[Xen-devel] [PATCH v3 2/6] arm: move GIC SGI kicking into separate function

[Andre Przywara <andre.przywara@xxxxxxxxxx>]

Currently we unconditionally send SGIs to all cores on SMP bringup.
Those SGIs (software generated interrupts) are to push a secondary
core through a gate in Xen code to filter the right CPU.
With PSCI we can explicitly specify the core to startup, so we don't
need the GIC kick here.
So we move the GIC kick into a function and call it explicitly from
the platforms that need it. This gets us get rid of
the empty cpu_up() platform functions in ARM32 and the comment in
there.

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxxxxx>
---
 xen/arch/arm/arm64/smpboot.c      |  2 +-
 xen/arch/arm/platform.c           |  2 +-
 xen/arch/arm/platforms/exynos5.c  | 11 +----------
 xen/arch/arm/platforms/omap5.c    | 11 +----------
 xen/arch/arm/platforms/vexpress.c | 10 +---------
 xen/arch/arm/smpboot.c            | 15 ++++++++++-----
 xen/include/asm-arm/smp.h         |  2 ++
 7 files changed, 17 insertions(+), 36 deletions(-)

diff --git a/xen/arch/arm/arm64/smpboot.c b/xen/arch/arm/arm64/smpboot.c
index 8696ed6..6a34bd4 100644
--- a/xen/arch/arm/arm64/smpboot.c
+++ b/xen/arch/arm/arm64/smpboot.c
@@ -38,7 +38,7 @@ static int __init smp_spin_table_cpu_up(int cpu)
 
     sev();
 
-    return 0;
+    return cpu_up_send_sgi(cpu);
 }
 
 static void __init smp_spin_table_init(int cpu, struct dt_device_node *dn)
diff --git a/xen/arch/arm/platform.c b/xen/arch/arm/platform.c
index 5ed8eb2..e13a354 100644
--- a/xen/arch/arm/platform.c
+++ b/xen/arch/arm/platform.c
@@ -112,7 +112,7 @@ int __init platform_cpu_up(int cpu)
     if ( platform && platform->cpu_up )
         return platform->cpu_up(cpu);
 
-    return -EAGAIN;
+    return -ENODEV;
 }
 
 int __init platform_smp_init(void)
diff --git a/xen/arch/arm/platforms/exynos5.c b/xen/arch/arm/platforms/exynos5.c
index fa6b465..65e584f 100644
--- a/xen/arch/arm/platforms/exynos5.c
+++ b/xen/arch/arm/platforms/exynos5.c
@@ -85,15 +85,6 @@ static int __init exynos5_smp_init(void)
     return 0;
 }
 
-static int __init exynos5_cpu_up(int cpu)
-{
-    /* Nothing to do here, the generic sev() will suffice to kick CPUs
-     * out of either the firmware or our own smp_up_cpu gate,
-     * depending on where they have ended up. */
-
-    return 0;
-}
-
 static void exynos5_reset(void)
 {
     void __iomem *pmu;
@@ -132,7 +123,7 @@ PLATFORM_START(exynos5, "SAMSUNG EXYNOS5")
     .init_time = exynos5_init_time,
     .specific_mapping = exynos5_specific_mapping,
     .smp_init = exynos5_smp_init,
-    .cpu_up = exynos5_cpu_up,
+    .cpu_up = cpu_up_send_sgi,
     .reset = exynos5_reset,
     .blacklist_dev = exynos5_blacklist_dev,
 PLATFORM_END
diff --git a/xen/arch/arm/platforms/omap5.c b/xen/arch/arm/platforms/omap5.c
index 3a3b16b..423d11b 100644
--- a/xen/arch/arm/platforms/omap5.c
+++ b/xen/arch/arm/platforms/omap5.c
@@ -144,15 +144,6 @@ static int __init omap5_smp_init(void)
     return 0;
 }
 
-static int __init omap5_cpu_up(int cpu)
-{
-    /* Nothing to do here, the generic sev() will suffice to kick CPUs
-     * out of either the firmware or our own smp_up_cpu gate,
-     * depending on where they have ended up. */
-
-    return 0;
-}
-
 static const char const *omap5_dt_compat[] __initconst =
 {
     "ti,omap5",
@@ -164,7 +155,7 @@ PLATFORM_START(omap5, "TI OMAP5")
     .init_time = omap5_init_time,
     .specific_mapping = omap5_specific_mapping,
     .smp_init = omap5_smp_init,
-    .cpu_up = omap5_cpu_up,
+    .cpu_up = cpu_up_send_sgi,
 PLATFORM_END
 
 /*
diff --git a/xen/arch/arm/platforms/vexpress.c 
b/xen/arch/arm/platforms/vexpress.c
index 9056366..6132056 100644
--- a/xen/arch/arm/platforms/vexpress.c
+++ b/xen/arch/arm/platforms/vexpress.c
@@ -144,14 +144,6 @@ static int __init vexpress_smp_init(void)
     return 0;
 }
 
-static int __init vexpress_cpu_up(int cpu)
-{
-    /* Nothing to do here, the generic sev() will suffice to kick CPUs
-     * out of either the firmware or our own smp_up_cpu gate,
-     * depending on where they have ended up. */
-
-    return 0;
-}
 #endif
 
 static const char * const vexpress_dt_compat[] __initconst =
@@ -180,7 +172,7 @@ PLATFORM_START(vexpress, "VERSATILE EXPRESS")
     .compatible = vexpress_dt_compat,
 #ifdef CONFIG_ARM_32
     .smp_init = vexpress_smp_init,
-    .cpu_up = vexpress_cpu_up,
+    .cpu_up = cpu_up_send_sgi,
 #endif
     .reset = vexpress_reset,
     .blacklist_dev = vexpress_blacklist_dev,
diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
index bd76d14..8d96c17 100644
--- a/xen/arch/arm/smpboot.c
+++ b/xen/arch/arm/smpboot.c
@@ -343,6 +343,16 @@ void stop_cpu(void)
         wfi();
 }
 
+int __init cpu_up_send_sgi(int cpu)
+{
+    /* We don't know the GIC ID of the CPU until it has woken up, so just
+     * signal everyone and rely on our own smp_up_cpu gate to ensure only
+     * the one we want gets through. */
+    send_SGI_allbutself(GIC_SGI_EVENT_CHECK);
+
+    return 0;
+}
+
 /* Bring up a remote CPU */
 int __cpu_up(unsigned int cpu)
 {
@@ -376,11 +386,6 @@ int __cpu_up(unsigned int cpu)
         return rc;
     }
 
-    /* We don't know the GIC ID of the CPU until it has woken up, so just 
signal
-     * everyone and rely on our own smp_up_cpu gate to ensure only the one we
-     * want gets through. */
-    send_SGI_allbutself(GIC_SGI_EVENT_CHECK);
-
     while ( !cpu_online(cpu) )
     {
         cpu_relax();
diff --git a/xen/include/asm-arm/smp.h b/xen/include/asm-arm/smp.h
index 1485cc6..a1de03c 100644
--- a/xen/include/asm-arm/smp.h
+++ b/xen/include/asm-arm/smp.h
@@ -21,6 +21,8 @@ extern int arch_smp_init(void);
 extern int arch_cpu_init(int cpu, struct dt_device_node *dn);
 extern int arch_cpu_up(int cpu);
 
+int cpu_up_send_sgi(int cpu);
+
 /* Secondary CPU entry point */
 extern void init_secondary(void);
 
-- 
1.7.12.1


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