linux/arch/mips/lib/bswapsi.c

#include <linux/export.h>
#include <linux/compiler.h>

unsigned int notrace __bswapsi2(unsigned int u)
{
	return (((u) & 0xff000000) >> 24) |
	       (((u) & 0x00ff0000) >>  8) |
	       (((u) & 0x0000ff00) <<  8) |
	       (((u) & 0x000000ff) << 24);
}

EXPORT_SYMBOL(__bswapsi2);
MIPS: lib: Audit and remove any unnecessary uses of module.h Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance for the presence of either and replace as needed. The compiler.h additions are for an implict presence of the "notrace" which module.h brought in but export.h does not. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14034/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 2016-08-22 03:58:15 +08:00			`#include <linux/export.h>`
			`#include <linux/compiler.h>`
MIPS: Use ARCH_USE_BUILTIN_BSWAP. ARCH_USE_BUILTIN_BSWAP will use __builtin_bswap16(), __builtin_bswap32() and __builtin_bswap64() where available. This allows better instruction scheduling. On pre-R2 processors it will result in 32 bit and 64 bit swapping being performed in a call to a __bswapsi2() rsp. __bswapdi2() functions, so we add these, too. For a 4.2 kernel with GCC 4.9 this yields the following kernel sizes: text data bss dec hex filename 3996071 155804 88992 4240867 40b5e3 vmlinux ip22 baseline 3985687 159900 88992 4234579 409d53 vmlinux ip22 + bswap patch 6913157 378552 251024 7542733 7317cd vmlinux ip27 baseline 6878581 378552 251024 7508157 7290bd vmlinux ip27 + bswap patch 5773777 268752 187424 6229953 5f0fc1 vmlinux malta baseline 5773401 268752 187424 6229577 5f0e49 vmlinux malta + bswap patch Presumably the code size improvments yield better cache hit rate thus better performance compensating for the extra function call but this will still need to be benchmarked. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 2015-09-29 18:19:48 +08:00
MIPS: lib: Mark intrinsics notrace On certain MIPS32 devices, the ftrace tracer "function_graph" uses __lshrdi3() during the capturing of trace data. ftrace then attempts to trace __lshrdi3() which leads to infinite recursion and a stack overflow. Fix this by marking __lshrdi3() as notrace. Mark the other compiler intrinsics as notrace in case the compiler decides to use them in the ftrace path. Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com> Cc: <linux-mips@linux-mips.org> Cc: <linux-kernel@vger.kernel.org> Cc: <stable@vger.kernel.org> # 4.2.x- Patchwork: https://patchwork.linux-mips.org/patch/13354/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 2016-05-25 18:06:35 +08:00			`unsigned int notrace __bswapsi2(unsigned int u)`
MIPS: Use ARCH_USE_BUILTIN_BSWAP. ARCH_USE_BUILTIN_BSWAP will use __builtin_bswap16(), __builtin_bswap32() and __builtin_bswap64() where available. This allows better instruction scheduling. On pre-R2 processors it will result in 32 bit and 64 bit swapping being performed in a call to a __bswapsi2() rsp. __bswapdi2() functions, so we add these, too. For a 4.2 kernel with GCC 4.9 this yields the following kernel sizes: text data bss dec hex filename 3996071 155804 88992 4240867 40b5e3 vmlinux ip22 baseline 3985687 159900 88992 4234579 409d53 vmlinux ip22 + bswap patch 6913157 378552 251024 7542733 7317cd vmlinux ip27 baseline 6878581 378552 251024 7508157 7290bd vmlinux ip27 + bswap patch 5773777 268752 187424 6229953 5f0fc1 vmlinux malta baseline 5773401 268752 187424 6229577 5f0e49 vmlinux malta + bswap patch Presumably the code size improvments yield better cache hit rate thus better performance compensating for the extra function call but this will still need to be benchmarked. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 2015-09-29 18:19:48 +08:00			`{`
			`return (((u) & 0xff000000) >> 24) \|`
			`(((u) & 0x00ff0000) >> 8) \|`
			`(((u) & 0x0000ff00) << 8) \|`
			`(((u) & 0x000000ff) << 24);`
			`}`

			`EXPORT_SYMBOL(__bswapsi2);`