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

Robin Murphy
2017-04-11T15:42:06Z

On 11/04/17 15:42, linucherian at gmail.com wrote:
> 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.

Ugh :(

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

I think it might be neater to have something like:

arm_smmu_page1(smmu) {
if (smmu->quirk)
return smmu->base;
return smmu->base + 64k;
}

and use it as the base in the appropriate places, rather than override
the individual registers. Much like ARM_SMMU_GR0_NS in the SMMUv2 driver.

Robin.

>
> 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,
>