lkml.org 
[lkml]   [2017]   [Aug]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH 6/6] iommu/arm-smmu-v3: Avoid ILLEGAL setting of STE.S1STALLD and CD.S
Date
It is ILLEGAL to set STE.S1STALLD if STALL_MODEL is not 0b00, which
means we should not disable stall mode if stall/terminate mode is not
configuable.

Meanwhile, it is also ILLEGAL when STALL_MODEL==0b10 && CD.S==0 which
means if stall mode is force we should always set CD.S.

This patch add ARM_SMMU_FEAT_TERMINATE feature bit for smmu, and use
TERMINATE feature checking to ensue above ILLEGAL cases from happening.

Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
---
drivers/iommu/arm-smmu-v3.c | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index dbda2eb..0745522 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -55,6 +55,7 @@
#define IDR0_STALL_MODEL_SHIFT 24
#define IDR0_STALL_MODEL_MASK 0x3
#define IDR0_STALL_MODEL_STALL (0 << IDR0_STALL_MODEL_SHIFT)
+#define IDR0_STALL_MODEL_NS (1 << IDR0_STALL_MODEL_SHIFT)
#define IDR0_STALL_MODEL_FORCE (2 << IDR0_STALL_MODEL_SHIFT)
#define IDR0_TTENDIAN_SHIFT 21
#define IDR0_TTENDIAN_MASK 0x3
@@ -766,6 +767,7 @@ struct arm_smmu_device {
#define ARM_SMMU_FEAT_SVM (1 << 15)
#define ARM_SMMU_FEAT_HA (1 << 16)
#define ARM_SMMU_FEAT_HD (1 << 17)
+#define ARM_SMMU_FEAT_TERMINATE (1 << 18)
u32 features;

#define ARM_SMMU_OPT_SKIP_PREFETCH (1 << 0)
@@ -1402,6 +1404,7 @@ static void arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain,
u64 val;
bool cd_live;
__u64 *cdptr = arm_smmu_get_cd_ptr(smmu_domain, ssid);
+ struct arm_smmu_device *smmu = smmu_domain->smmu;

/*
* This function handles the following cases:
@@ -1468,9 +1471,11 @@ static void arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain,
CTXDESC_CD_0_V;

/*
- * FIXME: STALL_MODEL==0b10 && CD.S==0 is ILLEGAL
+ * STALL_MODEL==0b10 && CD.S==0 is ILLEGAL
*/
- if (ssid && smmu_domain->s1_cfg.can_stall)
+ if ((ssid && smmu_domain->s1_cfg.can_stall) ||
+ (!(smmu->features & ARM_SMMU_FEAT_TERMINATE) &&
+ smmu->features & ARM_SMMU_FEAT_STALLS))
val |= CTXDESC_CD_0_S;

cdptr[0] = cpu_to_le64(val);
@@ -1690,12 +1695,13 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid,
dst[1] |= STRTAB_STE_1_PPAR;

/*
- * FIXME: it is illegal to set S1STALLD if STALL_MODEL=0b10
- * (force). But according to the spec, it *must* be set for
+ * According to spec, it is illegal to set S1STALLD if
+ * STALL_MODEL is not 0b00. And it *must* be set for
* devices that aren't capable of stalling (notably pci!)
- * So we need a "STALL_MODEL=0b00" feature bit.
*/
- if (smmu->features & ARM_SMMU_FEAT_STALLS && !ste->can_stall)
+ if (smmu->features & ARM_SMMU_FEAT_STALLS &&
+ smmu->features & ARM_SMMU_FEAT_TERMINATE &&
+ !ste->can_stall)
dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD);

val |= (s1ctxptr & STRTAB_STE_0_S1CTXPTR_MASK
@@ -4577,9 +4583,13 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)

switch (reg & IDR0_STALL_MODEL_MASK << IDR0_STALL_MODEL_SHIFT) {
case IDR0_STALL_MODEL_STALL:
+ smmu->features |= ARM_SMMU_FEAT_TERMINATE;
/* Fallthrough */
case IDR0_STALL_MODEL_FORCE:
smmu->features |= ARM_SMMU_FEAT_STALLS;
+ break;
+ case IDR0_STALL_MODEL_NS:
+ smmu->features |= ARM_SMMU_FEAT_TERMINATE;
}

if (reg & IDR0_S1P)
--
1.7.12.4
\
 
 \ /
  Last update: 2017-08-31 10:30    [W:0.139 / U:2.340 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site