diff mbox series

[2/4] iommu/exynos: Check if SysMMU v7 has VM registers

Message ID 20220702213724.3949-3-semen.protsenko@linaro.org
State New
Headers show
Series iommu/exynos: Add basic support for SysMMU v7 | expand

Commit Message

Sam Protsenko July 2, 2022, 9:37 p.m. UTC
SysMMU v7 can have Virtual Machine registers, which implement multiple
translation domains. The driver should know if it's true or not, as VM
registers shouldn't be accessed if not present. Read corresponding
capabilities register to obtain that info, and store it in driver data.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
---
 drivers/iommu/exynos-iommu.c | 42 ++++++++++++++++++++++++++++++------
 1 file changed, 36 insertions(+), 6 deletions(-)

Comments

Krzysztof Kozlowski July 3, 2022, 7:10 p.m. UTC | #1
On 02/07/2022 23:37, Sam Protsenko wrote:
> SysMMU v7 can have Virtual Machine registers, which implement multiple
> translation domains. The driver should know if it's true or not, as VM
> registers shouldn't be accessed if not present. Read corresponding
> capabilities register to obtain that info, and store it in driver data.
> 
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> ---
>  drivers/iommu/exynos-iommu.c | 42 ++++++++++++++++++++++++++++++------
>  1 file changed, 36 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> index 28f8c8d93aa3..df6ddbebbe2b 100644
> --- a/drivers/iommu/exynos-iommu.c
> +++ b/drivers/iommu/exynos-iommu.c
> @@ -135,6 +135,9 @@ static u32 lv2ent_offset(sysmmu_iova_t iova)
>  #define CFG_SYSSEL	(1 << 22) /* System MMU 3.2 only */
>  #define CFG_FLPDCACHE	(1 << 20) /* System MMU 3.2+ only */
>  
> +#define CAPA0_CAPA1_EXIST		BIT(11)
> +#define CAPA1_VCR_ENABLED		BIT(14)
> +
>  /* common registers */
>  #define REG_MMU_CTRL		0x000
>  #define REG_MMU_CFG		0x004
> @@ -171,6 +174,10 @@ static u32 lv2ent_offset(sysmmu_iova_t iova)
>  #define REG_V5_FAULT_AR_VA	0x070
>  #define REG_V5_FAULT_AW_VA	0x080
>  
> +/* v7.x registers */
> +#define REG_V7_CAPA0		0x870
> +#define REG_V7_CAPA1		0x874
> +
>  #define has_sysmmu(dev)		(dev_iommu_priv_get(dev) != NULL)
>  
>  static struct device *dma_dev;
> @@ -274,6 +281,9 @@ struct sysmmu_drvdata {
>  	unsigned int version;		/* our version */
>  
>  	struct iommu_device iommu;	/* IOMMU core handle */
> +
> +	/* v7 fields */
> +	bool has_vcr;			/* virtual machine control register */
>  };
>  
>  static struct exynos_iommu_domain *to_exynos_domain(struct iommu_domain *dom)
> @@ -364,11 +374,7 @@ static void __sysmmu_disable_clocks(struct sysmmu_drvdata *data)
>  
>  static void __sysmmu_get_version(struct sysmmu_drvdata *data)
>  {
> -	u32 ver;
> -
> -	__sysmmu_enable_clocks(data);
> -
> -	ver = readl(data->sfrbase + REG_MMU_VERSION);
> +	const u32 ver = readl(data->sfrbase + REG_MMU_VERSION);


No need for const for local, non-pointer variables. There is no benefit
in preventing the modification and it is not a constant.

>  
>  	/* controllers on some SoCs don't report proper version */
>  	if (ver == 0x80000001u)
> @@ -378,6 +384,29 @@ static void __sysmmu_get_version(struct sysmmu_drvdata *data)
>  
>  	dev_dbg(data->sysmmu, "hardware version: %d.%d\n",
>  		MMU_MAJ_VER(data->version), MMU_MIN_VER(data->version));
> +}
> +
> +static bool __sysmmu_has_capa1(struct sysmmu_drvdata *data)
> +{
> +	const u32 capa0 = readl(data->sfrbase + REG_V7_CAPA0);

Same here and further.


