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powerpc/64s: power4 nap fixup in C

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There is no need for this to be in asm, use the new intrrupt entry wrapper.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210406025508.821718-1-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2021-04-06 12:55:08 +10:00 committed by Michael Ellerman
parent 10f8f96179
commit 98db179a78
5 changed files with 35 additions and 45 deletions
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24
arch/powerpc/include/asm/interrupt.h
View File

@ -9,6 +9,17 @@
#include <asm/kprobes.h>
#include <asm/runlatch.h>
static inline void nap_adjust_return(struct pt_regs *regs)
{
#ifdef CONFIG_PPC_970_NAP
if (unlikely(test_thread_local_flags(_TLF_NAPPING))) {
/* Can avoid a test-and-clear because NMIs do not call this */
clear_thread_local_flags(_TLF_NAPPING);
regs->nip = (unsigned long)power4_idle_nap_return;
}
#endif
}
struct interrupt_state {
#ifdef CONFIG_PPC_BOOK3E_64
enum ctx_state ctx_state;
@ -124,6 +135,14 @@ static inline void interrupt_async_enter_prepare(struct pt_regs *regs, struct in
static inline void interrupt_async_exit_prepare(struct pt_regs *regs, struct interrupt_state *state)
{
/*
* Adjust at exit so the main handler sees the true NIA. This must
* come before irq_exit() because irq_exit can enable interrupts, and
* if another interrupt is taken before nap_adjust_return has run
* here, then that interrupt would return directly to idle nap return.
*/
nap_adjust_return(regs);
irq_exit();
interrupt_exit_prepare(regs, state);
}
@ -179,6 +198,11 @@ static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct inter
radix_enabled() || (mfmsr() & MSR_DR))
nmi_exit();
/*
* nmi does not call nap_adjust_return because nmi should not create
* new work to do (must use irq_work for that).
*/
#ifdef CONFIG_PPC64
if (TRAP(regs) != 0x900 && TRAP(regs) != 0xf00 && TRAP(regs) != 0x260)
this_cpu_set_ftrace_enabled(state->ftrace_enabled);

1
arch/powerpc/include/asm/processor.h
View File

@ -389,6 +389,7 @@ extern unsigned long isa300_idle_stop_mayloss(unsigned long psscr_val);
extern unsigned long isa206_idle_insn_mayloss(unsigned long type);
#ifdef CONFIG_PPC_970_NAP
extern void power4_idle_nap(void);
void power4_idle_nap_return(void);
#endif
extern unsigned long cpuidle_disable;

6
arch/powerpc/include/asm/thread_info.h
View File

@ -151,6 +151,12 @@ void arch_setup_new_exec(void);
#ifndef __ASSEMBLY__
static inline void clear_thread_local_flags(unsigned int flags)
{
struct thread_info *ti = current_thread_info();
ti->local_flags &= ~flags;
}
static inline bool test_thread_local_flags(unsigned int flags)
{
struct thread_info *ti = current_thread_info();

