Commit 98db179a authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc/64s: power4 nap fixup in C 



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

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Tested-by: default avatarAndreas Schwab <schwab@linux-m68k.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210406025508.821718-1-npiggin@gmail.com
parent 10f8f961

arch/powerpc/include/asm/interrupt.h

+24 −0
Original line number Diff line number Diff line
@@ -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);

arch/powerpc/include/asm/processor.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

arch/powerpc/include/asm/thread_info.h

+6 −0
Original line number Diff line number Diff line
@@ -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();

arch/powerpc/kernel/exceptions-64s.S

+0 −45
Original line number Diff line number Diff line
@@ -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);

arch/powerpc/kernel/idle_book3s.S

+4 −0
Original line number Diff line number Diff line
@@ -209,4 +209,8 @@ _GLOBAL(power4_idle_nap) 
	mtmsrd	r7

	isync

	b	1b



	.globl power4_idle_nap_return

power4_idle_nap_return:

	blr

#endif