[Xen-changelog] [xen master] xen/arm: gic: Check the size of the CPU and vCPU interface retrieved from DT

[patchbot@xxxxxxx]

commit 61edf8a6f837b45572704aceca7c71d67858c062
Author:     Julien Grall <julien.grall@xxxxxxxxxx>
AuthorDate: Thu Oct 8 19:23:52 2015 +0100
Commit:     Ian Campbell <ian.campbell@xxxxxxxxxx>
CommitDate: Fri Oct 23 14:27:06 2015 +0100

    xen/arm: gic: Check the size of the CPU and vCPU interface retrieved from DT
    
    The size of the CPU interface will be used in a follow-up patch to map the
    region in Xen memory.
    
    Based on GICv2 spec, the CPU interface should at least be 8KB, although
    most of the platform we are supporting use incorrectly the GICv1 size
    (i.e 4KB) in their DT. Only warn and update the size to avoid any
    breakage on these platforms.
    
    Furthermore, Xen is relying on the fact that the Virtual CPU interface
    is at least 8KB. As in reality the Virtual CPU interface matches the CPU
    interface, check that the 2 interfaces have the same size.
    
    For GICv3, vGICv2 is only available for guest. So we only need to check
    that the GICV is at least 8KB.
    
    Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
    Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
    [ ijc -- typos ]
---
 xen/arch/arm/gic-v2.c |   31 +++++++++++++++++++++++++++----
 xen/arch/arm/gic-v3.c |   19 +++++++++++++++++--
 2 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c
index 5841e59..2b18c8c 100644
--- a/xen/arch/arm/gic-v2.c
+++ b/xen/arch/arm/gic-v2.c
@@ -617,14 +617,16 @@ static hw_irq_controller gicv2_guest_irq_type = {
 static int __init gicv2_init(void)
 {
     int res;
-    paddr_t hbase, dbase, cbase, vbase;
+    paddr_t hbase, dbase;
+    paddr_t cbase, csize;
+    paddr_t vbase, vsize;
     const struct dt_device_node *node = gicv2_info.node;
 
     res = dt_device_get_address(node, 0, &dbase, NULL);
     if ( res )
         panic("GICv2: Cannot find a valid address for the distributor");
 
-    res = dt_device_get_address(node, 1, &cbase, NULL);
+    res = dt_device_get_address(node, 1, &cbase, &csize);
     if ( res )
         panic("GICv2: Cannot find a valid address for the CPU");
 
@@ -632,7 +634,7 @@ static int __init gicv2_init(void)
     if ( res )
         panic("GICv2: Cannot find a valid address for the hypervisor");
 
-    res = dt_device_get_address(node, 3, &vbase, NULL);
+    res = dt_device_get_address(node, 3, &vbase, &vsize);
     if ( res )
         panic("GICv2: Cannot find a valid address for the virtual CPU");
 
@@ -641,7 +643,28 @@ static int __init gicv2_init(void)
         panic("GICv2: Cannot find the maintenance IRQ");
     gicv2_info.maintenance_irq = res;
 
-    /* TODO: Add check on distributor, cpu size */
+    /* TODO: Add check on distributor */
+
+    /*
+     * The GICv2 CPU interface should at least be 8KB. Although, most of the DT
+     * don't correctly set it and use the GICv1 CPU interface size (i.e 4KB).
+     * Warn and then fixup.
+     */
+    if ( csize < SZ_8K )
+    {
+        printk(XENLOG_WARNING "GICv2: WARNING: "
+               "The GICC size is too small: %#"PRIx64" expected %#x\n",
+               csize, SZ_8K);
+        csize = SZ_8K;
+    }
+
+    /*
+     * Check if the CPU interface and virtual CPU interface have the
+     * same size.
+     */
+    if ( csize != vsize )
+        panic("GICv2: Sizes of GICC (%#"PRIpaddr") and GICV (%#"PRIpaddr") 
don't match\n",
+               csize, vsize);
 
     printk("GICv2 initialization:\n"
               "        gic_dist_addr=%"PRIpaddr"\n"
diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index 957c6e0..9833a8d 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -1143,7 +1143,8 @@ static void __init gicv3_init_v2(const struct 
dt_device_node *node,
                                  paddr_t dbase)
 {
     int res;
-    paddr_t cbase, vbase;
+    paddr_t cbase;
+    paddr_t vbase, vsize;
 
     /*
      * For GICv3 supporting GICv2, GICC and GICV base address will be
@@ -1155,10 +1156,24 @@ static void __init gicv3_init_v2(const struct 
dt_device_node *node,
         return;
 
     res = dt_device_get_address(node, 1 + gicv3.rdist_count + 2,
-                                &vbase, NULL);
+                                &vbase, &vsize);
     if ( res )
         return;
 
+    /*
+     * We emulate a vGICv2 using a GIC CPU interface of GUEST_GICC_SIZE.
+     * So only support GICv2 on GICv3 when the virtual CPU interface is
+     * at least GUEST_GICC_SIZE.
+     */
+    if ( vsize < GUEST_GICC_SIZE )
+    {
+        printk(XENLOG_WARNING
+               "GICv3: WARNING: Not enabling support for GICv2 compat mode.\n"
+               "Size of GICV (%#"PRIpaddr") must at least be %#llx.\n",
+               vsize, GUEST_GICC_SIZE);
+        return;
+    }
+
     printk("GICv3 compatible with GICv2 cbase %#"PRIpaddr" vbase 
%#"PRIpaddr"\n",
            cbase, vbase);
 
--
generated by git-patchbot for /home/xen/git/xen.git#master

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