From: Easwar Hariharan <eahariha@linux.microsoft.com>
To: stable@vger.kernel.org
Cc: Robin Murphy <robin.murphy@arm.com>, Will Deacon <will@kernel.org>
Subject: [PATCH 6.1 1/2] iommu/arm-smmu-v3: Set TTL invalidation hint better
Date: Thu, 5 Oct 2023 19:35:01 +0000 [thread overview]
Message-ID: <20231005193502.657149-2-eahariha@linux.microsoft.com> (raw)
In-Reply-To: <20231005193502.657149-1-eahariha@linux.microsoft.com>
From: Robin Murphy <robin.murphy@arm.com>
commit 6833b8f2e19945a41e4d5efd8c6d9f4cae9a5b7d upstream
When io-pgtable unmaps a whole table, rather than waste time walking it
to find the leaf entries to invalidate exactly, it simply expects
.tlb_flush_walk with nominal last-level granularity to invalidate any
leaf entries at higher intermediate levels as well. This works fine with
page-based invalidation, but with range commands we need to be careful
with the TTL hint - unconditionally setting it based on the given level
3 granule means that an invalidation for a level 1 table would strictly
not be required to affect level 2 block entries. It's easy to comply
with the expected behaviour by simply not setting the TTL hint for
non-leaf invalidations, so let's do that.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/b409d9a17c52dc0db51faee91d92737bb7975f5b.1685637456.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Easwar Hariharan <eahariha@linux.microsoft.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index db33dc87f69e..becf37c08877 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1889,8 +1889,13 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd,
/* Convert page size of 12,14,16 (log2) to 1,2,3 */
cmd->tlbi.tg = (tg - 10) / 2;
- /* Determine what level the granule is at */
- cmd->tlbi.ttl = 4 - ((ilog2(granule) - 3) / (tg - 3));
+ /*
+ * Determine what level the granule is at. For non-leaf, io-pgtable
+ * assumes .tlb_flush_walk can invalidate multiple levels at once,
+ * so ignore the nominal last-level granule and leave TTL=0.
+ */
+ if (cmd->tlbi.leaf)
+ cmd->tlbi.ttl = 4 - ((ilog2(granule) - 3) / (tg - 3));
num_pages = size >> tg;
}
--
2.34.1
next prev parent reply other threads:[~2023-10-05 19:35 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-05 19:35 [PATCH 6.1 0/2] ARM SMMUv3 errata fixes Easwar Hariharan
2023-10-05 19:35 ` Easwar Hariharan [this message]
2023-10-05 19:35 ` [PATCH 6.1 2/2] iommu/arm-smmu-v3: Avoid constructing invalid range commands Easwar Hariharan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231005193502.657149-2-eahariha@linux.microsoft.com \
--to=eahariha@linux.microsoft.com \
--cc=robin.murphy@arm.com \
--cc=stable@vger.kernel.org \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox