Re: new TODO list item

[Christophe JAILLET <christophe.jaillet@wanadoo.fr>]

Le 21/04/2020 à 10:12, Christoph Hellwig a écrit :
> Hi Janitors,
> 
> if someone feels like helping with a fairly trivial legacy API, the
> wrappers in include/linux/pci-dma-compat.h should go away.  This is
> mostly trivially scriptable, except for dma_alloc_coherent, where
> the GFP_ATOMIC passed by pci_alloc_consisteny should usually be replaced
> with GFP_KERNEL when not calling from an atomic context.
> 

Hi,
what would be the best approach to work on, it?

I've processed the current tree, with the coccinelle script below.
For 'dma_alloc_coherent' calls, I've left a GFP_ on purpose, so that one 
need to wonder which flag is the best.

'make'ing the files before sending patches should spot the places were a 
correct flag has not been defined.

What puzzles me is that the script below >20k lines file and the 
diffstat is:
     288 files changed, 3963 insertions(+), 3857 deletions(-)


1. Does sending patches one file at a time makes sense?
2. Should the PCI_DMA_ --> DMA_ conversion should be handled first? (the 
#defined values are the same, it should be straightforward)
3. Should a huge patch series be sent to fix all at once?
4. Should we update everything except 'dma_alloc_coherent' all at once, 
then one file at a time for the allocation with correct GFP_ flag?


I could help with 1. or 2nd step of 4. This could go in the right 
direction, but would require time.

Other tree wide approaches look complex to me.


CJ


-------------------------------------
@@
@@
-    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)

----------------------------------------