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qemu-e2k/hw/intc/armv7m_nvic.c
Peter Maydell 22a9c26af6 nvic: Don't apply group priority mask to negative priorities 
In several places we were unconditionally applying the
nvic_gprio_mask() to a priority value. This is incorrect
if the priority is one of the fixed negative priority
values (for NMI and HardFault), so don't do it.

This bug would have caused both NMI and HardFault to be
considered as the same priority and so NMI wouldn't
correctly preempt HardFault.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505137930-13255-5-git-send-email-peter.maydell@linaro.org
2017-09-14 18:43:17 +01:00

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/*
* ARM Nested Vectored Interrupt Controller
*
* Copyright (c) 2006-2007 CodeSourcery.
* Written by Paul Brook
*
* This code is licensed under the GPL.
*
* The ARMv7M System controller is fairly tightly tied in with the
* NVIC. Much of that is also implemented here.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "cpu.h"
#include "hw/sysbus.h"
#include "qemu/timer.h"
#include "hw/arm/arm.h"
#include "hw/intc/armv7m_nvic.h"
#include "target/arm/cpu.h"
#include "exec/exec-all.h"
#include "qemu/log.h"
#include "trace.h"
/* IRQ number counting:
*
* the num-irq property counts the number of external IRQ lines
*
* NVICState::num_irq counts the total number of exceptions
* (external IRQs, the 15 internal exceptions including reset,
* and one for the unused exception number 0).
*
* NVIC_MAX_IRQ is the highest permitted number of external IRQ lines.
*
* NVIC_MAX_VECTORS is the highest permitted number of exceptions.
*
* Iterating through all exceptions should typically be done with
* for (i = 1; i < s->num_irq; i++) to avoid the unused slot 0.
*
* The external qemu_irq lines are the NVIC's external IRQ lines,
* so line 0 is exception 16.
*
* In the terminology of the architecture manual, "interrupts" are
* a subcategory of exception referring to the external interrupts
* (which are exception numbers NVIC_FIRST_IRQ and upward).
* For historical reasons QEMU tends to use "interrupt" and
* "exception" more or less interchangeably.
*/
#define NVIC_FIRST_IRQ 16
#define NVIC_MAX_IRQ (NVIC_MAX_VECTORS - NVIC_FIRST_IRQ)
/* Effective running priority of the CPU when no exception is active
* (higher than the highest possible priority value)
*/
#define NVIC_NOEXC_PRIO 0x100
static const uint8_t nvic_id[] = {
0x00, 0xb0, 0x1b, 0x00, 0x0d, 0xe0, 0x05, 0xb1
};
static int nvic_pending_prio(NVICState *s)
{
/* return the priority of the current pending interrupt,
* or NVIC_NOEXC_PRIO if no interrupt is pending
*/
return s->vectpending ? s->vectors[s->vectpending].prio : NVIC_NOEXC_PRIO;
}
/* Return the value of the ISCR RETTOBASE bit:
* 1 if there is exactly one active exception
* 0 if there is more than one active exception
* UNKNOWN if there are no active exceptions (we choose 1,
* which matches the choice Cortex-M3 is documented as making).
*
* NB: some versions of the documentation talk about this
* counting "active exceptions other than the one shown by IPSR";
* this is only different in the obscure corner case where guest
* code has manually deactivated an exception and is about
* to fail an exception-return integrity check. The definition
* above is the one from the v8M ARM ARM and is also in line
* with the behaviour documented for the Cortex-M3.
*/
static bool nvic_rettobase(NVICState *s)
{
int irq, nhand = 0;
for (irq = ARMV7M_EXCP_RESET; irq < s->num_irq; irq++) {
if (s->vectors[irq].active) {
nhand++;
if (nhand == 2) {
return 0;
}
}
}
return 1;
}
/* Return the value of the ISCR ISRPENDING bit:
* 1 if an external interrupt is pending
* 0 if no external interrupt is pending
*/
static bool nvic_isrpending(NVICState *s)
{
int irq;
/* We can shortcut if the highest priority pending interrupt
* happens to be external or if there is nothing pending.
*/
if (s->vectpending > NVIC_FIRST_IRQ) {
return true;
}
if (s->vectpending == 0) {
return false;
}
for (irq = NVIC_FIRST_IRQ; irq < s->num_irq; irq++) {
if (s->vectors[irq].pending) {
return true;
}
}
return false;
}
/* Return a mask word which clears the subpriority bits from
* a priority value for an M-profile exception, leaving only
* the group priority.
*/
static inline uint32_t nvic_gprio_mask(NVICState *s)
{
return ~0U << (s->prigroup + 1);
}
/* Recompute vectpending and exception_prio */
static void nvic_recompute_state(NVICState *s)
{
int i;
int pend_prio = NVIC_NOEXC_PRIO;
int active_prio = NVIC_NOEXC_PRIO;
int pend_irq = 0;
for (i = 1; i < s->num_irq; i++) {
VecInfo *vec = &s->vectors[i];
if (vec->enabled && vec->pending && vec->prio < pend_prio) {
pend_prio = vec->prio;
pend_irq = i;
}
if (vec->active && vec->prio < active_prio) {
active_prio = vec->prio;
}
}
if (active_prio > 0) {
active_prio &= nvic_gprio_mask(s);
}
s->vectpending = pend_irq;
s->exception_prio = active_prio;
trace_nvic_recompute_state(s->vectpending, s->exception_prio);
}
/* Return the current execution priority of the CPU
* (equivalent to the pseudocode ExecutionPriority function).
* This is a value between -2 (NMI priority) and NVIC_NOEXC_PRIO.
