[Xen-devel] [RFC 1/2] xen/arm: Save and expose the p2m IPA address size

["Edgar E. Iglesias" <edgar.iglesias@xxxxxxxxx>]

From: "Edgar E. Iglesias" <edgar.iglesias@xxxxxxxxxx>

Save and expose the p2m IPA address size to arch specific code.
This is primarily needed to setup SMMUs as these share p2m
tables with guest CPUs.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xxxxxxxxxx>
---
 xen/arch/arm/p2m.c        | 7 ++++++-
 xen/include/asm-arm/p2m.h | 3 +++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 8dfee24..58df568 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -17,12 +17,15 @@
 #ifdef CONFIG_ARM_64
 static unsigned int __read_mostly p2m_root_order;
 static unsigned int __read_mostly p2m_root_level;
+static unsigned int __read_mostly p2m_ipa_bits;
 #define P2M_ROOT_ORDER    p2m_root_order
 #define P2M_ROOT_LEVEL p2m_root_level
+#define P2M_IPA_BITS p2m_ipa_bits
 #else
 /* First level P2M is alway 2 consecutive pages */
 #define P2M_ROOT_LEVEL 1
 #define P2M_ROOT_ORDER    1
+#define P2M_IPA_BITS 40
 #endif
 
 #define P2M_ROOT_PAGES    (1<<P2M_ROOT_ORDER)
@@ -1310,6 +1313,7 @@ int p2m_init(struct domain *d)
 
     p2m->root = NULL;
 
+    p2m->ipa_bits = P2M_IPA_BITS;
     p2m->max_mapped_gfn = 0;
     p2m->lowest_mapped_gfn = ULONG_MAX;
 
@@ -1557,9 +1561,10 @@ void __init setup_virt_paging(void)
 
     p2m_root_order = pa_range_info[pa_range].root_order;
     p2m_root_level = 2 - pa_range_info[pa_range].sl0;
+    p2m_ipa_bits = 64 - pa_range_info[pa_range].t0sz;
 
     printk("P2M: %d-bit IPA with %d-bit PA\n",
-           64 - pa_range_info[pa_range].t0sz,
+           p2m_ipa_bits,
            pa_range_info[pa_range].pabits);
 #endif
     printk("P2M: %d levels with order-%d root, VTCR 0x%lx\n",
diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
index 341df55..813ddd0 100644
--- a/xen/include/asm-arm/p2m.h
+++ b/xen/include/asm-arm/p2m.h
@@ -28,6 +28,9 @@ struct p2m_domain {
     /* Current VMID in use */
     uint8_t vmid;
 
+    /* Nr of bits in an IPA.  */
+    unsigned int ipa_bits;
+
     /* Highest guest frame that's ever been mapped in the p2m
      * Only takes into account ram and foreign mapping
      */
-- 
1.9.1


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