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target-arm: Minimal implementation of performance counters

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Newer Linux kernels assume the existence of the performance counter
cp15 registers. Provide a minimal implementation of these registers.
We support no events. This should be compliant with the ARM ARM,
except that we don't implement the cycle counter.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Peter Maydell 2011-03-22 12:16:16 +00:00
parent b501b5e461
commit 74594c9d81
4 changed files with 184 additions and 17 deletions
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8
target-arm/cpu.h
View File

@ -133,6 +133,12 @@ typedef struct CPUARMState {
uint32_t c7_par; /* Translation result. */
uint32_t c9_insn; /* Cache lockdown registers. */
uint32_t c9_data;
uint32_t c9_pmcr; /* performance monitor control register */
uint32_t c9_pmcnten; /* perf monitor counter enables */
uint32_t c9_pmovsr; /* perf monitor overflow status */
uint32_t c9_pmxevtyper; /* perf monitor event type */
uint32_t c9_pmuserenr; /* perf monitor user enable */
uint32_t c9_pminten; /* perf monitor interrupt enables */
uint32_t c13_fcse; /* FCSE PID. */
uint32_t c13_context; /* Context ID. */
uint32_t c13_tls1; /* User RW Thread register. */
@ -438,7 +444,7 @@ void cpu_arm_set_cp_io(CPUARMState *env, int cpnum,
#define cpu_signal_handler cpu_arm_signal_handler
#define cpu_list arm_cpu_list
#define CPU_SAVE_VERSION 3
#define CPU_SAVE_VERSION 4
/* MMU modes definitions */
#define MMU_MODE0_SUFFIX _kernel

161
target-arm/helper.c
View File

@ -270,6 +270,10 @@ void cpu_reset(CPUARMState *env)
}
env->vfp.xregs[ARM_VFP_FPEXC] = 0;
env->cp15.c2_base_mask = 0xffffc000u;
/* v7 performance monitor control register: same implementor
* field as main ID register, and we implement no event counters.
*/
env->cp15.c9_pmcr = (id & 0xff000000);
#endif
set_flush_to_zero(1, &env->vfp.standard_fp_status);
set_flush_inputs_to_zero(1, &env->vfp.standard_fp_status);
@ -1588,6 +1592,81 @@ void HELPER(set_cp15)(CPUState *env, uint32_t insn, uint32_t val)
case 1: /* TCM memory region registers. */
/* Not implemented. */
goto bad_reg;
case 12: /* Performance monitor control */
/* Performance monitors are implementation defined in v7,
* but with an ARM recommended set of registers, which we
* follow (although we don't actually implement any counters)
*/
if (!arm_feature(env, ARM_FEATURE_V7)) {
goto bad_reg;
}
switch (op2) {
case 0: /* performance monitor control register */
/* only the DP, X, D and E bits are writable */
env->cp15.c9_pmcr &= ~0x39;
env->cp15.c9_pmcr |= (val & 0x39);
break;
case 1: /* Count enable set register */
val &= (1 << 31);
env->cp15.c9_pmcnten |= val;
break;
case 2: /* Count enable clear */
val &= (1 << 31);
env->cp15.c9_pmcnten &= ~val;
break;
case 3: /* Overflow flag status */
env->cp15.c9_pmovsr &= ~val;
break;
case 4: /* Software increment */
/* RAZ/WI since we don't implement the software-count event */
break;
case 5: /* Event counter selection register */
/* Since we don't implement any events, writing to this register
* is actually UNPREDICTABLE. So we choose to RAZ/WI.
*/
break;
default:
goto bad_reg;
}
break;
case 13: /* Performance counters */
if (!arm_feature(env, ARM_FEATURE_V7)) {
goto bad_reg;
}
switch (op2) {
case 0: /* Cycle count register: not implemented, so RAZ/WI */
break;
case 1: /* Event type select */
env->cp15.c9_pmxevtyper = val & 0xff;
break;
case 2: /* Event count register */
/* Unimplemented (we have no events), RAZ/WI */
break;
default:
goto bad_reg;
}
break;
case 14: /* Performance monitor control */
if (!arm_feature(env, ARM_FEATURE_V7)) {
goto bad_reg;
}
switch (op2) {
case 0: /* user enable */
env->cp15.c9_pmuserenr = val & 1;
/* changes access rights for cp registers, so flush tbs */
tb_flush(env);
break;
case 1: /* interrupt enable set */
/* We have no event counters so only the C bit can be changed */
val &= (1 << 31);
env->cp15.c9_pminten |= val;
break;
case 2: /* interrupt enable clear */
val &= (1 << 31);
env->cp15.c9_pminten &= ~val;
break;
}
break;
default:
goto bad_reg;
}
@ -1879,27 +1958,81 @@ uint32_t HELPER(get_cp15)(CPUState *env, uint32_t insn)
return 0;
case 8: /* MMU TLB control. */
goto bad_reg;
case 9: /* Cache lockdown. */
switch (op1) {
case 0: /* L1 cache. */
if (arm_feature(env, ARM_FEATURE_OMAPCP))
return 0;
switch (op2) {
case 0:
return env->cp15.c9_data;
case 1:
return env->cp15.c9_insn;
case 9:
switch (crm) {
case 0: /* Cache lockdown */
switch (op1) {
case 0: /* L1 cache. */
if (arm_feature(env, ARM_FEATURE_OMAPCP)) {
return 0;
}
switch (op2) {
case 0:
return env->cp15.c9_data;
case 1:
return env->cp15.c9_insn;
default:
goto bad_reg;
}
case 1: /* L2 cache */
if (crm != 0) {
goto bad_reg;
}
/* L2 Lockdown and Auxiliary control. */
return 0;
default:
goto bad_reg;
}
case 1: /* L2 cache */
if (crm != 0)
break;
case 12: /* Performance monitor control */
if (!arm_feature(env, ARM_FEATURE_V7)) {
goto bad_reg;
/* L2 Lockdown and Auxiliary control. */
return 0;
}
switch (op2) {
case 0: /* performance monitor control register */
return env->cp15.c9_pmcr;
case 1: /* count enable set */
case 2: /* count enable clear */
return env->cp15.c9_pmcnten;
case 3: /* overflow flag status */
return env->cp15.c9_pmovsr;
case 4: /* software increment */
case 5: /* event counter selection register */
return 0; /* Unimplemented, RAZ/WI */
default:
goto bad_reg;
}
case 13: /* Performance counters */
if (!arm_feature(env, ARM_FEATURE_V7)) {
goto bad_reg;
}
switch (op2) {
case 1: /* Event type select */
return env->cp15.c9_pmxevtyper;
case 0: /* Cycle count register */
case 2: /* Event count register */
/* Unimplemented, so RAZ/WI */
return 0;
default:
goto bad_reg;
}
case 14: /* Performance monitor control */
if (!arm_feature(env, ARM_FEATURE_V7)) {
goto bad_reg;
}
switch (op2) {
case 0: /* user enable */
return env->cp15.c9_pmuserenr;
case 1: /* interrupt enable set */
case 2: /* interrupt enable clear */
return env->cp15.c9_pminten;
default:
goto bad_reg;
}
default:
goto bad_reg;
}
break;
case 10: /* MMU TLB lockdown. */
/* ??? TLB lockdown not implemented. */
return 0;