*/
static inline int nvic_exec_prio(NVICState *s)
{
CPUARMState *env = &s->cpu->env;
int running;
if (env->v7m.faultmask[env->v7m.secure]) {
running = -1;
} else if (env->v7m.primask[env->v7m.secure]) {
running = 0;
} else if (env->v7m.basepri[env->v7m.secure] > 0) {
running = env->v7m.basepri[env->v7m.secure] & nvic_gprio_mask(s);
} else {
running = NVIC_NOEXC_PRIO; /* lower than any possible priority */
}
/* consider priority of active handler */
return MIN(running, s->exception_prio);
}
bool armv7m_nvic_can_take_pending_exception(void *opaque)
{
NVICState *s = opaque;
return nvic_exec_prio(s) > nvic_pending_prio(s);
}
int armv7m_nvic_raw_execution_priority(void *opaque)
{
NVICState *s = opaque;
return s->exception_prio;
}
/* caller must call nvic_irq_update() after this */
static void set_prio(NVICState *s, unsigned irq, uint8_t prio)
{
assert(irq > ARMV7M_EXCP_NMI); /* only use for configurable prios */
assert(irq < s->num_irq);
s->vectors[irq].prio = prio;
trace_nvic_set_prio(irq, prio);
}
/* Recompute state and assert irq line accordingly.
* Must be called after changes to:
* vec->active, vec->enabled, vec->pending or vec->prio for any vector
* prigroup
*/
static void nvic_irq_update(NVICState *s)
{
int lvl;
int pend_prio;
nvic_recompute_state(s);
pend_prio = nvic_pending_prio(s);
/* Raise NVIC output if this IRQ would be taken, except that we
* ignore the effects of the BASEPRI, FAULTMASK and PRIMASK (which
* will be checked for in arm_v7m_cpu_exec_interrupt()); changes
* to those CPU registers don't cause us to recalculate the NVIC
* pending info.
*/
lvl = (pend_prio < s->exception_prio);
trace_nvic_irq_update(s->vectpending, pend_prio, s->exception_prio, lvl);
qemu_set_irq(s->excpout, lvl);
}
static void armv7m_nvic_clear_pending(void *opaque, int irq)
{
NVICState *s = (NVICState *)opaque;
VecInfo *vec;
assert(irq > ARMV7M_EXCP_RESET && irq < s->num_irq);
vec = &s->vectors[irq];
trace_nvic_clear_pending(irq, vec->enabled, vec->prio);
if (vec->pending) {
vec->pending = 0;
nvic_irq_update(s);
}
}
void armv7m_nvic_set_pending(void *opaque, int irq)
{
NVICState *s = (NVICState *)opaque;
VecInfo *vec;
assert(irq > ARMV7M_EXCP_RESET && irq < s->num_irq);
vec = &s->vectors[irq];
trace_nvic_set_pending(irq, vec->enabled, vec->prio);
if (irq >= ARMV7M_EXCP_HARD && irq < ARMV7M_EXCP_PENDSV) {
/* If a synchronous exception is pending then it may be
* escalated to HardFault if:
* * it is equal or lower priority to current execution
* * it is disabled
* (ie we need to take it immediately but we can't do so).
* Asynchronous exceptions (and interrupts) simply remain pending.
*
* For QEMU, we don't have any imprecise (asynchronous) faults,
* so we can assume that PREFETCH_ABORT and DATA_ABORT are always
* synchronous.
* Debug exceptions are awkward because only Debug exceptions
* resulting from the BKPT instruction should be escalated,
* but we don't currently implement any Debug exceptions other
* than those that result from BKPT, so we treat all debug exceptions
* as needing escalation.
*
* This all means we can identify whether to escalate based only on
* the exception number and don't (yet) need the caller to explicitly
* tell us whether this exception is synchronous or not.
*/
int running = nvic_exec_prio(s);
bool escalate = false;
if (vec->prio >= running) {
trace_nvic_escalate_prio(irq, vec->prio, running);
escalate = true;
} else if (!vec->enabled) {
trace_nvic_escalate_disabled(irq);
escalate = true;
}
if (escalate) {
if (running < 0) {
/* We want to escalate to HardFault but we can't take a
* synchronous HardFault at this point either. This is a
* Lockup condition due to a guest bug. We don't model
* Lockup, so report via cpu_abort() instead.
*/
cpu_abort(&s->cpu->parent_obj,
"Lockup: can't escalate %d to HardFault "
"(current priority %d)\n", irq, running);
}
/* We can do the escalation, so we take HardFault instead */
irq = ARMV7M_EXCP_HARD;
vec = &s->vectors[irq];
s->cpu->env.v7m.hfsr |= R_V7M_HFSR_FORCED_MASK;
}
}
if (!vec->pending) {
vec->pending = 1;
nvic_irq_update(s);
}
}
/* Make pending IRQ active. */
void armv7m_nvic_acknowledge_irq(void *opaque)
{
NVICState *s = (NVICState *)opaque;
CPUARMState *env = &s->cpu->env;
const int pending = s->vectpending;
const int running = nvic_exec_prio(s);
int pendgroupprio;
VecInfo *vec;
assert(pending > ARMV7M_EXCP_RESET && pending < s->num_irq);
vec = &s->vectors[pending];
assert(vec->enabled);
assert(vec->pending);
pendgroupprio = vec->prio;
if (pendgroupprio > 0) {
pendgroupprio &= nvic_gprio_mask(s);
}
assert(pendgroupprio < running);
trace_nvic_acknowledge_irq(pending, vec->prio);
vec->active = 1;
vec->pending = 0;
env->v7m.exception = s->vectpending;
nvic_irq_update(s);
}
int armv7m_nvic_complete_irq(void *opaque, int irq)
{
NVICState *s = (NVICState *)opaque;
VecInfo *vec;
int ret;
assert(irq > ARMV7M_EXCP_RESET && irq < s->num_irq);
vec = &s->vectors[irq];
trace_nvic_complete_irq(irq);
if (!vec->active) {
/* Tell the caller this was an illegal exception return */
return -1;
}
ret = nvic_rettobase(s);
vec->active = 0;
if (vec->level) {
/* Re-pend the exception if it's still held high; only
* happens for extenal IRQs
*/
assert(irq >= NVIC_FIRST_IRQ);
vec->pending = 1;
}
nvic_irq_update(s);
return ret;
}
/* callback when external interrupt line is changed */
static void set_irq_level(void *opaque, int n, int level)
{
NVICState *s = opaque;
VecInfo *vec;
n += NVIC_FIRST_IRQ;
assert(n >= NVIC_FIRST_IRQ && n < s->num_irq);
trace_nvic_set_irq_level(n, level);
/* The pending status of an external interrupt is
* latched on rising edge and exception handler return.
