[PATCH v4 0/4] Modularization of DFL private feature drivers

[PATCH v4 0/4] Modularization of DFL private feature drivers

[Xu Yilun]

This patchset makes it possible to develop independent driver modules
for DFL private features. It also helps to leverage existing kernel
drivers to enable some IP blocks in DFL.

Patch #1: An improvement of feature id definition. The feature id will be
          used as the key field for dfl device/driver matching.
Patch #2: Release the dfl mmio regions after enumeration, so that private
          feature drivers could request mmio region in their own drivers.
Patch #3: Introduce the dfl bus, then dfl devices could be supported by
          independent dfl drivers.
Patch #4: An example of the dfl driver for N3000 nios private feature.


Main changes from v1:
- Add the new Patch #1, to improve the feature id definition.
- Change the dfl bus uevent format.
- Change the dfl device's sysfs name format.
- refactor dfl_dev_add()
- Add the Patch #4 as an example of the dfl driver.
- A lot of minor fixes for comments from Hao and Tom.

Main changes from v2:
- Add the doc for dfl-n3000-nios driver.
- Minor fixes for comments from Tom.

Main changes from v3:
- improve the dfl devices' uevent format, 4 bits for type & 12 bits for id
- change dfl_device->type to u8
- A dedicate field in struct dfl_feature for dfl device instance.
- error out if dfl_device already exist on dfl_devs_init().
- Move the err log in regmap implementation, and delete
  n3000_nios_writel/readl(), they have nothing to wrapper now.
- Minor fixes and comments improvement.

Xu Yilun (4):
  fpga: dfl: change data type of feature id to u16
  fpga: dfl: map feature mmio resources in their own feature drivers
  fpga: dfl: create a dfl bus type to support DFL devices
  fpga: dfl: add support for N3000 Nios private feature

 Documentation/ABI/testing/sysfs-bus-dfl            |  15 +
 .../ABI/testing/sysfs-bus-dfl-devices-n3000-nios   |  18 +
 Documentation/fpga/dfl-n3000-nios.rst              |  41 ++
 Documentation/fpga/index.rst                       |   1 +
 drivers/fpga/Kconfig                               |  12 +
 drivers/fpga/Makefile                              |   2 +
 drivers/fpga/dfl-fme-perf.c                        |   2 +-
 drivers/fpga/dfl-n3000-nios.c                      | 475 +++++++++++++++++++++
 drivers/fpga/dfl-pci.c                             |  24 +-
 drivers/fpga/dfl.c                                 | 473 ++++++++++++++++----
 drivers/fpga/dfl.h                                 | 102 ++++-
 11 files changed, 1062 insertions(+), 103 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-dfl
 create mode 100644 Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
 create mode 100644 Documentation/fpga/dfl-n3000-nios.rst
 create mode 100644 drivers/fpga/dfl-n3000-nios.c

-- 
2.7.4

[PATCH v4 1/4] fpga: dfl: change data type of feature id to u16

[Xu Yilun]

The feature id is stored in a 12 bit field in DFH. So a u16 variable is
enough for feature id.

This patch changes all feature id related places to fit u16.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Acked-by: Wu Hao <hao.wu@intel.com>
---
v3: no change.
v4: no change.
---
 drivers/fpga/dfl-fme-perf.c |  2 +-
 drivers/fpga/dfl.c          | 29 +++++++++++++++--------------
 drivers/fpga/dfl.h          | 10 +++++-----
 3 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/drivers/fpga/dfl-fme-perf.c b/drivers/fpga/dfl-fme-perf.c
index 6ce1ed2..5312662 100644
--- a/drivers/fpga/dfl-fme-perf.c
+++ b/drivers/fpga/dfl-fme-perf.c
@@ -148,7 +148,7 @@ struct fme_perf_priv {
 	struct device *dev;
 	void __iomem *ioaddr;
 	struct pmu pmu;
-	u64 id;
+	u16 id;
 
 	u32 fab_users;
 	u32 fab_port_id;
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
index 649958a..18575d9 100644
--- a/drivers/fpga/dfl.c
+++ b/drivers/fpga/dfl.c
@@ -58,7 +58,7 @@ static const char *dfl_pdata_key_strings[DFL_ID_MAX] = {
  */
 struct dfl_dev_info {
 	const char *name;
-	u32 dfh_id;
+	u16 dfh_id;
 	struct idr id;
 	enum dfl_fpga_devt_type devt_type;
 };
@@ -134,7 +134,7 @@ static enum dfl_id_type feature_dev_id_type(struct platform_device *pdev)
 	return DFL_ID_MAX;
 }
 
-static enum dfl_id_type dfh_id_to_type(u32 id)
+static enum dfl_id_type dfh_id_to_type(u16 id)
 {
 	int i;
 
@@ -454,7 +454,7 @@ struct build_feature_devs_info {
  * @nr_irqs: number of irqs of this sub feature.
  */
 struct dfl_feature_info {
-	u64 fid;
+	u16 fid;
 	struct resource mmio_res;
 	void __iomem *ioaddr;
 	struct list_head node;
@@ -649,7 +649,7 @@ static inline u32 feature_size(void __iomem *start)
 	return ofst ? ofst : 4096;
 }
 
-static u64 feature_id(void __iomem *start)
+static u16 feature_id(void __iomem *start)
 {
 	u64 v = readq(start + DFH);
 	u16 id = FIELD_GET(DFH_ID, v);
@@ -667,7 +667,7 @@ static u64 feature_id(void __iomem *start)
 }
 
 static int parse_feature_irqs(struct build_feature_devs_info *binfo,
-			      resource_size_t ofst, u64 fid,
+			      resource_size_t ofst, u16 fid,
 			      unsigned int *irq_base, unsigned int *nr_irqs)
 {
 	void __iomem *base = binfo->ioaddr + ofst;
@@ -713,12 +713,12 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo,
 		return 0;
 	}
 
-	dev_dbg(binfo->dev, "feature: 0x%llx, irq_base: %u, nr_irqs: %u\n",
+	dev_dbg(binfo->dev, "feature: 0x%x, irq_base: %u, nr_irqs: %u\n",
 		fid, ibase, inr);
 
 	if (ibase + inr > binfo->nr_irqs) {
 		dev_err(binfo->dev,
-			"Invalid interrupt number in feature 0x%llx\n", fid);
+			"Invalid interrupt number in feature 0x%x\n", fid);
 		return -EINVAL;
 	}
 
@@ -726,7 +726,7 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo,
 		virq = binfo->irq_table[ibase + i];
 		if (virq < 0 || virq > NR_IRQS) {
 			dev_err(binfo->dev,
-				"Invalid irq table entry for feature 0x%llx\n",
+				"Invalid irq table entry for feature 0x%x\n",
 				fid);
 			return -EINVAL;
 		}
@@ -748,7 +748,7 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo,
 static int
 create_feature_instance(struct build_feature_devs_info *binfo,
 			struct dfl_fpga_enum_dfl *dfl, resource_size_t ofst,
-			resource_size_t size, u64 fid)
+			resource_size_t size, u16 fid)
 {
 	unsigned int irq_base, nr_irqs;
 	struct dfl_feature_info *finfo;
@@ -819,9 +819,10 @@ static int parse_feature_fiu(struct build_feature_devs_info *binfo,
 			     struct dfl_fpga_enum_dfl *dfl,
 			     resource_size_t ofst)
 {
-	u32 id, offset;
-	u64 v;
 	int ret = 0;
+	u32 offset;
+	u16 id;
+	u64 v;
 
 	v = readq(dfl->ioaddr + ofst + DFH);
 	id = FIELD_GET(DFH_ID, v);
@@ -855,8 +856,8 @@ static int parse_feature_private(struct build_feature_devs_info *binfo,
 				 resource_size_t ofst)
 {
 	if (!binfo->feature_dev) {
-		dev_err(binfo->dev, "the private feature %llx does not belong to any AFU.\n",
-			(unsigned long long)feature_id(dfl->ioaddr + ofst));
+		dev_err(binfo->dev, "the private feature 0x%x does not belong to any AFU.\n",
+			feature_id(dfl->ioaddr + ofst));
 		return -EINVAL;
 	}
 
@@ -1424,7 +1425,7 @@ static int do_set_irq_trigger(struct dfl_feature *feature, unsigned int idx,
 		return 0;
 
 	feature->irq_ctx[idx].name =
-		kasprintf(GFP_KERNEL, "fpga-irq[%u](%s-%llx)", idx,
+		kasprintf(GFP_KERNEL, "fpga-irq[%u](%s-%x)", idx,
 			  dev_name(&pdev->dev), feature->id);
 	if (!feature->irq_ctx[idx].name)
 		return -ENOMEM;
diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index a32dfba..bc61942 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -197,7 +197,7 @@ int dfl_fpga_check_port_id(struct platform_device *pdev, void *pport_id);
  * @id: unique dfl private feature id.
  */
 struct dfl_feature_id {
-	u64 id;
+	u16 id;
 };
 
 /**
@@ -240,7 +240,7 @@ struct dfl_feature_irq_ctx {
  */
 struct dfl_feature {
 	struct platform_device *dev;
-	u64 id;
+	u16 id;
 	int resource_index;
 	void __iomem *ioaddr;
 	struct dfl_feature_irq_ctx *irq_ctx;
@@ -365,7 +365,7 @@ struct platform_device *dfl_fpga_inode_to_feature_dev(struct inode *inode)
 	   (feature) < (pdata)->features + (pdata)->num; (feature)++)
 
 static inline
-struct dfl_feature *dfl_get_feature_by_id(struct device *dev, u64 id)
+struct dfl_feature *dfl_get_feature_by_id(struct device *dev, u16 id)
 {
 	struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
 	struct dfl_feature *feature;
@@ -378,7 +378,7 @@ struct dfl_feature *dfl_get_feature_by_id(struct device *dev, u64 id)
 }
 
 static inline
-void __iomem *dfl_get_feature_ioaddr_by_id(struct device *dev, u64 id)
+void __iomem *dfl_get_feature_ioaddr_by_id(struct device *dev, u16 id)
 {
 	struct dfl_feature *feature = dfl_get_feature_by_id(dev, id);
 
@@ -389,7 +389,7 @@ void __iomem *dfl_get_feature_ioaddr_by_id(struct device *dev, u64 id)
 	return NULL;
 }
 
-static inline bool is_dfl_feature_present(struct device *dev, u64 id)
+static inline bool is_dfl_feature_present(struct device *dev, u16 id)
 {
 	return !!dfl_get_feature_ioaddr_by_id(dev, id);
 }
-- 
2.7.4

Re: [PATCH v4 1/4] fpga: dfl: change data type of feature id to u16

[Moritz Fischer]

