Commit 55c25c2f authored by Jayachandran C's avatar Jayachandran C Committed by Ralf Baechle

MIPS: mm: Move some checks out of 'for' loop in DMA operations

The check cpu_needs_post_dma_flush() in mips_dma_sync_sg_for_cpu() and
the check !plat_device_is_coherent() in mips_dma_sync_sg_for_device()
can be moved outside the for loop.

As a side effect, this also avoids a GCC bug that caused kernel compile
to fail with the error:

arch/mips/mm/dma-default.c: In function 'mips_dma_sync_sg_for_cpu':
arch/mips/mm/dma-default.c:316:1: internal compiler error: in add_insn_before, at emit-rtl.c:3852

This gcc failure is seen in Code Sourcery toolchains [e.g. gcc version
4.7.2 (Sourcery CodeBench Lite 2012.09-99)] after commit "MIPS: Optimize
current_cpu_type() for better code."
Signed-off-by: default avatarJayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5907/Reviewed-by: default avatarMarkos Chandras <markos.chandras@imgtec.com>
Tested-by: default avatarMarkos Chandras <markos.chandras@imgtec.com>
Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent becee6b8
...@@ -308,12 +308,10 @@ static void mips_dma_sync_sg_for_cpu(struct device *dev, ...@@ -308,12 +308,10 @@ static void mips_dma_sync_sg_for_cpu(struct device *dev,
{ {
int i; int i;
/* Make sure that gcc doesn't leave the empty loop body. */ if (cpu_needs_post_dma_flush(dev))
for (i = 0; i < nelems; i++, sg++) { for (i = 0; i < nelems; i++, sg++)
if (cpu_needs_post_dma_flush(dev))
__dma_sync(sg_page(sg), sg->offset, sg->length, __dma_sync(sg_page(sg), sg->offset, sg->length,
direction); direction);
}
} }
static void mips_dma_sync_sg_for_device(struct device *dev, static void mips_dma_sync_sg_for_device(struct device *dev,
...@@ -321,12 +319,10 @@ static void mips_dma_sync_sg_for_device(struct device *dev, ...@@ -321,12 +319,10 @@ static void mips_dma_sync_sg_for_device(struct device *dev,
{ {
int i; int i;
/* Make sure that gcc doesn't leave the empty loop body. */ if (!plat_device_is_coherent(dev))
for (i = 0; i < nelems; i++, sg++) { for (i = 0; i < nelems; i++, sg++)
if (!plat_device_is_coherent(dev))
__dma_sync(sg_page(sg), sg->offset, sg->length, __dma_sync(sg_page(sg), sg->offset, sg->length,
direction); direction);
}
} }
int mips_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) int mips_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment