[Xen-devel] [PATCH v2 1/2] xen/arm: Add support of PSCI v1.0 for the host

[Julien Grall <julien.grall@xxxxxxxxxx>]

From Xen point of view, PSCI v0.2 and PSCI v1.0 are very similar. All
the PSCI calls used within Xen (PSCI_VERSION, CPU_ON, SYSTEM_OFF and
SYSTEM_RESET) behaves exactly the same.

Furthermore, based on the spec (5.3.1 DEN0022C), any 1.y version must be
compatible with 1.x when y > x for any functions existing in 1.x.

So check the presence of the new compatible string [1] and allow Xen to
boot on any platform using PSCI 1.x.

[1] 
http://lists.infradead.org/pipermail/linux-arm-kernel/2015-October/374547.html

Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>

---

Cc: Andre Przywara <andre.przywara@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>

    Changes in v2:
        - Update the commit message
        - Allow Xen to boot on any PSCI 1.x
        - Update the error message
---
 xen/arch/arm/psci.c        | 17 +++++++++++++----
 xen/include/asm-arm/psci.h | 13 +++++++++++++
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
index 172c6e7..44ccc2f 100644
--- a/xen/arch/arm/psci.c
+++ b/xen/arch/arm/psci.c
@@ -109,10 +109,16 @@ int __init psci_init_0_1(void)
 
 int __init psci_init_0_2(void)
 {
+    static const struct dt_device_match psci_ids[] __initconst =
+    {
+        DT_MATCH_COMPATIBLE("arm,psci-0.2"),
+        DT_MATCH_COMPATIBLE("arm,psci-1.0"),
+        { /* sentinel */ },
+    };
     int ret;
     const struct dt_device_node *psci;
 
-    psci = dt_find_compatible_node(NULL, NULL, "arm,psci-0.2");
+    psci = dt_find_matching_node(NULL, psci_ids);
     if ( !psci )
         return -EOPNOTSUPP;
 
@@ -122,15 +128,18 @@ int __init psci_init_0_2(void)
 
     psci_ver = call_smc(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
 
-    if ( psci_ver != XEN_PSCI_V_0_2 )
+    /* For the moment, we only support PSCI 0.2 and PSCI 1.x */
+    if ( psci_ver != PSCI_VERSION(0, 2) && PSCI_VERSION_MAJOR(psci_ver != 1) )
     {
-        printk("Error: PSCI version %#x is not supported.\n", psci_ver);
+        printk("Error: Unrecognized PSCI version %u.%u\n",
+               PSCI_VERSION_MAJOR(psci_ver), PSCI_VERSION_MINOR(psci_ver));
         return -EOPNOTSUPP;
     }
 
     psci_cpu_on_nr = PSCI_0_2_FN_NATIVE(CPU_ON);
 
-    printk(XENLOG_INFO "Using PSCI-0.2 for SMP bringup\n");
+    printk(XENLOG_INFO "Using PSCI-%u.%u for SMP bringup\n",
+           PSCI_VERSION_MAJOR(psci_ver), PSCI_VERSION_MINOR(psci_ver));
 
     return 0;
 }
diff --git a/xen/include/asm-arm/psci.h b/xen/include/asm-arm/psci.h
index 5d17ee3..d8a109f 100644
--- a/xen/include/asm-arm/psci.h
+++ b/xen/include/asm-arm/psci.h
@@ -87,6 +87,19 @@ void do_psci_0_2_system_reset(void);
 #define PSCI_0_2_POWER_STATE_TYPE_MASK      \
                     (0x1 << PSCI_0_2_POWER_STATE_TYPE_SHIFT)
 
+/* PSCI version decoding (independent of PSCI version) */
+#define PSCI_VERSION_MAJOR_SHIFT            16
+#define PSCI_VERSION_MINOR_MASK             \
+        ((1U << PSCI_VERSION_MAJOR_SHIFT) - 1)
+#define PSCI_VERSION_MAJOR_MASK             ~PSCI_VERSION_MINOR_MASK
+#define PSCI_VERSION_MAJOR(ver)             \
+        (((ver) & PSCI_VERSION_MAJOR_MASK) >> PSCI_VERSION_MAJOR_SHIFT)
+#define PSCI_VERSION_MINOR(ver)             \
+        ((ver) & PSCI_VERSION_MINOR_MASK)
+
+#define PSCI_VERSION(major, minor)          \
+    (((major) << PSCI_VERSION_MAJOR_SHIFT) | (minor))
+
 #endif /* __ASM_PSCI_H__ */
 
 /*
-- 
2.1.4


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel