[PATCH] iommu/arm-smmu-v3: Remove the page 1 fixup

[Jean-Philippe Brucker]

On Thu, Jan 21, 2021 at 02:09:42PM +0000, Robin Murphy wrote:
> Since we now keep track of page 1 via a separate pointer that already
> encapsulates aliasing to page 0 as necessary, we can remove the clunky
> fixup routine and simply use the relevant bases directly. The current
> architecture spec (IHI0070D.a) defines SMMU_{EVENTQ,PRIQ}_{PROD,CONS} as
> offsets relative to page 1, so the cleanup represents a little bit of
> convergence as well as just lines of code saved.
> 
> Signed-off-by: Robin Murphy <robin.murphy at arm.com>

Reviewed-by: Jean-Philippe Brucker <jean-philippe at linaro.org>

> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 42 ++++++++-------------
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h |  8 ++--
>  2 files changed, 20 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index 5a3492116bbc..15f4eea25148 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -90,15 +90,6 @@ static struct arm_smmu_option_prop arm_smmu_options[] = {
>  	{ 0, NULL},
>  };
>  
> -static inline void __iomem *arm_smmu_page1_fixup(unsigned long offset,
> -						 struct arm_smmu_device *smmu)
> -{
> -	if (offset > SZ_64K)
> -		return smmu->page1 + offset - SZ_64K;
> -
> -	return smmu->base + offset;
> -}
> -
>  static void parse_driver_options(struct arm_smmu_device *smmu)
>  {
>  	int i = 0;
> @@ -2613,6 +2604,7 @@ static struct iommu_ops arm_smmu_ops = {
>  /* Probing and initialisation functions */
>  static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
>  				   struct arm_smmu_queue *q,
> +				   void __iomem *page,
>  				   unsigned long prod_off,
>  				   unsigned long cons_off,
>  				   size_t dwords, const char *name)
> @@ -2641,8 +2633,8 @@ static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
>  			 1 << q->llq.max_n_shift, name);
>  	}
>  
> -	q->prod_reg	= arm_smmu_page1_fixup(prod_off, smmu);
> -	q->cons_reg	= arm_smmu_page1_fixup(cons_off, smmu);
> +	q->prod_reg	= page + prod_off;
> +	q->cons_reg	= page + cons_off;
>  	q->ent_dwords	= dwords;
>  
>  	q->q_base  = Q_BASE_RWA;
> @@ -2686,9 +2678,9 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
>  	int ret;
>  
>  	/* cmdq */
> -	ret = arm_smmu_init_one_queue(smmu, &smmu->cmdq.q, ARM_SMMU_CMDQ_PROD,
> -				      ARM_SMMU_CMDQ_CONS, CMDQ_ENT_DWORDS,
> -				      "cmdq");
> +	ret = arm_smmu_init_one_queue(smmu, &smmu->cmdq.q, smmu->base,
> +				      ARM_SMMU_CMDQ_PROD, ARM_SMMU_CMDQ_CONS,
> +				      CMDQ_ENT_DWORDS, "cmdq");
>  	if (ret)
>  		return ret;
>  
> @@ -2697,9 +2689,9 @@ 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,
> -				      "evtq");
> +	ret = arm_smmu_init_one_queue(smmu, &smmu->evtq.q, smmu->page1,
> +				      ARM_SMMU_EVTQ_PROD, ARM_SMMU_EVTQ_CONS,
> +				      EVTQ_ENT_DWORDS, "evtq");
>  	if (ret)
>  		return ret;
>  
> @@ -2707,9 +2699,9 @@ 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,
> -				       "priq");
> +	return arm_smmu_init_one_queue(smmu, &smmu->priq.q, smmu->page1,
> +				       ARM_SMMU_PRIQ_PROD, ARM_SMMU_PRIQ_CONS,
> +				       PRIQ_ENT_DWORDS, "priq");
>  }
>  
>  static int arm_smmu_init_l1_strtab(struct arm_smmu_device *smmu)
> @@ -3119,10 +3111,8 @@ 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.llq.prod,
> -		       arm_smmu_page1_fixup(ARM_SMMU_EVTQ_PROD, smmu));
> -	writel_relaxed(smmu->evtq.q.llq.cons,
> -		       arm_smmu_page1_fixup(ARM_SMMU_EVTQ_CONS, smmu));
> +	writel_relaxed(smmu->evtq.q.llq.prod, smmu->page1 + ARM_SMMU_EVTQ_PROD);
> +	writel_relaxed(smmu->evtq.q.llq.cons, smmu->page1 + ARM_SMMU_EVTQ_CONS);
>  
>  	enables |= CR0_EVTQEN;
>  	ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0,
> @@ -3137,9 +3127,9 @@ 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.llq.prod,
> -			       arm_smmu_page1_fixup(ARM_SMMU_PRIQ_PROD, smmu));
> +			       smmu->page1 + ARM_SMMU_PRIQ_PROD);
>  		writel_relaxed(smmu->priq.q.llq.cons,
> -			       arm_smmu_page1_fixup(ARM_SMMU_PRIQ_CONS, smmu));
> +			       smmu->page1 + ARM_SMMU_PRIQ_CONS);
>  
>  		enables |= CR0_PRIQEN;
>  		ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0,
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> index e094cd92df2d..63f1c114c810 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> @@ -139,15 +139,15 @@
>  #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		0xa8
> +#define ARM_SMMU_EVTQ_CONS		0xac
>  #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		0xc8
> +#define ARM_SMMU_PRIQ_CONS		0xcc
>  #define ARM_SMMU_PRIQ_IRQ_CFG0		0xd0
>  #define ARM_SMMU_PRIQ_IRQ_CFG1		0xd8
>  #define ARM_SMMU_PRIQ_IRQ_CFG2		0xdc
> -- 
> 2.17.1
>