*
* Pulsing the IRQ will always run the handler
* once, and the handler will re-run until the
* level is low when the handler completes.
*/
vec = &s->vectors[n];
if (level != vec->level) {
vec->level = level;
if (level) {
armv7m_nvic_set_pending(s, n);
}
}
}
static uint32_t nvic_readl(NVICState *s, uint32_t offset, MemTxAttrs attrs)
{
ARMCPU *cpu = s->cpu;
uint32_t val;
switch (offset) {
case 4: /* Interrupt Control Type. */
return ((s->num_irq - NVIC_FIRST_IRQ) / 32) - 1;
case 0xd00: /* CPUID Base. */
return cpu->midr;
case 0xd04: /* Interrupt Control State. */
/* VECTACTIVE */
val = cpu->env.v7m.exception;
/* VECTPENDING */
val |= (s->vectpending & 0xff) << 12;
/* ISRPENDING - set if any external IRQ is pending */
if (nvic_isrpending(s)) {
val |= (1 << 22);
}
/* RETTOBASE - set if only one handler is active */
if (nvic_rettobase(s)) {
val |= (1 << 11);
}
/* PENDSTSET */
if (s->vectors[ARMV7M_EXCP_SYSTICK].pending) {
val |= (1 << 26);
}
/* PENDSVSET */
if (s->vectors[ARMV7M_EXCP_PENDSV].pending) {
val |= (1 << 28);
}
/* NMIPENDSET */
if (s->vectors[ARMV7M_EXCP_NMI].pending) {
val |= (1 << 31);
}
/* ISRPREEMPT not implemented */
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 0xd10: /* System Control. */
/* TODO: Implement SLEEPONEXIT. */
return 0;
case 0xd14: /* Configuration Control. */
/* The BFHFNMIGN bit is the only non-banked bit; we
* keep it in the non-secure copy of the register.
*/
val = cpu->env.v7m.ccr[attrs.secure];
val |= cpu->env.v7m.ccr[M_REG_NS] & R_V7M_CCR_BFHFNMIGN_MASK;
return val;
case 0xd24: /* System Handler Status. */
val = 0;
if (s->vectors[ARMV7M_EXCP_MEM].active) {
val |= (1 << 0);
}
if (s->vectors[ARMV7M_EXCP_BUS].active) {
val |= (1 << 1);
}
if (s->vectors[ARMV7M_EXCP_USAGE].active) {
val |= (1 << 3);
}
if (s->vectors[ARMV7M_EXCP_SVC].active) {
val |= (1 << 7);
}
if (s->vectors[ARMV7M_EXCP_DEBUG].active) {
val |= (1 << 8);
}
if (s->vectors[ARMV7M_EXCP_PENDSV].active) {
val |= (1 << 10);
}
if (s->vectors[ARMV7M_EXCP_SYSTICK].active) {
val |= (1 << 11);
}
if (s->vectors[ARMV7M_EXCP_USAGE].pending) {
val |= (1 << 12);
}
if (s->vectors[ARMV7M_EXCP_MEM].pending) {
val |= (1 << 13);
}
if (s->vectors[ARMV7M_EXCP_BUS].pending) {
val |= (1 << 14);
}
if (s->vectors[ARMV7M_EXCP_SVC].pending) {
val |= (1 << 15);
}
if (s->vectors[ARMV7M_EXCP_MEM].enabled) {
val |= (1 << 16);
}
if (s->vectors[ARMV7M_EXCP_BUS].enabled) {
val |= (1 << 17);
}
if (s->vectors[ARMV7M_EXCP_USAGE].enabled) {
val |= (1 << 18);
}
return val;
case 0xd28: /* Configurable Fault Status. */
/* The BFSR bits [15:8] are shared between security states
* and we store them in the NS copy
*/
val = cpu->env.v7m.cfsr[attrs.secure];
val |= cpu->env.v7m.cfsr[M_REG_NS] & R_V7M_CFSR_BFSR_MASK;
return val;
case 0xd2c: /* Hard Fault Status. */
return cpu->env.v7m.hfsr;
case 0xd30: /* Debug Fault Status. */
return cpu->env.v7m.dfsr;
case 0xd34: /* MMFAR MemManage Fault Address */
return cpu->env.v7m.mmfar[attrs.secure];
case 0xd38: /* Bus Fault Address. */
return cpu->env.v7m.bfar;
case 0xd3c: /* Aux Fault Status. */
/* TODO: Implement fault status registers. */
qemu_log_mask(LOG_UNIMP,
"Aux Fault status registers unimplemented\n");
return 0;
case 0xd40: /* PFR0. */
return 0x00000030;
case 0xd44: /* PRF1. */
return 0x00000200;
case 0xd48: /* DFR0. */
return 0x00100000;
case 0xd4c: /* AFR0. */
return 0x00000000;
case 0xd50: /* MMFR0. */
return 0x00000030;
case 0xd54: /* MMFR1. */
return 0x00000000;
case 0xd58: /* MMFR2. */
return 0x00000000;
case 0xd5c: /* MMFR3. */
return 0x00000000;
case 0xd60: /* ISAR0. */
return 0x01141110;
case 0xd64: /* ISAR1. */
return 0x02111000;
case 0xd68: /* ISAR2. */
return 0x21112231;
case 0xd6c: /* ISAR3. */
return 0x01111110;
case 0xd70: /* ISAR4. */
return 0x01310102;
/* TODO: Implement debug registers. */
case 0xd90: /* MPU_TYPE */
/* Unified MPU; if the MPU is not present this value is zero */
return cpu->pmsav7_dregion << 8;
break;
case 0xd94: /* MPU_CTRL */
return cpu->env.v7m.mpu_ctrl[attrs.secure];
case 0xd98: /* MPU_RNR */
return cpu->env.pmsav7.rnr[attrs.secure];
case 0xd9c: /* MPU_RBAR */
case 0xda4: /* MPU_RBAR_A1 */
case 0xdac: /* MPU_RBAR_A2 */
case 0xdb4: /* MPU_RBAR_A3 */
{
int region = cpu->env.pmsav7.rnr[attrs.secure];
if (arm_feature(&cpu->env, ARM_FEATURE_V8)) {
/* PMSAv8M handling of the aliases is different from v7M:
* aliases A1, A2, A3 override the low two bits of the region
* number in MPU_RNR, and there is no 'region' field in the
* RBAR register.
