linux_dsm_epyc7002/arch/powerpc/include/asm/dbell.h
Nicholas Piggin a9af97aa0a powerpc/64s: msgclr when handling doorbell exceptions from system reset
msgsnd doorbell exceptions are cleared when the doorbell interrupt is
taken. However if a doorbell exception causes a system reset interrupt
wake from power saving state, the message is not cleared. Processing
the doorbell from the system reset interrupt requires msgclr to avoid
taking the exception again.

Testing this plus the previous wakup direct patch gives:

                                original         wakeup direct     msgclr
Different threads, same core:   315k/s           264k/s            345k/s
Different cores:                235k/s           242k/s            242k/s

Net speedup is +10% for same core, and +3% for different core.

Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-06-19 19:46:27 +10:00

108 lines
2.8 KiB
C

/*
* Copyright 2009 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* provides masks and opcode images for use by code generation, emulation
* and for instructions that older assemblers might not know about
*/
#ifndef _ASM_POWERPC_DBELL_H
#define _ASM_POWERPC_DBELL_H
#include <linux/smp.h>
#include <linux/threads.h>
#include <asm/ppc-opcode.h>
#include <asm/cpu_has_feature.h>
#define PPC_DBELL_MSG_BRDCAST (0x04000000)
#define PPC_DBELL_TYPE(x) (((x) & 0xf) << (63-36))
#define PPC_DBELL_TYPE_MASK PPC_DBELL_TYPE(0xf)
#define PPC_DBELL_LPID(x) ((x) << (63 - 49))
#define PPC_DBELL_PIR_MASK 0x3fff
enum ppc_dbell {
PPC_DBELL = 0, /* doorbell */
PPC_DBELL_CRIT = 1, /* critical doorbell */
PPC_G_DBELL = 2, /* guest doorbell */
PPC_G_DBELL_CRIT = 3, /* guest critical doorbell */
PPC_G_DBELL_MC = 4, /* guest mcheck doorbell */
PPC_DBELL_SERVER = 5, /* doorbell on server */
};
#ifdef CONFIG_PPC_BOOK3S
#define PPC_DBELL_MSGTYPE PPC_DBELL_SERVER
static inline void _ppc_msgsnd(u32 msg)
{
__asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGSND(%1), PPC_MSGSNDP(%1), %0)
: : "i" (CPU_FTR_HVMODE), "r" (msg));
}
/* sync before sending message */
static inline void ppc_msgsnd_sync(void)
{
__asm__ __volatile__ ("sync" : : : "memory");
}
/* sync after taking message interrupt */
static inline void ppc_msgsync(void)
{
/* sync is not required when taking messages from the same core */
__asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGSYNC " ; lwsync", "", %0)
: : "i" (CPU_FTR_HVMODE|CPU_FTR_ARCH_300));
}
static inline void _ppc_msgclr(u32 msg)
{
__asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGCLR(%1), PPC_MSGCLRP(%1), %0)
: : "i" (CPU_FTR_HVMODE), "r" (msg));
}
static inline void ppc_msgclr(enum ppc_dbell type)
{
u32 msg = PPC_DBELL_TYPE(type);
_ppc_msgclr(msg);
}
#else /* CONFIG_PPC_BOOK3S */
#define PPC_DBELL_MSGTYPE PPC_DBELL
static inline void _ppc_msgsnd(u32 msg)
{
__asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
}
/* sync before sending message */
static inline void ppc_msgsnd_sync(void)
{
__asm__ __volatile__ ("sync" : : : "memory");
}
/* sync after taking message interrupt */
static inline void ppc_msgsync(void)
{
}
#endif /* CONFIG_PPC_BOOK3S */
extern void doorbell_global_ipi(int cpu);
extern void doorbell_core_ipi(int cpu);
extern int doorbell_try_core_ipi(int cpu);
extern void doorbell_exception(struct pt_regs *regs);
static inline void ppc_msgsnd(enum ppc_dbell type, u32 flags, u32 tag)
{
u32 msg = PPC_DBELL_TYPE(type) | (flags & PPC_DBELL_MSG_BRDCAST) |
(tag & 0x07ffffff);
_ppc_msgsnd(msg);
}
#endif /* _ASM_POWERPC_DBELL_H */