[v3] hw/arm/aspeed: Unlock SCU when running kernel

Message ID 20171114122018.12204-1-joel@jms.id.au
State New
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Series
  • [v3] hw/arm/aspeed: Unlock SCU when running kernel
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Commit Message

Joel Stanley Nov. 14, 2017, 12:20 p.m.
The ASPEED hardware contains a lock register for the SCU that disables
any writes to the SCU when it is locked. The machine comes up with the
lock enabled, but on all known hardware u-boot will unlock it and leave
it unlocked when loading the kernel.

This means the kernel expects the SCU to be unlocked. When booting from
an emulated ROM the normal u-boot unlock path is executed. Things don't
go well when booting using the -kernel command line, as u-boot does not
run first.

Change behaviour so that when a kernel is passed to the machine, set the
reset value of the SCU to be unlocked.

Signed-off-by: Joel Stanley <joel@jms.id.au>
---
v3:
 - remove unused member from AspeedBoardConfig
v2:
 - use the correct value for the key
 - rename it ASPEED_SCU_PROT_KEY
---
 hw/arm/aspeed.c              | 9 +++++++++
 hw/arm/aspeed_soc.c          | 2 ++
 hw/misc/aspeed_scu.c         | 5 +++--
 include/hw/misc/aspeed_scu.h | 3 +++
 4 files changed, 17 insertions(+), 2 deletions(-)

Comments

Cédric Le Goater Nov. 15, 2017, 8:18 a.m. | #1
On 11/14/2017 01:20 PM, Joel Stanley wrote:
> The ASPEED hardware contains a lock register for the SCU that disables
> any writes to the SCU when it is locked. The machine comes up with the
> lock enabled, but on all known hardware u-boot will unlock it and leave
> it unlocked when loading the kernel.
> 
> This means the kernel expects the SCU to be unlocked. When booting from
> an emulated ROM the normal u-boot unlock path is executed. Things don't
> go well when booting using the -kernel command line, as u-boot does not
> run first.
> 
> Change behaviour so that when a kernel is passed to the machine, set the
> reset value of the SCU to be unlocked.
> 
> Signed-off-by: Joel Stanley <joel@jms.id.au>

Reviewed-by: Cédric Le Goater <clg@kaod.org>

Thanks,

C.


