[RFC PATCH 1/7] iommu/arm-smmu-v3: Introduce smmu option PAGE0_REGS_ONLY for Silicon errata.

linucherian at gmail.com
2017-04-11T14:42:39Z

From: Linu Cherian <linu.cherian@cavium.com>

Cavium 99xx SMMU implementation doesn't support page 1 register space
and PAGE0_REGS_ONLY option will be enabled as an errata workaround.

This option when turned on, replaces all page 1 offsets used for
EVTQ_PROD/CONS, PRIQ_PROD/CONS register access with page 0 offsets.

Signed-off-by: Linu Cherian <linu.cherian@cavium.com>
---
drivers/iommu/arm-smmu-v3.c | 44 ++++++++++++++++++++++++++++++++------------
1 file changed, 32 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 05b4592..df9f27b 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -176,15 +176,15 @@
#define ARM_SMMU_CMDQ_CONS 0x9c

#define ARM_SMMU_EVTQ_BASE 0xa0
-#define ARM_SMMU_EVTQ_PROD 0x100a8
-#define ARM_SMMU_EVTQ_CONS 0x100ac
+#define ARM_SMMU_EVTQ_PROD(s) (page1_offset_adjust(0x100a8, s))
+#define ARM_SMMU_EVTQ_CONS(s) (page1_offset_adjust(0x100ac, s))
#define ARM_SMMU_EVTQ_IRQ_CFG0 0xb0
#define ARM_SMMU_EVTQ_IRQ_CFG1 0xb8
#define ARM_SMMU_EVTQ_IRQ_CFG2 0xbc

#define ARM_SMMU_PRIQ_BASE 0xc0
-#define ARM_SMMU_PRIQ_PROD 0x100c8
-#define ARM_SMMU_PRIQ_CONS 0x100cc
+#define ARM_SMMU_PRIQ_PROD(s) (page1_offset_adjust(0x100c8, s))
+#define ARM_SMMU_PRIQ_CONS(s) (page1_offset_adjust(0x100cc, s))
#define ARM_SMMU_PRIQ_IRQ_CFG0 0xd0
#define ARM_SMMU_PRIQ_IRQ_CFG1 0xd8
#define ARM_SMMU_PRIQ_IRQ_CFG2 0xdc
@@ -412,6 +412,9 @@
#define MSI_IOVA_BASE 0x8000000
#define MSI_IOVA_LENGTH 0x100000

+#define ARM_SMMU_PAGE0_REGS_ONLY(s) \
+ ((s)->options & ARM_SMMU_OPT_PAGE0_REGS_ONLY)
+
static bool disable_bypass;
module_param_named(disable_bypass, disable_bypass, bool, S_IRUGO);
MODULE_PARM_DESC(disable_bypass,
@@ -597,6 +600,7 @@ struct arm_smmu_device {
u32 features;

#define ARM_SMMU_OPT_SKIP_PREFETCH (1 << 0)
+#define ARM_SMMU_OPT_PAGE0_REGS_ONLY (1 << 1)
u32 options;

struct arm_smmu_cmdq cmdq;
@@ -663,9 +667,19 @@ struct arm_smmu_option_prop {

static struct arm_smmu_option_prop arm_smmu_options[] = {
{ ARM_SMMU_OPT_SKIP_PREFETCH, "hisilicon,broken-prefetch-cmd" },
+ { ARM_SMMU_OPT_PAGE0_REGS_ONLY, "cavium-cn99xx,broken-page1-regspace"},
{ 0, NULL},
};

+static inline unsigned long page1_offset_adjust(
+ unsigned long off, struct arm_smmu_device *smmu)
+{
+ if (!ARM_SMMU_PAGE0_REGS_ONLY(smmu))
+ return off;
+ else
+ return (off - SZ_64K);
+}
+
static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
{
return container_of(dom, struct arm_smmu_domain, domain);
@@ -1983,8 +1997,10 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
return ret;

/* evtq */
- ret = arm_smmu_init_one_queue(smmu, &smmu->evtq.q, ARM_SMMU_EVTQ_PROD,
- ARM_SMMU_EVTQ_CONS, EVTQ_ENT_DWORDS);
+ ret = arm_smmu_init_one_queue(smmu, &smmu->evtq.q,
+ ARM_SMMU_EVTQ_PROD(smmu),
+ ARM_SMMU_EVTQ_CONS(smmu),
+ EVTQ_ENT_DWORDS);
if (ret)
return ret;

@@ -1992,8 +2008,10 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
if (!(smmu->features & ARM_SMMU_FEAT_PRI))
return 0;

- return arm_smmu_init_one_queue(smmu, &smmu->priq.q, ARM_SMMU_PRIQ_PROD,
- ARM_SMMU_PRIQ_CONS, PRIQ_ENT_DWORDS);
+ return arm_smmu_init_one_queue(smmu, &smmu->priq.q,
+ ARM_SMMU_PRIQ_PROD(smmu),
+ ARM_SMMU_PRIQ_CONS(smmu),
+ PRIQ_ENT_DWORDS);
}

static int arm_smmu_init_l1_strtab(struct arm_smmu_device *smmu)
@@ -2360,8 +2378,10 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)

/* Event queue */
writeq_relaxed(smmu->evtq.q.q_base, smmu->base + ARM_SMMU_EVTQ_BASE);
- writel_relaxed(smmu->evtq.q.prod, smmu->base + ARM_SMMU_EVTQ_PROD);
- writel_relaxed(smmu->evtq.q.cons, smmu->base + ARM_SMMU_EVTQ_CONS);
+ writel_relaxed(smmu->evtq.q.prod, smmu->base +
+ ARM_SMMU_EVTQ_PROD(smmu));
+ writel_relaxed(smmu->evtq.q.cons, smmu->base +
+ ARM_SMMU_EVTQ_CONS(smmu));

enables |= CR0_EVTQEN;
ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0,
@@ -2376,9 +2396,9 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
writeq_relaxed(smmu->priq.q.q_base,
smmu->base + ARM_SMMU_PRIQ_BASE);
writel_relaxed(smmu->priq.q.prod,
- smmu->base + ARM_SMMU_PRIQ_PROD);
+ smmu->base + ARM_SMMU_PRIQ_PROD(smmu));
writel_relaxed(smmu->priq.q.cons,
- smmu->base + ARM_SMMU_PRIQ_CONS);
+ smmu->base + ARM_SMMU_PRIQ_CONS(smmu));

enables |= CR0_PRIQEN;
ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0,
--
1.9.1