*/
int aliasno = (offset - 0xd9c) / 8; /* 0..3 */
if (aliasno) {
region = deposit32(region, 0, 2, aliasno);
}
if (region >= cpu->pmsav7_dregion) {
return 0;
}
return cpu->env.pmsav8.rbar[attrs.secure][region];
}
if (region >= cpu->pmsav7_dregion) {
return 0;
}
return (cpu->env.pmsav7.drbar[region] & 0x1f) | (region & 0xf);
}
case 0xda0: /* MPU_RASR (v7M), MPU_RLAR (v8M) */
case 0xda8: /* MPU_RASR_A1 (v7M), MPU_RLAR_A1 (v8M) */
case 0xdb0: /* MPU_RASR_A2 (v7M), MPU_RLAR_A2 (v8M) */
case 0xdb8: /* MPU_RASR_A3 (v7M), MPU_RLAR_A3 (v8M) */
{
int region = cpu->env.pmsav7.rnr[attrs.secure];
if (arm_feature(&cpu->env, ARM_FEATURE_V8)) {
/* PMSAv8M handling of the aliases is different from v7M:
* aliases A1, A2, A3 override the low two bits of the region
* number in MPU_RNR.
*/
int aliasno = (offset - 0xda0) / 8; /* 0..3 */
if (aliasno) {
region = deposit32(region, 0, 2, aliasno);
}
if (region >= cpu->pmsav7_dregion) {
return 0;
}
return cpu->env.pmsav8.rlar[attrs.secure][region];
}
if (region >= cpu->pmsav7_dregion) {
return 0;
}
return ((cpu->env.pmsav7.dracr[region] & 0xffff) << 16) |
(cpu->env.pmsav7.drsr[region] & 0xffff);
}
case 0xdc0: /* MPU_MAIR0 */
if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) {
goto bad_offset;
}
return cpu->env.pmsav8.mair0[attrs.secure];
case 0xdc4: /* MPU_MAIR1 */
if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) {
goto bad_offset;
}
return cpu->env.pmsav8.mair1[attrs.secure];
default:
bad_offset:
qemu_log_mask(LOG_GUEST_ERROR, "NVIC: Bad read offset 0x%x\n", offset);
return 0;
}
}
static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value,
MemTxAttrs attrs)
{
ARMCPU *cpu = s->cpu;
switch (offset) {
case 0xd04: /* Interrupt Control State. */
if (value & (1 << 31)) {
armv7m_nvic_set_pending(s, ARMV7M_EXCP_NMI);
}
if (value & (1 << 28)) {
armv7m_nvic_set_pending(s, ARMV7M_EXCP_PENDSV);
} else if (value & (1 << 27)) {
armv7m_nvic_clear_pending(s, ARMV7M_EXCP_PENDSV);
}
if (value & (1 << 26)) {
armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK);
} else if (value & (1 << 25)) {
armv7m_nvic_clear_pending(s, ARMV7M_EXCP_SYSTICK);
}
break;
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);
}
if (value & 2) {
qemu_log_mask(LOG_GUEST_ERROR,
"Setting VECTCLRACTIVE when not in DEBUG mode "
"is UNPREDICTABLE\n");
}
if (value & 1) {
qemu_log_mask(LOG_GUEST_ERROR,
"Setting VECTRESET when not in DEBUG mode "
"is UNPREDICTABLE\n");
}
s->prigroup = extract32(value, 8, 3);
nvic_irq_update(s);
}
break;
case 0xd10: /* System Control. */
/* TODO: Implement control registers. */
qemu_log_mask(LOG_UNIMP, "NVIC: SCR unimplemented\n");
break;
case 0xd14: /* Configuration Control. */
/* Enforce RAZ/WI on reserved and must-RAZ/WI bits */
value &= (R_V7M_CCR_STKALIGN_MASK |
R_V7M_CCR_BFHFNMIGN_MASK |
R_V7M_CCR_DIV_0_TRP_MASK |
R_V7M_CCR_UNALIGN_TRP_MASK |
R_V7M_CCR_USERSETMPEND_MASK |
R_V7M_CCR_NONBASETHRDENA_MASK);
if (arm_feature(&cpu->env, ARM_FEATURE_V8)) {
/* v8M makes NONBASETHRDENA and STKALIGN be RES1 */
value |= R_V7M_CCR_NONBASETHRDENA_MASK
| R_V7M_CCR_STKALIGN_MASK;
}
if (attrs.secure) {
/* the BFHFNMIGN bit is not banked; keep that in the NS copy */
cpu->env.v7m.ccr[M_REG_NS] =
(cpu->env.v7m.ccr[M_REG_NS] & ~R_V7M_CCR_BFHFNMIGN_MASK)
| (value & R_V7M_CCR_BFHFNMIGN_MASK);
value &= ~R_V7M_CCR_BFHFNMIGN_MASK;
}
cpu->env.v7m.ccr[attrs.secure] = value;
break;
case 0xd24: /* System Handler Control. */
s->vectors[ARMV7M_EXCP_MEM].active = (value & (1 << 0)) != 0;
s->vectors[ARMV7M_EXCP_BUS].active = (value & (1 << 1)) != 0;
s->vectors[ARMV7M_EXCP_USAGE].active = (value & (1 << 3)) != 0;
s->vectors[ARMV7M_EXCP_SVC].active = (value & (1 << 7)) != 0;
s->vectors[ARMV7M_EXCP_DEBUG].active = (value & (1 << 8)) != 0;
