From: majun258@huawei.com (majun (F))
To: linux-arm-kernel@lists.infradead.org
Subject: ARM: Question about irq-gic-v3-its.c
Date: Fri, 27 Nov 2015 10:31:20 +0800 [thread overview]
Message-ID: <5657C078.3020806@huawei.com> (raw)
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
reply other threads:[~2015-11-27 2:31 UTC|newest]
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