Re: [PATCH 16/25] PCI/P2PDMA: use the dev_pagemap internal refcount

Logan Gunthorpe
2019-06-17T20:10:18Z

On 2019-06-17 6:27 a.m., Christoph Hellwig wrote:
> The functionality is identical to the one currently open coded in
> p2pdma.c.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

I also did a quick test with the full patch-set to ensure that the setup
and tear down paths for p2pdma still work correctly and it all does.

Thanks,

Logan

> ---
> drivers/pci/p2pdma.c | 56 ++++----------------------------------------
> 1 file changed, 4 insertions(+), 52 deletions(-)
>
> diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
> index 48a88158e46a..608f84df604a 100644
> --- a/drivers/pci/p2pdma.c
> +++ b/drivers/pci/p2pdma.c
> @@ -24,12 +24,6 @@ struct pci_p2pdma {
> bool p2pmem_published;
> };
>
> -struct p2pdma_pagemap {
> - struct dev_pagemap pgmap;
> - struct percpu_ref ref;
> - struct completion ref_done;
> -};
> -
> static ssize_t size_show(struct device *dev, struct device_attribute *attr,
> char *buf)
> {
> @@ -78,32 +72,6 @@ static const struct attribute_group p2pmem_group = {
> .name = "p2pmem",
> };
>
> -static struct p2pdma_pagemap *to_p2p_pgmap(struct percpu_ref *ref)
> -{
> - return container_of(ref, struct p2pdma_pagemap, ref);
> -}
> -
> -static void pci_p2pdma_percpu_release(struct percpu_ref *ref)
> -{
> - struct p2pdma_pagemap *p2p_pgmap = to_p2p_pgmap(ref);
> -
> - complete(&p2p_pgmap->ref_done);
> -}
> -
> -static void pci_p2pdma_percpu_kill(struct dev_pagemap *pgmap)
> -{
> - percpu_ref_kill(pgmap->ref);
> -}
> -
> -static void pci_p2pdma_percpu_cleanup(struct dev_pagemap *pgmap)
> -{
> - struct p2pdma_pagemap *p2p_pgmap =
> - container_of(pgmap, struct p2pdma_pagemap, pgmap);
> -
> - wait_for_completion(&p2p_pgmap->ref_done);
> - percpu_ref_exit(&p2p_pgmap->ref);
> -}
> -
> static void pci_p2pdma_release(void *data)
> {
> struct pci_dev *pdev = data;
> @@ -153,11 +121,6 @@ static int pci_p2pdma_setup(struct pci_dev *pdev)
> return error;
> }
>
> -static const struct dev_pagemap_ops pci_p2pdma_pagemap_ops = {
> - .kill = pci_p2pdma_percpu_kill,
> - .cleanup = pci_p2pdma_percpu_cleanup,
> -};
> -
> /**
> * pci_p2pdma_add_resource - add memory for use as p2p memory
> * @pdev: the device to add the memory to
> @@ -171,7 +134,6 @@ static const struct dev_pagemap_ops pci_p2pdma_pagemap_ops = {
> int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
> u64 offset)
> {
> - struct p2pdma_pagemap *p2p_pgmap;
> struct dev_pagemap *pgmap;
> void *addr;
> int error;
> @@ -194,22 +156,12 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
> return error;
> }
>
> - p2p_pgmap = devm_kzalloc(&pdev->dev, sizeof(*p2p_pgmap), GFP_KERNEL);
> - if (!p2p_pgmap)
> + pgmap = devm_kzalloc(&pdev->dev, sizeof(*pgmap), GFP_KERNEL);
> + if (!pgmap)
> return -ENOMEM;
> -
> - init_completion(&p2p_pgmap->ref_done);
> - error = percpu_ref_init(&p2p_pgmap->ref,
> - pci_p2pdma_percpu_release, 0, GFP_KERNEL);
> - if (error)
> - goto pgmap_free;
> -
> - pgmap = &p2p_pgmap->pgmap;
> -
> pgmap->res.start = pci_resource_start(pdev, bar) + offset;
> pgmap->res.end = pgmap->res.start + size - 1;
> pgmap->res.flags = pci_resource_flags(pdev, bar);
> - pgmap->ref = &p2p_pgmap->ref;
> pgmap->type = MEMORY_DEVICE_PCI_P2PDMA;
> pgmap->pci_p2pdma_bus_offset = pci_bus_address(pdev, bar) -
> pci_resource_start(pdev, bar);
> @@ -223,7 +175,7 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
> error = gen_pool_add_owner(pdev->p2pdma->pool, (unsigned long)addr,
> pci_bus_address(pdev, bar) + offset,
> resource_size(&pgmap->res), dev_to_node(&pdev->dev),
> - &p2p_pgmap->ref);
> + pgmap->ref);
> if (error)
> goto pages_free;
>
> @@ -235,7 +187,7 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
> pages_free:
> devm_memunmap_pages(&pdev->dev, pgmap);
> pgmap_free:
> - devm_kfree(&pdev->dev, p2p_pgmap);
> + devm_kfree(&pdev->dev, pgmap);
> return error;
> }
> EXPORT_SYMBOL_GPL(pci_p2pdma_add_resource);
>