s->vectors[ARMV7M_EXCP_PENDSV].active = (value & (1 << 10)) != 0;
s->vectors[ARMV7M_EXCP_SYSTICK].active = (value & (1 << 11)) != 0;
s->vectors[ARMV7M_EXCP_USAGE].pending = (value & (1 << 12)) != 0;
s->vectors[ARMV7M_EXCP_MEM].pending = (value & (1 << 13)) != 0;
s->vectors[ARMV7M_EXCP_BUS].pending = (value & (1 << 14)) != 0;
s->vectors[ARMV7M_EXCP_SVC].pending = (value & (1 << 15)) != 0;
s->vectors[ARMV7M_EXCP_MEM].enabled = (value & (1 << 16)) != 0;
s->vectors[ARMV7M_EXCP_BUS].enabled = (value & (1 << 17)) != 0;
s->vectors[ARMV7M_EXCP_USAGE].enabled = (value & (1 << 18)) != 0;
nvic_irq_update(s);
break;
case 0xd28: /* Configurable Fault Status. */
cpu->env.v7m.cfsr[attrs.secure] &= ~value; /* W1C */
if (attrs.secure) {
/* The BFSR bits [15:8] are shared between security states
* and we store them in the NS copy.
*/
cpu->env.v7m.cfsr[M_REG_NS] &= ~(value & R_V7M_CFSR_BFSR_MASK);
}
break;
case 0xd2c: /* Hard Fault Status. */
cpu->env.v7m.hfsr &= ~value; /* W1C */
break;
case 0xd30: /* Debug Fault Status. */
cpu->env.v7m.dfsr &= ~value; /* W1C */
break;
case 0xd34: /* Mem Manage Address. */
cpu->env.v7m.mmfar[attrs.secure] = value;
return;
case 0xd38: /* Bus Fault Address. */
cpu->env.v7m.bfar = value;
return;
case 0xd3c: /* Aux Fault Status. */
qemu_log_mask(LOG_UNIMP,
"NVIC: Aux fault status registers unimplemented\n");
break;
case 0xd90: /* MPU_TYPE */
return; /* RO */
case 0xd94: /* MPU_CTRL */
if ((value &
(R_V7M_MPU_CTRL_HFNMIENA_MASK | R_V7M_MPU_CTRL_ENABLE_MASK))
== R_V7M_MPU_CTRL_HFNMIENA_MASK) {
qemu_log_mask(LOG_GUEST_ERROR, "MPU_CTRL: HFNMIENA and !ENABLE is "
"UNPREDICTABLE\n");
}
cpu->env.v7m.mpu_ctrl[attrs.secure]
= value & (R_V7M_MPU_CTRL_ENABLE_MASK |
R_V7M_MPU_CTRL_HFNMIENA_MASK |
R_V7M_MPU_CTRL_PRIVDEFENA_MASK);
tlb_flush(CPU(cpu));
break;
case 0xd98: /* MPU_RNR */
if (value >= cpu->pmsav7_dregion) {
qemu_log_mask(LOG_GUEST_ERROR, "MPU region out of range %"
PRIu32 "/%" PRIu32 "\n",
value, cpu->pmsav7_dregion);
} else {
cpu->env.pmsav7.rnr[attrs.secure] = value;
}
break;
case 0xd9c: /* MPU_RBAR */
case 0xda4: /* MPU_RBAR_A1 */
case 0xdac: /* MPU_RBAR_A2 */
case 0xdb4: /* MPU_RBAR_A3 */
{
int region;
if (arm_feature(&cpu->env, ARM_FEATURE_V8)) {
/* PMSAv8M handling of the aliases is different from v7M:
* aliases A1, A2, A3 override the low two bits of the region
* number in MPU_RNR, and there is no 'region' field in the
* RBAR register.
*/
int aliasno = (offset - 0xd9c) / 8; /* 0..3 */
region = cpu->env.pmsav7.rnr[attrs.secure];
if (aliasno) {
region = deposit32(region, 0, 2, aliasno);
}
if (region >= cpu->pmsav7_dregion) {
return;
}
cpu->env.pmsav8.rbar[attrs.secure][region] = value;
tlb_flush(CPU(cpu));
return;
}
if (value & (1 << 4)) {
/* VALID bit means use the region number specified in this
* value and also update MPU_RNR.REGION with that value.
*/
region = extract32(value, 0, 4);
if (region >= cpu->pmsav7_dregion) {
qemu_log_mask(LOG_GUEST_ERROR,
"MPU region out of range %u/%" PRIu32 "\n",
region, cpu->pmsav7_dregion);
return;
}
cpu->env.pmsav7.rnr[attrs.secure] = region;
} else {
region = cpu->env.pmsav7.rnr[attrs.secure];
}
if (region >= cpu->pmsav7_dregion) {
return;
}
cpu->env.pmsav7.drbar[region] = value & ~0x1f;
tlb_flush(CPU(cpu));
break;
}
case 0xda0: /* MPU_RASR (v7M), MPU_RLAR (v8M) */
case 0xda8: /* MPU_RASR_A1 (v7M), MPU_RLAR_A1 (v8M) */
case 0xdb0: /* MPU_RASR_A2 (v7M), MPU_RLAR_A2 (v8M) */
case 0xdb8: /* MPU_RASR_A3 (v7M), MPU_RLAR_A3 (v8M) */
{
int region = cpu->env.pmsav7.rnr[attrs.secure];
if (arm_feature(&cpu->env, ARM_FEATURE_V8)) {
/* PMSAv8M handling of the aliases is different from v7M:
* aliases A1, A2, A3 override the low two bits of the region
* number in MPU_RNR.
