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| author |   Robin Murphy <robin.murphy@arm.com> | 2018-07-23 23:16:11 +0100 |
|---|---|---|
| committer |   Christoph Hellwig <hch@lst.de> | 2018-07-27 19:01:06 +0200 |
| commit | 6757cdae44449dec2af68cd4db0a5f9a30e66b38 (patch) | |
| tree | 261295beb90a0c9994e253dfbe46007a6c08974f /drivers/acpi | |
| parent | iommu/dma: Respect bus DMA limit for IOVAs (diff) | |
| download | linux-dev-6757cdae44449dec2af68cd4db0a5f9a30e66b38.tar.xz linux-dev-6757cdae44449dec2af68cd4db0a5f9a30e66b38.zip | |
ACPI/IORT: Don't set default coherent DMA mask
Now that we can track upstream DMA constraints properly with
bus_dma_mask instead of trying (and failing) to maintain it in
coherent_dma_mask, it doesn't make much sense for the firmware code to
be touching the latter at all. It's merely papering over bugs wherein a
driver has failed to call dma_set_coherent_mask() *and* the bus code has
not initialised any default value.
We don't really want to encourage more drivers coercing dma_mask so
we'll continue to fix that up if necessary, but add a warning to help
flush out any such buggy bus code that remains.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/arm64/iort.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c index bc51cff5505e..08f26db2da7e 100644 --- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -978,20 +978,20 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size) int ret, msb; /* - * Set default coherent_dma_mask to 32 bit. Drivers are expected to - * setup the correct supported mask. + * If @dev is expected to be DMA-capable then the bus code that created + * it should have initialised its dma_mask pointer by this point. For + * now, we'll continue the legacy behaviour of coercing it to the + * coherent mask if not, but we'll no longer do so quietly. */ - if (!dev->coherent_dma_mask) - dev->coherent_dma_mask = DMA_BIT_MASK(32); - - /* - * Set it to coherent_dma_mask by default if the architecture - * code has not set it. - */ - if (!dev->dma_mask) + if (!dev->dma_mask) { + dev_warn(dev, "DMA mask not set\n"); dev->dma_mask = &dev->coherent_dma_mask; + } - size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); + if (dev->coherent_dma_mask) + size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); + else + size = 1ULL << 32; if (dev_is_pci(dev)) { ret = acpi_dma_get_range(dev, &dmaaddr, &offset, &size); |