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authorJim Quinlan <james.quinlan@broadcom.com>2020-09-17 19:43:40 +0300
committerChristoph Hellwig <hch@lst.de>2020-09-17 19:43:56 +0300
commite0d072782c734d27f5af062c62266f2598f68542 (patch)
treef259e9eaab55ae8ffedaea07a19e8f147dcceb9a /drivers/of/address.c
parent6eb0233ec2d0df288fe8515d5b0b2b15562e05bb (diff)
downloadlinux-e0d072782c734d27f5af062c62266f2598f68542.tar.xz
dma-mapping: introduce DMA range map, supplanting dma_pfn_offset
The new field 'dma_range_map' in struct device is used to facilitate the use of single or multiple offsets between mapping regions of cpu addrs and dma addrs. It subsumes the role of "dev->dma_pfn_offset" which was only capable of holding a single uniform offset and had no region bounds checking. The function of_dma_get_range() has been modified so that it takes a single argument -- the device node -- and returns a map, NULL, or an error code. The map is an array that holds the information regarding the DMA regions. Each range entry contains the address offset, the cpu_start address, the dma_start address, and the size of the region. of_dma_configure() is the typical manner to set range offsets but there are a number of ad hoc assignments to "dev->dma_pfn_offset" in the kernel driver code. These cases now invoke the function dma_direct_set_offset(dev, cpu_addr, dma_addr, size). Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com> [hch: various interface cleanups] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Diffstat (limited to 'drivers/of/address.c')
-rw-r--r--drivers/of/address.c73
1 files changed, 32 insertions, 41 deletions
diff --git a/drivers/of/address.c b/drivers/of/address.c
index da4f7341323f..eb9ab4f1e80b 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -13,6 +13,7 @@
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/string.h>
+#include <linux/dma-direct.h> /* for bus_dma_region */
#include "of_private.h"
@@ -937,33 +938,33 @@ void __iomem *of_io_request_and_map(struct device_node *np, int index,
}
EXPORT_SYMBOL(of_io_request_and_map);
+#ifdef CONFIG_HAS_DMA
/**
- * of_dma_get_range - Get DMA range info
+ * of_dma_get_range - Get DMA range info and put it into a map array
* @np: device node to get DMA range info
- * @dma_addr: pointer to store initial DMA address of DMA range
- * @paddr: pointer to store initial CPU address of DMA range
- * @size: pointer to store size of DMA range
+ * @map: dma range structure to return
*
* Look in bottom up direction for the first "dma-ranges" property
- * and parse it.
- * dma-ranges format:
+ * and parse it. Put the information into a DMA offset map array.
+ *
+ * dma-ranges format:
* DMA addr (dma_addr) : naddr cells
* CPU addr (phys_addr_t) : pna cells
* size : nsize cells
*
- * It returns -ENODEV if "dma-ranges" property was not found
- * for this device in DT.
+ * It returns -ENODEV if "dma-ranges" property was not found for this
+ * device in the DT.
*/
-int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size)
+int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map)
{
struct device_node *node = of_node_get(np);
const __be32 *ranges = NULL;
- int len;
- int ret = 0;
bool found_dma_ranges = false;
struct of_range_parser parser;
struct of_range range;
- u64 dma_start = U64_MAX, dma_end = 0, dma_offset = 0;
+ struct bus_dma_region *r;
+ int len, num_ranges = 0;
+ int ret = 0;
while (node) {
ranges = of_get_property(node, "dma-ranges", &len);
@@ -989,49 +990,39 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz
}
of_dma_range_parser_init(&parser, node);
+ for_each_of_range(&parser, &range)
+ num_ranges++;
+
+ r = kcalloc(num_ranges + 1, sizeof(*r), GFP_KERNEL);
+ if (!r) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ /*
+ * Record all info in the generic DMA ranges array for struct device.
+ */
+ *map = r;
+ of_dma_range_parser_init(&parser, node);
for_each_of_range(&parser, &range) {
pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
range.bus_addr, range.cpu_addr, range.size);
-
- if (dma_offset && range.cpu_addr - range.bus_addr != dma_offset) {
- pr_warn("Can't handle multiple dma-ranges with different offsets on node(%pOF)\n", node);
- /* Don't error out as we'd break some existing DTs */
- continue;
- }
if (range.cpu_addr == OF_BAD_ADDR) {
pr_err("translation of DMA address(%llx) to CPU address failed node(%pOF)\n",
range.bus_addr, node);
continue;
}
- dma_offset = range.cpu_addr - range.bus_addr;
-
- /* Take lower and upper limits */
- if (range.bus_addr < dma_start)
- dma_start = range.bus_addr;
- if (range.bus_addr + range.size > dma_end)
- dma_end = range.bus_addr + range.size;
- }
-
- if (dma_start >= dma_end) {
- ret = -EINVAL;
- pr_debug("Invalid DMA ranges configuration on node(%pOF)\n",
- node);
- goto out;
+ r->cpu_start = range.cpu_addr;
+ r->dma_start = range.bus_addr;
+ r->size = range.size;
+ r->offset = range.cpu_addr - range.bus_addr;
+ r++;
}
-
- *dma_addr = dma_start;
- *size = dma_end - dma_start;
- *paddr = dma_start + dma_offset;
-
- pr_debug("final: dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
- *dma_addr, *paddr, *size);
-
out:
of_node_put(node);
-
return ret;
}
+#endif /* CONFIG_HAS_DMA */
/**
* of_dma_is_coherent - Check if device is coherent