45
arch/powerpc/kernel/exceptions-64s.S
View File

@ -692,25 +692,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
ld r1,GPR1(r1)
.endm
/*
* When the idle code in power4_idle puts the CPU into NAP mode,
* it has to do so in a loop, and relies on the external interrupt
* and decrementer interrupt entry code to get it out of the loop.
* It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
* to signal that it is in the loop and needs help to get out.
*/
#ifdef CONFIG_PPC_970_NAP
#define FINISH_NAP \
BEGIN_FTR_SECTION \
ld r11, PACA_THREAD_INFO(r13); \
ld r9,TI_LOCAL_FLAGS(r11); \
andi. r10,r9,_TLF_NAPPING; \
bnel power4_fixup_nap; \
END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
#else
#define FINISH_NAP
#endif
/*
* There are a few constraints to be concerned with.
* - Real mode exceptions code/data must be located at their physical location.
@ -1248,7 +1229,6 @@ EXC_COMMON_BEGIN(machine_check_common)
*/
GEN_COMMON machine_check
FINISH_NAP
/* Enable MSR_RI when finished with PACA_EXMC */
li r10,MSR_RI
mtmsrd r10,1
@ -1571,7 +1551,6 @@ EXC_VIRT_BEGIN(hardware_interrupt, 0x4500, 0x100)
EXC_VIRT_END(hardware_interrupt, 0x4500, 0x100)
EXC_COMMON_BEGIN(hardware_interrupt_common)
GEN_COMMON hardware_interrupt
FINISH_NAP
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_IRQ
b interrupt_return
@ -1801,7 +1780,6 @@ EXC_VIRT_BEGIN(decrementer, 0x4900, 0x80)
EXC_VIRT_END(decrementer, 0x4900, 0x80)
EXC_COMMON_BEGIN(decrementer_common)
GEN_COMMON decrementer
FINISH_NAP
addi r3,r1,STACK_FRAME_OVERHEAD
bl timer_interrupt
b interrupt_return
@ -1886,7 +1864,6 @@ EXC_VIRT_BEGIN(doorbell_super, 0x4a00, 0x100)
EXC_VIRT_END(doorbell_super, 0x4a00, 0x100)
EXC_COMMON_BEGIN(doorbell_super_common)
GEN_COMMON doorbell_super
FINISH_NAP
addi r3,r1,STACK_FRAME_OVERHEAD
#ifdef CONFIG_PPC_DOORBELL
bl doorbell_exception
@ -2237,7 +2214,6 @@ EXC_COMMON_BEGIN(hmi_exception_early_common)
EXC_COMMON_BEGIN(hmi_exception_common)
GEN_COMMON hmi_exception
FINISH_NAP
addi r3,r1,STACK_FRAME_OVERHEAD
bl handle_hmi_exception
b interrupt_return
@ -2266,7 +2242,6 @@ EXC_VIRT_BEGIN(h_doorbell, 0x4e80, 0x20)
EXC_VIRT_END(h_doorbell, 0x4e80, 0x20)
EXC_COMMON_BEGIN(h_doorbell_common)
GEN_COMMON h_doorbell
FINISH_NAP
addi r3,r1,STACK_FRAME_OVERHEAD
#ifdef CONFIG_PPC_DOORBELL
bl doorbell_exception
@ -2299,7 +2274,6 @@ EXC_VIRT_BEGIN(h_virt_irq, 0x4ea0, 0x20)
EXC_VIRT_END(h_virt_irq, 0x4ea0, 0x20)
EXC_COMMON_BEGIN(h_virt_irq_common)
GEN_COMMON h_virt_irq
FINISH_NAP
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_IRQ
b interrupt_return
@ -2345,7 +2319,6 @@ EXC_VIRT_BEGIN(performance_monitor, 0x4f00, 0x20)
EXC_VIRT_END(performance_monitor, 0x4f00, 0x20)
EXC_COMMON_BEGIN(performance_monitor_common)
GEN_COMMON performance_monitor
FINISH_NAP
addi r3,r1,STACK_FRAME_OVERHEAD
bl performance_monitor_exception
b interrupt_return
@ -3096,24 +3069,6 @@ USE_FIXED_SECTION(virt_trampolines)
__end_interrupts:
DEFINE_FIXED_SYMBOL(__end_interrupts)
#ifdef CONFIG_PPC_970_NAP
/*
* Called by exception entry code if _TLF_NAPPING was set, this clears
* the NAPPING flag, and redirects the exception exit to
* power4_fixup_nap_return.
*/
.globl power4_fixup_nap
EXC_COMMON_BEGIN(power4_fixup_nap)
andc r9,r9,r10
std r9,TI_LOCAL_FLAGS(r11)
LOAD_REG_ADDR(r10, power4_idle_nap_return)
std r10,_NIP(r1)
blr
power4_idle_nap_return:
blr
#endif
CLOSE_FIXED_SECTION(real_vectors);
CLOSE_FIXED_SECTION(real_trampolines);
CLOSE_FIXED_SECTION(virt_vectors);

4
arch/powerpc/kernel/idle_book3s.S
View File

@ -209,4 +209,8 @@ _GLOBAL(power4_idle_nap)
mtmsrd r7
isync
b 1b
.globl power4_idle_nap_return
power4_idle_nap_return:
blr
#endif