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authorMarc Zyngier <marc.zyngier@arm.com>2015-03-06 16:37:41 +0000
committerJason Cooper <jason@lakedaemon.net>2015-03-08 05:32:52 +0000
commitf54b97ed0b17d3da5f98ba8188cd5646415a922d (patch)
tree4664ec806519ff6d594d547d8b31be5bc774fc0a
parent16acae729564ee0c3918342d8556cc42eeb29942 (diff)
irqchip: gicv3-its: Allocate enough memory for the full range of DeviceID
The ITS table allocator is only allocating a single page per table. This works fine for most things, but leads to silent lack of interrupt delivery if we end-up with a device that has an ID that is out of the range defined by a single page of memory. Even worse, depending on the page size, behaviour changes, which is not a very good experience. A solution is actually to allocate memory for the full range of ID that the ITS supports. A massive waste memory wise, but at least a safe bet. Tested on a Phytium SoC. Tested-by: Chen Baozi <chenbaozi@kylinos.com.cn> Acked-by: Chen Baozi <chenbaozi@kylinos.com.cn> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Link: https://lkml.kernel.org/r/1425659870-11832-3-git-send-email-marc.zyngier@arm.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
-rw-r--r--drivers/irqchip/irq-gic-v3-its.c25
-rw-r--r--include/linux/irqchip/arm-gic-v3.h2
2 files changed, 23 insertions, 4 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index c217ebcf7a48..733b32fda390 100644
--- 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);
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 800544bc7bfd..cbdd440d486d 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -166,6 +166,8 @@
#define GITS_TRANSLATER 0x10040
+#define GITS_TYPER_DEVBITS_SHIFT 13
+#define GITS_TYPER_DEVBITS(r) ((((r) >> GITS_TYPER_DEVBITS_SHIFT) & 0x1f) + 1)
#define GITS_TYPER_PTA (1UL << 19)
#define GITS_CBASER_VALID (1UL << 63)