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s390/ism: Properly fix receive message buffer allocation

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[ Upstream commit 83781384a96b95e2b6403d3c8a002b2c89031770 ]

Since [1], dma_alloc_coherent() does not accept requests for GFP_COMP
anymore, even on archs that may be able to fulfill this. Functionality that
relied on the receive buffer being a compound page broke at that point:
The SMC-D protocol, that utilizes the ism device driver, passes receive
buffers to the splice processor in a struct splice_pipe_desc with a
single entry list of struct pages. As the buffer is no longer a compound
page, the splice processor now rejects requests to handle more than a
page worth of data.

Replace dma_alloc_coherent() and allocate a buffer with folio_alloc and
create a DMA map for it with dma_map_page(). Since only receive buffers
on ISM devices use DMA, qualify the mapping as FROM_DEVICE.
Since ISM devices are available on arch s390, only, and on that arch all
DMA is coherent, there is no need to introduce and export some kind of
dma_sync_to_cpu() method to be called by the SMC-D protocol layer.

Analogously, replace dma_free_coherent by a two step dma_unmap_page,
then folio_put to free the receive buffer.

[1] https://lore.kernel.org/all/20221113163535.884299-1-hch@lst.de/

Fixes: c08004eede4b ("s390/ism: don't pass bogus GFP_ flags to dma_alloc_coherent")
Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Gerd Bayer 2024-04-15 15:15:07 +02:00 committed by Greg Kroah-Hartman
parent f8de1b6208
commit 121fb75414
1 changed files with 28 additions and 9 deletions
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37
drivers/s390/net/ism_drv.c
View File

@ -291,13 +291,16 @@ out:
static void ism_free_dmb(struct ism_dev *ism, struct ism_dmb *dmb)
{
clear_bit(dmb->sba_idx, ism->sba_bitmap);
dma_free_coherent(&ism->pdev->dev, dmb->dmb_len,
dmb->cpu_addr, dmb->dma_addr);
dma_unmap_page(&ism->pdev->dev, dmb->dma_addr, dmb->dmb_len,
DMA_FROM_DEVICE);
folio_put(virt_to_folio(dmb->cpu_addr));
}
static int ism_alloc_dmb(struct ism_dev *ism, struct ism_dmb *dmb)
{
struct folio *folio;
unsigned long bit;
int rc;
if (PAGE_ALIGN(dmb->dmb_len) > dma_get_max_seg_size(&ism->pdev->dev))
return -EINVAL;
@ -314,14 +317,30 @@ static int ism_alloc_dmb(struct ism_dev *ism, struct ism_dmb *dmb)
test_and_set_bit(dmb->sba_idx, ism->sba_bitmap))
return -EINVAL;
dmb->cpu_addr = dma_alloc_coherent(&ism->pdev->dev, dmb->dmb_len,
&dmb->dma_addr,
GFP_KERNEL | __GFP_NOWARN |
__GFP_NOMEMALLOC | __GFP_NORETRY);
if (!dmb->cpu_addr)
clear_bit(dmb->sba_idx, ism->sba_bitmap);
folio = folio_alloc(GFP_KERNEL | __GFP_NOWARN | __GFP_NOMEMALLOC |
__GFP_NORETRY, get_order(dmb->dmb_len));
return dmb->cpu_addr ? 0 : -ENOMEM;
if (!folio) {
rc = -ENOMEM;
goto out_bit;
}
dmb->cpu_addr = folio_address(folio);
dmb->dma_addr = dma_map_page(&ism->pdev->dev,
virt_to_page(dmb->cpu_addr), 0,
dmb->dmb_len, DMA_FROM_DEVICE);
if (dma_mapping_error(&ism->pdev->dev, dmb->dma_addr)) {
rc = -ENOMEM;
goto out_free;
}
return 0;
out_free:
kfree(dmb->cpu_addr);
out_bit:
clear_bit(dmb->sba_idx, ism->sba_bitmap);
return rc;
}
int ism_register_dmb(struct ism_dev *ism, struct ism_dmb *dmb,