[V2 0/2] Introduce PSCI-0.2 supports

[V2 0/2] Introduce PSCI-0.2 supports

[suravee.suthikulpanit]

From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

This patch series introduce PSCI-0.2 supports for:
  * PSCI_VERSION
  * CPU_ON
  * SYSTEM_OFF
  * SYSTEM_RESET

Then, it modifies the shutdown/restart logic to use PSCI-0.2 interface
by default when available.

Note: This probably do not need to target the 4.5 release.

Changes in V2:
    * 1/2:
        - Use "uint32_t" instead of "int" for psci_ver. (Julien, Ian)
        - In psci_init(), modify logic to first try PSCI-0.2, and fallback to 0.1
          when not supports (Julien, Ian).
        - Fix call_psci_system_off() and psci_system_reset()
        - Rewording of error messages (Julien, Ian)

Suravee Suthikulpanit (2):
  xen/arm: Initial support for PSCI-0.2 (cpu_on, system_off,
    system_reset)
  xen/arm: Use PSCI-0.2 for machine_halt/restart by default

 xen/arch/arm/arm64/smpboot.c |  2 +-
 xen/arch/arm/platform.c      |  2 +-
 xen/arch/arm/psci.c          | 80 +++++++++++++++++++++++++++++++++++++++-----
 xen/arch/arm/shutdown.c      | 25 ++++++++++----
 xen/include/asm-arm/psci.h   |  4 ++-
 5 files changed, 95 insertions(+), 18 deletions(-)

-- 
1.9.3

[V2 1/2] xen/arm: Initial support for PSCI-0.2 (cpu_on, system_off, system_reset)

[suravee.suthikulpanit]

From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

This patch adds SMC calls to suport PSCI-0.2:
  * PSCI_VERSION
  * CPU_ON
  * SYSTEM_OFF
  * SYSTEM_RESET

First, the psci_init() is refactored to handle both PSCI-0.1 and PSCI-0.2.

To add support for PSCI_VERSION, this patch replaces the "bool_t psci_available"
variable with "int psci_ver", which contains the PSCI_VERSION as described in the
PSCI-0.2 spec. For v0.1, this psci_ver is 1.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
---
 xen/arch/arm/arm64/smpboot.c |  2 +-
 xen/arch/arm/platform.c      |  2 +-
 xen/arch/arm/psci.c          | 80 +++++++++++++++++++++++++++++++++++++++-----
 xen/include/asm-arm/psci.h   |  4 ++-
 4 files changed, 76 insertions(+), 12 deletions(-)

diff --git a/xen/arch/arm/arm64/smpboot.c b/xen/arch/arm/arm64/smpboot.c
index 9146476..341cc77 100644
--- a/xen/arch/arm/arm64/smpboot.c
+++ b/xen/arch/arm/arm64/smpboot.c
@@ -54,7 +54,7 @@ static void __init smp_spin_table_init(int cpu, struct dt_device_node *dn)
 
 static int __init smp_psci_init(int cpu)
 {
-    if ( !psci_available )
+    if ( !psci_ver )
     {
         printk("CPU%d asks for PSCI, but DTB has no PSCI node\n", cpu);
         return -ENODEV;
diff --git a/xen/arch/arm/platform.c b/xen/arch/arm/platform.c
index 74c3328..cb4cda8 100644
--- a/xen/arch/arm/platform.c
+++ b/xen/arch/arm/platform.c
@@ -110,7 +110,7 @@ int __init platform_specific_mapping(struct domain *d)
 #ifdef CONFIG_ARM_32
 int __init platform_cpu_up(int cpu)
 {
-    if ( psci_available )
+    if ( psci_ver )
         return call_psci_cpu_on(cpu);
 
     if ( platform && platform->cpu_up )
diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
index b6360d5..604ff4c 100644
--- a/xen/arch/arm/psci.c
+++ b/xen/arch/arm/psci.c
@@ -23,7 +23,7 @@
 #include <xen/smp.h>
 #include <asm/psci.h>
 
-bool_t psci_available;
+uint32_t psci_ver;
 
 #ifdef CONFIG_ARM_32
 #define REG_PREFIX "r"
@@ -58,16 +58,23 @@ int call_psci_cpu_on(int cpu)
                                 cpu_logical_map(cpu), __pa(init_secondary), 0);
 }
 
-int __init psci_init(void)
+void call_psci_system_off(void)
+{
+    if ( psci_ver > XEN_PSCI_V_0_1 )
+        __invoke_psci_fn_smc(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
+}
+
+void call_psci_system_reset(void)
+{
+    if ( psci_ver > XEN_PSCI_V_0_1 )
+        __invoke_psci_fn_smc(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
+}
+
+int __init psci_is_smc_method(const struct dt_device_node *psci)
 {
-    const struct dt_device_node *psci;
     int ret;
     const char *prop_str;
 
-    psci = dt_find_compatible_node(NULL, NULL, "arm,psci");
-    if ( !psci )
-        return -ENODEV;
-
     ret = dt_property_read_string(psci, "method", &prop_str);
     if ( ret )
     {
@@ -85,19 +92,74 @@ int __init psci_init(void)
         return -EINVAL;
     }
 
+    return 0;
+}
+
+int __init psci_init_0_1(void)
+{
+    int ret;
+    const struct dt_device_node *psci;
+
+    psci = dt_find_compatible_node(NULL, NULL, "arm,psci");
+    if ( !psci )
+        return -EOPNOTSUPP;
+
+    ret = psci_is_smc_method(psci);
+    if ( ret )
+        return -EINVAL;
+
     if ( !dt_property_read_u32(psci, "cpu_on", &psci_cpu_on_nr) )
     {
         printk("/psci node is missing the \"cpu_on\" property\n");
         return -ENOENT;
     }
 