On Mon, Aug 10, 2020 at 10:41:10AM +0800, Xu Yilun wrote:
> The feature id is stored in a 12 bit field in DFH. So a u16 variable is
> enough for feature id.
> 
> This patch changes all feature id related places to fit u16.
> 
> Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> Reviewed-by: Tom Rix <trix@redhat.com>
> Acked-by: Wu Hao <hao.wu@intel.com>
> ---
> v3: no change.
> v4: no change.
> ---
>  drivers/fpga/dfl-fme-perf.c |  2 +-
>  drivers/fpga/dfl.c          | 29 +++++++++++++++--------------
>  drivers/fpga/dfl.h          | 10 +++++-----
>  3 files changed, 21 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/fpga/dfl-fme-perf.c b/drivers/fpga/dfl-fme-perf.c
> index 6ce1ed2..5312662 100644
> --- a/drivers/fpga/dfl-fme-perf.c
> +++ b/drivers/fpga/dfl-fme-perf.c
> @@ -148,7 +148,7 @@ struct fme_perf_priv {
>  	struct device *dev;
>  	void __iomem *ioaddr;
>  	struct pmu pmu;
> -	u64 id;
> +	u16 id;
>  
>  	u32 fab_users;
>  	u32 fab_port_id;
> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> index 649958a..18575d9 100644
> --- a/drivers/fpga/dfl.c
> +++ b/drivers/fpga/dfl.c
> @@ -58,7 +58,7 @@ static const char *dfl_pdata_key_strings[DFL_ID_MAX] = {
>   */
>  struct dfl_dev_info {
>  	const char *name;
> -	u32 dfh_id;
> +	u16 dfh_id;
>  	struct idr id;
>  	enum dfl_fpga_devt_type devt_type;
>  };
> @@ -134,7 +134,7 @@ static enum dfl_id_type feature_dev_id_type(struct platform_device *pdev)
>  	return DFL_ID_MAX;
>  }
>  
> -static enum dfl_id_type dfh_id_to_type(u32 id)
> +static enum dfl_id_type dfh_id_to_type(u16 id)
>  {
>  	int i;
>  
> @@ -454,7 +454,7 @@ struct build_feature_devs_info {
>   * @nr_irqs: number of irqs of this sub feature.
>   */
>  struct dfl_feature_info {
> -	u64 fid;
> +	u16 fid;
>  	struct resource mmio_res;
>  	void __iomem *ioaddr;
>  	struct list_head node;
> @@ -649,7 +649,7 @@ static inline u32 feature_size(void __iomem *start)
>  	return ofst ? ofst : 4096;
>  }
>  
> -static u64 feature_id(void __iomem *start)
> +static u16 feature_id(void __iomem *start)
>  {
>  	u64 v = readq(start + DFH);
>  	u16 id = FIELD_GET(DFH_ID, v);
> @@ -667,7 +667,7 @@ static u64 feature_id(void __iomem *start)
>  }
>  
>  static int parse_feature_irqs(struct build_feature_devs_info *binfo,
> -			      resource_size_t ofst, u64 fid,
> +			      resource_size_t ofst, u16 fid,
>  			      unsigned int *irq_base, unsigned int *nr_irqs)
>  {
>  	void __iomem *base = binfo->ioaddr + ofst;
> @@ -713,12 +713,12 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo,
>  		return 0;
>  	}
>  
> -	dev_dbg(binfo->dev, "feature: 0x%llx, irq_base: %u, nr_irqs: %u\n",
> +	dev_dbg(binfo->dev, "feature: 0x%x, irq_base: %u, nr_irqs: %u\n",
>  		fid, ibase, inr);
>  
>  	if (ibase + inr > binfo->nr_irqs) {
>  		dev_err(binfo->dev,
> -			"Invalid interrupt number in feature 0x%llx\n", fid);
> +			"Invalid interrupt number in feature 0x%x\n", fid);
>  		return -EINVAL;
>  	}
>  
> @@ -726,7 +726,7 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo,
>  		virq = binfo->irq_table[ibase + i];
>  		if (virq < 0 || virq > NR_IRQS) {
>  			dev_err(binfo->dev,
> -				"Invalid irq table entry for feature 0x%llx\n",
> +				"Invalid irq table entry for feature 0x%x\n",
>  				fid);
>  			return -EINVAL;
>  		}
> @@ -748,7 +748,7 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo,
>  static int
>  create_feature_instance(struct build_feature_devs_info *binfo,
>  			struct dfl_fpga_enum_dfl *dfl, resource_size_t ofst,
> -			resource_size_t size, u64 fid)
> +			resource_size_t size, u16 fid)
>  {
>  	unsigned int irq_base, nr_irqs;
>  	struct dfl_feature_info *finfo;
> @@ -819,9 +819,10 @@ static int parse_feature_fiu(struct build_feature_devs_info *binfo,
>  			     struct dfl_fpga_enum_dfl *dfl,
>  			     resource_size_t ofst)
>  {
> -	u32 id, offset;
> -	u64 v;
>  	int ret = 0;
> +	u32 offset;
> +	u16 id;
> +	u64 v;
>  
>  	v = readq(dfl->ioaddr + ofst + DFH);
>  	id = FIELD_GET(DFH_ID, v);
> @@ -855,8 +856,8 @@ static int parse_feature_private(struct build_feature_devs_info *binfo,
>  				 resource_size_t ofst)
>  {
>  	if (!binfo->feature_dev) {
> -		dev_err(binfo->dev, "the private feature %llx does not belong to any AFU.\n",
> -			(unsigned long long)feature_id(dfl->ioaddr + ofst));
> +		dev_err(binfo->dev, "the private feature 0x%x does not belong to any AFU.\n",
> +			feature_id(dfl->ioaddr + ofst));
>  		return -EINVAL;
>  	}
>  
> @@ -1424,7 +1425,7 @@ static int do_set_irq_trigger(struct dfl_feature *feature, unsigned int idx,
>  		return 0;
>  
>  	feature->irq_ctx[idx].name =
> -		kasprintf(GFP_KERNEL, "fpga-irq[%u](%s-%llx)", idx,
> +		kasprintf(GFP_KERNEL, "fpga-irq[%u](%s-%x)", idx,
>  			  dev_name(&pdev->dev), feature->id);
>  	if (!feature->irq_ctx[idx].name)
>  		return -ENOMEM;
> diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
> index a32dfba..bc61942 100644
> --- a/drivers/fpga/dfl.h
> +++ b/drivers/fpga/dfl.h
> @@ -197,7 +197,7 @@ int dfl_fpga_check_port_id(struct platform_device *pdev, void *pport_id);
>   * @id: unique dfl private feature id.
>   */
>  struct dfl_feature_id {
> -	u64 id;
> +	u16 id;
>  };
>  
>  /**
> @@ -240,7 +240,7 @@ struct dfl_feature_irq_ctx {
>   */
>  struct dfl_feature {
>  	struct platform_device *dev;
> -	u64 id;
> +	u16 id;
>  	int resource_index;
>  	void __iomem *ioaddr;
>  	struct dfl_feature_irq_ctx *irq_ctx;
> @@ -365,7 +365,7 @@ struct platform_device *dfl_fpga_inode_to_feature_dev(struct inode *inode)
>  	   (feature) < (pdata)->features + (pdata)->num; (feature)++)
>  
>  static inline
> -struct dfl_feature *dfl_get_feature_by_id(struct device *dev, u64 id)
> +struct dfl_feature *dfl_get_feature_by_id(struct device *dev, u16 id)
>  {
>  	struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
>  	struct dfl_feature *feature;
> @@ -378,7 +378,7 @@ struct dfl_feature *dfl_get_feature_by_id(struct device *dev, u64 id)
>  }
>  
>  static inline
> -void __iomem *dfl_get_feature_ioaddr_by_id(struct device *dev, u64 id)
> +void __iomem *dfl_get_feature_ioaddr_by_id(struct device *dev, u16 id)
>  {
>  	struct dfl_feature *feature = dfl_get_feature_by_id(dev, id);
>  
> @@ -389,7 +389,7 @@ void __iomem *dfl_get_feature_ioaddr_by_id(struct device *dev, u64 id)
>  	return NULL;
>  }
>  
> -static inline bool is_dfl_feature_present(struct device *dev, u64 id)
> +static inline bool is_dfl_feature_present(struct device *dev, u16 id)
>  {
>  	return !!dfl_get_feature_ioaddr_by_id(dev, id);
>  }
> -- 
> 2.7.4
> 

Applied to for-next,

Thanks

RE: [PATCH v4 1/4] fpga: dfl: change data type of feature id to u16

[David Laight]

From: Moritz Fischer
> Sent: 12 August 2020 04:56
> 
> On Mon, Aug 10, 2020 at 10:41:10AM +0800, Xu Yilun wrote:
> > The feature id is stored in a 12 bit field in DFH. So a u16 variable is
> > enough for feature id.
> >
> > This patch changes all feature id related places to fit u16.

How much bigger does it make the kernel?

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: [PATCH v4 1/4] fpga: dfl: change data type of feature id to u16

[Xu Yilun]

On Wed, Aug 12, 2020 at 08:52:39AM +0000, David Laight wrote:
> From: Moritz Fischer
> > Sent: 12 August 2020 04:56
> > 
> > On Mon, Aug 10, 2020 at 10:41:10AM +0800, Xu Yilun wrote:
> > > The feature id is stored in a 12 bit field in DFH. So a u16 variable is
> > > enough for feature id.
> > >
> > > This patch changes all feature id related places to fit u16.
> 
> How much bigger does it make the kernel?

The patch changes the definition of feature id from u64 to u16, and will
make the kernel slightly smaller.

Actually it is not the main purpose of this change. In the following
patches we will put the feature_id definiton in mod_devicetable.h in
order to support MODULE_DEVICE_TABLE(). The modpost will also use the
definitions in mod_devicetable.h but seems it doesn't support u64 now.
So we reduced the unnecessary bits definition in feature_id to fit
modpost.

Thanks,
Yilun

> 
> 	David
> 
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)

RE: [PATCH v4 1/4] fpga: dfl: change data type of feature id to u16

[David Laight]

From: Xu Yilun
> Sent: 13 August 2020 08:59
> On Wed, Aug 12, 2020 at 08:52:39AM +0000, David Laight wrote:
> > From: Moritz Fischer
> > > Sent: 12 August 2020 04:56
> > >
> > > On Mon, Aug 10, 2020 at 10:41:10AM +0800, Xu Yilun wrote:
> > > > The feature id is stored in a 12 bit field in DFH. So a u16 variable is
> > > > enough for feature id.
> > > >
> > > > This patch changes all feature id related places to fit u16.
> >
> > How much bigger does it make the kernel?
> 
> The patch changes the definition of feature id from u64 to u16, and will
> make the kernel slightly smaller.

Unlikely.
Most of the structures will gain a 'pad' field.
Using u16 for function parameters and results almost certainly
requires instructions to mask the value.
Any arithmetic on u16 will require masking instructions on
(probably) all architectures except x86.

Using 'unsigned int' is probably best.

u16 is never a good idea unless you are defining enough
of them in a structure (eg as an array) to reduce the
structure size below some threshold.
(Or are matching some hardware layout.)

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: [PATCH v4 1/4] fpga: dfl: change data type of feature id to u16

[Xu Yilun]

On Thu, Aug 13, 2020 at 08:28:05AM +0000, David Laight wrote:
> From: Xu Yilun
> > Sent: 13 August 2020 08:59
> > On Wed, Aug 12, 2020 at 08:52:39AM +0000, David Laight wrote:
> > > From: Moritz Fischer
> > > > Sent: 12 August 2020 04:56
> > > >
> > > > On Mon, Aug 10, 2020 at 10:41:10AM +0800, Xu Yilun wrote:
> > > > > The feature id is stored in a 12 bit field in DFH. So a u16 variable is
> > > > > enough for feature id.
> > > > >
> > > > > This patch changes all feature id related places to fit u16.
> > >
> > > How much bigger does it make the kernel?
> > 
> > The patch changes the definition of feature id from u64 to u16, and will
> > make the kernel slightly smaller.
> 
> Unlikely.
> Most of the structures will gain a 'pad' field.
> Using u16 for function parameters and results almost certainly
> requires instructions to mask the value.
> Any arithmetic on u16 will require masking instructions on
> (probably) all architectures except x86.
> 
> Using 'unsigned int' is probably best.
> 
> u16 is never a good idea unless you are defining enough
> of them in a structure (eg as an array) to reduce the
> structure size below some threshold.
> (Or are matching some hardware layout.)

I got it. Thanks for your detailed explanation. I think we may change them to
u32. Is it the same case for u8? Think we may also change the dfl_device_id.type.


Hi Moritz:

The patch is applied to for-next, is it possible we recall it, or we
make another fix after it?

Thanks,
Yilun.

> 
> 	David
> 
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)

RE: [PATCH v4 1/4] fpga: dfl: change data type of feature id to u16

[David Laight]

From: Xu Yilun <yilun.xu@intel.com>
> Sent: 13 August 2020 10:04
> 
> On Thu, Aug 13, 2020 at 08:28:05AM +0000, David Laight wrote:
> > From: Xu Yilun
> > > Sent: 13 August 2020 08:59
> > > On Wed, Aug 12, 2020 at 08:52:39AM +0000, David Laight wrote:
> > > > From: Moritz Fischer
> > > > > Sent: 12 August 2020 04:56
> > > > >
> > > > > On Mon, Aug 10, 2020 at 10:41:10AM +0800, Xu Yilun wrote:
> > > > > > The feature id is stored in a 12 bit field in DFH. So a u16 variable is
> > > > > > enough for feature id.
> > > > > >
> > > > > > This patch changes all feature id related places to fit u16.
> > > >
> > > > How much bigger does it make the kernel?
> > >
> > > The patch changes the definition of feature id from u64 to u16, and will
> > > make the kernel slightly smaller.
> >
> > Unlikely.
> > Most of the structures will gain a 'pad' field.
> > Using u16 for function parameters and results almost certainly
> > requires instructions to mask the value.
> > Any arithmetic on u16 will require masking instructions on
> > (probably) all architectures except x86.
> >
> > Using 'unsigned int' is probably best.
> >
> > u16 is never a good idea unless you are defining enough
> > of them in a structure (eg as an array) to reduce the
> > structure size below some threshold.
> > (Or are matching some hardware layout.)
> 
> I got it. Thanks for your detailed explanation. I think we may change them to
> u32. Is it the same case for u8? Think we may also change the dfl_device_id.type.

Loosely 'yes' but it isn't worth the churn of 'random' changes.
And they aren't often passed to/from functions - which I'm 98% sure
requires masking.

I commented because the compiler was going to add pad fields after
your u16 values - so you'd get do space saving and probably more code.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: [PATCH v4 1/4] fpga: dfl: change data type of feature id to u16

[Moritz Fischer]

On Thu, Aug 13, 2020 at 05:04:09PM +0800, Xu Yilun wrote:
> On Thu, Aug 13, 2020 at 08:28:05AM +0000, David Laight wrote:
> > From: Xu Yilun
> > > Sent: 13 August 2020 08:59
> > > On Wed, Aug 12, 2020 at 08:52:39AM +0000, David Laight wrote:
> > > > From: Moritz Fischer
> > > > > Sent: 12 August 2020 04:56
> > > > >
> > > > > On Mon, Aug 10, 2020 at 10:41:10AM +0800, Xu Yilun wrote:
> > > > > > The feature id is stored in a 12 bit field in DFH. So a u16 variable is
> > > > > > enough for feature id.
> > > > > >
> > > > > > This patch changes all feature id related places to fit u16.
> > > >
> > > > How much bigger does it make the kernel?
> > > 
> > > The patch changes the definition of feature id from u64 to u16, and will
> > > make the kernel slightly smaller.
> > 
> > Unlikely.
> > Most of the structures will gain a 'pad' field.
> > Using u16 for function parameters and results almost certainly
> > requires instructions to mask the value.
> > Any arithmetic on u16 will require masking instructions on
> > (probably) all architectures except x86.
> > 
> > Using 'unsigned int' is probably best.
> > 
> > u16 is never a good idea unless you are defining enough
> > of them in a structure (eg as an array) to reduce the
> > structure size below some threshold.
> > (Or are matching some hardware layout.)
> 
> I got it. Thanks for your detailed explanation. I think we may change them to
> u32. Is it the same case for u8? Think we may also change the dfl_device_id.type.
> 
> 
> Hi Moritz:
> 
> The patch is applied to for-next, is it possible we recall it, or we
> make another fix after it?
> 
> Thanks,
> Yilun.

Sorry for the delay, can you send a follow-up please?

Cheers,
Moritz

Re: [PATCH v4 1/4] fpga: dfl: change data type of feature id to u16

[Xu Yilun]

On Wed, Aug 19, 2020 at 09:14:31PM -0700, Moritz Fischer wrote:
> On Thu, Aug 13, 2020 at 05:04:09PM +0800, Xu Yilun wrote:
> > On Thu, Aug 13, 2020 at 08:28:05AM +0000, David Laight wrote:
> > > From: Xu Yilun
> > > > Sent: 13 August 2020 08:59
> > > > On Wed, Aug 12, 2020 at 08:52:39AM +0000, David Laight wrote:
> > > > > From: Moritz Fischer
> > > > > > Sent: 12 August 2020 04:56
> > > > > >
> > > > > > On Mon, Aug 10, 2020 at 10:41:10AM +0800, Xu Yilun wrote:
> > > > > > > The feature id is stored in a 12 bit field in DFH. So a u16 variable is
> > > > > > > enough for feature id.
> > > > > > >
> > > > > > > This patch changes all feature id related places to fit u16.
> > > > >
> > > > > How much bigger does it make the kernel?
> > > > 
> > > > The patch changes the definition of feature id from u64 to u16, and will
> > > > make the kernel slightly smaller.
> > > 
> > > Unlikely.
> > > Most of the structures will gain a 'pad' field.
> > > Using u16 for function parameters and results almost certainly
> > > requires instructions to mask the value.
> > > Any arithmetic on u16 will require masking instructions on
> > > (probably) all architectures except x86.
> > > 
> > > Using 'unsigned int' is probably best.
> > > 
> > > u16 is never a good idea unless you are defining enough
> > > of them in a structure (eg as an array) to reduce the
> > > structure size below some threshold.
> > > (Or are matching some hardware layout.)
> > 
> > I got it. Thanks for your detailed explanation. I think we may change them to
> > u32. Is it the same case for u8? Think we may also change the dfl_device_id.type.
> > 
> > 
> > Hi Moritz:
> > 
> > The patch is applied to for-next, is it possible we recall it, or we
> > make another fix after it?
> > 
> > Thanks,
> > Yilun.
> 
> Sorry for the delay, can you send a follow-up please?

Hi moritz:

I think I don't have to change it now. As discussed with David, these
fields aren't often accessed. So it should be OK.

Thanks,
Yilun.

> 
> Cheers,
> Moritz

[PATCH v4 2/4] fpga: dfl: map feature mmio resources in their own feature drivers

[Xu Yilun]

This patch makes preparation for modularization of DFL sub feature
drivers.

Currently, if we need to support a new DFL sub feature, an entry should
be added to fme/port_feature_drvs[] in dfl-fme/port-main.c. And we need
to re-compile the whole DFL modules. That make the DFL drivers hard to be
extended.

Another consideration is that DFL may contain some IP blocks which are
already supported by kernel, most of them are supported by platform
device drivers. We could create platform devices for these IP blocks and
get them supported by these drivers.

An important issue is that platform device drivers usually requests mmio
resources on probe. But now dfl mmio is mapped in dfl bus driver (e.g.
dfl-pci) as a whole region. Then platform device drivers for sub features
can't request their own mmio resources again. This is what the patch
trying to resolve.

This patch changes the DFL enumeration. DFL bus driver will unmap mmio
resources after first step enumeration and pass enumeration info to DFL
framework. Then DFL framework will map the mmio resources again, do 2nd
step enumeration, and also unmap the mmio resources. In this way, sub
feature drivers could then request their own mmio resources as needed.

An exception is that mmio resource of FIU headers are still mapped in dfl
bus driver. The FIU headers have some fundamental functions (sriov set,
port enable/disable) needed for dfl bus devices and other sub features.
They should not be unmapped as long as dfl bus device is alive.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Acked-by: Wu Hao <hao.wu@intel.com>
---
v2: delete dfl_binfo_shift() cause no shift is possible for FIU parsing.
    Only map bar0 for first phase enumeration in dfl-pci, we can find
      all dfl mmio resource info in bar0.
    Some minor fixes for comments from Hao & Tom.
v3: no change
v4: minor fixes for Hao's comments.
---
 drivers/fpga/dfl-pci.c |  24 +++----
 drivers/fpga/dfl.c     | 185 +++++++++++++++++++++++++++++++++----------------
 drivers/fpga/dfl.h     |   7 +-
 3 files changed, 139 insertions(+), 77 deletions(-)

diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
index e220bec..a2203d0 100644
--- a/drivers/fpga/dfl-pci.c
+++ b/drivers/fpga/dfl-pci.c
@@ -31,12 +31,12 @@ struct cci_drvdata {
 	struct dfl_fpga_cdev *cdev;	/* container device */
 };
 
-static void __iomem *cci_pci_ioremap_bar(struct pci_dev *pcidev, int bar)
+static void __iomem *cci_pci_ioremap_bar0(struct pci_dev *pcidev)
 {
-	if (pcim_iomap_regions(pcidev, BIT(bar), DRV_NAME))
+	if (pcim_iomap_regions(pcidev, BIT(0), DRV_NAME))
 		return NULL;
 
-	return pcim_iomap_table(pcidev)[bar];
+	return pcim_iomap_table(pcidev)[0];
 }
 
 static int cci_pci_alloc_irq(struct pci_dev *pcidev)
@@ -156,8 +156,8 @@ static int cci_enumerate_feature_devs(struct pci_dev *pcidev)
 			goto irq_free_exit;
 	}
 
-	/* start to find Device Feature List from Bar 0 */
-	base = cci_pci_ioremap_bar(pcidev, 0);
+	/* start to find Device Feature List in Bar 0 */
+	base = cci_pci_ioremap_bar0(pcidev);
 	if (!base) {
 		ret = -ENOMEM;
 		goto irq_free_exit;
@@ -172,7 +172,7 @@ static int cci_enumerate_feature_devs(struct pci_dev *pcidev)
 		start = pci_resource_start(pcidev, 0);
 		len = pci_resource_len(pcidev, 0);
 
-		dfl_fpga_enum_info_add_dfl(info, start, len, base);
+		dfl_fpga_enum_info_add_dfl(info, start, len);
 
 		/*
 		 * find more Device Feature Lists (e.g. Ports) per information
@@ -196,26 +196,24 @@ static int cci_enumerate_feature_devs(struct pci_dev *pcidev)
 			 */
 			bar = FIELD_GET(FME_PORT_OFST_BAR_ID, v);
 			offset = FIELD_GET(FME_PORT_OFST_DFH_OFST, v);
-			base = cci_pci_ioremap_bar(pcidev, bar);
-			if (!base)
-				continue;
-
 			start = pci_resource_start(pcidev, bar) + offset;
 			len = pci_resource_len(pcidev, bar) - offset;
 
-			dfl_fpga_enum_info_add_dfl(info, start, len,
-						   base + offset);
+			dfl_fpga_enum_info_add_dfl(info, start, len);
 		}
 	} else if (dfl_feature_is_port(base)) {
 		start = pci_resource_start(pcidev, 0);
 		len = pci_resource_len(pcidev, 0);
 
-		dfl_fpga_enum_info_add_dfl(info, start, len, base);
+		dfl_fpga_enum_info_add_dfl(info, start, len);
 	} else {
 		ret = -ENODEV;
 		goto irq_free_exit;
 	}
 
+	/* release I/O mappings for next step enumeration */
+	pcim_iounmap_regions(pcidev, BIT(0));
+
 	/* start enumeration with prepared enumeration information */
 	cdev = dfl_fpga_feature_devs_enumerate(info);
 	if (IS_ERR(cdev)) {
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
index 18575d9..b5257d7 100644
--- a/drivers/fpga/dfl.c
+++ b/drivers/fpga/dfl.c
@@ -250,6 +250,8 @@ int dfl_fpga_check_port_id(struct platform_device *pdev, void *pport_id)
 }
 EXPORT_SYMBOL_GPL(dfl_fpga_check_port_id);
 
+#define is_header_feature(feature) ((feature)->id == FEATURE_ID_FIU_HEADER)
+
 /**
  * dfl_fpga_dev_feature_uinit - uinit for sub features of dfl feature device
  * @pdev: feature device.
@@ -273,8 +275,22 @@ static int dfl_feature_instance_init(struct platform_device *pdev,
 				     struct dfl_feature *feature,
 				     struct dfl_feature_driver *drv)
 {
+	void __iomem *base;
 	int ret = 0;
 
+	if (!is_header_feature(feature)) {
+		base = devm_platform_ioremap_resource(pdev,
+						      feature->resource_index);
+		if (IS_ERR(base)) {
+			dev_err(&pdev->dev,
+				"ioremap failed for feature 0x%x!\n",
+				feature->id);
+			return PTR_ERR(base);
+		}
+
+		feature->ioaddr = base;
+	}
+
 	if (drv->ops->init) {
 		ret = drv->ops->init(pdev, feature);
 		if (ret)
@@ -427,7 +443,9 @@ EXPORT_SYMBOL_GPL(dfl_fpga_dev_ops_unregister);
  * @irq_table: Linux IRQ numbers for all irqs, indexed by local irq index of
  *	       this device.
  * @feature_dev: current feature device.
- * @ioaddr: header register region address of feature device in enumeration.
+ * @ioaddr: header register region address of current FIU in enumeration.
+ * @start: register resource start of current FIU.
+ * @len: max register resource length of current FIU.
  * @sub_features: a sub features linked list for feature device in enumeration.
  * @feature_num: number of sub features for feature device in enumeration.
  */
@@ -439,6 +457,8 @@ struct build_feature_devs_info {
 
 	struct platform_device *feature_dev;
 	void __iomem *ioaddr;
+	resource_size_t start;
+	resource_size_t len;
 	struct list_head sub_features;
 	int feature_num;
 };
@@ -484,10 +504,7 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo)
 	struct dfl_feature_platform_data *pdata;
 	struct dfl_feature_info *finfo, *p;
 	enum dfl_id_type type;
-	int ret, index = 0;
-
-	if (!fdev)
-		return 0;
+	int ret, index = 0, res_idx = 0;
 
 	type = feature_dev_id_type(fdev);
 	if (WARN_ON_ONCE(type >= DFL_ID_MAX))
@@ -530,16 +547,30 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo)
 
 	/* fill features and resource information for feature dev */
 	list_for_each_entry_safe(finfo, p, &binfo->sub_features, node) {
-		struct dfl_feature *feature = &pdata->features[index];
+		struct dfl_feature *feature = &pdata->features[index++];
 		struct dfl_feature_irq_ctx *ctx;
 		unsigned int i;
 
 		/* save resource information for each feature */
 		feature->dev = fdev;
 		feature->id = finfo->fid;
-		feature->resource_index = index;
-		feature->ioaddr = finfo->ioaddr;
-		fdev->resource[index++] = finfo->mmio_res;
+
+		/*
+		 * map header resource for dfl bus device. Don't add header
+		 * resource to feature devices, or the resource tree will be
+		 * disordered and cause warning on resource release
+		 */
+		if (is_header_feature(feature)) {
+			feature->resource_index = -1;
+			feature->ioaddr =
+				devm_ioremap_resource(binfo->dev,
+						      &finfo->mmio_res);
+			if (IS_ERR(feature->ioaddr))
+				return PTR_ERR(feature->ioaddr);
+		} else {
+			feature->resource_index = res_idx;
+			fdev->resource[res_idx++] = finfo->mmio_res;
+		}
 
 		if (finfo->nr_irqs) {
 			ctx = devm_kcalloc(binfo->dev, finfo->nr_irqs,
@@ -582,19 +613,13 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo)
 
 static int
 build_info_create_dev(struct build_feature_devs_info *binfo,
-		      enum dfl_id_type type, void __iomem *ioaddr)
+		      enum dfl_id_type type)
 {
 	struct platform_device *fdev;
-	int ret;
 
 	if (type >= DFL_ID_MAX)
 		return -EINVAL;
 