*/
int aliasno = (offset - 0xd9c) / 8; /* 0..3 */
region = cpu->env.pmsav7.rnr[attrs.secure];
if (aliasno) {
region = deposit32(region, 0, 2, aliasno);
}
if (region >= cpu->pmsav7_dregion) {
return;
}
cpu->env.pmsav8.rlar[attrs.secure][region] = value;
tlb_flush(CPU(cpu));
return;
}
if (region >= cpu->pmsav7_dregion) {
return;
}
cpu->env.pmsav7.drsr[region] = value & 0xff3f;
cpu->env.pmsav7.dracr[region] = (value >> 16) & 0x173f;
tlb_flush(CPU(cpu));
break;
}
case 0xdc0: /* MPU_MAIR0 */
if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) {
goto bad_offset;
}
if (cpu->pmsav7_dregion) {
/* Register is RES0 if no MPU regions are implemented */
cpu->env.pmsav8.mair0[attrs.secure] = value;
}
/* We don't need to do anything else because memory attributes
* only affect cacheability, and we don't implement caching.
*/
break;
case 0xdc4: /* MPU_MAIR1 */
if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) {
goto bad_offset;
}
if (cpu->pmsav7_dregion) {
/* Register is RES0 if no MPU regions are implemented */
cpu->env.pmsav8.mair1[attrs.secure] = value;
}
/* We don't need to do anything else because memory attributes
* only affect cacheability, and we don't implement caching.
*/
break;
case 0xf00: /* Software Triggered Interrupt Register */
{
int excnum = (value & 0x1ff) + NVIC_FIRST_IRQ;
if (excnum < s->num_irq) {
armv7m_nvic_set_pending(s, excnum);
}
break;
}
default:
bad_offset:
qemu_log_mask(LOG_GUEST_ERROR,
"NVIC: Bad write offset 0x%x\n", offset);
}
}
static bool nvic_user_access_ok(NVICState *s, hwaddr offset, MemTxAttrs attrs)
{
/* Return true if unprivileged access to this register is permitted. */
switch (offset) {
case 0xf00: /* STIR: accessible only if CCR.USERSETMPEND permits */
/* For access via STIR_NS it is the NS CCR.USERSETMPEND that
* controls access even though the CPU is in Secure state (I_QDKX).
*/
return s->cpu->env.v7m.ccr[attrs.secure] & R_V7M_CCR_USERSETMPEND_MASK;
default:
/* All other user accesses cause a BusFault unconditionally */
return false;
}
}
static MemTxResult nvic_sysreg_read(void *opaque, hwaddr addr,
uint64_t *data, unsigned size,
MemTxAttrs attrs)
{
NVICState *s = (NVICState *)opaque;
uint32_t offset = addr;
unsigned i, startvec, end;
uint32_t val;
if (attrs.user && !nvic_user_access_ok(s, addr, attrs)) {
/* Generate BusFault for unprivileged accesses */
return MEMTX_ERROR;
}
switch (offset) {
/* reads of set and clear both return the status */
case 0x100 ... 0x13f: /* NVIC Set enable */
offset += 0x80;
/* fall through */
case 0x180 ... 0x1bf: /* NVIC Clear enable */
val = 0;
startvec = offset - 0x180 + NVIC_FIRST_IRQ; /* vector # */
for (i = 0, end = size * 8; i < end && startvec + i < s->num_irq; i++) {
if (s->vectors[startvec + i].enabled) {
val |= (1 << i);
}
}
break;
case 0x200 ... 0x23f: /* NVIC Set pend */
offset += 0x80;
/* fall through */
case 0x280 ... 0x2bf: /* NVIC Clear pend */
val = 0;
startvec = offset - 0x280 + NVIC_FIRST_IRQ; /* vector # */
for (i = 0, end = size * 8; i < end && startvec + i < s->num_irq; i++) {
if (s->vectors[startvec + i].pending) {
val |= (1 << i);
}
}
break;
case 0x300 ... 0x33f: /* NVIC Active */
val = 0;
startvec = offset - 0x300 + NVIC_FIRST_IRQ; /* vector # */
for (i = 0, end = size * 8; i < end && startvec + i < s->num_irq; i++) {
if (s->vectors[startvec + i].active) {
val |= (1 << i);
}
}
break;
case 0x400 ... 0x5ef: /* NVIC Priority */
val = 0;
startvec = offset - 0x400 + NVIC_FIRST_IRQ; /* vector # */
for (i = 0; i < size && startvec + i < s->num_irq; i++) {
val |= s->vectors[startvec + i].prio << (8 * i);
}
break;
case 0xd18 ... 0xd23: /* System Handler Priority. */
val = 0;
for (i = 0; i < size; i++) {
val |= s->vectors[(offset - 0xd14) + i].prio << (i * 8);
}
break;
case 0xfe0 ... 0xfff: /* ID. */
if (offset & 3) {
val = 0;
} else {
val = nvic_id[(offset - 0xfe0) >> 2];
}
break;
default:
if (size == 4) {
val = nvic_readl(s, offset, attrs);
} else {
qemu_log_mask(LOG_GUEST_ERROR,
"NVIC: Bad read of size %d at offset 0x%x\n",
size, offset);
val = 0;
}
}
trace_nvic_sysreg_read(addr, val, size);
*data = val;
return MEMTX_OK;
}
static MemTxResult nvic_sysreg_write(void *opaque, hwaddr addr,
uint64_t value, unsigned size,
MemTxAttrs attrs)
{
NVICState *s = (NVICState *)opaque;
uint32_t offset = addr;
unsigned i, startvec, end;
unsigned setval = 0;
trace_nvic_sysreg_write(addr, value, size);
if (attrs.user && !nvic_user_access_ok(s, addr, attrs)) {
/* Generate BusFault for unprivileged accesses */
return MEMTX_ERROR;
}
switch (offset) {
case 0x100 ... 0x13f: /* NVIC Set enable */
offset += 0x80;
setval = 1;
