[PATCH v7 14/28] xen/arm: ITS: Initialize physical ITS and export lpi support

[vijay.kilari@gmail.com]

From: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>

Initialize physical ITS if HW supports LPIs.

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
---
v7: - Export lpi support information to vgic-v3 driver from gic-v3.
    - Drop gic_lpi_supported() helper function
    - Add boot param to enable or disable physical ITS
v6: - Updated lpi_supported gic_info member for GICv2 and GICv3
    - Introduced helper gic_lpi_supported() and exported
v5: - Made check of its dt node availability before
      setting lpi_supported flag
---
 xen/arch/arm/gic-v3.c             |   38 ++++++++++++++++++++++++++++++++++---
 xen/arch/arm/vgic-v3.c            |    5 ++++-
 xen/include/asm-arm/gic_v3_defs.h |    4 +++-
 xen/include/asm-arm/vgic.h        |    2 +-
 4 files changed, 43 insertions(+), 6 deletions(-)

diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index c4c77a7..ac8a0ea 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -55,6 +55,18 @@ static struct {
 } gicv3;
 
 static struct gic_info gicv3_info;
+/* Enable/Disable ITS support */
+static bool_t its_enable  = 1;
+/* Availability of ITS support after successful ITS initialization */
+static bool_t its_enabled = 0;
+
+static void __init parse_its_param(char *s)
+{
+    if ( !parse_bool(s) )
+        its_enable = 0;
+}
+
+custom_param("its", parse_its_param);
 
 /* per-cpu re-distributor base */
 DEFINE_PER_CPU(struct rdist, rdist);
@@ -590,7 +602,7 @@ static void __init gicv3_dist_init(void)
      * Here we override HW supported number of LPIs and
      * limit to to LPIs specified in nr_lpis.
      */
-    if ( gicv3_dist_supports_lpis() )
+    if ( its_enabled && gicv3_dist_supports_lpis() )
         gicv3_info.nr_irq_ids = nr_lpis + FIRST_GIC_LPI;
     else
     {
@@ -714,6 +726,10 @@ static int __cpuinit gicv3_cpu_init(void)
     if ( gicv3_enable_redist() )
         return -ENODEV;
 
+    /* Give LPIs a spin */
+    if ( its_enabled && gicv3_dist_supports_lpis() )
+        its_cpu_init();
+
     /* Set priority on PPI and SGI interrupts */
     priority = (GIC_PRI_IPI << 24 | GIC_PRI_IPI << 16 | GIC_PRI_IPI << 8 |
                 GIC_PRI_IPI);
@@ -1303,14 +1319,30 @@ static int __init gicv3_init(void)
                i, r->base, r->base + r->size);
     }
 
-    vgic_v3_setup_hw(dbase, gicv3.rdist_count, gicv3.rdist_regions,
-                     gicv3.rdist_stride);
+    reg = readl_relaxed(GICD + GICD_TYPER);
+
+    gicv3.rdist_data.id_bits = ((reg >> GICD_TYPE_ID_BITS_SHIFT) &
+                                GICD_TYPE_ID_BITS_MASK) + 1;
+
     gicv3_init_v2(node, dbase);
 
     spin_lock_init(&gicv3.lock);
 
     spin_lock(&gicv3.lock);
 
+    if ( its_enable && gicv3_dist_supports_lpis() )
+    {
+        /*
+         * LPI support is enabled only if HW supports it and
+         * ITS dt node is available
+         */
+        if ( !its_init(&gicv3.rdist_data) )
+            its_enabled = 1;
+    }
+
+    vgic_v3_setup_hw(dbase, gicv3.rdist_count, gicv3.rdist_regions,
+                     gicv3.rdist_stride, its_enabled);
+
     gicv3_dist_init();
     res = gicv3_cpu_init();
     gicv3_hyp_init();
diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c
index 12c5d87..52d4277 100644
--- a/xen/arch/arm/vgic-v3.c
+++ b/xen/arch/arm/vgic-v3.c
@@ -51,6 +51,8 @@
 
 static struct {
     bool_t enabled;
+    /* Check if its supported */
+    bool_t lpi_support;
     /* Distributor interface address */
     paddr_t dbase;
     /* Re-distributor regions */
@@ -62,9 +64,10 @@ static struct {
 void vgic_v3_setup_hw(paddr_t dbase,
                       unsigned int nr_rdist_regions,
                       const struct rdist_region *regions,
-                      uint32_t rdist_stride)
+                      uint32_t rdist_stride, bool_t lpi_support)
 {
     vgic_v3_hw.enabled = 1;
+    vgic_v3_hw.lpi_support = lpi_support;
     vgic_v3_hw.dbase = dbase;
     vgic_v3_hw.nr_rdist_regions = nr_rdist_regions;
     vgic_v3_hw.regions = regions;
diff --git a/xen/include/asm-arm/gic_v3_defs.h b/xen/include/asm-arm/gic_v3_defs.h
index 1bc88f6..f819589 100644
--- a/xen/include/asm-arm/gic_v3_defs.h
+++ b/xen/include/asm-arm/gic_v3_defs.h
@@ -46,7 +46,9 @@
 #define GICC_SRE_EL2_ENEL1           (1UL << 3)
 
 /* Additional bits in GICD_TYPER defined by GICv3 */
-#define GICD_TYPE_ID_BITS_SHIFT 19
+#define GICD_TYPE_ID_BITS_SHIFT      (19)
+#define GICD_TYPE_ID_BITS_MASK       (0x1f)
+#define GICD_TYPE_LPIS               (0x1UL << 17)
 
 #define GICD_TYPER_LPIS_SUPPORTED    (1U << 17)
 #define GICD_CTLR_RWP                (1UL << 31)
diff --git a/xen/include/asm-arm/vgic.h b/xen/include/asm-arm/vgic.h
index cf5a790..2bf061f 100644
--- a/xen/include/asm-arm/vgic.h
+++ b/xen/include/asm-arm/vgic.h
@@ -362,7 +362,7 @@ struct rdist_region;
 void vgic_v3_setup_hw(paddr_t dbase,
                       unsigned int nr_rdist_regions,
                       const struct rdist_region *regions,
-                      uint32_t rdist_stride);
+                      uint32_t rdist_stride, bool_t lpi_support);
 #endif
 
 #endif /* __ASM_ARM_VGIC_H__ */
-- 
1.7.9.5