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target/ppc: Fix support for "STOP light" states on POWER9 

STOP must act differently based on PSSCR:EC on POWER9. When set, it
acts like the P7/P8 power management instructions and wake up at 0x100
based on the wakeup conditions in LPCR.

When PSSCR:EC is clear however it will wakeup at the next instruction
after STOP (if EE is clear) or take the corresponding interrupts (if
EE is set).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190215161648.9600-4-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Benjamin Herrenschmidt 2019-02-15 17:16:41 +01:00 committed by David Gibson
parent 3621e2c960
commit 21c0d66a9c
5 changed files with 35 additions and 6 deletions
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1
target/ppc/cpu-qom.h
View File

@ -122,6 +122,7 @@ typedef enum {
PPC_PM_NAP,
PPC_PM_SLEEP,
PPC_PM_RVWINKLE,
PPC_PM_STOP,
} powerpc_pm_insn_t;
/*****************************************************************************/

12
target/ppc/cpu.h
View File

@ -414,6 +414,10 @@ struct ppc_slb_t {
#define LPCR_HVICE PPC_BIT(62) /* HV Virtualisation Int Enable */
#define LPCR_HDICE PPC_BIT(63)
/* PSSCR bits */
#define PSSCR_ESL PPC_BIT(42) /* Enable State Loss */
#define PSSCR_EC PPC_BIT(43) /* Exit Criterion */
#define msr_sf ((env->msr >> MSR_SF) & 1)
#define msr_isf ((env->msr >> MSR_ISF) & 1)
#define msr_shv ((env->msr >> MSR_SHV) & 1)
@ -1110,9 +1114,11 @@ struct CPUPPCState {
* instructions and SPRs are diallowed if MSR:HV is 0
*/
bool has_hv_mode;
/* On P7/P8, set when in PM state, we need to handle resume
* in a special way (such as routing some resume causes to
* 0x100), so flag this here.
/*
* On P7/P8/P9, set when in PM state, we need to handle resume in
* a special way (such as routing some resume causes to 0x100), so
* flag this here.
*/
bool in_pm_state;
#endif

8
target/ppc/excp_helper.c
View File

@ -97,7 +97,10 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
asrr0 = -1;
asrr1 = -1;
/* check for special resume at 0x100 from doze/nap/sleep/winkle on P7/P8 */
/*
* check for special resume at 0x100 from doze/nap/sleep/winkle on
* P7/P8/P9
*/
if (env->in_pm_state) {
env->in_pm_state = false;
@ -960,7 +963,8 @@ void helper_pminsn(CPUPPCState *env, powerpc_pm_insn_t insn)
env->pending_interrupts &= ~(1 << PPC_INTERRUPT_HDECR);
/* Condition for waking up at 0x100 */
env->in_pm_state = true;
env->in_pm_state = (insn != PPC_PM_STOP) ||
(env->spr[SPR_PSSCR] & PSSCR_EC);
}
#endif /* defined(TARGET_PPC64) */

13
target/ppc/translate.c
View File

@ -3589,7 +3589,18 @@ static void gen_nap(DisasContext *ctx)
static void gen_stop(DisasContext *ctx)
{
gen_nap(ctx);
#if defined(CONFIG_USER_ONLY)
GEN_PRIV;
#else
TCGv_i32 t;
CHK_HV;
t = tcg_const_i32(PPC_PM_STOP);
gen_helper_pminsn(cpu_env, t);
tcg_temp_free_i32(t);
/* Stop translation, as the CPU is supposed to sleep from now */
gen_exception_nip(ctx, EXCP_HLT, ctx->base.pc_next);
#endif /* defined(CONFIG_USER_ONLY) */
}
static void gen_sleep(DisasContext *ctx)

7
target/ppc/translate_init.inc.c
View File

@ -8801,9 +8801,16 @@ static bool cpu_has_work_POWER9(CPUState *cs)
CPUPPCState *env = &cpu->env;
if (cs->halted) {
uint64_t psscr = env->spr[SPR_PSSCR];
if (!(cs->interrupt_request & CPU_INTERRUPT_HARD)) {
return false;
}
/* If EC is clear, just return true on any pending interrupt */
if (!(psscr & PSSCR_EC)) {
return true;
}
/* External Exception */
if ((env->pending_interrupts & (1u << PPC_INTERRUPT_EXT)) &&
(env->spr[SPR_LPCR] & LPCR_EEE)) {