-	/* we will create a new device, commit current device first */
-	ret = build_info_commit_dev(binfo);
-	if (ret)
-		return ret;
-
 	/*
 	 * we use -ENODEV as the initialization indicator which indicates
 	 * whether the id need to be reclaimed
@@ -605,7 +630,7 @@ build_info_create_dev(struct build_feature_devs_info *binfo,
 
 	binfo->feature_dev = fdev;
 	binfo->feature_num = 0;
-	binfo->ioaddr = ioaddr;
+
 	INIT_LIST_HEAD(&binfo->sub_features);
 
 	fdev->id = dfl_id_alloc(type, &fdev->dev);
@@ -747,18 +772,17 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo,
  */
 static int
 create_feature_instance(struct build_feature_devs_info *binfo,
-			struct dfl_fpga_enum_dfl *dfl, resource_size_t ofst,
-			resource_size_t size, u16 fid)
+			resource_size_t ofst, resource_size_t size, u16 fid)
 {
 	unsigned int irq_base, nr_irqs;
 	struct dfl_feature_info *finfo;
 	int ret;
 
 	/* read feature size and id if inputs are invalid */
-	size = size ? size : feature_size(dfl->ioaddr + ofst);
-	fid = fid ? fid : feature_id(dfl->ioaddr + ofst);
+	size = size ? size : feature_size(binfo->ioaddr + ofst);
+	fid = fid ? fid : feature_id(binfo->ioaddr + ofst);
 
-	if (dfl->len - ofst < size)
+	if (binfo->len - ofst < size)
 		return -EINVAL;
 
 	ret = parse_feature_irqs(binfo, ofst, fid, &irq_base, &nr_irqs);
@@ -770,12 +794,11 @@ create_feature_instance(struct build_feature_devs_info *binfo,
 		return -ENOMEM;
 
 	finfo->fid = fid;
-	finfo->mmio_res.start = dfl->start + ofst;
+	finfo->mmio_res.start = binfo->start + ofst;
 	finfo->mmio_res.end = finfo->mmio_res.start + size - 1;
 	finfo->mmio_res.flags = IORESOURCE_MEM;
 	finfo->irq_base = irq_base;
 	finfo->nr_irqs = nr_irqs;
-	finfo->ioaddr = dfl->ioaddr + ofst;
 
 	list_add_tail(&finfo->node, &binfo->sub_features);
 	binfo->feature_num++;
@@ -784,7 +807,6 @@ create_feature_instance(struct build_feature_devs_info *binfo,
 }
 
 static int parse_feature_port_afu(struct build_feature_devs_info *binfo,
-				  struct dfl_fpga_enum_dfl *dfl,
 				  resource_size_t ofst)
 {
 	u64 v = readq(binfo->ioaddr + PORT_HDR_CAP);
@@ -792,21 +814,22 @@ static int parse_feature_port_afu(struct build_feature_devs_info *binfo,
 
 	WARN_ON(!size);
 
-	return create_feature_instance(binfo, dfl, ofst, size, FEATURE_ID_AFU);
+	return create_feature_instance(binfo, ofst, size, FEATURE_ID_AFU);
 }
 
+#define is_feature_dev_detected(binfo) (!!(binfo)->feature_dev)
+
 static int parse_feature_afu(struct build_feature_devs_info *binfo,
-			     struct dfl_fpga_enum_dfl *dfl,
 			     resource_size_t ofst)
 {
-	if (!binfo->feature_dev) {
+	if (!is_feature_dev_detected(binfo)) {
 		dev_err(binfo->dev, "this AFU does not belong to any FIU.\n");
 		return -EINVAL;
 	}
 
 	switch (feature_dev_id_type(binfo->feature_dev)) {
 	case PORT_ID:
-		return parse_feature_port_afu(binfo, dfl, ofst);
+		return parse_feature_port_afu(binfo, ofst);
 	default:
 		dev_info(binfo->dev, "AFU belonging to FIU %s is not supported yet.\n",
 			 binfo->feature_dev->name);
@@ -815,8 +838,39 @@ static int parse_feature_afu(struct build_feature_devs_info *binfo,
 	return 0;
 }
 
+static int dfl_binfo_prepare(struct build_feature_devs_info *binfo,
+			     resource_size_t start, resource_size_t len)
+{
+	struct device *dev = binfo->dev;
+	void __iomem *ioaddr;
+
+	if (!devm_request_mem_region(dev, start, len, dev_name(dev))) {
+		dev_err(dev, "request region fail, start:%pa, len:%pa\n",
+			&start, &len);
+		return -EBUSY;
+	}
+
+	ioaddr = devm_ioremap(dev, start, len);
+	if (!ioaddr) {
+		dev_err(dev, "ioremap region fail, start:%pa, len:%pa\n",
+			&start, &len);
+		return -ENOMEM;
+	}
+
+	binfo->start = start;
+	binfo->len = len;
+	binfo->ioaddr = ioaddr;
+
+	return 0;
+}
+
+static void dfl_binfo_complete(struct build_feature_devs_info *binfo)
+{
+	devm_iounmap(binfo->dev, binfo->ioaddr);
+	devm_release_mem_region(binfo->dev, binfo->start, binfo->len);
+}
+
 static int parse_feature_fiu(struct build_feature_devs_info *binfo,
-			     struct dfl_fpga_enum_dfl *dfl,
 			     resource_size_t ofst)
 {
 	int ret = 0;
@@ -824,27 +878,39 @@ static int parse_feature_fiu(struct build_feature_devs_info *binfo,
 	u16 id;
 	u64 v;
 
-	v = readq(dfl->ioaddr + ofst + DFH);
+	if (is_feature_dev_detected(binfo)) {
+		dfl_binfo_complete(binfo);
+
+		ret = build_info_commit_dev(binfo);
+		if (ret)
+			return ret;
+
+		ret = dfl_binfo_prepare(binfo, binfo->start + ofst,
+					binfo->len - ofst);
+		if (ret)
+			return ret;
+	}
+
+	v = readq(binfo->ioaddr + DFH);
 	id = FIELD_GET(DFH_ID, v);
 
 	/* create platform device for dfl feature dev */
-	ret = build_info_create_dev(binfo, dfh_id_to_type(id),
-				    dfl->ioaddr + ofst);
+	ret = build_info_create_dev(binfo, dfh_id_to_type(id));
 	if (ret)
 		return ret;
 
-	ret = create_feature_instance(binfo, dfl, ofst, 0, 0);
+	ret = create_feature_instance(binfo, 0, 0, 0);
 	if (ret)
 		return ret;
 	/*
 	 * find and parse FIU's child AFU via its NEXT_AFU register.
 	 * please note that only Port has valid NEXT_AFU pointer per spec.
 	 */
-	v = readq(dfl->ioaddr + ofst + NEXT_AFU);
+	v = readq(binfo->ioaddr + NEXT_AFU);
 
 	offset = FIELD_GET(NEXT_AFU_NEXT_DFH_OFST, v);
 	if (offset)
-		return parse_feature_afu(binfo, dfl, ofst + offset);
+		return parse_feature_afu(binfo, offset);
 
 	dev_dbg(binfo->dev, "No AFUs detected on FIU %d\n", id);
 
@@ -852,41 +918,39 @@ static int parse_feature_fiu(struct build_feature_devs_info *binfo,
 }
 
 static int parse_feature_private(struct build_feature_devs_info *binfo,
-				 struct dfl_fpga_enum_dfl *dfl,
 				 resource_size_t ofst)
 {
-	if (!binfo->feature_dev) {
+	if (!is_feature_dev_detected(binfo)) {
 		dev_err(binfo->dev, "the private feature 0x%x does not belong to any AFU.\n",
-			feature_id(dfl->ioaddr + ofst));
+			feature_id(binfo->ioaddr + ofst));
 		return -EINVAL;
 	}
 
-	return create_feature_instance(binfo, dfl, ofst, 0, 0);
+	return create_feature_instance(binfo, ofst, 0, 0);
 }
 
 /**
  * parse_feature - parse a feature on given device feature list
  *
  * @binfo: build feature devices information.
- * @dfl: device feature list to parse
- * @ofst: offset to feature header on this device feature list
+ * @ofst: offset to current FIU header
  */
 static int parse_feature(struct build_feature_devs_info *binfo,
-			 struct dfl_fpga_enum_dfl *dfl, resource_size_t ofst)
+			 resource_size_t ofst)
 {
 	u64 v;
 	u32 type;
 
-	v = readq(dfl->ioaddr + ofst + DFH);
+	v = readq(binfo->ioaddr + ofst + DFH);
 	type = FIELD_GET(DFH_TYPE, v);
 
 	switch (type) {
 	case DFH_TYPE_AFU:
-		return parse_feature_afu(binfo, dfl, ofst);
+		return parse_feature_afu(binfo, ofst);
 	case DFH_TYPE_PRIVATE:
-		return parse_feature_private(binfo, dfl, ofst);
+		return parse_feature_private(binfo, ofst);
 	case DFH_TYPE_FIU:
-		return parse_feature_fiu(binfo, dfl, ofst);
+		return parse_feature_fiu(binfo, ofst);
 	default:
 		dev_info(binfo->dev,
 			 "Feature Type %x is not supported.\n", type);
@@ -896,14 +960,17 @@ static int parse_feature(struct build_feature_devs_info *binfo,
 }
 
 static int parse_feature_list(struct build_feature_devs_info *binfo,
-			      struct dfl_fpga_enum_dfl *dfl)
+			      resource_size_t start, resource_size_t len)
 {
-	void __iomem *start = dfl->ioaddr;
-	void __iomem *end = dfl->ioaddr + dfl->len;
+	resource_size_t end = start + len;
 	int ret = 0;
 	u32 ofst = 0;
 	u64 v;
 
+	ret = dfl_binfo_prepare(binfo, start, len);
+	if (ret)
+		return ret;
+
 	/* walk through the device feature list via DFH's next DFH pointer. */
 	for (; start < end; start += ofst) {
 		if (end - start < DFH_SIZE) {
@@ -911,11 +978,11 @@ static int parse_feature_list(struct build_feature_devs_info *binfo,
 			return -EINVAL;
 		}
 
-		ret = parse_feature(binfo, dfl, start - dfl->ioaddr);
+		ret = parse_feature(binfo, start - binfo->start);
 		if (ret)
 			return ret;
 
-		v = readq(start + DFH);
+		v = readq(binfo->ioaddr + start - binfo->start + DFH);
 		ofst = FIELD_GET(DFH_NEXT_HDR_OFST, v);
 
 		/* stop parsing if EOL(End of List) is set or offset is 0 */
@@ -924,7 +991,12 @@ static int parse_feature_list(struct build_feature_devs_info *binfo,
 	}
 
 	/* commit current feature device when reach the end of list */
-	return build_info_commit_dev(binfo);
+	dfl_binfo_complete(binfo);
+
+	if (is_feature_dev_detected(binfo))
+		ret = build_info_commit_dev(binfo);
+
+	return ret;
 }
 
 struct dfl_fpga_enum_info *dfl_fpga_enum_info_alloc(struct device *dev)
@@ -977,7 +1049,6 @@ EXPORT_SYMBOL_GPL(dfl_fpga_enum_info_free);
  * @info: ptr to dfl_fpga_enum_info
  * @start: mmio resource address of the device feature list.
  * @len: mmio resource length of the device feature list.
- * @ioaddr: mapped mmio resource address of the device feature list.
  *
  * One FPGA device may have one or more Device Feature Lists (DFLs), use this
  * function to add information of each DFL to common data structure for next
@@ -986,8 +1057,7 @@ EXPORT_SYMBOL_GPL(dfl_fpga_enum_info_free);
  * Return: 0 on success, negative error code otherwise.
  */
 int dfl_fpga_enum_info_add_dfl(struct dfl_fpga_enum_info *info,
-			       resource_size_t start, resource_size_t len,
-			       void __iomem *ioaddr)
+			       resource_size_t start, resource_size_t len)
 {
 	struct dfl_fpga_enum_dfl *dfl;
 
@@ -997,7 +1067,6 @@ int dfl_fpga_enum_info_add_dfl(struct dfl_fpga_enum_info *info,
 
 	dfl->start = start;
 	dfl->len = len;
-	dfl->ioaddr = ioaddr;
 
 	list_add_tail(&dfl->node, &info->dfls);
 