-    psci_available = 1;
+    psci_ver = XEN_PSCI_V_0_1;
+
+    printk(XENLOG_INFO "Using PSCI-0.1 for SMP bringup\n");
+
+    return 0;
+}
+
+int __init psci_init_0_2(void)
+{
+    int ret;
+    const struct dt_device_node *psci;
+
+    psci = dt_find_compatible_node(NULL, NULL, "arm,psci-0.2");
+    if ( !psci )
+	return -EOPNOTSUPP;
+
+    ret = psci_is_smc_method(psci);
+    if ( ret )
+        return -EINVAL;
+
+    psci_ver = __invoke_psci_fn_smc(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
+
+    if ( psci_ver != XEN_PSCI_V_0_2 )
+    {
+        printk("Error: PSCI version %#x is not supported.\n", psci_ver);
+        return -EOPNOTSUPP;
+    }
+
+    psci_cpu_on_nr = PSCI_0_2_FN_CPU_ON;
 
-    printk(XENLOG_INFO "Using PSCI for SMP bringup\n");
+    printk(XENLOG_INFO "Using PSCI-0.2 for SMP bringup\n");
 
     return 0;
 }
 
+int __init psci_init(void)
+{
+    int ret;
+
+    ret = psci_init_0_2();
+    if ( ret )
+        ret = psci_init_0_1();
+
+    return ret;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/asm-arm/psci.h b/xen/include/asm-arm/psci.h
index 9777c03..5d17ee3 100644
--- a/xen/include/asm-arm/psci.h
+++ b/xen/include/asm-arm/psci.h
@@ -13,10 +13,12 @@
 #define PSCI_DISABLED               -8
 
 /* availability of PSCI on the host for SMP bringup */
-extern bool_t psci_available;
+extern uint32_t psci_ver;
 
 int psci_init(void);
 int call_psci_cpu_on(int cpu);
+void call_psci_system_off(void);
+void call_psci_system_reset(void);
 
 /* functions to handle guest PSCI requests */
 int32_t do_psci_cpu_on(uint32_t vcpuid, register_t entry_point);
-- 
1.9.3

[V2 2/2] xen/arm: Use PSCI-0.2 for machine_halt/restart by default

[suravee.suthikulpanit]

From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

"machine_halt()" and "machine_restart()" are modified to use PSCI interface
by default if PSCI-0.2 is supported. The "raw_machine_reset()" is also removed
since this is unnecessary.

For non-PSCI, platform_poweroff() and platform_reset() are used instead.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
---
 xen/arch/arm/shutdown.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/xen/arch/arm/shutdown.c b/xen/arch/arm/shutdown.c
index adc0529..4988b03 100644
--- a/xen/arch/arm/shutdown.c
+++ b/xen/arch/arm/shutdown.c
@@ -5,11 +5,7 @@
 #include <xen/lib.h>
 #include <xen/smp.h>
 #include <asm/platform.h>
-
-static void raw_machine_reset(void)
-{
-    platform_reset();
-}
+#include <asm/psci.h>
 
 static void noreturn halt_this_cpu(void *arg)
 {
@@ -18,10 +14,23 @@ static void noreturn halt_this_cpu(void *arg)
 
 void machine_halt(void)
 {
+    int timeout = 10;
+
     watchdog_disable();
     console_start_sync();
     local_irq_enable();
     smp_call_function(halt_this_cpu, NULL, 0);
+    local_irq_disable();
+
+    /* Wait at most another 10ms for all other CPUs to go offline. */
+    while ( (num_online_cpus() > 1) && (timeout-- > 0) )
+        mdelay(1);
+
+    /* This is mainly for PSCI-0.2, which does not return if success. */
+    call_psci_system_off();
+
+    /* Alternative halt procedure */
+    platform_poweroff();
     halt_this_cpu(NULL);
 }
 
@@ -39,9 +48,13 @@ void machine_restart(unsigned int delay_millisecs)
     while ( (num_online_cpus() > 1) && (timeout-- > 0) )
         mdelay(1);
 
+    /* This is mainly for PSCI-0.2, which does not return if success. */
+    call_psci_system_reset();
+
+    /* Alternative reset procedure */
     while ( 1 )
     {
-        raw_machine_reset();
+        platform_reset();
         mdelay(100);
     }
 }
-- 
1.9.3

Re: [V2 1/2] xen/arm: Initial support for PSCI-0.2 (cpu_on, system_off, system_reset)

[Julien Grall]

Hi Suravee,

On 10/02/2014 10:29 PM, suravee.suthikulpanit@amd.com wrote:
> From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> 
> This patch adds SMC calls to suport PSCI-0.2:

s/suport/support/

>   * PSCI_VERSION
>   * CPU_ON
>   * SYSTEM_OFF
>   * SYSTEM_RESET
>
> First, the psci_init() is refactored to handle both PSCI-0.1 and PSCI-0.2.
> 
> To add support for PSCI_VERSION, this patch replaces the "bool_t psci_available"
> variable with "int psci_ver", which contains the PSCI_VERSION as described in the
> PSCI-0.2 spec. For v0.1, this psci_ver is 1.
> 
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

We would have to implement CPU_OFF at some point. As it's not done for
PSCI v0.1, I guess it's not too important.

Reviewed-by: Julien Grall <julien.grall@linaro.org>

Regards,

-- 
Julien Grall