[PATCH v2 0/2] Add an embedded controller to sbsa-ref machine

[PATCH v2 0/2] Add an embedded controller to sbsa-ref machine

[Graeme Gregory]

This series is to an add embedded controller to the sbsa-ref machine
so that PSCI can communicate platform power states to the platform
which in this case is QEMU.

v1->v2
 - broke out the EC itself as hw/misc/sbsa_ec.c as seperate patch
 - applied review comments to date

[PATCH v2 1/2] hw/misc/sbsa_ec : Add an embedded controller for sbsa-ref

[Graeme Gregory]

A difference between sbsa platform and the virt platform is PSCI is
handled by ARM-TF in the sbsa platform. This means that the PSCI code
there needs to communicate some of the platform power changes down
to the qemu code for things like shutdown/reset control.

Space has been left to extend the EC if we find other use cases in
future where ARM-TF and qemu need to communicate.

Signed-off-by: Graeme Gregory <graeme@nuviainc.com>
---
 hw/misc/meson.build |  2 +
 hw/misc/sbsa_ec.c   | 98 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+)
 create mode 100644 hw/misc/sbsa_ec.c

diff --git a/hw/misc/meson.build b/hw/misc/meson.build
index 84fed0494d..e1576b81cf 100644
--- a/hw/misc/meson.build
+++ b/hw/misc/meson.build
@@ -97,3 +97,5 @@ specific_ss.add(when: 'CONFIG_MAC_VIA', if_true: files('mac_via.c'))
 
 specific_ss.add(when: 'CONFIG_MIPS_CPS', if_true: files('mips_cmgcr.c', 'mips_cpc.c'))
 specific_ss.add(when: 'CONFIG_MIPS_ITU', if_true: files('mips_itu.c'))
+
+specific_ss.add(when: 'CONFIG_SBSA_REF', if_true: files('sbsa_ec.c'))
diff --git a/hw/misc/sbsa_ec.c b/hw/misc/sbsa_ec.c
new file mode 100644
index 0000000000..9a7d7f914a
--- /dev/null
+++ b/hw/misc/sbsa_ec.c
@@ -0,0 +1,98 @@
+/*
+ * ARM SBSA Reference Platform Embedded Controller
+ *
+ * A device to allow PSCI running in the secure side of sbsa-ref machine
+ * to communicate platform power states to qemu.
+ *
+ * Copyright (c) 2020 Nuvia Inc
+ * Written by Graeme Gregory <graeme@nuviainc.com>
+ *
+ * SPDX-License-Identifer: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "qemu/log.h"
+#include "hw/sysbus.h"
+#include "sysemu/runstate.h"
+
+typedef struct {
+    SysBusDevice parent_obj;
+    MemoryRegion iomem;
+} SECUREECState;
+
+#define TYPE_SBSA_EC      "sbsa-ec"
+#define SECURE_EC(obj) OBJECT_CHECK(SECUREECState, (obj), TYPE_SBSA_EC)
+
+enum sbsa_ec_powerstates {
+    SBSA_EC_CMD_POWEROFF = 0x01,
+    SBSA_EC_CMD_REBOOT = 0x02,
+};
+
+static uint64_t sbsa_ec_read(void *opaque, hwaddr offset, unsigned size)
+{
+    /* No use for this currently */
+    qemu_log_mask(LOG_GUEST_ERROR, "sbsa-ec: no readable registers");
+    return 0;
+}
+
+static void sbsa_ec_write(void *opaque, hwaddr offset,
+                     uint64_t value, unsigned size)
+{
+    if (offset == 0) { /* PSCI machine power command register */
+        switch (value) {
+        case SBSA_EC_CMD_POWEROFF:
+            qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
+            break;
+        case SBSA_EC_CMD_REBOOT:
+            qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
+            break;
+        default:
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "sbsa-ec: unknown power command");
+        }
+    } else {
+        qemu_log_mask(LOG_GUEST_ERROR, "sbsa-ec: unknown EC register");
+    }
+}
+
+static const MemoryRegionOps sbsa_ec_ops = {
+    .read = sbsa_ec_read,
+    .write = sbsa_ec_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid.min_access_size = 4,
+    .valid.max_access_size = 4,
+};
+
+static void sbsa_ec_init(Object *obj)
+{
+    SECUREECState *s = SECURE_EC(obj);
+    SysBusDevice *dev = SYS_BUS_DEVICE(obj);
+
+    memory_region_init_io(&s->iomem, obj, &sbsa_ec_ops, s, "sbsa-ec",
+                          0x1000);
+    sysbus_init_mmio(dev, &s->iomem);
+}
+
+static void sbsa_ec_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    /* No vmstate or reset required: device has no internal state */
+    dc->user_creatable = false;
+}
+
+static const TypeInfo sbsa_ec_info = {
+    .name          = TYPE_SBSA_EC,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SECUREECState),
+    .instance_init = sbsa_ec_init,
+    .class_init    = sbsa_ec_class_init,
+};
+
+static void sbsa_ec_register_type(void)
+{
+    type_register_static(&sbsa_ec_info);
+}
+
+type_init(sbsa_ec_register_type);
-- 
2.25.1

