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| author |   Christophe Leroy <christophe.leroy@c-s.fr> | 2019-08-20 14:34:12 +0000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2019-08-27 13:03:36 +1000 |
| commit | c691b4b83b6a348f7b9d13c36916e73c2e1d85e4 (patch) | |
| tree | 86e35a779a1f8eea5dfa32654d4afff910c32aa5 /arch/powerpc/include/asm/ppc_asm.h | |
| parent | powerpc/mm: split out early ioremap path. (diff) | |
| download | linux-dev-c691b4b83b6a348f7b9d13c36916e73c2e1d85e4.tar.xz linux-dev-c691b4b83b6a348f7b9d13c36916e73c2e1d85e4.zip | |
powerpc: rewrite LOAD_REG_IMMEDIATE() as an intelligent macro
Today LOAD_REG_IMMEDIATE() is a basic #define which loads all
parts on a value into a register, including the parts that are NUL.
This means always 2 instructions on PPC32 and always 5 instructions
on PPC64. And those instructions cannot run in parallele as they are
updating the same register.
Ex: LOAD_REG_IMMEDIATE(r1,THREAD_SIZE) in head_64.S results in:
3c 20 00 00 lis r1,0
60 21 00 00 ori r1,r1,0
78 21 07 c6 rldicr r1,r1,32,31
64 21 00 00 oris r1,r1,0
60 21 40 00 ori r1,r1,16384
Rewrite LOAD_REG_IMMEDIATE() with GAS macro in order to skip
the parts that are NUL.
Rename existing LOAD_REG_IMMEDIATE() as LOAD_REG_IMMEDIATE_SYM()
and use that one for loading value of symbols which are not known
at compile time.
Now LOAD_REG_IMMEDIATE(r1,THREAD_SIZE) in head_64.S results in:
38 20 40 00 li r1,16384
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d60ce8dd3a383c7adbfc322bf1d53d81724a6000.1566311636.git.christophe.leroy@c-s.fr
Diffstat (limited to 'arch/powerpc/include/asm/ppc_asm.h')
| -rw-r--r-- | arch/powerpc/include/asm/ppc_asm.h | 42 |
1 files changed, 37 insertions, 5 deletions
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index e0637730a8e7..20a00209c965 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -311,13 +311,43 @@ n: addis reg,reg,(name - 0b)@ha; \ addi reg,reg,(name - 0b)@l; -#ifdef __powerpc64__ -#ifdef HAVE_AS_ATHIGH +#if defined(__powerpc64__) && defined(HAVE_AS_ATHIGH) #define __AS_ATHIGH high #else #define __AS_ATHIGH h #endif -#define LOAD_REG_IMMEDIATE(reg,expr) \ + +.macro __LOAD_REG_IMMEDIATE_32 r, x + .if (\x) >= 0x8000 || (\x) < -0x8000 + lis \r, (\x)@__AS_ATHIGH + .if (\x) & 0xffff != 0 + ori \r, \r, (\x)@l + .endif + .else + li \r, (\x)@l + .endif +.endm + +.macro __LOAD_REG_IMMEDIATE r, x + .if (\x) >= 0x80000000 || (\x) < -0x80000000 + __LOAD_REG_IMMEDIATE_32 \r, (\x) >> 32 + sldi \r, \r, 32 + .if (\x) & 0xffff0000 != 0 + oris \r, \r, (\x)@__AS_ATHIGH + .endif + .if (\x) & 0xffff != 0 + ori \r, \r, (\x)@l + .endif + .else + __LOAD_REG_IMMEDIATE_32 \r, \x + .endif +.endm + +#ifdef __powerpc64__ + +#define LOAD_REG_IMMEDIATE(reg, expr) __LOAD_REG_IMMEDIATE reg, expr + +#define LOAD_REG_IMMEDIATE_SYM(reg,expr) \ lis reg,(expr)@highest; \ ori reg,reg,(expr)@higher; \ rldicr reg,reg,32,31; \ @@ -335,11 +365,13 @@ n: #else /* 32-bit */ -#define LOAD_REG_IMMEDIATE(reg,expr) \ +#define LOAD_REG_IMMEDIATE(reg, expr) __LOAD_REG_IMMEDIATE_32 reg, expr + +#define LOAD_REG_IMMEDIATE_SYM(reg,expr) \ lis reg,(expr)@ha; \ addi reg,reg,(expr)@l; -#define LOAD_REG_ADDR(reg,name) LOAD_REG_IMMEDIATE(reg, name) +#define LOAD_REG_ADDR(reg,name) LOAD_REG_IMMEDIATE_SYM(reg, name) #define LOAD_REG_ADDRBASE(reg, name) lis reg,name@ha #define ADDROFF(name) name@l |