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| author | Marc Zyngier <marc.zyngier@arm.com> | 2015-03-06 16:37:41 +0000 |
|---|---|---|
| committer | Jason Cooper <jason@lakedaemon.net> | 2015-03-08 05:32:52 +0000 |
| commit | f54b97ed0b17d3da5f98ba8188cd5646415a922d (patch) | |
| tree | 4664ec806519ff6d594d547d8b31be5bc774fc0a /drivers/irqchip | |
| parent | 16acae729564ee0c3918342d8556cc42eeb29942 (diff) | |
| download | linux-f54b97ed0b17d3da5f98ba8188cd5646415a922d.tar.bz2 | |
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>
Diffstat (limited to 'drivers/irqchip')
| -rw-r--r-- | drivers/irqchip/irq-gic-v3-its.c | 25 |
1 files changed, 21 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); |