irqchip/gic-v3-its: Generalize device table allocation

As we want to use 2-level tables for VCPUs, let's hack the device
table allocator in order to make it slightly more generic. It
will get reused in subsequent patches.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 71d71f757a1741c3ca4e541fbea61ad207bda620..15a007f982536ac5ebacf74fd302b8fcf64ab5ab 100644 (file)
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1392,26 +1392,19 @@ static struct its_baser *its_get_baser(struct its_node *its, u32 type)
        return NULL;
 }
 
-static bool its_alloc_device_table(struct its_node *its, u32 dev_id)
+static bool its_alloc_table_entry(struct its_baser *baser, u32 id)
 {
-       struct its_baser *baser;
        struct page *page;
        u32 esz, idx;
        __le64 *table;
 
-       baser = its_get_baser(its, GITS_BASER_TYPE_DEVICE);
-
-       /* Don't allow device id that exceeds ITS hardware limit */
-       if (!baser)
-               return (ilog2(dev_id) < its->device_ids);
-
        /* Don't allow device id that exceeds single, flat table limit */
        esz = GITS_BASER_ENTRY_SIZE(baser->val);
        if (!(baser->val & GITS_BASER_INDIRECT))
-               return (dev_id < (PAGE_ORDER_TO_SIZE(baser->order) / esz));
+               return (id < (PAGE_ORDER_TO_SIZE(baser->order) / esz));
 
        /* Compute 1st level table index & check if that exceeds table limit */
-       idx = dev_id >> ilog2(baser->psz / esz);
+       idx = id >> ilog2(baser->psz / esz);
        if (idx >= (PAGE_ORDER_TO_SIZE(baser->order) / GITS_LVL1_ENTRY_SIZE))
                return false;
 
@@ -1440,6 +1433,19 @@ static bool its_alloc_device_table(struct its_node *its, u32 dev_id)
        return true;
 }
 
+static bool its_alloc_device_table(struct its_node *its, u32 dev_id)
+{
+       struct its_baser *baser;
+
+       baser = its_get_baser(its, GITS_BASER_TYPE_DEVICE);
+
+       /* Don't allow device id that exceeds ITS hardware limit */
+       if (!baser)
+               return (ilog2(dev_id) < its->device_ids);
+
+       return its_alloc_table_entry(baser, dev_id);
+}
+
 static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
                                            int nvecs)
 {