12
target-arm/machine.c
View File

@ -44,6 +44,12 @@ void cpu_save(QEMUFile *f, void *opaque)
qemu_put_be32(f, env->cp15.c7_par);
qemu_put_be32(f, env->cp15.c9_insn);
qemu_put_be32(f, env->cp15.c9_data);
qemu_put_be32(f, env->cp15.c9_pmcr);
qemu_put_be32(f, env->cp15.c9_pmcnten);
qemu_put_be32(f, env->cp15.c9_pmovsr);
qemu_put_be32(f, env->cp15.c9_pmxevtyper);
qemu_put_be32(f, env->cp15.c9_pmuserenr);
qemu_put_be32(f, env->cp15.c9_pminten);
qemu_put_be32(f, env->cp15.c13_fcse);
qemu_put_be32(f, env->cp15.c13_context);
qemu_put_be32(f, env->cp15.c13_tls1);
@ -152,6 +158,12 @@ int cpu_load(QEMUFile *f, void *opaque, int version_id)
env->cp15.c7_par = qemu_get_be32(f);
env->cp15.c9_insn = qemu_get_be32(f);
env->cp15.c9_data = qemu_get_be32(f);
env->cp15.c9_pmcr = qemu_get_be32(f);
env->cp15.c9_pmcnten = qemu_get_be32(f);
env->cp15.c9_pmovsr = qemu_get_be32(f);
env->cp15.c9_pmxevtyper = qemu_get_be32(f);
env->cp15.c9_pmuserenr = qemu_get_be32(f);
env->cp15.c9_pminten = qemu_get_be32(f);
env->cp15.c13_fcse = qemu_get_be32(f);
env->cp15.c13_context = qemu_get_be32(f);
env->cp15.c13_tls1 = qemu_get_be32(f);

20
target-arm/translate.c
View File

@ -2472,12 +2472,28 @@ static int disas_cp_insn(CPUState *env, DisasContext *s, uint32_t insn)
return 0;
}
static int cp15_user_ok(uint32_t insn)
static int cp15_user_ok(CPUState *env, uint32_t insn)
{
int cpn = (insn >> 16) & 0xf;
int cpm = insn & 0xf;
int op = ((insn >> 5) & 7) | ((insn >> 18) & 0x38);
if (arm_feature(env, ARM_FEATURE_V7) && cpn == 9) {
/* Performance monitor registers fall into three categories:
* (a) always UNDEF in usermode
* (b) UNDEF only if PMUSERENR.EN is 0
* (c) always read OK and UNDEF on write (PMUSERENR only)
*/
if ((cpm == 12 && (op < 6)) ||
(cpm == 13 && (op < 3))) {
return env->cp15.c9_pmuserenr;
} else if (cpm == 14 && op == 0 && (insn & ARM_CP_RW_BIT)) {
/* PMUSERENR, read only */
return 1;
}
return 0;
}
if (cpn == 13 && cpm == 0) {
/* TLS register. */
if (op == 2 || (op == 3 && (insn & ARM_CP_RW_BIT)))
@ -2564,7 +2580,7 @@ static int disas_cp15_insn(CPUState *env, DisasContext *s, uint32_t insn)
/* cdp */
return 1;
}
if (IS_USER(s) && !cp15_user_ok(insn)) {
if (IS_USER(s) && !cp15_user_ok(env, insn)) {
return 1;
}