@@ -1120,7 +1189,7 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)
 	 * Lists.
 	 */
 	list_for_each_entry(dfl, &info->dfls, node) {
-		ret = parse_feature_list(binfo, dfl);
+		ret = parse_feature_list(binfo, dfl->start, dfl->len);
 		if (ret) {
 			remove_feature_devs(cdev);
 			build_info_free(binfo);
diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index bc61942..5973769 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -441,22 +441,17 @@ struct dfl_fpga_enum_info {
  *
  * @start: base address of this device feature list.
  * @len: size of this device feature list.
- * @ioaddr: mapped base address of this device feature list.
  * @node: node in list of device feature lists.
  */
 struct dfl_fpga_enum_dfl {
 	resource_size_t start;
 	resource_size_t len;
-
-	void __iomem *ioaddr;
-
 	struct list_head node;
 };
 
 struct dfl_fpga_enum_info *dfl_fpga_enum_info_alloc(struct device *dev);
 int dfl_fpga_enum_info_add_dfl(struct dfl_fpga_enum_info *info,
-			       resource_size_t start, resource_size_t len,
-			       void __iomem *ioaddr);
+			       resource_size_t start, resource_size_t len);
 int dfl_fpga_enum_info_add_irq(struct dfl_fpga_enum_info *info,
 			       unsigned int nr_irqs, int *irq_table);
 void dfl_fpga_enum_info_free(struct dfl_fpga_enum_info *info);
-- 
2.7.4

RE: [PATCH v4 2/4] fpga: dfl: map feature mmio resources in their own feature drivers

[Wu, Hao]

> -----Original Message-----
> From: linux-fpga-owner@vger.kernel.org <linux-fpga-owner@vger.kernel.org>
> On Behalf Of Xu Yilun
> Sent: Monday, August 10, 2020 10:41 AM
> To: mdf@kernel.org; linux-fpga@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Cc: trix@redhat.com; lgoncalv@redhat.com; Xu, Yilun <yilun.xu@intel.com>;
> Wu, Hao <hao.wu@intel.com>; Matthew Gerlach
> <matthew.gerlach@linux.intel.com>; Weight, Russell H
> <russell.h.weight@intel.com>
> Subject: [PATCH v4 2/4] fpga: dfl: map feature mmio resources in their own
> feature drivers
> 
> This patch makes preparation for modularization of DFL sub feature
> drivers.
> 
> Currently, if we need to support a new DFL sub feature, an entry should
> be added to fme/port_feature_drvs[] in dfl-fme/port-main.c. And we need

I think it's afu-main.c

> to re-compile the whole DFL modules. That make the DFL drivers hard to be
> extended.

And maybe we can drop this description or move it to cover letter as it's not
the problem this patch is going to resolve.

> 
> Another consideration is that DFL may contain some IP blocks which are
> already supported by kernel, most of them are supported by platform
> device drivers. We could create platform devices for these IP blocks and
> get them supported by these drivers.
> 
> An important issue is that platform device drivers usually requests mmio
> resources on probe. But now dfl mmio is mapped in dfl bus driver (e.g.
> dfl-pci) as a whole region. Then platform device drivers for sub features
> can't request their own mmio resources again. This is what the patch
> trying to resolve.
> 
> This patch changes the DFL enumeration. DFL bus driver will unmap mmio
> resources after first step enumeration and pass enumeration info to DFL
> framework. Then DFL framework will map the mmio resources again, do 2nd
> step enumeration, and also unmap the mmio resources. In this way, sub
> feature drivers could then request their own mmio resources as needed.
> 
> An exception is that mmio resource of FIU headers are still mapped in dfl
> bus driver. The FIU headers have some fundamental functions (sriov set,
> port enable/disable) needed for dfl bus devices and other sub features.
> They should not be unmapped as long as dfl bus device is alive.
> 
> Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> Signed-off-by: Wu Hao <hao.wu@intel.com>
> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> Reviewed-by: Tom Rix <trix@redhat.com>
> Acked-by: Wu Hao <hao.wu@intel.com>
> ---
> v2: delete dfl_binfo_shift() cause no shift is possible for FIU parsing.
>     Only map bar0 for first phase enumeration in dfl-pci, we can find
>       all dfl mmio resource info in bar0.
>     Some minor fixes for comments from Hao & Tom.
> v3: no change
> v4: minor fixes for Hao's comments.
> ---
>  drivers/fpga/dfl-pci.c |  24 +++----
>  drivers/fpga/dfl.c     | 185 +++++++++++++++++++++++++++++++++--------------
> --
>  drivers/fpga/dfl.h     |   7 +-
>  3 files changed, 139 insertions(+), 77 deletions(-)
> 
> diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
> index e220bec..a2203d0 100644
> --- a/drivers/fpga/dfl-pci.c
> +++ b/drivers/fpga/dfl-pci.c
> @@ -31,12 +31,12 @@ struct cci_drvdata {
>  	struct dfl_fpga_cdev *cdev;	/* container device */
>  };
> 
> -static void __iomem *cci_pci_ioremap_bar(struct pci_dev *pcidev, int bar)
> +static void __iomem *cci_pci_ioremap_bar0(struct pci_dev *pcidev)
>  {
> -	if (pcim_iomap_regions(pcidev, BIT(bar), DRV_NAME))
> +	if (pcim_iomap_regions(pcidev, BIT(0), DRV_NAME))
>  		return NULL;
> 
> -	return pcim_iomap_table(pcidev)[bar];
> +	return pcim_iomap_table(pcidev)[0];
>  }
> 
>  static int cci_pci_alloc_irq(struct pci_dev *pcidev)
> @@ -156,8 +156,8 @@ static int cci_enumerate_feature_devs(struct pci_dev
> *pcidev)
>  			goto irq_free_exit;
>  	}
> 
> -	/* start to find Device Feature List from Bar 0 */
> -	base = cci_pci_ioremap_bar(pcidev, 0);
> +	/* start to find Device Feature List in Bar 0 */
> +	base = cci_pci_ioremap_bar0(pcidev);
>  	if (!base) {
>  		ret = -ENOMEM;
>  		goto irq_free_exit;
> @@ -172,7 +172,7 @@ static int cci_enumerate_feature_devs(struct pci_dev
> *pcidev)
>  		start = pci_resource_start(pcidev, 0);
>  		len = pci_resource_len(pcidev, 0);
> 
> -		dfl_fpga_enum_info_add_dfl(info, start, len, base);
> +		dfl_fpga_enum_info_add_dfl(info, start, len);
> 
>  		/*
>  		 * find more Device Feature Lists (e.g. Ports) per information
> @@ -196,26 +196,24 @@ static int cci_enumerate_feature_devs(struct
> pci_dev *pcidev)
>  			 */
>  			bar = FIELD_GET(FME_PORT_OFST_BAR_ID, v);
>  			offset = FIELD_GET(FME_PORT_OFST_DFH_OFST, v);
> -			base = cci_pci_ioremap_bar(pcidev, bar);
> -			if (!base)
> -				continue;
> -
>  			start = pci_resource_start(pcidev, bar) + offset;
>  			len = pci_resource_len(pcidev, bar) - offset;
> 
> -			dfl_fpga_enum_info_add_dfl(info, start, len,
> -						   base + offset);
> +			dfl_fpga_enum_info_add_dfl(info, start, len);
>  		}
>  	} else if (dfl_feature_is_port(base)) {
>  		start = pci_resource_start(pcidev, 0);
>  		len = pci_resource_len(pcidev, 0);
> 
> -		dfl_fpga_enum_info_add_dfl(info, start, len, base);
> +		dfl_fpga_enum_info_add_dfl(info, start, len);
>  	} else {
>  		ret = -ENODEV;
>  		goto irq_free_exit;
>  	}
> 
> +	/* release I/O mappings for next step enumeration */
> +	pcim_iounmap_regions(pcidev, BIT(0));
> +
>  	/* start enumeration with prepared enumeration information */
>  	cdev = dfl_fpga_feature_devs_enumerate(info);
>  	if (IS_ERR(cdev)) {
> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> index 18575d9..b5257d7 100644
> --- a/drivers/fpga/dfl.c
> +++ b/drivers/fpga/dfl.c
> @@ -250,6 +250,8 @@ int dfl_fpga_check_port_id(struct platform_device
> *pdev, void *pport_id)
>  }
>  EXPORT_SYMBOL_GPL(dfl_fpga_check_port_id);
> 
> +#define is_header_feature(feature) ((feature)->id ==
> FEATURE_ID_FIU_HEADER)
> +
>  /**
>   * dfl_fpga_dev_feature_uinit - uinit for sub features of dfl feature device
>   * @pdev: feature device.
> @@ -273,8 +275,22 @@ static int dfl_feature_instance_init(struct
> platform_device *pdev,
>  				     struct dfl_feature *feature,
>  				     struct dfl_feature_driver *drv)
>  {
> +	void __iomem *base;
>  	int ret = 0;
> 
> +	if (!is_header_feature(feature)) {
> +		base = devm_platform_ioremap_resource(pdev,
> +						      feature->resource_index);
> +		if (IS_ERR(base)) {
> +			dev_err(&pdev->dev,
> +				"ioremap failed for feature 0x%x!\n",
> +				feature->id);
> +			return PTR_ERR(base);
> +		}
> +
> +		feature->ioaddr = base;
> +	}
> +
>  	if (drv->ops->init) {
>  		ret = drv->ops->init(pdev, feature);
>  		if (ret)
> @@ -427,7 +443,9 @@ EXPORT_SYMBOL_GPL(dfl_fpga_dev_ops_unregister);
>   * @irq_table: Linux IRQ numbers for all irqs, indexed by local irq index of
>   *	       this device.
>   * @feature_dev: current feature device.
> - * @ioaddr: header register region address of feature device in enumeration.
> + * @ioaddr: header register region address of current FIU in enumeration.
> + * @start: register resource start of current FIU.
> + * @len: max register resource length of current FIU.
>   * @sub_features: a sub features linked list for feature device in
> enumeration.
>   * @feature_num: number of sub features for feature device in
> enumeration.
>   */
> @@ -439,6 +457,8 @@ struct build_feature_devs_info {
> 
>  	struct platform_device *feature_dev;
>  	void __iomem *ioaddr;
> +	resource_size_t start;
> +	resource_size_t len;
>  	struct list_head sub_features;
>  	int feature_num;
>  };
> @@ -484,10 +504,7 @@ static int build_info_commit_dev(struct
> build_feature_devs_info *binfo)
>  	struct dfl_feature_platform_data *pdata;
>  	struct dfl_feature_info *finfo, *p;
>  	enum dfl_id_type type;
> -	int ret, index = 0;
> -
> -	if (!fdev)
> -		return 0;
> +	int ret, index = 0, res_idx = 0;
> 
>  	type = feature_dev_id_type(fdev);
>  	if (WARN_ON_ONCE(type >= DFL_ID_MAX))
> @@ -530,16 +547,30 @@ static int build_info_commit_dev(struct
> build_feature_devs_info *binfo)
> 
>  	/* fill features and resource information for feature dev */
>  	list_for_each_entry_safe(finfo, p, &binfo->sub_features, node) {
> -		struct dfl_feature *feature = &pdata->features[index];
> +		struct dfl_feature *feature = &pdata->features[index++];
>  		struct dfl_feature_irq_ctx *ctx;
>  		unsigned int i;
> 
>  		/* save resource information for each feature */
>  		feature->dev = fdev;
>  		feature->id = finfo->fid;
> -		feature->resource_index = index;
> -		feature->ioaddr = finfo->ioaddr;
> -		fdev->resource[index++] = finfo->mmio_res;
> +
> +		/*
> +		 * map header resource for dfl bus device. Don't add header
> +		 * resource to feature devices, or the resource tree will be
> +		 * disordered and cause warning on resource release

I didn't get this description well, could you please explain it a little more
here?

