[PATCH 2/3] arm: a37xx: pci: Optimize a3700_fdt_fix_pcie_regions() when fixup offset is zero

Pali Rohár
2021-07-08T18:19:19Z

If fixup offset is zero then there is nothing to fix. All calculation in
this case just increase addresses by value zero which results in identity.
So in this case skip whole fixup re-calculation as it is not needed.

This is just an optimization for special case when fix_offset is zero which
skips code path which does only identity operations (meaning nothing). No
functional changes.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
arch/arm/mach-mvebu/armada3700/cpu.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/arm/mach-mvebu/armada3700/cpu.c b/arch/arm/mach-mvebu/armada3700/cpu.c
index 4dd9de471b4e..64838b16c4d8 100644
--- a/arch/arm/mach-mvebu/armada3700/cpu.c
+++ b/arch/arm/mach-mvebu/armada3700/cpu.c
@@ -339,6 +339,10 @@ int a3700_fdt_fix_pcie_regions(void *blob)
/* Calculate fixup offset from first child address (in last cell) */
fix_offset = base - fdt32_to_cpu(ranges[2]);

+ /* If fixup offset is zero then there is nothing to fix */
+ if (!fix_offset)
+ return 0;
+
/*
* Fix address (last cell) of each child address and each parent
* address
--
2.20.1