diff options
| author | Robin Murphy <robin.murphy@arm.com> | 2024-04-19 19:54:41 +0300 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2024-04-26 13:07:23 +0300 |
| commit | ba503cf41c90e173f9421f7882d84b228bada97a (patch) | |
| tree | 61b50d237001d770aee7385fdf1df1d6d8f83d08 /drivers/of/device.c | |
| parent | 0c3457926e7e65710f32e02920c7d423417c93a2 (diff) | |
| download | linux-ba503cf41c90e173f9421f7882d84b228bada97a.tar.xz | |
OF: Simplify DMA range calculations
Juggling start, end, and size values for a range is somewhat redundant
and a little hard to follow. Consolidate down to just using inclusive
start and end, which saves us worrying about size overflows for full
64-bit ranges (note that passing a potentially-overflowed value through
to arch_setup_dma_ops() is benign for all current implementations, and
this is working towards removing that anyway).
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/3e0a72fe3d79eae660e4284bb32f2cb39868ccd7.1713523152.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/of/device.c')
| -rw-r--r-- | drivers/of/device.c | 19 |
1 files changed, 8 insertions, 11 deletions
diff --git a/drivers/of/device.c b/drivers/of/device.c index a988bee2ee5a..841ccd3a19d1 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -96,7 +96,7 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, const struct bus_dma_region *map = NULL; struct device_node *bus_np; u64 dma_start = 0; - u64 mask, end, size = 0; + u64 mask, end = 0; bool coherent; int iommu_ret; int ret; @@ -118,17 +118,15 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, return ret == -ENODEV ? 0 : ret; } else { const struct bus_dma_region *r = map; - u64 dma_end = 0; /* Determine the overall bounds of all DMA regions */ for (dma_start = ~0; r->size; r++) { /* Take lower and upper limits */ if (r->dma_start < dma_start) dma_start = r->dma_start; - if (r->dma_start + r->size > dma_end) - dma_end = r->dma_start + r->size; + if (r->dma_start + r->size > end) + end = r->dma_start + r->size; } - size = dma_end - dma_start; } /* @@ -142,16 +140,15 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, dev->dma_mask = &dev->coherent_dma_mask; } - if (!size && dev->coherent_dma_mask) - size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); - else if (!size) - size = 1ULL << 32; + if (!end && dev->coherent_dma_mask) + end = dev->coherent_dma_mask; + else if (!end) + end = (1ULL << 32) - 1; /* * Limit coherent and dma mask based on size and default mask * set by the driver. */ - end = dma_start + size - 1; mask = DMA_BIT_MASK(ilog2(end) + 1); dev->coherent_dma_mask &= mask; *dev->dma_mask &= mask; @@ -185,7 +182,7 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, } else dev_dbg(dev, "device is behind an iommu\n"); - arch_setup_dma_ops(dev, dma_start, size, coherent); + arch_setup_dma_ops(dev, dma_start, end - dma_start + 1, coherent); if (iommu_ret) of_dma_set_restricted_buffer(dev, np); |