[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <3e0a72fe3d79eae660e4284bb32f2cb39868ccd7.1713523152.git.robin.murphy@arm.com>
Date: Fri, 19 Apr 2024 17:54:41 +0100
From: Robin Murphy <robin.murphy@....com>
To: Joerg Roedel <joro@...tes.org>,
Christoph Hellwig <hch@....de>
Cc: Vineet Gupta <vgupta@...nel.org>,
Russell King <linux@...linux.org.uk>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will@...nel.org>,
Huacai Chen <chenhuacai@...nel.org>,
WANG Xuerui <kernel@...0n.name>,
Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
Paul Walmsley <paul.walmsley@...ive.com>,
Palmer Dabbelt <palmer@...belt.com>,
Albert Ou <aou@...s.berkeley.edu>,
Lorenzo Pieralisi <lpieralisi@...nel.org>,
Hanjun Guo <guohanjun@...wei.com>,
Sudeep Holla <sudeep.holla@....com>,
"K. Y. Srinivasan" <kys@...rosoft.com>,
Haiyang Zhang <haiyangz@...rosoft.com>,
Wei Liu <wei.liu@...nel.org>,
Dexuan Cui <decui@...rosoft.com>,
Suravee Suthikulpanit <suravee.suthikulpanit@....com>,
David Woodhouse <dwmw2@...radead.org>,
Lu Baolu <baolu.lu@...ux.intel.com>,
Niklas Schnelle <schnelle@...ux.ibm.com>,
Matthew Rosato <mjrosato@...ux.ibm.com>,
Gerald Schaefer <gerald.schaefer@...ux.ibm.com>,
Jean-Philippe Brucker <jean-philippe@...aro.org>,
Rob Herring <robh+dt@...nel.org>,
Frank Rowand <frowand.list@...il.com>,
Marek Szyprowski <m.szyprowski@...sung.com>,
Jason Gunthorpe <jgg@...pe.ca>,
linux-kernel@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org,
linux-acpi@...r.kernel.org,
iommu@...ts.linux.dev,
devicetree@...r.kernel.org,
Rob Herring <robh@...nel.org>,
Jason Gunthorpe <jgg@...dia.com>
Subject: [PATCH v4 2/7] 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@...nel.org>
Reviewed-by: Jason Gunthorpe <jgg@...dia.com>
Signed-off-by: Robin Murphy <robin.murphy@....com>
---
drivers/of/device.c | 19 ++++++++-----------
1 file 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);
--
2.39.2.101.g768bb238c484.dirty
Powered by blists - more mailing lists