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authorPeter Maydell <peter.maydell@linaro.org>2019-02-21 18:17:46 +0000
committerPeter Maydell <peter.maydell@linaro.org>2019-02-21 18:17:46 +0000
commit37e571f1e0101f9aab29235afa651028723eb4c5 (patch)
treed3b7bf1a5229fcb179fa865920a1c90c97cc074e
parent6c1f6f2733a7692793135ea5ce72b829add99a50 (diff)
downloadqemu-arm-37e571f1e0101f9aab29235afa651028723eb4c5.tar.gz
hw/misc/tz-ppc: Support having unused ports in the middle of the range
The Peripheral Protection Controller's handling of unused ports is that if there is nothing connected to the port's downstream then it does not create the sysbus MMIO region for the upstream end of the port. This results in odd behaviour when there is an unused port in the middle of the range: since sysbus MMIO regions are implicitly consecutively allocated, any used ports above the unused ones end up with sysbus MMIO region numbers that don't match the port number. Avoid this numbering mismatch by creating dummy MMIO regions for the unused ports. This doesn't change anything for our existing boards, which don't have any gaps in the middle of the port ranges they use; but it will be needed for the Musca board. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
-rw-r--r--hw/misc/tz-ppc.c32
-rw-r--r--include/hw/misc/tz-ppc.h8
2 files changed, 39 insertions, 1 deletions
diff --git a/hw/misc/tz-ppc.c b/hw/misc/tz-ppc.c
index 3dd045c15f..2e04837bea 100644
--- a/hw/misc/tz-ppc.c
+++ b/hw/misc/tz-ppc.c
@@ -181,6 +181,21 @@ static const MemoryRegionOps tz_ppc_ops = {
.endianness = DEVICE_LITTLE_ENDIAN,
};
+static bool tz_ppc_dummy_accepts(void *opaque, hwaddr addr,
+ unsigned size, bool is_write,
+ MemTxAttrs attrs)
+{
+ /*
+ * Board code should never map the upstream end of an unused port,
+ * so we should never try to make a memory access to it.
+ */
+ g_assert_not_reached();
+}
+
+static const MemoryRegionOps tz_ppc_dummy_ops = {
+ .valid.accepts = tz_ppc_dummy_accepts,
+};
+
static void tz_ppc_reset(DeviceState *dev)
{
TZPPC *s = TZ_PPC(dev);
@@ -210,16 +225,33 @@ static void tz_ppc_realize(DeviceState *dev, Error **errp)
SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
TZPPC *s = TZ_PPC(dev);
int i;
+ int max_port = 0;
/* We can't create the upstream end of the port until realize,
* as we don't know the size of the MR used as the downstream until then.
*/
for (i = 0; i < TZ_NUM_PORTS; i++) {
+ if (s->port[i].downstream) {
+ max_port = i;
+ }
+ }
+
+ for (i = 0; i <= max_port; i++) {
TZPPCPort *port = &s->port[i];
char *name;
uint64_t size;
if (!port->downstream) {
+ /*
+ * Create dummy sysbus MMIO region so the sysbus region
+ * numbering doesn't get out of sync with the port numbers.
+ * The size is entirely arbitrary.
+ */
+ name = g_strdup_printf("tz-ppc-dummy-port[%d]", i);
+ memory_region_init_io(&port->upstream, obj, &tz_ppc_dummy_ops,
+ port, name, 0x10000);
+ sysbus_init_mmio(sbd, &port->upstream);
+ g_free(name);
continue;
}
diff --git a/include/hw/misc/tz-ppc.h b/include/hw/misc/tz-ppc.h
index fc8b806e4d..080d6e2ec1 100644
--- a/include/hw/misc/tz-ppc.h
+++ b/include/hw/misc/tz-ppc.h
@@ -38,7 +38,13 @@
*
* QEMU interface:
* + sysbus MMIO regions 0..15: MemoryRegions defining the upstream end
- * of each of the 16 ports of the PPC
+ * of each of the 16 ports of the PPC. When a port is unused (i.e. no
+ * downstream MemoryRegion is connected to it) at the end of the 0..15
+ * range then no sysbus MMIO region is created for its upstream. When an
+ * unused port lies in the middle of the range with other used ports at
+ * higher port numbers, a dummy MMIO region is created to ensure that
+ * port N's upstream is always sysbus MMIO region N. Dummy regions should
+ * not be mapped, and will assert if any access is made to them.
* + Property "port[0..15]": MemoryRegion defining the downstream device(s)
* for each of the 16 ports of the PPC
* + Named GPIO inputs "cfg_nonsec[0..15]": set to 1 if the port should be