linux-kernel - [PATCHv5 7/9] iommu/tegra: smmu: allow duplicate ASID wirte

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1384853593-32202-8-git-send-email-hdoyu@nvidia.com>
Date:	Tue, 19 Nov 2013 11:33:11 +0200
From:	Hiroshi Doyu <hdoyu@...dia.com>
To:	<swarren@...dia.com>, <will.deacon@....com>,
	<grant.likely@...aro.org>, <thierry.reding@...il.com>,
	<swarren@...dotorg.org>, <galak@...eaurora.org>
CC:	Hiroshi Doyu <hdoyu@...dia.com>, <mark.rutland@....com>,
	<devicetree@...r.kernel.org>, <iommu@...ts.linux-foundation.org>,
	<linux-tegra@...r.kernel.org>,
	<linux-arm-kernel@...ts.infradead.org>,
	<lorenzo.pieralisi@....com>, <linux-kernel@...r.kernel.org>
Subject: [PATCHv5 7/9] iommu/tegra: smmu: allow duplicate ASID wirte

The device, which belongs to the same ASID, can try to enable the same
ASID as the other swgroup devices. This should be allowed but just
skip the actual register write. If the write value is different, it
will return -EINVAL.

Signed-off-by: Hiroshi Doyu <hdoyu@...dia.com>
---
v4:
This was the part of v3, which isn't used any more.
  [PATCHv3 10/19] iommu/tegra: smmu: Get "nvidia,swgroups" from DT
---
 drivers/iommu/tegra-smmu.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index e915201a..c2ed075 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -418,9 +418,13 @@ static int __smmu_client_set_hwgrp(struct smmu_client *c,
 		offs = HWGRP_ASID_REG(i);
 		val = smmu_read(smmu, offs);
 		if (on) {
-			if (WARN_ON(val & mask))
-				goto err_hw_busy;
-			val |= mask;
+			if (val) {
+				if (WARN_ON(val != mask))
+					return -EINVAL;
+				goto skip;
+			}
+
+			val = mask;
 			memcpy(c->hwgrp, map, sizeof(u64));
 		} else {
 			WARN_ON((val & mask) == mask);
@@ -430,16 +434,8 @@ static int __smmu_client_set_hwgrp(struct smmu_client *c,
 	}
 
 	FLUSH_SMMU_REGS(smmu);
+skip:
 	return 0;
-
-err_hw_busy:
-	for_each_set_bit(i, map, TEGRA_SWGROUP_MAX) {
-		offs = HWGRP_ASID_REG(i);
-		val = smmu_read(smmu, offs);
-		val &= ~mask;
-		smmu_write(smmu, val, offs);
-	}
-	return -EBUSY;
 }
 
 static int smmu_client_set_hwgrp(struct smmu_client *c,
-- 
1.8.1.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/