/* fall through */
case 0x180 ... 0x1bf: /* NVIC Clear enable */
startvec = 8 * (offset - 0x180) + NVIC_FIRST_IRQ;
for (i = 0, end = size * 8; i < end && startvec + i < s->num_irq; i++) {
if (value & (1 << i)) {
s->vectors[startvec + i].enabled = setval;
}
}
nvic_irq_update(s);
return MEMTX_OK;
case 0x200 ... 0x23f: /* NVIC Set pend */
/* the special logic in armv7m_nvic_set_pending()
* is not needed since IRQs are never escalated
*/
offset += 0x80;
setval = 1;
/* fall through */
case 0x280 ... 0x2bf: /* NVIC Clear pend */
startvec = 8 * (offset - 0x280) + NVIC_FIRST_IRQ; /* vector # */
for (i = 0, end = size * 8; i < end && startvec + i < s->num_irq; i++) {
if (value & (1 << i)) {
s->vectors[startvec + i].pending = setval;
}
}
nvic_irq_update(s);
return MEMTX_OK;
case 0x300 ... 0x33f: /* NVIC Active */
return MEMTX_OK; /* R/O */
case 0x400 ... 0x5ef: /* NVIC Priority */
startvec = 8 * (offset - 0x400) + NVIC_FIRST_IRQ; /* vector # */
for (i = 0; i < size && startvec + i < s->num_irq; i++) {
set_prio(s, startvec + i, (value >> (i * 8)) & 0xff);
}
nvic_irq_update(s);
return MEMTX_OK;
case 0xd18 ... 0xd23: /* System Handler Priority. */
for (i = 0; i < size; i++) {
unsigned hdlidx = (offset - 0xd14) + i;
set_prio(s, hdlidx, (value >> (i * 8)) & 0xff);
}
nvic_irq_update(s);
return MEMTX_OK;
}
if (size == 4) {
nvic_writel(s, offset, value, attrs);
return MEMTX_OK;
}
qemu_log_mask(LOG_GUEST_ERROR,
"NVIC: Bad write of size %d at offset 0x%x\n", size, offset);
/* This is UNPREDICTABLE; treat as RAZ/WI */
return MEMTX_OK;
}
static const MemoryRegionOps nvic_sysreg_ops = {
.read_with_attrs = nvic_sysreg_read,
.write_with_attrs = nvic_sysreg_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static MemTxResult nvic_sysreg_ns_write(void *opaque, hwaddr addr,
uint64_t value, unsigned size,
MemTxAttrs attrs)
{
if (attrs.secure) {
/* S accesses to the alias act like NS accesses to the real region */
attrs.secure = 0;
return nvic_sysreg_write(opaque, addr, value, size, attrs);
} else {
/* NS attrs are RAZ/WI for privileged, and BusFault for user */
if (attrs.user) {
return MEMTX_ERROR;
}
return MEMTX_OK;
}
}
static MemTxResult nvic_sysreg_ns_read(void *opaque, hwaddr addr,
uint64_t *data, unsigned size,
MemTxAttrs attrs)
{
if (attrs.secure) {
/* S accesses to the alias act like NS accesses to the real region */
attrs.secure = 0;
return nvic_sysreg_read(opaque, addr, data, size, attrs);
} else {
/* NS attrs are RAZ/WI for privileged, and BusFault for user */
if (attrs.user) {
return MEMTX_ERROR;
}
*data = 0;
return MEMTX_OK;
}
}
static const MemoryRegionOps nvic_sysreg_ns_ops = {
.read_with_attrs = nvic_sysreg_ns_read,
.write_with_attrs = nvic_sysreg_ns_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static int nvic_post_load(void *opaque, int version_id)
{
NVICState *s = opaque;
unsigned i;
/* Check for out of range priority settings */
if (s->vectors[ARMV7M_EXCP_RESET].prio != -3 ||
s->vectors[ARMV7M_EXCP_NMI].prio != -2 ||
s->vectors[ARMV7M_EXCP_HARD].prio != -1) {
return 1;
}
for (i = ARMV7M_EXCP_MEM; i < s->num_irq; i++) {
if (s->vectors[i].prio & ~0xff) {
return 1;
}
}
nvic_recompute_state(s);
return 0;
}
static const VMStateDescription vmstate_VecInfo = {
.name = "armv7m_nvic_info",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_INT16(prio, VecInfo),
VMSTATE_UINT8(enabled, VecInfo),
VMSTATE_UINT8(pending, VecInfo),
VMSTATE_UINT8(active, VecInfo),
VMSTATE_UINT8(level, VecInfo),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription vmstate_nvic = {
.name = "armv7m_nvic",
.version_id = 4,
.minimum_version_id = 4,
.post_load = &nvic_post_load,
.fields = (VMStateField[]) {
VMSTATE_STRUCT_ARRAY(vectors, NVICState, NVIC_MAX_VECTORS, 1,
vmstate_VecInfo, VecInfo),
VMSTATE_UINT32(prigroup, NVICState),
VMSTATE_END_OF_LIST()
}
};
static Property props_nvic[] = {
/* Number of external IRQ lines (so excluding the 16 internal exceptions) */
DEFINE_PROP_UINT32("num-irq", NVICState, num_irq, 64),
DEFINE_PROP_END_OF_LIST()
};
static void armv7m_nvic_reset(DeviceState *dev)
{
NVICState *s = NVIC(dev);
s->vectors[ARMV7M_EXCP_NMI].enabled = 1;
s->vectors[ARMV7M_EXCP_HARD].enabled = 1;
/* MEM, BUS, and USAGE are enabled through
* the System Handler Control register
*/
s->vectors[ARMV7M_EXCP_SVC].enabled = 1;
s->vectors[ARMV7M_EXCP_DEBUG].enabled = 1;
s->vectors[ARMV7M_EXCP_PENDSV].enabled = 1;
s->vectors[ARMV7M_EXCP_SYSTICK].enabled = 1;
s->vectors[ARMV7M_EXCP_RESET].prio = -3;
s->vectors[ARMV7M_EXCP_NMI].prio = -2;
s->vectors[ARMV7M_EXCP_HARD].prio = -1;
/* Strictly speaking the reset handler should be enabled.
