irqchip: gicv3-its: Allocate enough memory for the full range of DeviceID

[firefly-linux-kernel-4.4.55.git] / drivers / irqchip / irq-gic-v3-its.c

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index d8996bdf0f61e95e45ee670e44e565d045fb9535..733b32fda3903ffa93199fcc88af52b2c8622779 100644 (file)
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -806,14 +806,31 @@ static int its_alloc_tables(struct its_node *its)
                u64 val = readq_relaxed(its->base + GITS_BASER + i * 8);
                u64 type = GITS_BASER_TYPE(val);
                u64 entry_size = GITS_BASER_ENTRY_SIZE(val);
+               int order = 0;
+               int alloc_size;
                u64 tmp;
                void *base;
 
                if (type == GITS_BASER_TYPE_NONE)
                        continue;
 
-               /* We're lazy and only allocate a single page for now */
-               base = (void *)get_zeroed_page(GFP_KERNEL);
+               /*
+                * Allocate as many entries as required to fit the
+                * range of device IDs that the ITS can grok... The ID
+                * space being incredibly sparse, this results in a
+                * massive waste of memory.
+                *
+                * For other tables, only allocate a single page.
+                */
+               if (type == GITS_BASER_TYPE_DEVICE) {
+                       u64 typer = readq_relaxed(its->base + GITS_TYPER);
+                       u32 ids = GITS_TYPER_DEVBITS(typer);
+
+                       order = get_order((1UL << ids) * entry_size);
+               }
+
+               alloc_size = (1 << order) * PAGE_SIZE;
+               base = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
                if (!base) {
                        err = -ENOMEM;
                        goto out_free;
@@ -841,7 +858,7 @@ retry_baser:
                        break;
                }
 
-               val |= (PAGE_SIZE / psz) - 1;
+               val |= (alloc_size / psz) - 1;
 
                writeq_relaxed(val, its->base + GITS_BASER + i * 8);
                tmp = readq_relaxed(its->base + GITS_BASER + i * 8);
@@ -882,7 +899,7 @@ retry_baser:
                }
 
                pr_info("ITS: allocated %d %s @%lx (psz %dK, shr %d)\n",
-                       (int)(PAGE_SIZE / entry_size),
+                       (int)(alloc_size / entry_size),
                        its_base_type_string[type],
                        (unsigned long)virt_to_phys(base),
                        psz / SZ_1K, (int)shr >> GITS_BASER_SHAREABILITY_SHIFT);
@@ -1382,12 +1399,11 @@ static bool gic_rdists_supports_plpis(void)
 
 int its_cpu_init(void)
 {
-       if (!gic_rdists_supports_plpis()) {
-               pr_info("CPU%d: LPIs not supported\n", smp_processor_id());
-               return -ENXIO;
-       }
-
        if (!list_empty(&its_nodes)) {
+               if (!gic_rdists_supports_plpis()) {
+                       pr_info("CPU%d: LPIs not supported\n", smp_processor_id());
+                       return -ENXIO;
+               }
                its_cpu_init_lpis();
                its_cpu_init_collection();
        }