2 files changed, 47 insertions, 4 deletions

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 56353f6b5952..9687f8afebff 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -802,6 +802,7 @@ static int its_alloc_tables(struct its_node *its)
         int i;
         int psz = SZ_64K;
         u64 shr = GITS_BASER_InnerShareable;
+        u64 cache = GITS_BASER_WaWb;
 
         for (i = 0; i < GITS_BASER_NR_REGS; i++) {
                 u64 val = readq_relaxed(its->base + GITS_BASER + i * 8);
@@ -848,7 +849,7 @@ retry_baser:
                 val = (virt_to_phys(base)                                |
                        (type << GITS_BASER_TYPE_SHIFT)                   |
                        ((entry_size - 1) << GITS_BASER_ENTRY_SIZE_SHIFT) |
-                       GITS_BASER_WaWb                                   |
+                       cache                                             |
                        shr                                               |
                        GITS_BASER_VALID);
 
@@ -874,9 +875,12 @@ retry_baser:
                          * Shareability didn't stick. Just use
                          * whatever the read reported, which is likely
                          * to be the only thing this redistributor
-                         * supports.
+                         * supports. If that's zero, make it
+                         * non-cacheable as well.
                          */
                         shr = tmp & GITS_BASER_SHAREABILITY_MASK;
+                        if (!shr)
+                                cache = GITS_BASER_nC;
                         goto retry_baser;
                 }
 
@@ -980,6 +984,17 @@ static void its_cpu_init_lpis(void)
         tmp = readq_relaxed(rbase + GICR_PROPBASER);
 
         if ((tmp ^ val) & GICR_PROPBASER_SHAREABILITY_MASK) {
+                if (!(tmp & GICR_PROPBASER_SHAREABILITY_MASK)) {
+                        /*
+                         * The HW reports non-shareable, we must
+                         * remove the cacheability attributes as
+                         * well.
+                         */
+                        val &= ~(GICR_PROPBASER_SHAREABILITY_MASK |
+                                 GICR_PROPBASER_CACHEABILITY_MASK);
+                        val |= GICR_PROPBASER_nC;
+                        writeq_relaxed(val, rbase + GICR_PROPBASER);
+                }
                 pr_info_once("GIC: using cache flushing for LPI property table\n");
                 gic_rdists->flags |= RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING;
         }
@@ -990,6 +1005,18 @@ static void its_cpu_init_lpis(void)
                GICR_PENDBASER_WaWb);
 
         writeq_relaxed(val, rbase + GICR_PENDBASER);
+        tmp = readq_relaxed(rbase + GICR_PENDBASER);
+
+        if (!(tmp & GICR_PENDBASER_SHAREABILITY_MASK)) {
+                /*
+                 * The HW reports non-shareable, we must remove the
+                 * cacheability attributes as well.
+                 */
+                val &= ~(GICR_PENDBASER_SHAREABILITY_MASK |
+                         GICR_PENDBASER_CACHEABILITY_MASK);
+                val |= GICR_PENDBASER_nC;
+                writeq_relaxed(val, rbase + GICR_PENDBASER);
+        }
 
         /* Enable LPIs */
         val = readl_relaxed(rbase + GICR_CTLR);
@@ -1422,14 +1449,26 @@ static int its_probe(struct device_node *node, struct irq_domain *parent)
 
         writeq_relaxed(baser, its->base + GITS_CBASER);
         tmp = readq_relaxed(its->base + GITS_CBASER);
-        writeq_relaxed(0, its->base + GITS_CWRITER);
-        writel_relaxed(GITS_CTLR_ENABLE, its->base + GITS_CTLR);
 
         if ((tmp ^ baser) & GITS_CBASER_SHAREABILITY_MASK) {
+                if (!(tmp & GITS_CBASER_SHAREABILITY_MASK)) {
+                        /*
+                         * The HW reports non-shareable, we must
+                         * remove the cacheability attributes as
+                         * well.
+                         */
+                        baser &= ~(GITS_CBASER_SHAREABILITY_MASK |
+                                   GITS_CBASER_CACHEABILITY_MASK);
+                        baser |= GITS_CBASER_nC;
+                        writeq_relaxed(baser, its->base + GITS_CBASER);
+                }
                 pr_info("ITS: using cache flushing for cmd queue\n");
                 its->flags |= ITS_FLAGS_CMDQ_NEEDS_FLUSHING;
         }
 
+        writeq_relaxed(0, its->base + GITS_CWRITER);
+        writel_relaxed(GITS_CTLR_ENABLE, its->base + GITS_CTLR);
+
         if (of_property_read_bool(its->msi_chip.of_node, "msi-controller")) {
                 its->domain = irq_domain_add_tree(NULL, &its_domain_ops, its);
                 if (!its->domain) {
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 826a4bd63d4a..ffbc034c8810 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -126,6 +126,7 @@
 #define GICR_PROPBASER_WaWb             (5U << 7)
 #define GICR_PROPBASER_RaWaWt           (6U << 7)
 #define GICR_PROPBASER_RaWaWb           (7U << 7)
+#define GICR_PROPBASER_CACHEABILITY_MASK (7U << 7)
 #define GICR_PROPBASER_IDBITS_MASK      (0x1f)
 
 #define GICR_PENDBASER_NonShareable     (0U << 10)
@@ -140,6 +141,7 @@
 #define GICR_PENDBASER_WaWb             (5U << 7)
 #define GICR_PENDBASER_RaWaWt           (6U << 7)
 #define GICR_PENDBASER_RaWaWb           (7U << 7)
+#define GICR_PENDBASER_CACHEABILITY_MASK (7U << 7)
 
 /*
  * Re-Distributor registers, offsets from SGI_base
@@ -195,6 +197,7 @@
 #define GITS_CBASER_WaWb                (5UL << 59)
 #define GITS_CBASER_RaWaWt              (6UL << 59)
 #define GITS_CBASER_RaWaWb              (7UL << 59)
+#define GITS_CBASER_CACHEABILITY_MASK   (7UL << 59)
 #define GITS_CBASER_NonShareable        (0UL << 10)
 #define GITS_CBASER_InnerShareable      (1UL << 10)
 #define GITS_CBASER_OuterShareable      (2UL << 10)
@@ -211,6 +214,7 @@
 #define GITS_BASER_WaWb                 (5UL << 59)
 #define GITS_BASER_RaWaWt               (6UL << 59)
 #define GITS_BASER_RaWaWb               (7UL << 59)
+#define GITS_BASER_CACHEABILITY_MASK    (7UL << 59)
 #define GITS_BASER_TYPE_SHIFT           (56)
 #define GITS_BASER_TYPE(r)              (((r) >> GITS_BASER_TYPE_SHIFT) & 7)
 #define GITS_BASER_ENTRY_SIZE_SHIFT     (48)