> +		 */
> +		if (is_header_feature(feature)) {
> +			feature->resource_index = -1;
> +			feature->ioaddr =
> +				devm_ioremap_resource(binfo->dev,
> +						      &finfo->mmio_res);
> +			if (IS_ERR(feature->ioaddr))
> +				return PTR_ERR(feature->ioaddr);
> +		} else {
> +			feature->resource_index = res_idx;
> +			fdev->resource[res_idx++] = finfo->mmio_res;
> +		}
> 
>  		if (finfo->nr_irqs) {
>  			ctx = devm_kcalloc(binfo->dev, finfo->nr_irqs,
> @@ -582,19 +613,13 @@ static int build_info_commit_dev(struct
> build_feature_devs_info *binfo)
> 
>  static int
>  build_info_create_dev(struct build_feature_devs_info *binfo,
> -		      enum dfl_id_type type, void __iomem *ioaddr)
> +		      enum dfl_id_type type)
>  {
>  	struct platform_device *fdev;
> -	int ret;
> 
>  	if (type >= DFL_ID_MAX)
>  		return -EINVAL;
> 
> -	/* we will create a new device, commit current device first */
> -	ret = build_info_commit_dev(binfo);
> -	if (ret)
> -		return ret;
> -
>  	/*
>  	 * we use -ENODEV as the initialization indicator which indicates
>  	 * whether the id need to be reclaimed
> @@ -605,7 +630,7 @@ build_info_create_dev(struct
> build_feature_devs_info *binfo,
> 
>  	binfo->feature_dev = fdev;
>  	binfo->feature_num = 0;
> -	binfo->ioaddr = ioaddr;
> +
>  	INIT_LIST_HEAD(&binfo->sub_features);
> 
>  	fdev->id = dfl_id_alloc(type, &fdev->dev);
> @@ -747,18 +772,17 @@ static int parse_feature_irqs(struct
> build_feature_devs_info *binfo,
>   */
>  static int
>  create_feature_instance(struct build_feature_devs_info *binfo,
> -			struct dfl_fpga_enum_dfl *dfl, resource_size_t ofst,
> -			resource_size_t size, u16 fid)
> +			resource_size_t ofst, resource_size_t size, u16 fid)
>  {
>  	unsigned int irq_base, nr_irqs;
>  	struct dfl_feature_info *finfo;
>  	int ret;
> 
>  	/* read feature size and id if inputs are invalid */
> -	size = size ? size : feature_size(dfl->ioaddr + ofst);
> -	fid = fid ? fid : feature_id(dfl->ioaddr + ofst);
> +	size = size ? size : feature_size(binfo->ioaddr + ofst);
> +	fid = fid ? fid : feature_id(binfo->ioaddr + ofst);
> 
> -	if (dfl->len - ofst < size)
> +	if (binfo->len - ofst < size)
>  		return -EINVAL;
> 
>  	ret = parse_feature_irqs(binfo, ofst, fid, &irq_base, &nr_irqs);
> @@ -770,12 +794,11 @@ create_feature_instance(struct
> build_feature_devs_info *binfo,
>  		return -ENOMEM;
> 
>  	finfo->fid = fid;
> -	finfo->mmio_res.start = dfl->start + ofst;
> +	finfo->mmio_res.start = binfo->start + ofst;
>  	finfo->mmio_res.end = finfo->mmio_res.start + size - 1;
>  	finfo->mmio_res.flags = IORESOURCE_MEM;
>  	finfo->irq_base = irq_base;
>  	finfo->nr_irqs = nr_irqs;
> -	finfo->ioaddr = dfl->ioaddr + ofst;
> 
>  	list_add_tail(&finfo->node, &binfo->sub_features);
>  	binfo->feature_num++;
> @@ -784,7 +807,6 @@ create_feature_instance(struct
> build_feature_devs_info *binfo,
>  }
> 
>  static int parse_feature_port_afu(struct build_feature_devs_info *binfo,
> -				  struct dfl_fpga_enum_dfl *dfl,
>  				  resource_size_t ofst)
>  {
>  	u64 v = readq(binfo->ioaddr + PORT_HDR_CAP);
> @@ -792,21 +814,22 @@ static int parse_feature_port_afu(struct
> build_feature_devs_info *binfo,
> 
>  	WARN_ON(!size);
> 
> -	return create_feature_instance(binfo, dfl, ofst, size,
> FEATURE_ID_AFU);
> +	return create_feature_instance(binfo, ofst, size, FEATURE_ID_AFU);
>  }
> 
> +#define is_feature_dev_detected(binfo) (!!(binfo)->feature_dev)
> +
>  static int parse_feature_afu(struct build_feature_devs_info *binfo,
> -			     struct dfl_fpga_enum_dfl *dfl,
>  			     resource_size_t ofst)
>  {
> -	if (!binfo->feature_dev) {
> +	if (!is_feature_dev_detected(binfo)) {
>  		dev_err(binfo->dev, "this AFU does not belong to any
> FIU.\n");
>  		return -EINVAL;
>  	}
> 
>  	switch (feature_dev_id_type(binfo->feature_dev)) {
>  	case PORT_ID:
> -		return parse_feature_port_afu(binfo, dfl, ofst);
> +		return parse_feature_port_afu(binfo, ofst);
>  	default:
>  		dev_info(binfo->dev, "AFU belonging to FIU %s is not
> supported yet.\n",
>  			 binfo->feature_dev->name);
> @@ -815,8 +838,39 @@ static int parse_feature_afu(struct
> build_feature_devs_info *binfo,
>  	return 0;
>  }
> 
> +static int dfl_binfo_prepare(struct build_feature_devs_info *binfo,
> +			     resource_size_t start, resource_size_t len)
> +{
> +	struct device *dev = binfo->dev;
> +	void __iomem *ioaddr;
> +
> +	if (!devm_request_mem_region(dev, start, len, dev_name(dev))) {
> +		dev_err(dev, "request region fail, start:%pa, len:%pa\n",
> +			&start, &len);
> +		return -EBUSY;
> +	}
> +
> +	ioaddr = devm_ioremap(dev, start, len);
> +	if (!ioaddr) {
> +		dev_err(dev, "ioremap region fail, start:%pa, len:%pa\n",
> +			&start, &len);
> +		return -ENOMEM;
> +	}
> +
> +	binfo->start = start;
> +	binfo->len = len;
> +	binfo->ioaddr = ioaddr;
> +
> +	return 0;
> +}
> +
> +static void dfl_binfo_complete(struct build_feature_devs_info *binfo)
> +{
> +	devm_iounmap(binfo->dev, binfo->ioaddr);
> +	devm_release_mem_region(binfo->dev, binfo->start, binfo->len);
> +}
> +
>  static int parse_feature_fiu(struct build_feature_devs_info *binfo,
> -			     struct dfl_fpga_enum_dfl *dfl,
>  			     resource_size_t ofst)
>  {
>  	int ret = 0;
> @@ -824,27 +878,39 @@ static int parse_feature_fiu(struct
> build_feature_devs_info *binfo,
>  	u16 id;
>  	u64 v;
> 
> -	v = readq(dfl->ioaddr + ofst + DFH);
> +	if (is_feature_dev_detected(binfo)) {
> +		dfl_binfo_complete(binfo);

Some functions are dfl_bind_xxxx but other are build_info_xxxx.
If possible, could we unify them using same format? E.g.
build_info_prepare/complete_xxx

Thanks
Hao

Re: [PATCH v4 2/4] fpga: dfl: map feature mmio resources in their own feature drivers

[Xu Yilun]

On Mon, Aug 10, 2020 at 01:56:44PM +0800, Wu, Hao wrote:
> > -----Original Message-----
> > From: linux-fpga-owner@vger.kernel.org <linux-fpga-owner@vger.kernel.org>
> > On Behalf Of Xu Yilun
> > Sent: Monday, August 10, 2020 10:41 AM
> > To: mdf@kernel.org; linux-fpga@vger.kernel.org; linux-
> > kernel@vger.kernel.org
> > Cc: trix@redhat.com; lgoncalv@redhat.com; Xu, Yilun <yilun.xu@intel.com>;
> > Wu, Hao <hao.wu@intel.com>; Matthew Gerlach
> > <matthew.gerlach@linux.intel.com>; Weight, Russell H
> > <russell.h.weight@intel.com>
> > Subject: [PATCH v4 2/4] fpga: dfl: map feature mmio resources in their own
> > feature drivers
> >
> > This patch makes preparation for modularization of DFL sub feature
> > drivers.
> >
> > Currently, if we need to support a new DFL sub feature, an entry should
> > be added to fme/port_feature_drvs[] in dfl-fme/port-main.c. And we need
> 
> I think it's afu-main.c

Yes, I'll change it.

> 
> > to re-compile the whole DFL modules. That make the DFL drivers hard to be
> > extended.
> 
> And maybe we can drop this description or move it to cover letter as it's not
> the problem this patch is going to resolve.

OK.

> 
> >
> > Another consideration is that DFL may contain some IP blocks which are
> > already supported by kernel, most of them are supported by platform
> > device drivers. We could create platform devices for these IP blocks and
> > get them supported by these drivers.
> >
> > An important issue is that platform device drivers usually requests mmio
> > resources on probe. But now dfl mmio is mapped in dfl bus driver (e.g.
> > dfl-pci) as a whole region. Then platform device drivers for sub features
> > can't request their own mmio resources again. This is what the patch
> > trying to resolve.
> >
> > This patch changes the DFL enumeration. DFL bus driver will unmap mmio
> > resources after first step enumeration and pass enumeration info to DFL
> > framework. Then DFL framework will map the mmio resources again, do 2nd
> > step enumeration, and also unmap the mmio resources. In this way, sub
> > feature drivers could then request their own mmio resources as needed.
> >
> > An exception is that mmio resource of FIU headers are still mapped in dfl
> > bus driver. The FIU headers have some fundamental functions (sriov set,
> > port enable/disable) needed for dfl bus devices and other sub features.
> > They should not be unmapped as long as dfl bus device is alive.
> >
> > Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> > Signed-off-by: Wu Hao <hao.wu@intel.com>
> > Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> > Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> > Reviewed-by: Tom Rix <trix@redhat.com>
> > Acked-by: Wu Hao <hao.wu@intel.com>
> > ---
> > v2: delete dfl_binfo_shift() cause no shift is possible for FIU parsing.
> >     Only map bar0 for first phase enumeration in dfl-pci, we can find
> >       all dfl mmio resource info in bar0.
> >     Some minor fixes for comments from Hao & Tom.
> > v3: no change
> > v4: minor fixes for Hao's comments.
> > ---
> >  drivers/fpga/dfl-pci.c |  24 +++----
> >  drivers/fpga/dfl.c     | 185 +++++++++++++++++++++++++++++++++--------------
> > --
> >  drivers/fpga/dfl.h     |   7 +-
> >  3 files changed, 139 insertions(+), 77 deletions(-)
> >
> > diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
> > index e220bec..a2203d0 100644
> > --- a/drivers/fpga/dfl-pci.c
> > +++ b/drivers/fpga/dfl-pci.c
> > @@ -31,12 +31,12 @@ struct cci_drvdata {
> >  struct dfl_fpga_cdev *cdev;/* container device */
> >  };
> >
> > -static void __iomem *cci_pci_ioremap_bar(struct pci_dev *pcidev, int bar)
> > +static void __iomem *cci_pci_ioremap_bar0(struct pci_dev *pcidev)
> >  {
> > -if (pcim_iomap_regions(pcidev, BIT(bar), DRV_NAME))
> > +if (pcim_iomap_regions(pcidev, BIT(0), DRV_NAME))
> >  return NULL;
> >
> > -return pcim_iomap_table(pcidev)[bar];
> > +return pcim_iomap_table(pcidev)[0];
> >  }
> >
> >  static int cci_pci_alloc_irq(struct pci_dev *pcidev)
> > @@ -156,8 +156,8 @@ static int cci_enumerate_feature_devs(struct pci_dev
> > *pcidev)
> >  goto irq_free_exit;
> >  }
> >
> > -/* start to find Device Feature List from Bar 0 */
> > -base = cci_pci_ioremap_bar(pcidev, 0);
> > +/* start to find Device Feature List in Bar 0 */
> > +base = cci_pci_ioremap_bar0(pcidev);
> >  if (!base) {
> >  ret = -ENOMEM;
> >  goto irq_free_exit;
> > @@ -172,7 +172,7 @@ static int cci_enumerate_feature_devs(struct pci_dev
> > *pcidev)
> >  start = pci_resource_start(pcidev, 0);
> >  len = pci_resource_len(pcidev, 0);
> >
> > -dfl_fpga_enum_info_add_dfl(info, start, len, base);
> > +dfl_fpga_enum_info_add_dfl(info, start, len);
> >
> >  /*
> >   * find more Device Feature Lists (e.g. Ports) per information
> > @@ -196,26 +196,24 @@ static int cci_enumerate_feature_devs(struct
> > pci_dev *pcidev)
> >   */
> >  bar = FIELD_GET(FME_PORT_OFST_BAR_ID, v);
> >  offset = FIELD_GET(FME_PORT_OFST_DFH_OFST, v);
> > -base = cci_pci_ioremap_bar(pcidev, bar);
> > -if (!base)
> > -continue;
> > -
> >  start = pci_resource_start(pcidev, bar) + offset;
> >  len = pci_resource_len(pcidev, bar) - offset;
> >
> > -dfl_fpga_enum_info_add_dfl(info, start, len,
> > -   base + offset);
> > +dfl_fpga_enum_info_add_dfl(info, start, len);
> >  }
> >  } else if (dfl_feature_is_port(base)) {
> >  start = pci_resource_start(pcidev, 0);
> >  len = pci_resource_len(pcidev, 0);
> >
> > -dfl_fpga_enum_info_add_dfl(info, start, len, base);
> > +dfl_fpga_enum_info_add_dfl(info, start, len);
> >  } else {
> >  ret = -ENODEV;
> >  goto irq_free_exit;
> >  }
> >
> > +/* release I/O mappings for next step enumeration */
> > +pcim_iounmap_regions(pcidev, BIT(0));
> > +
> >  /* start enumeration with prepared enumeration information */
> >  cdev = dfl_fpga_feature_devs_enumerate(info);
> >  if (IS_ERR(cdev)) {
> > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> > index 18575d9..b5257d7 100644
> > --- a/drivers/fpga/dfl.c
> > +++ b/drivers/fpga/dfl.c
> > @@ -250,6 +250,8 @@ int dfl_fpga_check_port_id(struct platform_device
> > *pdev, void *pport_id)
> >  }
> >  EXPORT_SYMBOL_GPL(dfl_fpga_check_port_id);
> >
> > +#define is_header_feature(feature) ((feature)->id ==
> > FEATURE_ID_FIU_HEADER)
> > +
> >  /**
> >   * dfl_fpga_dev_feature_uinit - uinit for sub features of dfl feature device
> >   * @pdev: feature device.
> > @@ -273,8 +275,22 @@ static int dfl_feature_instance_init(struct
> > platform_device *pdev,
> >       struct dfl_feature *feature,
> >       struct dfl_feature_driver *drv)
> >  {
> > +void __iomem *base;
> >  int ret = 0;
> >
> > +if (!is_header_feature(feature)) {
> > +base = devm_platform_ioremap_resource(pdev,
> > +      feature->resource_index);
> > +if (IS_ERR(base)) {
> > +dev_err(&pdev->dev,
> > +"ioremap failed for feature 0x%x!\n",
> > +feature->id);
> > +return PTR_ERR(base);
> > +}
> > +
> > +feature->ioaddr = base;
> > +}
> > +
> >  if (drv->ops->init) {
> >  ret = drv->ops->init(pdev, feature);
> >  if (ret)
> > @@ -427,7 +443,9 @@ EXPORT_SYMBOL_GPL(dfl_fpga_dev_ops_unregister);
> >   * @irq_table: Linux IRQ numbers for all irqs, indexed by local irq index of
> >   *       this device.
> >   * @feature_dev: current feature device.
> > - * @ioaddr: header register region address of feature device in enumeration.
> > + * @ioaddr: header register region address of current FIU in enumeration.
> > + * @start: register resource start of current FIU.
> > + * @len: max register resource length of current FIU.
> >   * @sub_features: a sub features linked list for feature device in
> > enumeration.
> >   * @feature_num: number of sub features for feature device in
> > enumeration.
> >   */
> > @@ -439,6 +457,8 @@ struct build_feature_devs_info {
> >
> >  struct platform_device *feature_dev;
> >  void __iomem *ioaddr;
> > +resource_size_t start;
> > +resource_size_t len;
> >  struct list_head sub_features;
> >  int feature_num;
> >  };
> > @@ -484,10 +504,7 @@ static int build_info_commit_dev(struct
> > build_feature_devs_info *binfo)
> >  struct dfl_feature_platform_data *pdata;
> >  struct dfl_feature_info *finfo, *p;
> >  enum dfl_id_type type;
> > -int ret, index = 0;
> > -
> > -if (!fdev)
> > -return 0;
> > +int ret, index = 0, res_idx = 0;
> >
> >  type = feature_dev_id_type(fdev);
> >  if (WARN_ON_ONCE(type >= DFL_ID_MAX))
> > @@ -530,16 +547,30 @@ static int build_info_commit_dev(struct
> > build_feature_devs_info *binfo)
> >
> >  /* fill features and resource information for feature dev */
> >  list_for_each_entry_safe(finfo, p, &binfo->sub_features, node) {
> > -struct dfl_feature *feature = &pdata->features[index];
> > +struct dfl_feature *feature = &pdata->features[index++];
> >  struct dfl_feature_irq_ctx *ctx;
> >  unsigned int i;
> >
> >  /* save resource information for each feature */
> >  feature->dev = fdev;
> >  feature->id = finfo->fid;
> > -feature->resource_index = index;
> > -feature->ioaddr = finfo->ioaddr;
> > -fdev->resource[index++] = finfo->mmio_res;
> > +
> > +/*
> > + * map header resource for dfl bus device. Don't add header
> > + * resource to feature devices, or the resource tree will be
> > + * disordered and cause warning on resource release
> 
> I didn't get this description well, could you please explain it a little more
> here?

