[Xen-changelog] [xen master] xen/arm: vgic-v3: Set stride during domain initialization

[patchbot@xxxxxxx]

commit 4636e9fb40130240b74da0148ea96307cc251800
Author:     Julien Grall <julien.grall@xxxxxxxxxx>
AuthorDate: Mon Feb 16 14:50:46 2015 +0000
Commit:     Ian Campbell <ian.campbell@xxxxxxxxxx>
CommitDate: Thu Feb 19 16:55:28 2015 +0000

    xen/arm: vgic-v3: Set stride during domain initialization
    
    The stride may not be set if the hardware GIC is using the default
    layout. It happens on the Foundation model.
    
    On GICv3, the default stride is 2 * 64K. Therefore it's possible to avoid
    checking at every redistributor MMIO access if the stride is not set.
    
    Because domU uses a static stride configuration this only happens for
    dom0, so we can move this code in gicv_v3_init. Take the opportunity to move
    the stride setting a bit earlier because the loop to set regions will 
require
    the stride.
    
    Also, use 2 * 64K rather than 128K and explain the reason.
    
    Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
    Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
 xen/arch/arm/gic-v3.c  |   11 ++++++++++-
 xen/arch/arm/vgic-v3.c |   12 ++----------
 2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index 47452ca..7b33ff7 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -897,12 +897,21 @@ static int gicv_v3_init(struct domain *d)
     {
         d->arch.vgic.dbase = gicv3.dbase;
         d->arch.vgic.dbase_size = gicv3.dbase_size;
+
+        d->arch.vgic.rdist_stride = gicv3.rdist_stride;
+        /*
+         * If the stride is not set, the default stride for GICv3 is 2 * 64K:
+         *     - first 64k page for Control and Physical LPIs
+         *     - second 64k page for Control and Generation of SGIs
+         */
+        if ( !d->arch.vgic.rdist_stride )
+            d->arch.vgic.rdist_stride = 2 * SZ_64K;
+
         for ( i = 0; i < gicv3.rdist_count; i++ )
         {
             d->arch.vgic.rbase[i] = gicv3.rdist_regions[i].base;
             d->arch.vgic.rbase_size[i] = gicv3.rdist_regions[i].size;
         }
-        d->arch.vgic.rdist_stride = gicv3.rdist_stride;
         d->arch.vgic.rdist_count = gicv3.rdist_count;
     }
     else
diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c
index 2c14717..c5a743a 100644
--- a/xen/arch/arm/vgic-v3.c
+++ b/xen/arch/arm/vgic-v3.c
@@ -625,11 +625,7 @@ static int vgic_v3_rdistr_mmio_read(struct vcpu *v, 
mmio_info_t *info)
 
     perfc_incr(vgicr_reads);
 
-    if ( v->domain->arch.vgic.rdist_stride != 0 )
-        offset = info->gpa & (v->domain->arch.vgic.rdist_stride - 1);
-    else
-        /* If stride is not set. Default 128K */
-        offset = info->gpa & (SZ_128K - 1);
+    offset = info->gpa & (v->domain->arch.vgic.rdist_stride - 1);
 
     if ( offset < SZ_64K )
         return __vgic_v3_rdistr_rd_mmio_read(v, info, offset);
@@ -649,11 +645,7 @@ static int vgic_v3_rdistr_mmio_write(struct vcpu *v, 
mmio_info_t *info)
 
     perfc_incr(vgicr_writes);
 
-    if ( v->domain->arch.vgic.rdist_stride != 0 )
-        offset = info->gpa & (v->domain->arch.vgic.rdist_stride - 1);
-    else
-        /* If stride is not set. Default 128K */
-        offset = info->gpa & (SZ_128K - 1);
+    offset = info->gpa & (v->domain->arch.vgic.rdist_stride - 1);
 
     if ( offset < SZ_64K )
         return __vgic_v3_rdistr_rd_mmio_write(v, info, offset);
--
generated by git-patchbot for /home/xen/git/xen.git#master

_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog