[PATCH RFC XEN v1 02/14] xen: arm: Provide a mechanism to read (and decode) an LR from a saved VCPU

[Ian Campbell <ian.campbell@citrix.com>]

This will allow generic vgic save code to get at this state without needing
to know about gic v2 vs v3 etc.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
---
 xen/arch/arm/gic-v2.c     | 20 ++++++++++++++++----
 xen/arch/arm/gic-v3.c     | 21 ++++++++++++++++-----
 xen/arch/arm/gic.c        |  5 +++++
 xen/include/asm-arm/gic.h |  7 +++++++
 4 files changed, 44 insertions(+), 9 deletions(-)

diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c
index 01e36b5..5cc4cc3 100644
--- a/xen/arch/arm/gic-v2.c
+++ b/xen/arch/arm/gic-v2.c
@@ -417,11 +417,8 @@ static void gicv2_clear_lr(int lr)
     writel_gich(0, GICH_LR + lr * 4);
 }
 
-static void gicv2_read_lr(int lr, struct gic_lr *lr_reg)
+static void gicv2_decode_lr_value(uint32_t lrv, struct gic_lr *lr_reg)
 {
-    uint32_t lrv;
-
-    lrv          = readl_gich(GICH_LR + lr * 4);
     lr_reg->pirq = (lrv >> GICH_V2_LR_PHYSICAL_SHIFT) & GICH_V2_LR_PHYSICAL_MASK;
     lr_reg->virq = (lrv >> GICH_V2_LR_VIRTUAL_SHIFT) & GICH_V2_LR_VIRTUAL_MASK;
     lr_reg->priority = (lrv >> GICH_V2_LR_PRIORITY_SHIFT) & GICH_V2_LR_PRIORITY_MASK;
@@ -430,6 +427,14 @@ static void gicv2_read_lr(int lr, struct gic_lr *lr_reg)
     lr_reg->grp       = (lrv >> GICH_V2_LR_GRP_SHIFT) & GICH_V2_LR_GRP_MASK;
 }
 
+static void gicv2_read_lr(int lr, struct gic_lr *lr_reg)
+{
+    uint32_t lrv;
+
+    lrv = readl_gich(GICH_LR + lr * 4);
+    gicv2_decode_lr_value(lrv, lr_reg);
+}
+
 static void gicv2_write_lr(int lr, const struct gic_lr *lr_reg)
 {
     uint32_t lrv = 0;
@@ -447,6 +452,12 @@ static void gicv2_write_lr(int lr, const struct gic_lr *lr_reg)
     writel_gich(lrv, GICH_LR + lr * 4);
 }
 
+static void gicv2_vcpu_saved_lr(const struct vcpu *v, int lr,
+                                struct gic_lr *lr_val)
+{
+    gicv2_decode_lr_value(v->arch.gic.v2.lr[lr], lr_val);
+}
+
 static void gicv2_hcr_status(uint32_t flag, bool_t status)
 {
     uint32_t hcr = readl_gich(GICH_HCR);
@@ -746,6 +757,7 @@ const static struct gic_hw_operations gicv2_ops = {
     .save_state          = gicv2_save_state,
     .restore_state       = gicv2_restore_state,
     .dump_state          = gicv2_dump_state,
+    .vcpu_saved_lr       = gicv2_vcpu_saved_lr,
     .gic_host_irq_type   = &gicv2_host_irq_type,
     .gic_guest_irq_type  = &gicv2_guest_irq_type,
     .eoi_irq             = gicv2_eoi_irq,
diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index 4fe0c37..342aa4a 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -908,12 +908,8 @@ static void gicv3_clear_lr(int lr)
     gicv3_ich_write_lr(lr, 0);
 }
 
-static void gicv3_read_lr(int lr, struct gic_lr *lr_reg)
+static void gicv3_decode_lr_value(uint64_t lrv, struct gic_lr *lr_reg)
 {
-    uint64_t lrv;
-
-    lrv = gicv3_ich_read_lr(lr);
-
     lr_reg->pirq = (lrv >> GICH_LR_PHYSICAL_SHIFT) & GICH_LR_PHYSICAL_MASK;
     lr_reg->virq = (lrv >> GICH_LR_VIRTUAL_SHIFT) & GICH_LR_VIRTUAL_MASK;
 
@@ -923,6 +919,14 @@ static void gicv3_read_lr(int lr, struct gic_lr *lr_reg)
     lr_reg->grp       = (lrv >> GICH_LR_GRP_SHIFT) & GICH_LR_GRP_MASK;
 }
 
+static void gicv3_read_lr(int lr, struct gic_lr *lr_reg)
+{
+    uint64_t lrv;
+
+    lrv = gicv3_ich_read_lr(lr);
+    gicv3_decode_lr_value(lrv, lr_reg);
+}
+
 static void gicv3_write_lr(int lr_reg, const struct gic_lr *lr)
 {
     uint64_t lrv = 0;
@@ -937,6 +941,12 @@ static void gicv3_write_lr(int lr_reg, const struct gic_lr *lr)
     gicv3_ich_write_lr(lr_reg, lrv);
 }
 
+static void gicv3_vcpu_saved_lr(const struct vcpu *v, int lr,
+                                struct gic_lr *lr_val)
+{
+    gicv3_decode_lr_value(v->arch.gic.v3.lr[lr], lr_val);
+}
+
 static void gicv3_hcr_status(uint32_t flag, bool_t status)
 {
     uint32_t hcr;
@@ -1298,6 +1308,7 @@ static const struct gic_hw_operations gicv3_ops = {
     .save_state          = gicv3_save_state,
     .restore_state       = gicv3_restore_state,
     .dump_state          = gicv3_dump_state,
+    .vcpu_saved_lr       = gicv3_vcpu_saved_lr,
     .gic_host_irq_type   = &gicv3_host_irq_type,
     .gic_guest_irq_type  = &gicv3_guest_irq_type,
     .eoi_irq             = gicv3_eoi_irq,
diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index bea39d6..8d219e3 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -108,6 +108,11 @@ void gic_restore_state(struct vcpu *v)
     gic_restore_pending_irqs(v);
 }
 
+void gic_vcpu_saved_lr(const struct vcpu *v, int lr, struct gic_lr *lr_val)
+{
+    gic_hw_ops->vcpu_saved_lr(v, lr, lr_val);
+}
+
 /*
  * needs to be called with a valid cpu_mask, ie each cpu in the mask has
  * already called gic_cpu_init
diff --git a/xen/include/asm-arm/gic.h b/xen/include/asm-arm/gic.h
index 818384b..b6516f4 100644
--- a/xen/include/asm-arm/gic.h
+++ b/xen/include/asm-arm/gic.h
@@ -263,6 +263,10 @@ extern int gicv_setup(struct domain *d);
 extern void gic_save_state(struct vcpu *v);
 extern void gic_restore_state(struct vcpu *v);
 
+/* Save/restore */
+extern void gic_vcpu_saved_lr(const struct vcpu *v, int lr,
+                              struct gic_lr *lr_val);
+
 /* SGI (AKA IPIs) */
 enum gic_sgi {
     GIC_SGI_EVENT_CHECK = 0,
@@ -318,6 +322,9 @@ struct gic_hw_operations {
     /* Dump GIC LR register information */
     void (*dump_state)(const struct vcpu *);
 
+    /* Get saved LR state */
+    void (*vcpu_saved_lr)(const struct vcpu *v, int lr, struct gic_lr *lr_val);
+
     /* hw_irq_controller to enable/disable/eoi host irq */
     hw_irq_controller *gic_host_irq_type;
 
-- 
2.6.1