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

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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>
This commit is contained in:
Marc Zyngier 2015-03-06 16:37:41 +00:00 committed by Jason Cooper
parent 16acae7295
commit f54b97ed0b
2 changed files with 23 additions and 4 deletions
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25
drivers/irqchip/irq-gic-v3-its.c
View File

@ -806,14 +806,31 @@ static int its_alloc_tables(struct its_node *its)
u64 val = readq_relaxed(its->base + GITS_BASER + i * 8); u64 val = readq_relaxed(its->base + GITS_BASER + i * 8);
u64 type = GITS_BASER_TYPE(val); u64 type = GITS_BASER_TYPE(val);
u64 entry_size = GITS_BASER_ENTRY_SIZE(val); u64 entry_size = GITS_BASER_ENTRY_SIZE(val);
int order = 0;
int alloc_size;
u64 tmp; u64 tmp;
void *base; void *base;
if (type == GITS_BASER_TYPE_NONE) if (type == GITS_BASER_TYPE_NONE)
continue; 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) { if (!base) {
err = -ENOMEM; err = -ENOMEM;
goto out_free; goto out_free;
@ -841,7 +858,7 @@ retry_baser:
break; break;
} }
val |= (PAGE_SIZE / psz) - 1; val |= (alloc_size / psz) - 1;
writeq_relaxed(val, its->base + GITS_BASER + i * 8); writeq_relaxed(val, its->base + GITS_BASER + i * 8);
tmp = readq_relaxed(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", 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], its_base_type_string[type],
(unsigned long)virt_to_phys(base), (unsigned long)virt_to_phys(base),
psz / SZ_1K, (int)shr >> GITS_BASER_SHAREABILITY_SHIFT); psz / SZ_1K, (int)shr >> GITS_BASER_SHAREABILITY_SHIFT);

2
include/linux/irqchip/arm-gic-v3.h
View File

@ -166,6 +166,8 @@
#define GITS_TRANSLATER 0x10040 #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_TYPER_PTA (1UL << 19)
#define GITS_CBASER_VALID (1UL << 63) #define GITS_CBASER_VALID (1UL << 63)