Yes. I could improve the comments.

The mmio resource of FIU headerS should be owned by dfl bus device
(e.g. dfl-pci), cause they have some fundamental functions (sriov
set, port enable/disable) needed for dfl bus devices and other sub
features. They should not be unmapped as long as dfl bus device is
alive.

So we should not assign them to feature devices (dfl-fme/afu) again.

> 
> > + */
> > +if (is_header_feature(feature)) {
> > +feature->resource_index = -1;
> > +feature->ioaddr =
> > +devm_ioremap_resource(binfo->dev,
> > +      &finfo->mmio_res);
> > +if (IS_ERR(feature->ioaddr))
> > +return PTR_ERR(feature->ioaddr);
> > +} else {
> > +feature->resource_index = res_idx;
> > +fdev->resource[res_idx++] = finfo->mmio_res;
> > +}
> >
> >  if (finfo->nr_irqs) {
> >  ctx = devm_kcalloc(binfo->dev, finfo->nr_irqs,
> > @@ -582,19 +613,13 @@ static int build_info_commit_dev(struct
> > build_feature_devs_info *binfo)
> >
> >  static int
> >  build_info_create_dev(struct build_feature_devs_info *binfo,
> > -      enum dfl_id_type type, void __iomem *ioaddr)
> > +      enum dfl_id_type type)
> >  {
> >  struct platform_device *fdev;
> > -int ret;
> >
> >  if (type >= DFL_ID_MAX)
> >  return -EINVAL;
> >
> > -/* we will create a new device, commit current device first */
> > -ret = build_info_commit_dev(binfo);
> > -if (ret)
> > -return ret;
> > -
> >  /*
> >   * we use -ENODEV as the initialization indicator which indicates
> >   * whether the id need to be reclaimed
> > @@ -605,7 +630,7 @@ build_info_create_dev(struct
> > build_feature_devs_info *binfo,
> >
> >  binfo->feature_dev = fdev;
> >  binfo->feature_num = 0;
> > -binfo->ioaddr = ioaddr;
> > +
> >  INIT_LIST_HEAD(&binfo->sub_features);
> >
> >  fdev->id = dfl_id_alloc(type, &fdev->dev);
> > @@ -747,18 +772,17 @@ static int parse_feature_irqs(struct
> > build_feature_devs_info *binfo,
> >   */
> >  static int
> >  create_feature_instance(struct build_feature_devs_info *binfo,
> > -struct dfl_fpga_enum_dfl *dfl, resource_size_t ofst,
> > -resource_size_t size, u16 fid)
> > +resource_size_t ofst, resource_size_t size, u16 fid)
> >  {
> >  unsigned int irq_base, nr_irqs;
> >  struct dfl_feature_info *finfo;
> >  int ret;
> >
> >  /* read feature size and id if inputs are invalid */
> > -size = size ? size : feature_size(dfl->ioaddr + ofst);
> > -fid = fid ? fid : feature_id(dfl->ioaddr + ofst);
> > +size = size ? size : feature_size(binfo->ioaddr + ofst);
> > +fid = fid ? fid : feature_id(binfo->ioaddr + ofst);
> >
> > -if (dfl->len - ofst < size)
> > +if (binfo->len - ofst < size)
> >  return -EINVAL;
> >
> >  ret = parse_feature_irqs(binfo, ofst, fid, &irq_base, &nr_irqs);
> > @@ -770,12 +794,11 @@ create_feature_instance(struct
> > build_feature_devs_info *binfo,
> >  return -ENOMEM;
> >
> >  finfo->fid = fid;
> > -finfo->mmio_res.start = dfl->start + ofst;
> > +finfo->mmio_res.start = binfo->start + ofst;
> >  finfo->mmio_res.end = finfo->mmio_res.start + size - 1;
> >  finfo->mmio_res.flags = IORESOURCE_MEM;
> >  finfo->irq_base = irq_base;
> >  finfo->nr_irqs = nr_irqs;
> > -finfo->ioaddr = dfl->ioaddr + ofst;
> >
> >  list_add_tail(&finfo->node, &binfo->sub_features);
> >  binfo->feature_num++;
> > @@ -784,7 +807,6 @@ create_feature_instance(struct
> > build_feature_devs_info *binfo,
> >  }
> >
> >  static int parse_feature_port_afu(struct build_feature_devs_info *binfo,
> > -  struct dfl_fpga_enum_dfl *dfl,
> >    resource_size_t ofst)
> >  {
> >  u64 v = readq(binfo->ioaddr + PORT_HDR_CAP);
> > @@ -792,21 +814,22 @@ static int parse_feature_port_afu(struct
> > build_feature_devs_info *binfo,
> >
> >  WARN_ON(!size);
> >
> > -return create_feature_instance(binfo, dfl, ofst, size,
> > FEATURE_ID_AFU);
> > +return create_feature_instance(binfo, ofst, size, FEATURE_ID_AFU);
> >  }
> >
> > +#define is_feature_dev_detected(binfo) (!!(binfo)->feature_dev)
> > +
> >  static int parse_feature_afu(struct build_feature_devs_info *binfo,
> > -     struct dfl_fpga_enum_dfl *dfl,
> >       resource_size_t ofst)
> >  {
> > -if (!binfo->feature_dev) {
> > +if (!is_feature_dev_detected(binfo)) {
> >  dev_err(binfo->dev, "this AFU does not belong to any
> > FIU.\n");
> >  return -EINVAL;
> >  }
> >
> >  switch (feature_dev_id_type(binfo->feature_dev)) {
> >  case PORT_ID:
> > -return parse_feature_port_afu(binfo, dfl, ofst);
> > +return parse_feature_port_afu(binfo, ofst);
> >  default:
> >  dev_info(binfo->dev, "AFU belonging to FIU %s is not
> > supported yet.\n",
> >   binfo->feature_dev->name);
> > @@ -815,8 +838,39 @@ static int parse_feature_afu(struct
> > build_feature_devs_info *binfo,
> >  return 0;
> >  }
> >
> > +static int dfl_binfo_prepare(struct build_feature_devs_info *binfo,
> > +     resource_size_t start, resource_size_t len)
> > +{
> > +struct device *dev = binfo->dev;
> > +void __iomem *ioaddr;
> > +
> > +if (!devm_request_mem_region(dev, start, len, dev_name(dev))) {
> > +dev_err(dev, "request region fail, start:%pa, len:%pa\n",
> > +&start, &len);
> > +return -EBUSY;
> > +}
> > +
> > +ioaddr = devm_ioremap(dev, start, len);
> > +if (!ioaddr) {
> > +dev_err(dev, "ioremap region fail, start:%pa, len:%pa\n",
> > +&start, &len);
> > +return -ENOMEM;
> > +}
> > +
> > +binfo->start = start;
> > +binfo->len = len;
> > +binfo->ioaddr = ioaddr;
> > +
> > +return 0;
> > +}
> > +
> > +static void dfl_binfo_complete(struct build_feature_devs_info *binfo)
> > +{
> > +devm_iounmap(binfo->dev, binfo->ioaddr);
> > +devm_release_mem_region(binfo->dev, binfo->start, binfo->len);
> > +}
> > +
> >  static int parse_feature_fiu(struct build_feature_devs_info *binfo,
> > -     struct dfl_fpga_enum_dfl *dfl,
> >       resource_size_t ofst)
> >  {
> >  int ret = 0;
> > @@ -824,27 +878,39 @@ static int parse_feature_fiu(struct
> > build_feature_devs_info *binfo,
> >  u16 id;
> >  u64 v;
> >
> > -v = readq(dfl->ioaddr + ofst + DFH);
> > +if (is_feature_dev_detected(binfo)) {
> > +dfl_binfo_complete(binfo);
> 
> Some functions are dfl_bind_xxxx but other are build_info_xxxx.
> If possible, could we unify them using same format? E.g.
> build_info_prepare/complete_xxx

Yes I'll fix them.

> 
> Thanks
> Hao

[PATCH v4 3/4] fpga: dfl: create a dfl bus type to support DFL devices

[Xu Yilun]

A new bus type "dfl" is introduced for private features which are not
initialized by DFL feature drivers (dfl-fme & dfl-afu drivers). So these
private features could be handled by separate driver modules.

