[PATCHv6 10/13] iommu/tegra: smmu: allow duplicate ASID wirte
From: Hiroshi Doyu <hidden>
Date: 2013-11-21 13:41:50
Also in:
linux-devicetree, linux-iommu, linux-tegra, lkml
Subsystem:
iommu subsystem, tegra iommu drivers, the rest · Maintainers:
Joerg Roedel, Will Deacon, Thierry Reding, Linus Torvalds
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 <redacted> --- 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 1a1bcdf..76356db 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,
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1.8.1.5