nvic: Implement AIRCR changes for v8M
The Application Interrupt and Reset Control Register has some changes
for v8M:
* new bits SYSRESETREQS, BFHFNMINS and PRIS: these all have
real state if the security extension is implemented and otherwise
are constant
* the PRIGROUP field is banked between security states
* non-secure code can be blocked from using the SYSRESET bit
to reset the system if SYSRESETREQS is set
Implement the new state and the changes to register read and write.
For the moment we ignore the effects of the secure PRIGROUP.
We will implement the effects of PRIS and BFHFNMIS later.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-6-git-send-email-peter.maydell@linaro.org
diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c
index fa5dd23..d745f38 100644
--- a/hw/intc/armv7m_nvic.c
+++ b/hw/intc/armv7m_nvic.c
@@ -129,7 +129,7 @@
*/
static inline uint32_t nvic_gprio_mask(NVICState *s)
{
- return ~0U << (s->prigroup + 1);
+ return ~0U << (s->prigroup[M_REG_NS] + 1);
}
/* Recompute vectpending and exception_prio */
@@ -451,8 +451,21 @@
return val;
case 0xd08: /* Vector Table Offset. */
return cpu->env.v7m.vecbase[attrs.secure];
- case 0xd0c: /* Application Interrupt/Reset Control. */
- return 0xfa050000 | (s->prigroup << 8);
+ case 0xd0c: /* Application Interrupt/Reset Control (AIRCR) */
+ val = 0xfa050000 | (s->prigroup[attrs.secure] << 8);
+ if (attrs.secure) {
+ /* s->aircr stores PRIS, BFHFNMINS, SYSRESETREQS */
+ val |= cpu->env.v7m.aircr;
+ } else {
+ if (arm_feature(&cpu->env, ARM_FEATURE_V8)) {
+ /* BFHFNMINS is R/O from NS; other bits are RAZ/WI. If
+ * security isn't supported then BFHFNMINS is RAO (and
+ * the bit in env.v7m.aircr is always set).
+ */
+ val |= cpu->env.v7m.aircr & R_V7M_AIRCR_BFHFNMINS_MASK;
+ }
+ }
+ return val;
case 0xd10: /* System Control. */
/* TODO: Implement SLEEPONEXIT. */
return 0;
@@ -660,22 +673,35 @@
case 0xd08: /* Vector Table Offset. */
cpu->env.v7m.vecbase[attrs.secure] = value & 0xffffff80;
break;
- case 0xd0c: /* Application Interrupt/Reset Control. */
- if ((value >> 16) == 0x05fa) {
- if (value & 4) {
- qemu_irq_pulse(s->sysresetreq);
+ case 0xd0c: /* Application Interrupt/Reset Control (AIRCR) */
+ if ((value >> R_V7M_AIRCR_VECTKEY_SHIFT) == 0x05fa) {
+ if (value & R_V7M_AIRCR_SYSRESETREQ_MASK) {
+ if (attrs.secure ||
+ !(cpu->env.v7m.aircr & R_V7M_AIRCR_SYSRESETREQS_MASK)) {
+ qemu_irq_pulse(s->sysresetreq);
+ }
}
- if (value & 2) {
+ if (value & R_V7M_AIRCR_VECTCLRACTIVE_MASK) {
qemu_log_mask(LOG_GUEST_ERROR,
"Setting VECTCLRACTIVE when not in DEBUG mode "
"is UNPREDICTABLE\n");
}
- if (value & 1) {
+ if (value & R_V7M_AIRCR_VECTRESET_MASK) {
+ /* NB: this bit is RES0 in v8M */
qemu_log_mask(LOG_GUEST_ERROR,
"Setting VECTRESET when not in DEBUG mode "
"is UNPREDICTABLE\n");
}
- s->prigroup = extract32(value, 8, 3);
+ s->prigroup[attrs.secure] = extract32(value,