* However, we don't simulate soft resets through the NVIC,
* and the reset vector should never be pended.
* So we leave it disabled to catch logic errors.
*/
s->exception_prio = NVIC_NOEXC_PRIO;
s->vectpending = 0;
}
static void nvic_systick_trigger(void *opaque, int n, int level)
{
NVICState *s = opaque;
if (level) {
/* SysTick just asked us to pend its exception.
* (This is different from an external interrupt line's
* behaviour.)
*/
armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK);
}
}
static void armv7m_nvic_realize(DeviceState *dev, Error **errp)
{
NVICState *s = NVIC(dev);
SysBusDevice *systick_sbd;
Error *err = NULL;
int regionlen;
s->cpu = ARM_CPU(qemu_get_cpu(0));
assert(s->cpu);
if (s->num_irq > NVIC_MAX_IRQ) {
error_setg(errp, "num-irq %d exceeds NVIC maximum", s->num_irq);
return;
}
qdev_init_gpio_in(dev, set_irq_level, s->num_irq);
/* include space for internal exception vectors */
s->num_irq += NVIC_FIRST_IRQ;
object_property_set_bool(OBJECT(&s->systick), true, "realized", &err);
if (err != NULL) {
error_propagate(errp, err);
return;
}
systick_sbd = SYS_BUS_DEVICE(&s->systick);
sysbus_connect_irq(systick_sbd, 0,
qdev_get_gpio_in_named(dev, "systick-trigger", 0));
/* The NVIC and System Control Space (SCS) starts at 0xe000e000
* and looks like this:
* 0x004 - ICTR
* 0x010 - 0xff - systick
* 0x100..0x7ec - NVIC
* 0x7f0..0xcff - Reserved
* 0xd00..0xd3c - SCS registers
* 0xd40..0xeff - Reserved or Not implemented
* 0xf00 - STIR
*
* Some registers within this space are banked between security states.
* In v8M there is a second range 0xe002e000..0xe002efff which is the
* NonSecure alias SCS; secure accesses to this behave like NS accesses
* to the main SCS range, and non-secure accesses (including when
* the security extension is not implemented) are RAZ/WI.
* Note that both the main SCS range and the alias range are defined
* to be exempt from memory attribution (R_BLJT) and so the memory
* transaction attribute always matches the current CPU security
* state (attrs.secure == env->v7m.secure). In the nvic_sysreg_ns_ops
* wrappers we change attrs.secure to indicate the NS access; so
* generally code determining which banked register to use should
* use attrs.secure; code determining actual behaviour of the system
* should use env->v7m.secure.
*/
regionlen = arm_feature(&s->cpu->env, ARM_FEATURE_V8) ? 0x21000 : 0x1000;
memory_region_init(&s->container, OBJECT(s), "nvic", regionlen);
/* The system register region goes at the bottom of the priority
* stack as it covers the whole page.
*/
memory_region_init_io(&s->sysregmem, OBJECT(s), &nvic_sysreg_ops, s,
"nvic_sysregs", 0x1000);
memory_region_add_subregion(&s->container, 0, &s->sysregmem);
memory_region_add_subregion_overlap(&s->container, 0x10,
sysbus_mmio_get_region(systick_sbd, 0),
1);
if (arm_feature(&s->cpu->env, ARM_FEATURE_V8)) {
memory_region_init_io(&s->sysreg_ns_mem, OBJECT(s),
&nvic_sysreg_ns_ops, s,
"nvic_sysregs_ns", 0x1000);
memory_region_add_subregion(&s->container, 0x20000, &s->sysreg_ns_mem);
}
sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->container);
}
static void armv7m_nvic_instance_init(Object *obj)
{
/* We have a different default value for the num-irq property
* than our superclass. This function runs after qdev init
* has set the defaults from the Property array and before
* any user-specified property setting, so just modify the
* value in the GICState struct.
*/
DeviceState *dev = DEVICE(obj);
NVICState *nvic = NVIC(obj);
SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
object_initialize(&nvic->systick, sizeof(nvic->systick), TYPE_SYSTICK);
qdev_set_parent_bus(DEVICE(&nvic->systick), sysbus_get_default());
sysbus_init_irq(sbd, &nvic->excpout);
qdev_init_gpio_out_named(dev, &nvic->sysresetreq, "SYSRESETREQ", 1);
qdev_init_gpio_in_named(dev, nvic_systick_trigger, "systick-trigger", 1);
}
static void armv7m_nvic_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->vmsd = &vmstate_nvic;
dc->props = props_nvic;
dc->reset = armv7m_nvic_reset;
dc->realize = armv7m_nvic_realize;
}
static const TypeInfo armv7m_nvic_info = {
.name = TYPE_NVIC,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_init = armv7m_nvic_instance_init,
.instance_size = sizeof(NVICState),
.class_init = armv7m_nvic_class_init,
.class_size = sizeof(SysBusDeviceClass),
};
static void armv7m_nvic_register_types(void)
{
type_register_static(&armv7m_nvic_info);
}
type_init(armv7m_nvic_register_types)
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