Best regards,
Krzysztof
Sam Protsenko July 8, 2022, 1:34 p.m. UTC | #2
On Sun, 3 Jul 2022 at 22:10, Krzysztof Kozlowski
<krzysztof.kozlowski@linaro.org> wrote:
>
> On 02/07/2022 23:37, Sam Protsenko wrote:
> > SysMMU v7 can have Virtual Machine registers, which implement multiple
> > translation domains. The driver should know if it's true or not, as VM
> > registers shouldn't be accessed if not present. Read corresponding
> > capabilities register to obtain that info, and store it in driver data.
> >
> > Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> > ---
> >  drivers/iommu/exynos-iommu.c | 42 ++++++++++++++++++++++++++++++------
> >  1 file changed, 36 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> > index 28f8c8d93aa3..df6ddbebbe2b 100644
> > --- a/drivers/iommu/exynos-iommu.c
> > +++ b/drivers/iommu/exynos-iommu.c
> > @@ -135,6 +135,9 @@ static u32 lv2ent_offset(sysmmu_iova_t iova)
> >  #define CFG_SYSSEL   (1 << 22) /* System MMU 3.2 only */
> >  #define CFG_FLPDCACHE        (1 << 20) /* System MMU 3.2+ only */
> >
> > +#define CAPA0_CAPA1_EXIST            BIT(11)
> > +#define CAPA1_VCR_ENABLED            BIT(14)
> > +
> >  /* common registers */
> >  #define REG_MMU_CTRL         0x000
> >  #define REG_MMU_CFG          0x004
> > @@ -171,6 +174,10 @@ static u32 lv2ent_offset(sysmmu_iova_t iova)
> >  #define REG_V5_FAULT_AR_VA   0x070
> >  #define REG_V5_FAULT_AW_VA   0x080
> >
> > +/* v7.x registers */
> > +#define REG_V7_CAPA0         0x870
> > +#define REG_V7_CAPA1         0x874
> > +
> >  #define has_sysmmu(dev)              (dev_iommu_priv_get(dev) != NULL)
> >
> >  static struct device *dma_dev;
> > @@ -274,6 +281,9 @@ struct sysmmu_drvdata {
> >       unsigned int version;           /* our version */
> >
> >       struct iommu_device iommu;      /* IOMMU core handle */
> > +
> > +     /* v7 fields */
> > +     bool has_vcr;                   /* virtual machine control register */
> >  };
> >
> >  static struct exynos_iommu_domain *to_exynos_domain(struct iommu_domain *dom)
> > @@ -364,11 +374,7 @@ static void __sysmmu_disable_clocks(struct sysmmu_drvdata *data)
> >
> >  static void __sysmmu_get_version(struct sysmmu_drvdata *data)
> >  {
> > -     u32 ver;
> > -
> > -     __sysmmu_enable_clocks(data);
> > -
> > -     ver = readl(data->sfrbase + REG_MMU_VERSION);
> > +     const u32 ver = readl(data->sfrbase + REG_MMU_VERSION);
>
>
> No need for const for local, non-pointer variables. There is no benefit
> in preventing the modification and it is not a constant.
>

I'd say it's more a matter of taste, having "const" kinda disciplines
one. But I don't mind removing those bits, will do in v2.

> >
> >       /* controllers on some SoCs don't report proper version */
> >       if (ver == 0x80000001u)
> > @@ -378,6 +384,29 @@ static void __sysmmu_get_version(struct sysmmu_drvdata *data)
> >
> >       dev_dbg(data->sysmmu, "hardware version: %d.%d\n",
> >               MMU_MAJ_VER(data->version), MMU_MIN_VER(data->version));
> > +}
> > +
> > +static bool __sysmmu_has_capa1(struct sysmmu_drvdata *data)
> > +{
> > +     const u32 capa0 = readl(data->sfrbase + REG_V7_CAPA0);
>
> Same here and further.
>
>
> Best regards,
> Krzysztof
diff mbox series

