1 files changed, 38 insertions, 4 deletions

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 39261798c59f..6bd881be24ea 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -55,6 +55,16 @@ struct its_collection {
 };
 
 /*
+ * The ITS_BASER structure - contains memory information and cached
+ * value of BASER register configuration.
+ */
+struct its_baser {
+        void            *base;
+        u64             val;
+        u32             order;
+};
+
+/*
  * The ITS structure - contains most of the infrastructure, with the
  * top-level MSI domain, the command queue, the collections, and the
  * list of devices writing to it.
@@ -66,14 +76,12 @@ struct its_node {
         unsigned long           phys_base;
         struct its_cmd_block    *cmd_base;
         struct its_cmd_block    *cmd_write;
-        struct {
-                void            *base;
-                u32             order;
-        } tables[GITS_BASER_NR_REGS];
+        struct its_baser        tables[GITS_BASER_NR_REGS];
         struct its_collection   *collections;
         struct list_head        its_device_list;
         u64                     flags;
         u32                     ite_size;
+        u32                     device_ids;
 };
 
 #define ITS_ITT_ALIGN           SZ_256
@@ -838,6 +846,8 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
                 ids     = GITS_TYPER_DEVBITS(typer);
         }
 
+        its->device_ids = ids;
+
         for (i = 0; i < GITS_BASER_NR_REGS; i++) {
                 u64 val = readq_relaxed(its->base + GITS_BASER + i * 8);
                 u64 type = GITS_BASER_TYPE(val);
@@ -913,6 +923,7 @@ retry_baser:
                 }
 
                 val |= alloc_pages - 1;
+                its->tables[i].val = val;
 
                 writeq_relaxed(val, its->base + GITS_BASER + i * 8);
                 tmp = readq_relaxed(its->base + GITS_BASER + i * 8);
@@ -1138,9 +1149,22 @@ static struct its_device *its_find_device(struct its_node *its, u32 dev_id)
         return its_dev;
 }
 
+static struct its_baser *its_get_baser(struct its_node *its, u32 type)
+{
+        int i;
+
+        for (i = 0; i < GITS_BASER_NR_REGS; i++) {
+                if (GITS_BASER_TYPE(its->tables[i].val) == type)
+                        return &its->tables[i];
+        }
+
+        return NULL;
+}
+
 static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
                                             int nvecs)
 {
+        struct its_baser *baser;
         struct its_device *dev;
         unsigned long *lpi_map;
         unsigned long flags;
@@ -1151,6 +1175,16 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
         int nr_ites;
         int sz;
 
+        baser = its_get_baser(its, GITS_BASER_TYPE_DEVICE);
+
+        /* Don't allow 'dev_id' that exceeds single, flat table limit */
+        if (baser) {
+                if (dev_id >= (PAGE_ORDER_TO_SIZE(baser->order) /
+                              GITS_BASER_ENTRY_SIZE(baser->val)))
+                        return NULL;
+        } else if (ilog2(dev_id) >= its->device_ids)
+                return NULL;
+
         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
         /*
          * At least one bit of EventID is being used, hence a minimum