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powerpc/irq: Inline call_do_irq() and call_do_softirq() 

call_do_irq() and call_do_softirq() are simple enough to be
worth inlining.

Inlining them avoids an mflr/mtlr pair plus a save/reload on stack.

This is inspired from S390 arch. Several other arches do more or
less the same. The way sparc arch does seems odd thought.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210320122227.345427-1-mpe@ellerman.id.au
This commit is contained in:
Christophe Leroy 2021-03-19 06:34:43 +00:00 committed by Michael Ellerman
parent d2313da4ff
commit 48cf12d889
4 changed files with 41 additions and 49 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/powerpc/include/asm/irq.h
View File

@ -53,8 +53,6 @@ extern void *mcheckirq_ctx[NR_CPUS];
extern void *hardirq_ctx[NR_CPUS];
extern void *softirq_ctx[NR_CPUS];
void call_do_softirq(void *sp);
void call_do_irq(struct pt_regs *regs, void *sp);
extern void do_IRQ(struct pt_regs *regs);
extern void __init init_IRQ(void);
extern void __do_irq(struct pt_regs *regs);

41
arch/powerpc/kernel/irq.c
View File

@ -667,6 +667,47 @@ static inline void check_stack_overflow(void)
}
}
static __always_inline void call_do_softirq(const void *sp)
{
/* Temporarily switch r1 to sp, call __do_softirq() then restore r1. */
asm volatile (
PPC_STLU " %%r1, %[offset](%[sp]) ;"
"mr %%r1, %[sp] ;"
"bl %[callee] ;"
PPC_LL " %%r1, 0(%%r1) ;"
: // Outputs
: // Inputs
[sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_OVERHEAD),
[callee] "i" (__do_softirq)
: // Clobbers
"lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6",
"cr7", "r0", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
"r11", "r12"
);
}
static __always_inline void call_do_irq(struct pt_regs *regs, void *sp)
{
register unsigned long r3 asm("r3") = (unsigned long)regs;
/* Temporarily switch r1 to sp, call __do_irq() then restore r1. */
asm volatile (
PPC_STLU " %%r1, %[offset](%[sp]) ;"
"mr %%r1, %[sp] ;"
"bl %[callee] ;"
PPC_LL " %%r1, 0(%%r1) ;"
: // Outputs
"+r" (r3)
: // Inputs
[sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_OVERHEAD),
[callee] "i" (__do_irq)
: // Clobbers
"lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6",
"cr7", "r0", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
"r11", "r12"
);
}
void __do_irq(struct pt_regs *regs)
{
unsigned int irq;

25
arch/powerpc/kernel/misc_32.S
View File

@ -27,31 +27,6 @@
.text
_GLOBAL(call_do_softirq)
mflr r0
stw r0,4(r1)
stwu r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
mr r1,r3
bl __do_softirq
lwz r1,0(r1)
lwz r0,4(r1)
mtlr r0
blr
/*
* void call_do_irq(struct pt_regs *regs, void *sp);
*/
_GLOBAL(call_do_irq)
mflr r0
stw r0,4(r1)
stwu r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r4)
mr r1,r4
bl __do_irq
lwz r1,0(r1)
lwz r0,4(r1)
mtlr r0
blr
/*
* This returns the high 64 bits of the product of two 64-bit numbers.
*/

22
arch/powerpc/kernel/misc_64.S
View File

@ -27,28 +27,6 @@
.text
_GLOBAL(call_do_softirq)
mflr r0
std r0,16(r1)
stdu r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
mr r1,r3
bl __do_softirq
ld r1,0(r1)
ld r0,16(r1)
mtlr r0
blr
_GLOBAL(call_do_irq)
mflr r0
std r0,16(r1)
stdu r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r4)
mr r1,r4
bl __do_irq
ld r1,0(r1)
ld r0,16(r1)
mtlr r0
blr
_GLOBAL(__bswapdi2)
EXPORT_SYMBOL(__bswapdi2)
srdi r8,r3,32