Patch

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 28f8c8d93aa3..df6ddbebbe2b 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -135,6 +135,9 @@  static u32 lv2ent_offset(sysmmu_iova_t iova)
 #define CFG_SYSSEL	(1 << 22) /* System MMU 3.2 only */
 #define CFG_FLPDCACHE	(1 << 20) /* System MMU 3.2+ only */
 
+#define CAPA0_CAPA1_EXIST		BIT(11)
+#define CAPA1_VCR_ENABLED		BIT(14)
+
 /* common registers */
 #define REG_MMU_CTRL		0x000
 #define REG_MMU_CFG		0x004
@@ -171,6 +174,10 @@  static u32 lv2ent_offset(sysmmu_iova_t iova)
 #define REG_V5_FAULT_AR_VA	0x070
 #define REG_V5_FAULT_AW_VA	0x080
 
+/* v7.x registers */
+#define REG_V7_CAPA0		0x870
+#define REG_V7_CAPA1		0x874
+
 #define has_sysmmu(dev)		(dev_iommu_priv_get(dev) != NULL)
 
 static struct device *dma_dev;
@@ -274,6 +281,9 @@  struct sysmmu_drvdata {
 	unsigned int version;		/* our version */
 
 	struct iommu_device iommu;	/* IOMMU core handle */
+
+	/* v7 fields */
+	bool has_vcr;			/* virtual machine control register */
 };
 
 static struct exynos_iommu_domain *to_exynos_domain(struct iommu_domain *dom)
@@ -364,11 +374,7 @@  static void __sysmmu_disable_clocks(struct sysmmu_drvdata *data)
 
 static void __sysmmu_get_version(struct sysmmu_drvdata *data)
 {
-	u32 ver;
-
-	__sysmmu_enable_clocks(data);
-
-	ver = readl(data->sfrbase + REG_MMU_VERSION);
+	const u32 ver = readl(data->sfrbase + REG_MMU_VERSION);
 
 	/* controllers on some SoCs don't report proper version */
 	if (ver == 0x80000001u)
@@ -378,6 +384,29 @@  static void __sysmmu_get_version(struct sysmmu_drvdata *data)
 
 	dev_dbg(data->sysmmu, "hardware version: %d.%d\n",
 		MMU_MAJ_VER(data->version), MMU_MIN_VER(data->version));
+}
+
+static bool __sysmmu_has_capa1(struct sysmmu_drvdata *data)
+{
+	const u32 capa0 = readl(data->sfrbase + REG_V7_CAPA0);
+
+	return capa0 & CAPA0_CAPA1_EXIST;
+}
+
+static void __sysmmu_get_vcr(struct sysmmu_drvdata *data)
+{
+	const u32 capa1 = readl(data->sfrbase + REG_V7_CAPA1);
+
+	data->has_vcr = capa1 & CAPA1_VCR_ENABLED;
+}
+
+static void sysmmu_get_hw_info(struct sysmmu_drvdata *data)
+{
+	__sysmmu_enable_clocks(data);
+
+	__sysmmu_get_version(data);
+	if (MMU_MAJ_VER(data->version) >= 7 && __sysmmu_has_capa1(data))
+		__sysmmu_get_vcr(data);
 
 	__sysmmu_disable_clocks(data);
 }
@@ -623,6 +652,8 @@  static int exynos_sysmmu_probe(struct platform_device *pdev)
 	data->sysmmu = dev;
 	spin_lock_init(&data->lock);
 
+	sysmmu_get_hw_info(data);
+
 	ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL,
 				     dev_name(data->sysmmu));
 	if (ret)
@@ -634,7 +665,6 @@  static int exynos_sysmmu_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, data);
 
-	__sysmmu_get_version(data);
 	if (PG_ENT_SHIFT < 0) {
 		if (MMU_MAJ_VER(data->version) < 5) {
 			PG_ENT_SHIFT = SYSMMU_PG_ENT_SHIFT;