> ---
> v3:
>  - remove unused member from AspeedBoardConfig
> v2:
>  - use the correct value for the key
>  - rename it ASPEED_SCU_PROT_KEY
> ---
>  hw/arm/aspeed.c              | 9 +++++++++
>  hw/arm/aspeed_soc.c          | 2 ++
>  hw/misc/aspeed_scu.c         | 5 +++--
>  include/hw/misc/aspeed_scu.h | 3 +++
>  4 files changed, 17 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/arm/aspeed.c b/hw/arm/aspeed.c
> index ab895ad490af..7088c907bd23 100644
> --- a/hw/arm/aspeed.c
> +++ b/hw/arm/aspeed.c
> @@ -186,6 +186,15 @@ static void aspeed_board_init(MachineState *machine,
>                              &error_abort);
>      object_property_set_int(OBJECT(&bmc->soc), cfg->num_cs, "num-cs",
>                              &error_abort);
> +    if (machine->kernel_filename) {
> +        /*
> +         * When booting with a -kernel command line there is no u-boot
> +         * that runs to unlock the SCU. In this case set the default to
> +         * be unlocked as the kernel expects
> +         */
> +        object_property_set_int(OBJECT(&bmc->soc), ASPEED_SCU_PROT_KEY,
> +                                "hw-prot-key", &error_abort);
> +    }
>      object_property_set_bool(OBJECT(&bmc->soc), true, "realized",
>                               &error_abort);
>  
> diff --git a/hw/arm/aspeed_soc.c b/hw/arm/aspeed_soc.c
> index 5aa3d2ddd9cd..c83b7e207b86 100644
> --- a/hw/arm/aspeed_soc.c
> +++ b/hw/arm/aspeed_soc.c
> @@ -154,6 +154,8 @@ static void aspeed_soc_init(Object *obj)
>                                "hw-strap1", &error_abort);
>      object_property_add_alias(obj, "hw-strap2", OBJECT(&s->scu),
>                                "hw-strap2", &error_abort);
> +    object_property_add_alias(obj, "hw-prot-key", OBJECT(&s->scu),
> +                              "hw-prot-key", &error_abort);
>  
>      object_initialize(&s->fmc, sizeof(s->fmc), sc->info->fmc_typename);
>      object_property_add_child(obj, "fmc", OBJECT(&s->fmc), NULL);
> diff --git a/hw/misc/aspeed_scu.c b/hw/misc/aspeed_scu.c
> index 95022d3607ad..74537ce9755d 100644
> --- a/hw/misc/aspeed_scu.c
> +++ b/hw/misc/aspeed_scu.c
> @@ -85,7 +85,6 @@
>  #define BMC_REV              TO_REG(0x19C)
>  #define BMC_DEV_ID           TO_REG(0x1A4)
>  
> -#define PROT_KEY_UNLOCK 0x1688A8A8
>  #define SCU_IO_REGION_SIZE 0x1000
>  
>  static const uint32_t ast2400_a0_resets[ASPEED_SCU_NR_REGS] = {
> @@ -192,7 +191,7 @@ static void aspeed_scu_write(void *opaque, hwaddr offset, uint64_t data,
>      }
>  
>      if (reg > PROT_KEY && reg < CPU2_BASE_SEG1 &&
> -            s->regs[PROT_KEY] != PROT_KEY_UNLOCK) {
> +            s->regs[PROT_KEY] != ASPEED_SCU_PROT_KEY) {
>          qemu_log_mask(LOG_GUEST_ERROR, "%s: SCU is locked!\n", __func__);
>          return;
>      }
> @@ -246,6 +245,7 @@ static void aspeed_scu_reset(DeviceState *dev)
>      s->regs[SILICON_REV] = s->silicon_rev;
>      s->regs[HW_STRAP1] = s->hw_strap1;
>      s->regs[HW_STRAP2] = s->hw_strap2;
> +    s->regs[PROT_KEY] = s->hw_prot_key;
>  }
>  
>  static uint32_t aspeed_silicon_revs[] = {
> @@ -299,6 +299,7 @@ static Property aspeed_scu_properties[] = {
>      DEFINE_PROP_UINT32("silicon-rev", AspeedSCUState, silicon_rev, 0),
>      DEFINE_PROP_UINT32("hw-strap1", AspeedSCUState, hw_strap1, 0),
>      DEFINE_PROP_UINT32("hw-strap2", AspeedSCUState, hw_strap2, 0),
> +    DEFINE_PROP_UINT32("hw-prot-key", AspeedSCUState, hw_prot_key, 0),
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> diff --git a/include/hw/misc/aspeed_scu.h b/include/hw/misc/aspeed_scu.h
> index bd4ac013f997..d70cc0aeca61 100644
> --- a/include/hw/misc/aspeed_scu.h
> +++ b/include/hw/misc/aspeed_scu.h
> @@ -29,6 +29,7 @@ typedef struct AspeedSCUState {
>      uint32_t silicon_rev;
>      uint32_t hw_strap1;
>      uint32_t hw_strap2;
> +    uint32_t hw_prot_key;
>  } AspeedSCUState;
>  
>  #define AST2400_A0_SILICON_REV   0x02000303U
> @@ -38,6 +39,8 @@ typedef struct AspeedSCUState {
>  
>  extern bool is_supported_silicon_rev(uint32_t silicon_rev);
>  
> +#define ASPEED_SCU_PROT_KEY      0x1688A8A8
> +
>  /*
>   * Extracted from Aspeed SDK v00.03.21. Fixes and extra definitions
>   * were added.
>
Peter Maydell Nov. 15, 2017, 11:56 a.m. | #2
On 15 November 2017 at 08:18, Cédric Le Goater <clg@kaod.org> wrote:
> On 11/14/2017 01:20 PM, Joel Stanley wrote:
>> The ASPEED hardware contains a lock register for the SCU that disables
>> any writes to the SCU when it is locked. The machine comes up with the
>> lock enabled, but on all known hardware u-boot will unlock it and leave
>> it unlocked when loading the kernel.
>>
>> This means the kernel expects the SCU to be unlocked. When booting from
>> an emulated ROM the normal u-boot unlock path is executed. Things don't
>> go well when booting using the -kernel command line, as u-boot does not
>> run first.
>>
>> Change behaviour so that when a kernel is passed to the machine, set the
>> reset value of the SCU to be unlocked.
>>
>> Signed-off-by: Joel Stanley <joel@jms.id.au>
>
> Reviewed-by: Cédric Le Goater <clg@kaod.org>

Thanks. Should this go into 2.11 ? It sounds like the kind of
bugfix that ought to...

-- PMM
Cédric Le Goater Nov. 15, 2017, 1:13 p.m. | #3
On 11/15/2017 11:56 AM, Peter Maydell wrote:
> On 15 November 2017 at 08:18, Cédric Le Goater <clg@kaod.org> wrote:
>> On 11/14/2017 01:20 PM, Joel Stanley wrote:
>>> The ASPEED hardware contains a lock register for the SCU that disables
>>> any writes to the SCU when it is locked. The machine comes up with the
>>> lock enabled, but on all known hardware u-boot will unlock it and leave
>>> it unlocked when loading the kernel.
>>>
>>> This means the kernel expects the SCU to be unlocked. When booting from
>>> an emulated ROM the normal u-boot unlock path is executed. Things don't
>>> go well when booting using the -kernel command line, as u-boot does not
>>> run first.
>>>
>>> Change behaviour so that when a kernel is passed to the machine, set the
>>> reset value of the SCU to be unlocked.
>>>
>>> Signed-off-by: Joel Stanley <joel@jms.id.au>
>>
>> Reviewed-by: Cédric Le Goater <clg@kaod.org>
> 
> Thanks. Should this go into 2.11 ? It sounds like the kind of
> bugfix that ought to...

