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[PATCH v2 05/10] xen/arm: smmuv3: Remove the page 1 fixup

Rahul Singh posted 10 patches 3 years, 5 months ago
There is a newer version of this series
[PATCH v2 05/10] xen/arm: smmuv3: Remove the page 1 fixup
Posted by Rahul Singh 3 years, 5 months ago 
From: Robin Murphy <robin.murphy@arm.com>

Backport Linux commit 86d2d9214880. This is the clean backport without
any changes.

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@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 86d2d9214880
Signed-off-by: Rahul Singh <rahul.singh@arm.com>
---
Changes in v2:
 - fix commit msg.
---
 xen/drivers/passthrough/arm/smmu-v3.c | 42 ++++++++++-----------------
 xen/drivers/passthrough/arm/smmu-v3.h |  8 ++---
 2 files changed, 20 insertions(+), 30 deletions(-)

diff --git a/xen/drivers/passthrough/arm/smmu-v3.c b/xen/drivers/passthrough/arm/smmu-v3.c
index 85ad066266..f5485a8a1c 100644
--- a/xen/drivers/passthrough/arm/smmu-v3.c
+++ b/xen/drivers/passthrough/arm/smmu-v3.c
@@ -235,15 +235,6 @@ 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 struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
 {
 	return container_of(dom, struct arm_smmu_domain, domain);
@@ -1578,6 +1569,7 @@ static int arm_smmu_dt_xlate(struct device *dev,
 /* 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)
@@ -1606,8 +1598,8 @@ 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 + prod_off;
 	q->ent_dwords	= dwords;
 
 	q->q_base  = Q_BASE_RWA;
@@ -1624,16 +1616,16 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
 
 	/* cmdq */
 	spin_lock_init(&smmu->cmdq.lock);
-	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;
 
 	/* 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;
 
@@ -1641,9 +1633,9 @@ 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)
@@ -2087,10 +2079,8 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu)
 
 	/* 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,
@@ -2105,9 +2095,9 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu)
 		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/xen/drivers/passthrough/arm/smmu-v3.h b/xen/drivers/passthrough/arm/smmu-v3.h
index c45d2f16c4..0742bc393f 100644
--- a/xen/drivers/passthrough/arm/smmu-v3.h
+++ b/xen/drivers/passthrough/arm/smmu-v3.h
@@ -130,15 +130,15 @@
 #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
-- 
2.25.1
Re: [PATCH v2 05/10] xen/arm: smmuv3: Remove the page 1 fixup
Posted by Stefano Stabellini 3 years, 5 months ago 
On Fri, 2 Sep 2022, Rahul Singh wrote:
> From: Robin Murphy <robin.murphy@arm.com>
> 
> Backport Linux commit 86d2d9214880. This is the clean backport without
> any changes.
> 
> 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@arm.com>
> Signed-off-by: Will Deacon <will@kernel.org>
> Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 86d2d9214880
> Signed-off-by: Rahul Singh <rahul.singh@arm.com>
> ---
> Changes in v2:
>  - fix commit msg.
> ---
>  xen/drivers/passthrough/arm/smmu-v3.c | 42 ++++++++++-----------------
>  xen/drivers/passthrough/arm/smmu-v3.h |  8 ++---
>  2 files changed, 20 insertions(+), 30 deletions(-)
> 
> diff --git a/xen/drivers/passthrough/arm/smmu-v3.c b/xen/drivers/passthrough/arm/smmu-v3.c
> index 85ad066266..f5485a8a1c 100644
> --- a/xen/drivers/passthrough/arm/smmu-v3.c
> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
> @@ -235,15 +235,6 @@ 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 struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
>  {
>  	return container_of(dom, struct arm_smmu_domain, domain);
> @@ -1578,6 +1569,7 @@ static int arm_smmu_dt_xlate(struct device *dev,
>  /* 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)
> @@ -1606,8 +1598,8 @@ 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 + prod_off;

In the original patch it was:

-	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;

Specifically the second line seems to be wrong here?
Re: [PATCH v2 05/10] xen/arm: smmuv3: Remove the page 1 fixup
Posted by Rahul Singh 3 years, 5 months ago 
Hi Stefano,

> On 3 Sep 2022, at 12:17 am, Stefano Stabellini <sstabellini@kernel.org> wrote:
> 
> On Fri, 2 Sep 2022, Rahul Singh wrote:
>> From: Robin Murphy <robin.murphy@arm.com>
>> 
>> Backport Linux commit 86d2d9214880. This is the clean backport without
>> any changes.
>> 
>> 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@arm.com>
>> Signed-off-by: Will Deacon <will@kernel.org>
>> Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 86d2d9214880
>> Signed-off-by: Rahul Singh <rahul.singh@arm.com>
>> ---
>> Changes in v2:
>> - fix commit msg.
>> ---
>> xen/drivers/passthrough/arm/smmu-v3.c | 42 ++++++++++-----------------
>> xen/drivers/passthrough/arm/smmu-v3.h |  8 ++---
>> 2 files changed, 20 insertions(+), 30 deletions(-)
>> 
>> diff --git a/xen/drivers/passthrough/arm/smmu-v3.c b/xen/drivers/passthrough/arm/smmu-v3.c
>> index 85ad066266..f5485a8a1c 100644
>> --- a/xen/drivers/passthrough/arm/smmu-v3.c
>> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
>> @@ -235,15 +235,6 @@ 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 struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
>> {
>> 	return container_of(dom, struct arm_smmu_domain, domain);
>> @@ -1578,6 +1569,7 @@ static int arm_smmu_dt_xlate(struct device *dev,
>> /* 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)
>> @@ -1606,8 +1598,8 @@ 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 + prod_off;
> 
> In the original patch it was:
> 
> -	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;
> 
> Specifically the second line seems to be wrong here?

Yes you are right I somehow miss that . I will fix that.

Regards.
Rahul

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