[PATCH v2 2/2] hw/arm/sbsa-ref : Add embedded controller in secure memory

[Graeme Gregory]

Add the previously created sbsa-ec device to the sbsa-ref machine in
secure memory so the PSCI implementation in ARM-TF can access it, but
not expose it to non secure firmware or OS except by via ARM-TF.

Signed-off-by: Graeme Gregory <graeme@nuviainc.com>
---
 hw/arm/sbsa-ref.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/hw/arm/sbsa-ref.c b/hw/arm/sbsa-ref.c
index 2a7d9a61fc..8614709bfb 100644
--- a/hw/arm/sbsa-ref.c
+++ b/hw/arm/sbsa-ref.c
@@ -62,6 +62,7 @@ enum {
     SBSA_CPUPERIPHS,
     SBSA_GIC_DIST,
     SBSA_GIC_REDIST,
+    SBSA_SECURE_EC,
     SBSA_SMMU,
     SBSA_UART,
     SBSA_RTC,
@@ -107,6 +108,7 @@ static const MemMapEntry sbsa_ref_memmap[] = {
     [SBSA_CPUPERIPHS] =         { 0x40000000, 0x00040000 },
     [SBSA_GIC_DIST] =           { 0x40060000, 0x00010000 },
     [SBSA_GIC_REDIST] =         { 0x40080000, 0x04000000 },
+    [SBSA_SECURE_EC] =          { 0x50000000, 0x00001000 },
     [SBSA_UART] =               { 0x60000000, 0x00001000 },
     [SBSA_RTC] =                { 0x60010000, 0x00001000 },
     [SBSA_GPIO] =               { 0x60020000, 0x00001000 },
@@ -585,6 +587,16 @@ static void *sbsa_ref_dtb(const struct arm_boot_info *binfo, int *fdt_size)
     return board->fdt;
 }
 
+static void create_secure_ec(MemoryRegion *mem)
+{
+    hwaddr base = sbsa_ref_memmap[SBSA_SECURE_EC].base;
+    DeviceState *dev = qdev_new("sbsa-ec");
+    SysBusDevice *s = SYS_BUS_DEVICE(dev);
+
+    memory_region_add_subregion(mem, base,
+                                sysbus_mmio_get_region(s, 0));
+}
+
 static void sbsa_ref_init(MachineState *machine)
 {
     unsigned int smp_cpus = machine->smp.cpus;
@@ -708,6 +720,8 @@ static void sbsa_ref_init(MachineState *machine)
 
     create_pcie(sms);
 
+    create_secure_ec(secure_sysmem);
+
     sms->bootinfo.ram_size = machine->ram_size;
     sms->bootinfo.nb_cpus = smp_cpus;
     sms->bootinfo.board_id = -1;
-- 
2.25.1

Re: [PATCH v2 0/2] Add an embedded controller to sbsa-ref machine

[Leif Lindholm]

On Wed, Aug 26, 2020 at 15:19:50 +0100, Graeme Gregory wrote:
> This series is to an add embedded controller to the sbsa-ref machine
> so that PSCI can communicate platform power states to the platform
> which in this case is QEMU.
> 
> v1->v2
>  - broke out the EC itself as hw/misc/sbsa_ec.c as seperate patch
>  - applied review comments to date

For the series:
Reviewed-by: Leif Lindholm <leif@nuviainc.com>
Tested-by: Leif Lindholm <leif@nuviainc.com>

Thanks!

Re: [PATCH v2 0/2] Add an embedded controller to sbsa-ref machine

[Peter Maydell]

On Wed, 26 Aug 2020 at 15:19, Graeme Gregory <graeme@nuviainc.com> wrote:
>
> This series is to an add embedded controller to the sbsa-ref machine
> so that PSCI can communicate platform power states to the platform
> which in this case is QEMU.
>
> v1->v2
>  - broke out the EC itself as hw/misc/sbsa_ec.c as seperate patch
>  - applied review comments to date
>



Applied to target-arm.next, thanks.

-- PMM