nvic: Add NS alias SCS region

For v8M the range 0xe002e000..0xe002efff is an alias region which
for secure accesses behaves like a NonSecure access to the main
SCS region. (For nonsecure accesses including when the security
extension is not implemented, it is RAZ/WI.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1503414539-28762-11-git-send-email-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2017-09-07 13:54:53 +01:00
parent 8bfc26ea30
commit f104919d15
2 changed files with 66 additions and 1 deletions

View File

@ -1040,6 +1040,47 @@ static const MemoryRegionOps nvic_sysreg_ops = {
.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;
@ -1141,6 +1182,7 @@ 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);
@ -1173,8 +1215,23 @@ static void armv7m_nvic_realize(DeviceState *dev, Error **errp)
* 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.
*/
memory_region_init(&s->container, OBJECT(s), "nvic", 0x1000);
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.
*/
@ -1185,6 +1242,13 @@ static void armv7m_nvic_realize(DeviceState *dev, Error **errp)
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);
}

View File

@ -50,6 +50,7 @@ typedef struct NVICState {
int exception_prio; /* group prio of the highest prio active exception */
MemoryRegion sysregmem;
MemoryRegion sysreg_ns_mem;
MemoryRegion container;
uint32_t num_irq;