Yes. Please.

Thanks,

C.

Patch

diff --git a/hw/arm/aspeed.c b/hw/arm/aspeed.c
index ab895ad490af..7088c907bd23 100644
--- a/hw/arm/aspeed.c
+++ b/hw/arm/aspeed.c
@@ -186,6 +186,15 @@  static void aspeed_board_init(MachineState *machine,
                             &error_abort);
     object_property_set_int(OBJECT(&bmc->soc), cfg->num_cs, "num-cs",
                             &error_abort);
+    if (machine->kernel_filename) {
+        /*
+         * When booting with a -kernel command line there is no u-boot
+         * that runs to unlock the SCU. In this case set the default to
+         * be unlocked as the kernel expects
+         */
+        object_property_set_int(OBJECT(&bmc->soc), ASPEED_SCU_PROT_KEY,
+                                "hw-prot-key", &error_abort);
+    }
     object_property_set_bool(OBJECT(&bmc->soc), true, "realized",
                              &error_abort);
 
diff --git a/hw/arm/aspeed_soc.c b/hw/arm/aspeed_soc.c
index 5aa3d2ddd9cd..c83b7e207b86 100644
--- a/hw/arm/aspeed_soc.c
+++ b/hw/arm/aspeed_soc.c
@@ -154,6 +154,8 @@  static void aspeed_soc_init(Object *obj)
                               "hw-strap1", &error_abort);
     object_property_add_alias(obj, "hw-strap2", OBJECT(&s->scu),
                               "hw-strap2", &error_abort);
+    object_property_add_alias(obj, "hw-prot-key", OBJECT(&s->scu),
+                              "hw-prot-key", &error_abort);
 
     object_initialize(&s->fmc, sizeof(s->fmc), sc->info->fmc_typename);
     object_property_add_child(obj, "fmc", OBJECT(&s->fmc), NULL);
diff --git a/hw/misc/aspeed_scu.c b/hw/misc/aspeed_scu.c
index 95022d3607ad..74537ce9755d 100644
--- a/hw/misc/aspeed_scu.c
+++ b/hw/misc/aspeed_scu.c
@@ -85,7 +85,6 @@ 
 #define BMC_REV              TO_REG(0x19C)
 #define BMC_DEV_ID           TO_REG(0x1A4)
 
-#define PROT_KEY_UNLOCK 0x1688A8A8
 #define SCU_IO_REGION_SIZE 0x1000
 
 static const uint32_t ast2400_a0_resets[ASPEED_SCU_NR_REGS] = {
@@ -192,7 +191,7 @@  static void aspeed_scu_write(void *opaque, hwaddr offset, uint64_t data,
     }
 
     if (reg > PROT_KEY && reg < CPU2_BASE_SEG1 &&
-            s->regs[PROT_KEY] != PROT_KEY_UNLOCK) {
+            s->regs[PROT_KEY] != ASPEED_SCU_PROT_KEY) {
         qemu_log_mask(LOG_GUEST_ERROR, "%s: SCU is locked!\n", __func__);
         return;
     }
@@ -246,6 +245,7 @@  static void aspeed_scu_reset(DeviceState *dev)
     s->regs[SILICON_REV] = s->silicon_rev;
     s->regs[HW_STRAP1] = s->hw_strap1;
     s->regs[HW_STRAP2] = s->hw_strap2;
+    s->regs[PROT_KEY] = s->hw_prot_key;
 }
 
 static uint32_t aspeed_silicon_revs[] = {
@@ -299,6 +299,7 @@  static Property aspeed_scu_properties[] = {
     DEFINE_PROP_UINT32("silicon-rev", AspeedSCUState, silicon_rev, 0),
     DEFINE_PROP_UINT32("hw-strap1", AspeedSCUState, hw_strap1, 0),
     DEFINE_PROP_UINT32("hw-strap2", AspeedSCUState, hw_strap2, 0),
+    DEFINE_PROP_UINT32("hw-prot-key", AspeedSCUState, hw_prot_key, 0),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/misc/aspeed_scu.h b/include/hw/misc/aspeed_scu.h
index bd4ac013f997..d70cc0aeca61 100644
--- a/include/hw/misc/aspeed_scu.h
+++ b/include/hw/misc/aspeed_scu.h
@@ -29,6 +29,7 @@  typedef struct AspeedSCUState {
     uint32_t silicon_rev;
     uint32_t hw_strap1;
     uint32_t hw_strap2;
+    uint32_t hw_prot_key;
 } AspeedSCUState;
 
 #define AST2400_A0_SILICON_REV   0x02000303U
@@ -38,6 +39,8 @@  typedef struct AspeedSCUState {
 
 extern bool is_supported_silicon_rev(uint32_t silicon_rev);
 
+#define ASPEED_SCU_PROT_KEY      0x1688A8A8
+
 /*
  * Extracted from Aspeed SDK v00.03.21. Fixes and extra definitions
  * were added.