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authorH. Peter Anvin <hpa@zytor.com>2016-06-08 12:38:38 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2016-06-08 12:41:20 -0700
commit117780eef7740729e803bdcc0d5f2f48137ea8e3 (patch)
tree63bd519e1d8b115d332fcb6e63ee4f94ee235161 /arch/x86/boot
parent2823d4da5d8a0c222747b24eceb65f5b30717d02 (diff)
downloadlinux-117780eef7740729e803bdcc0d5f2f48137ea8e3.tar.bz2
x86, asm: use bool for bitops and other assembly outputs
The gcc people have confirmed that using "bool" when combined with inline assembly always is treated as a byte-sized operand that can be assumed to be 0 or 1, which is exactly what the SET instruction emits. Change the output types and intermediate variables of as many operations as practical to "bool". Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1465414726-197858-3-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Diffstat (limited to 'arch/x86/boot')
-rw-r--r--arch/x86/boot/bitops.h8
-rw-r--r--arch/x86/boot/boot.h8
-rw-r--r--arch/x86/boot/string.c2
3 files changed, 10 insertions, 8 deletions
diff --git a/arch/x86/boot/bitops.h b/arch/x86/boot/bitops.h
index 878e4b9940d9..0d41d68131cc 100644
--- a/arch/x86/boot/bitops.h
+++ b/arch/x86/boot/bitops.h
@@ -16,14 +16,16 @@
#define BOOT_BITOPS_H
#define _LINUX_BITOPS_H /* Inhibit inclusion of <linux/bitops.h> */
-static inline int constant_test_bit(int nr, const void *addr)
+#include <linux/types.h>
+
+static inline bool constant_test_bit(int nr, const void *addr)
{
const u32 *p = (const u32 *)addr;
return ((1UL << (nr & 31)) & (p[nr >> 5])) != 0;
}
-static inline int variable_test_bit(int nr, const void *addr)
+static inline bool variable_test_bit(int nr, const void *addr)
{
- u8 v;
+ bool v;
const u32 *p = (const u32 *)addr;
asm("btl %2,%1; setc %0" : "=qm" (v) : "m" (*p), "Ir" (nr));
diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h
index 9011a88353de..2edb2d53c3a2 100644
--- a/arch/x86/boot/boot.h
+++ b/arch/x86/boot/boot.h
@@ -176,16 +176,16 @@ static inline void wrgs32(u32 v, addr_t addr)
}
/* Note: these only return true/false, not a signed return value! */
-static inline int memcmp_fs(const void *s1, addr_t s2, size_t len)
+static inline bool memcmp_fs(const void *s1, addr_t s2, size_t len)
{
- u8 diff;
+ bool diff;
asm volatile("fs; repe; cmpsb; setnz %0"
: "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len));
return diff;
}
-static inline int memcmp_gs(const void *s1, addr_t s2, size_t len)
+static inline bool memcmp_gs(const void *s1, addr_t s2, size_t len)
{
- u8 diff;
+ bool diff;
asm volatile("gs; repe; cmpsb; setnz %0"
: "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len));
return diff;
diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c
index 318b8465d302..cc3bd583dce1 100644
--- a/arch/x86/boot/string.c
+++ b/arch/x86/boot/string.c
@@ -17,7 +17,7 @@
int memcmp(const void *s1, const void *s2, size_t len)
{
- u8 diff;
+ bool diff;
asm("repe; cmpsb; setnz %0"
: "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len));
return diff;