+ R_V7M_AIRCR_PRIGROUP_SHIFT,
+ R_V7M_AIRCR_PRIGROUP_LENGTH);
+ if (attrs.secure) {
+ /* These bits are only writable by secure */
+ cpu->env.v7m.aircr = value &
+ (R_V7M_AIRCR_SYSRESETREQS_MASK |
+ R_V7M_AIRCR_BFHFNMINS_MASK |
+ R_V7M_AIRCR_PRIS_MASK);
+ }
nvic_irq_update(s);
}
break;
@@ -1193,6 +1219,7 @@
.fields = (VMStateField[]) {
VMSTATE_STRUCT_ARRAY(sec_vectors, NVICState, NVIC_INTERNAL_VECTORS, 1,
vmstate_VecInfo, VecInfo),
+ VMSTATE_UINT32(prigroup[M_REG_S], NVICState),
VMSTATE_END_OF_LIST()
}
};
@@ -1205,7 +1232,7 @@
.fields = (VMStateField[]) {
VMSTATE_STRUCT_ARRAY(vectors, NVICState, NVIC_MAX_VECTORS, 1,
vmstate_VecInfo, VecInfo),
- VMSTATE_UINT32(prigroup, NVICState),
+ VMSTATE_UINT32(prigroup[M_REG_NS], NVICState),
VMSTATE_END_OF_LIST()
},
.subsections = (const VMStateDescription*[]) {
diff --git a/include/hw/intc/armv7m_nvic.h b/include/hw/intc/armv7m_nvic.h
index 329774e8..e96e488 100644
--- a/include/hw/intc/armv7m_nvic.h
+++ b/include/hw/intc/armv7m_nvic.h
@@ -55,7 +55,8 @@
* Entries in sec_vectors[] for non-banked exception numbers are unused.
*/
VecInfo sec_vectors[NVIC_INTERNAL_VECTORS];
- uint32_t prigroup;
+ /* The PRIGROUP field in AIRCR is banked */
+ uint32_t prigroup[M_REG_NUM_BANKS];
/* The following fields are all cached state that can be recalculated
* from the vectors[] and sec_vectors[] arrays and the prigroup field:
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 20a3445..3344979 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -187,6 +187,13 @@
if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
env->v7m.secure = true;
+ } else {
+ /* This bit resets to 0 if security is supported, but 1 if
+ * it is not. The bit is not present in v7M, but we set it
+ * here so we can avoid having to make checks on it conditional
+ * on ARM_FEATURE_V8 (we don't let the guest see the bit).
+ */
+ env->v7m.aircr = R_V7M_AIRCR_BFHFNMINS_MASK;
}
/* In v7M the reset value of this bit is IMPDEF, but ARM recommends
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 6e50ae2..a52ec6b 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -449,6 +449,7 @@
int exception;
uint32_t primask[M_REG_NUM_BANKS];
uint32_t faultmask[M_REG_NUM_BANKS];
+ uint32_t aircr; /* only holds r/w state if security extn implemented */
uint32_t secure; /* Is CPU in Secure state? (not guest visible) */
} v7m;
@@ -1200,6 +1201,17 @@
FIELD(V7M_CCR, DC, 16, 1)
FIELD(V7M_CCR, IC, 17, 1)
+/* V7M AIRCR bits */
+FIELD(V7M_AIRCR, VECTRESET, 0, 1)
+FIELD(V7M_AIRCR, VECTCLRACTIVE, 1, 1)
+FIELD(V7M_AIRCR, SYSRESETREQ, 2, 1)
+FIELD(V7M_AIRCR, SYSRESETREQS, 3, 1)
+FIELD(V7M_AIRCR, PRIGROUP, 8, 3)
+FIELD(V7M_AIRCR, BFHFNMINS, 13, 1)
+FIELD(V7M_AIRCR, PRIS, 14, 1)
+FIELD(V7M_AIRCR, ENDIANNESS, 15, 1)
+FIELD(V7M_AIRCR, VECTKEY, 16, 16)
+
/* V7M CFSR bits for MMFSR */
FIELD(V7M_CFSR, IACCVIOL, 0, 1)
FIELD(V7M_CFSR, DACCVIOL, 1, 1)
