* ARM: Question about irq-gic-v3-its.c
@ 2015-11-27 2:31 majun (F)
0 siblings, 0 replies; only message in thread
From: majun (F) @ 2015-11-27 2:31 UTC (permalink / raw)
To: linux-arm-kernel
Hi Marc:
I think there is a bug in current its_alloc_tables().
When "val |= alloc_pages - 1;" is called
the "alloc_pages" is not updated accroding to "psz" value.
I mean we need do
alloc_pages = (alloc_size / psz);
Further more, I also have a question about GITS_CBASER register.
In gic-v3 spec:
Bits [7:0]. Size. The number of '4kB' pages of physical memory provided for the command queue, minus
one.
But In its_alloc_tables() function,
alloc_pages = (alloc_size / psz); // majun: pze = 64KB
if (alloc_pages > GITS_BASER_PAGES_MAX) {
alloc_pages = GITS_BASER_PAGES_MAX;
order = get_order(GITS_BASER_PAGES_MAX * psz);
pr_warn("ITS at 0x%lx: Device Table too large, reduce its page order to %u (%u pages)\n",
its->phys_base, order, alloc_pages);
}
GITS_BASER_PAGES_MAX = 256
I think this value means the maximum page number of 4KB ,right ?
But when calc alloc_pages for first time, the psz = 64KB.
So, I think maybe this is a bug too.
Thanks!
Ma Jun
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2015-11-27 2:31 ARM: Question about irq-gic-v3-its.c majun (F)
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