_for_cpu(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_dma_sync_single_for_device(e1, e2, e3, e4)
+    dma_sync_single_for_device(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_dma_sync_sg_for_cpu(e1, e2, e3, e4)
+    dma_sync_sg_for_cpu(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_dma_sync_sg_for_device(e1, e2, e3, e4)
+    dma_sync_sg_for_device(&e1->dev, e2, e3, e4)

@@
expression e1, e2;
@@
-    pci_dma_mapping_error(e1, e2)
+    dma_mapping_error(&e1->dev, e2)

@@
expression e1, e2;
@@
-    pci_set_dma_mask(e1, e2)
+    dma_set_mask(&e1->dev, e2)

@@
expression e1, e2;
@@
-    pci_set_consistent_dma_mask(e1, e2)
+    dma_set_coherent_mask(&e1->dev, e2)

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
If needed, see post from Christoph Hellwig on the kernel-janitors ML:
    https://marc.info/?l=kernel-janitors&m=158745678307186&w=4
---
  drivers/net/ethernet/nvidia/forcedeth.c | 6 +-----
  1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c
index 8724d6a9ed02..ef3fb4cc90af 100644
--- a/drivers/net/ethernet/nvidia/forcedeth.c
+++ b/drivers/net/ethernet/nvidia/forcedeth.c
@@ -5782,15 +5782,11 @@ static int nv_probe(struct pci_dev *pci_dev, const struct pci_device_id *id)
                 np->desc_ver = DESC_VER_3;
                 np->txrxctl_bits = NVREG_TXRXCTL_DESC_3;
                 if (dma_64bit) {
-                       if (pci_set_dma_mask(pci_dev, DMA_BIT_MASK(39)))
+                       if (dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(39)))
                                 dev_info(&pci_dev->dev,
                                          "64-bit DMA failed, using 32-bit addressing\n");
                         else
                                 dev->features |= NETIF_F_HIGHDMA;
-                       if (pci_set_consistent_dma_mask(pci_dev, DMA_BIT_MASK(39))) {
-                               dev_info(&pci_dev->dev,
-                                        "64-bit DMA (consistent) failed, using 32-bit ring buffers\n");
-                       }

 From the commit log, "pci_set_consistent_dma_mask(e1, e2)" should be
replaced by "dma_set_coherent_mask(&e1->dev, e2)".
But in this snippet,  "pci_set_consistent_dma_mask(e1, e2)" is not
replaced by "dma_set_coherent_mask(&e1->dev, e2)".

Why?

Hi,
in the commit log I said that:
    The patch has been generated with the coccinelle script below.

    It has been hand modified to use 'dma_set_mask_and_coherent()'
    instead of 'pci_set_dma_mask()/pci_set_consistent_dma_mask()' when
    applicable.
    This is less verbose.

When I started this task proposed by Christoph Hellwig ([1]), their were 
150 files using using 'pci_set_dma_mask()' ([2]). Many of them were good 
candidate for using 'dma_set_mask_and_coherent()' but this 
transformation can not easily be done by coccinelle because it depends 
on the way the code has been written.

So, I decided to hand modify and include the transformation in the many 
patches have sent to remove this deprecated API.
Up to now, it has never been an issue.

I *DO* know that it should have been a 2 steps process but this clean-up 
was too big for me (i.e. 150 files) and doing the job twice was 
discouraging.

My first motivation was to remove the deprecated API. Simplifying code 
and using 'dma_set_mask_and_coherent()' when applicable was just a bonus.

So, if desired, I can send a v2 without the additional transformation 
but I won't send 2 patches for that. The 'dma_set_mask_and_coherent()' 
transformation would be left apart, for whoever feels like cleaning it.

CJ


[1]: https://marc.info/?l=kernel-janitors&m=158745678307186&w=4
[2]: https://elixir.bootlin.com/linux/v5.8/A/ident/pci_set_dma_mask



Zhu Yanjun


                 }
         } else if (id->driver_data & DEV_HAS_LARGEDESC) {
                 /* packet format 2: supports jumbo frames */
--
2.30.2









