A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-30 11:41:38 -04:00
Code Issues Projects Releases Packages Wiki Activity

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

Browse source 
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 <[email protected]>
Acked-by: Chen Baozi <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jason Cooper <[email protected]>
This commit is contained in:
Marc Zyngier 2015-03-06 16:37:41 +00:00 • committed by Jason Cooper
commit f54b97ed0b
2 changed files with 23 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

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 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);