[Xen-changelog] [xen master] arm: gic-v3: deactivate interrupts during initialization

[patchbot@xxxxxxx]

commit 0322e0db5b29a0d1ce4b452885e34023e3a4b00e
Author:     Peng Fan <peng.fan@xxxxxxx>
AuthorDate: Tue Feb 5 05:55:35 2019 +0000
Commit:     Stefano Stabellini <sstabellini@xxxxxxxxxx>
CommitDate: Wed Feb 6 11:20:41 2019 -0800

    arm: gic-v3: deactivate interrupts during initialization
    
    On i.MX8, we implemented partition reboot which means Cortex-A reboot
    will not impact M4 cores and System control Unit core. However GICv3 is
    not reset because we also need to support A72 Cluster reboot without
    affecting A53 Cluster.
    
    The gic-v3 controller is configured with EOImode to 1, so during xen
    reboot, there is a function call "smp_call_function(halt_this_cpu, NULL, 
0);"
    but halt_this_cpu never returns, that means other CPUs have no chance to
    deactivate the SGI interrupt, because the deactivate_irq operation is at
    the end of do_sgi. During the next boot of Xen, CPU0 will issue
    GIC_SGI_CALL_FUNCTION to other CPUs. As the Active state for SGI is left
    untouched during the reboot, the GIC_SGI_CALL_FUNCTION will still be active
    on the non-boot CPUs. This means the interrupt cannot be triggered again
    until it get deactivated.
    
    And according to IHI0069D_gic_architecture_specification, chapter
    "8.11.3 GICR_ICACTIVER0, Interrupt Clear-Active Register 0", the RW
    field of GICR_ICACTIVER0 resets to a value that is architecturally UNKNOWN.
    So make sure all interrupts are deactivated during initialization by
    clearing the state.
    
    Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
    Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 xen/arch/arm/gic-v3.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index c9200d24e1..0f6cbf6224 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -626,9 +626,12 @@ static void __init gicv3_dist_init(void)
         writel_relaxed(priority, GICD + GICD_IPRIORITYR + (i / 4) * 4);
     }
 
-    /* Disable all global interrupts */
+    /* Disable/deactivate all global interrupts */
     for ( i = NR_GIC_LOCAL_IRQS; i < nr_lines; i += 32 )
+    {
         writel_relaxed(0xffffffff, GICD + GICD_ICENABLER + (i / 32) * 4);
+        writel_relaxed(0xffffffff, GICD + GICD_ICACTIVER + (i / 32) * 4);
+    }
 
     /*
      * Configure SPIs as non-secure Group-1. This will only matter
@@ -835,6 +838,11 @@ static int gicv3_cpu_init(void)
                 GICD_RDIST_SGI_BASE + GICR_IPRIORITYR0 + (i / 4) * 4);
 
     /*
+     * The activate state is unknown at boot, so make sure all
+     * SGIs and PPIs are de-activated.
+     */
+    writel_relaxed(0xffffffff, GICD_RDIST_SGI_BASE + GICR_ICACTIVER0);
+    /*
      * Disable all PPI interrupts, ensure all SGI interrupts are
      * enabled.
      */
--
generated by git-patchbot for /home/xen/git/xen.git#master

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