DFL feature drivers (dfl-fme, dfl-port) will create DFL devices on
enumeration. DFL drivers could be registered on this bus to match these
DFL devices. They are matched by dfl type & feature_id.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Tom Rix <trix@redhat.com>
---
v2: change the bus uevent format.
    change the dfl device's sysfs name format.
    refactor dfl_dev_add().
    minor fixes for comments from Hao and Tom.
v3: no change.
v4: improve the uevent format, 4 bits for type & 12 bits for id.
    change dfl_device->type to u8.
    A dedicate field in struct dfl_feature for dfl device instance.
    error out if dfl_device already exist on dfl_devs_init().
---
 Documentation/ABI/testing/sysfs-bus-dfl |  15 ++
 drivers/fpga/dfl.c                      | 263 +++++++++++++++++++++++++++++++-
 drivers/fpga/dfl.h                      |  85 +++++++++++
 3 files changed, 355 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-dfl

diff --git a/Documentation/ABI/testing/sysfs-bus-dfl b/Documentation/ABI/testing/sysfs-bus-dfl
new file mode 100644
index 0000000..4d74cc0
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-dfl
@@ -0,0 +1,15 @@
+What:		/sys/bus/dfl/devices/dfl_dev.X/type
+Date:		July 2020
+KernelVersion:	5.10
+Contact:	Xu Yilun <yilun.xu@intel.com>
+Description:	Read-only. It returns type of DFL FIU of the device. Now DFL
+		supports 2 FIU types, 0 for FME, 1 for PORT.
+		Format: 0x%x
+
+What:		/sys/bus/dfl/devices/dfl_dev.X/feature_id
+Date:		July 2020
+KernelVersion:	5.10
+Contact:	Xu Yilun <yilun.xu@intel.com>
+Description:	Read-only. It returns feature identifier local to its DFL FIU
+		type.
+		Format: 0x%x
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
index b5257d7..51cef85 100644
--- a/drivers/fpga/dfl.c
+++ b/drivers/fpga/dfl.c
@@ -30,12 +30,6 @@ static DEFINE_MUTEX(dfl_id_mutex);
  * index to dfl_chardevs table. If no chardev support just set devt_type
  * as one invalid index (DFL_FPGA_DEVT_MAX).
  */
-enum dfl_id_type {
-	FME_ID,		/* fme id allocation and mapping */
-	PORT_ID,	/* port id allocation and mapping */
-	DFL_ID_MAX,
-};
-
 enum dfl_fpga_devt_type {
 	DFL_FPGA_DEVT_FME,
 	DFL_FPGA_DEVT_PORT,
@@ -250,6 +244,245 @@ int dfl_fpga_check_port_id(struct platform_device *pdev, void *pport_id)
 }
 EXPORT_SYMBOL_GPL(dfl_fpga_check_port_id);
 
+static DEFINE_IDA(dfl_device_ida);
+
+static const struct dfl_device_id *
+dfl_match_one_device(const struct dfl_device_id *id, struct dfl_device *ddev)
+{
+	if (id->type == ddev->type && id->feature_id == ddev->feature_id)
+		return id;
+
+	return NULL;
+}
+
+static int dfl_bus_match(struct device *dev, struct device_driver *drv)
+{
+	struct dfl_device *ddev = to_dfl_dev(dev);
+	struct dfl_driver *ddrv = to_dfl_drv(drv);
+	const struct dfl_device_id *id_entry = ddrv->id_table;
+
+	if (id_entry) {
+		while (id_entry->feature_id) {
+			if (dfl_match_one_device(id_entry, ddev)) {
+				ddev->id_entry = id_entry;
+				return 1;
+			}
+			id_entry++;
+		}
+	}
+
+	return 0;
+}
+
+static int dfl_bus_probe(struct device *dev)
+{
+	struct dfl_device *ddev = to_dfl_dev(dev);
+	struct dfl_driver *ddrv = to_dfl_drv(dev->driver);
+
+	return ddrv->probe(ddev);
+}
+
+static int dfl_bus_remove(struct device *dev)
+{
+	struct dfl_device *ddev = to_dfl_dev(dev);
+	struct dfl_driver *ddrv = to_dfl_drv(dev->driver);
+
+	if (ddrv->remove)
+		ddrv->remove(ddev);
+
+	return 0;
+}
+
+static int dfl_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct dfl_device *ddev = to_dfl_dev(dev);
+
+	/* The type has 4 valid bits and feature_id has 12 valid bits */
+	return add_uevent_var(env, "MODALIAS=dfl:t%01Xf%03X",
+			      ddev->type, ddev->feature_id);
+}
+
+/* show dfl info fields */
+#define dfl_info_attr(field, format_string)				\
+static ssize_t								\
+field##_show(struct device *dev, struct device_attribute *attr,		\
+	     char *buf)							\
+{									\
+	struct dfl_device *ddev = to_dfl_dev(dev);			\
+									\
+	return sprintf(buf, format_string, ddev->field);		\
+}									\
+static DEVICE_ATTR_RO(field)
+
+dfl_info_attr(type, "0x%x\n");
+dfl_info_attr(feature_id, "0x%x\n");
+
+static struct attribute *dfl_dev_attrs[] = {
+	&dev_attr_type.attr,
+	&dev_attr_feature_id.attr,
+	NULL,
+};
+
+ATTRIBUTE_GROUPS(dfl_dev);
+
+static struct bus_type dfl_bus_type = {
+	.name		= "dfl",
+	.match		= dfl_bus_match,
+	.probe		= dfl_bus_probe,
+	.remove		= dfl_bus_remove,
+	.uevent		= dfl_bus_uevent,
+	.dev_groups	= dfl_dev_groups,
+};
+
+static void release_dfl_dev(struct device *dev)
+{
+	struct dfl_device *ddev = to_dfl_dev(dev);
+
+	if (ddev->mmio_res.parent)
+		release_resource(&ddev->mmio_res);
+
+	ida_simple_remove(&dfl_device_ida, ddev->id);
+	kfree(ddev->irqs);
+	kfree(ddev);
+}
+
+static struct dfl_device *
+dfl_dev_add(struct dfl_feature_platform_data *pdata,
+	    struct dfl_feature *feature)
+{
+	struct platform_device *pdev = pdata->dev;
+	struct resource *parent_res;
+	struct dfl_device *ddev;
+	int id, i, ret;
+
+	ddev = kzalloc(sizeof(*ddev), GFP_KERNEL);
+	if (!ddev)
+		return ERR_PTR(-ENOMEM);
+
+	id = ida_simple_get(&dfl_device_ida, 0, 0, GFP_KERNEL);
+	if (id < 0) {
+		dev_err(&pdev->dev, "unable to get id\n");
+		kfree(ddev);
+		return ERR_PTR(id);
+	}
+
+	/* freeing resources by put_device() after device_initialize() */
+	device_initialize(&ddev->dev);
+	ddev->dev.parent = &pdev->dev;
+	ddev->dev.bus = &dfl_bus_type;
+	ddev->dev.release = release_dfl_dev;
+	ddev->id = id;
+	ret = dev_set_name(&ddev->dev, "dfl_dev.%d", id);
+	if (ret)
+		goto put_dev;
+
+	ddev->type = feature_dev_id_type(pdev);
+	ddev->feature_id = feature->id;
+	ddev->cdev = pdata->dfl_cdev;
+
+	/* add mmio resource */
+	parent_res = &pdev->resource[feature->resource_index];
+	ddev->mmio_res.flags = IORESOURCE_MEM;
+	ddev->mmio_res.start = parent_res->start;
+	ddev->mmio_res.end = parent_res->end;
+	ddev->mmio_res.name = dev_name(&ddev->dev);
+	ret = insert_resource(parent_res, &ddev->mmio_res);
+	if (ret) {
+		dev_err(&pdev->dev, "%s failed to claim resource: %pR\n",
+			dev_name(&ddev->dev), &ddev->mmio_res);
+		goto put_dev;
+	}
+
+	/* then add irq resource */
+	if (feature->nr_irqs) {
+		ddev->irqs = kcalloc(feature->nr_irqs,
+				     sizeof(*ddev->irqs), GFP_KERNEL);
+		if (!ddev->irqs) {
+			ret = -ENOMEM;
+			goto put_dev;
+		}
+
+		for (i = 0; i < feature->nr_irqs; i++)
+			ddev->irqs[i] = feature->irq_ctx[i].irq;
+
+		ddev->num_irqs = feature->nr_irqs;
+	}
+
+	ret = device_add(&ddev->dev);
+	if (ret)
+		goto put_dev;
+
+	dev_info(&pdev->dev, "add dfl_dev: %s\n", dev_name(&ddev->dev));
+	return ddev;
+
+put_dev:
+	/* calls release_dfl_dev() which does the clean up  */
+	put_device(&ddev->dev);
+	return ERR_PTR(ret);
+}
+
+static void dfl_devs_uinit(struct dfl_feature_platform_data *pdata)
+{
+	struct dfl_feature *feature;
+
+	dfl_fpga_dev_for_each_feature(pdata, feature) {
+		if (feature->ddev) {
+			device_unregister(&feature->ddev->dev);
+			feature->ddev = NULL;
+		}
+	}
+}
+
+static int dfl_devs_init(struct platform_device *pdev)
+{
+	struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	struct dfl_feature *feature;
+	struct dfl_device *ddev;
+	int ret;
+
+	dfl_fpga_dev_for_each_feature(pdata, feature) {
+		if (feature->ioaddr)
+			continue;
+
+		if (feature->ddev) {
+			ret = -EBUSY;
+			goto err;
+		}
+
+		ddev = dfl_dev_add(pdata, feature);
+		if (IS_ERR(ddev)) {
+			ret = PTR_ERR(ddev);
+			goto err;
+		}
+
+		feature->ddev = ddev;
+	}
+
+	return 0;
+
+err:
+	dfl_devs_uinit(pdata);
+	return ret;
+}
+
+int __dfl_driver_register(struct dfl_driver *dfl_drv, struct module *owner)
+{
+	if (!dfl_drv || !dfl_drv->probe || !dfl_drv->id_table)
+		return -EINVAL;
+
+	dfl_drv->drv.owner = owner;
+	dfl_drv->drv.bus = &dfl_bus_type;
+
+	return driver_register(&dfl_drv->drv);
+}
+EXPORT_SYMBOL(__dfl_driver_register);
+
+void dfl_driver_unregister(struct dfl_driver *dfl_drv)
+{
+	driver_unregister(&dfl_drv->drv);
+}
+EXPORT_SYMBOL(dfl_driver_unregister);
+
 #define is_header_feature(feature) ((feature)->id == FEATURE_ID_FIU_HEADER)
 
 /**
@@ -261,12 +494,15 @@ void dfl_fpga_dev_feature_uinit(struct platform_device *pdev)
 	struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct dfl_feature *feature;
 
-	dfl_fpga_dev_for_each_feature(pdata, feature)
+	dfl_devs_uinit(pdata);
+
+	dfl_fpga_dev_for_each_feature(pdata, feature) {
 		if (feature->ops) {
 			if (feature->ops->uinit)
 				feature->ops->uinit(pdev, feature);
 			feature->ops = NULL;
 		}
+	}
 }
 EXPORT_SYMBOL_GPL(dfl_fpga_dev_feature_uinit);
 
@@ -347,6 +583,10 @@ int dfl_fpga_dev_feature_init(struct platform_device *pdev,
 		drv++;
 	}
 
+	ret = dfl_devs_init(pdev);
+	if (ret)
+		goto exit;
+
 	return 0;
 exit:
 	dfl_fpga_dev_feature_uinit(pdev);
@@ -1282,11 +1522,17 @@ static int __init dfl_fpga_init(void)
 {
 	int ret;
 
+	ret = bus_register(&dfl_bus_type);
+	if (ret)
+		return ret;
+
 	dfl_ids_init();
 
 	ret = dfl_chardev_init();
-	if (ret)
+	if (ret) {
 		dfl_ids_destroy();
+		bus_unregister(&dfl_bus_type);
+	}
 
 	return ret;
 }
@@ -1624,6 +1870,7 @@ static void __exit dfl_fpga_exit(void)
 {
 	dfl_chardev_uinit();
 	dfl_ids_destroy();
+	bus_unregister(&dfl_bus_type);
 }
 
 module_init(dfl_fpga_init);
diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index 5973769..d7fd03a 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -246,6 +246,7 @@ struct dfl_feature {
 	struct dfl_feature_irq_ctx *irq_ctx;
 	unsigned int nr_irqs;
 	const struct dfl_feature_ops *ops;
+	struct dfl_device *ddev;
 	void *priv;
 };
 
@@ -514,4 +515,88 @@ long dfl_feature_ioctl_set_irq(struct platform_device *pdev,
 			       struct dfl_feature *feature,
 			       unsigned long arg);
 
+/**
+ * enum dfl_id_type - define the DFL FIU types
+ */
+enum dfl_id_type {
+	FME_ID,
+	PORT_ID,
+	DFL_ID_MAX,
+};
+
+/**
+ * struct dfl_device_id -  dfl device identifier
+ * @type: Type of DFL FIU of the device. See enum dfl_id_type.
+ * @feature_id: contains 12 bits feature identifier local to its DFL FIU type.
+ * @driver_data: Driver specific data
+ */
+struct dfl_device_id {
+	u8 type;
+	u16 feature_id;
+	unsigned long driver_data;
+};
+
+/**
+ * struct dfl_device - represent an dfl device on dfl bus
+ *
+ * @dev: Generic device interface.
+ * @id: id of the dfl device
+ * @type: Type of DFL FIU of the device. See enum dfl_id_type.
+ * @feature_id: 16 bits feature identifier local to its DFL FIU type.
+ * @mmio_res: MMIO resource of this dfl device.
+ * @irqs: List of Linux IRQ numbers of this dfl device.
+ * @num_irqs: number of IRQs supported by this dfl device.
+ * @cdev: pointer to DFL FPGA container device this dfl device belongs to.
+ * @id_entry: matched id entry in dfl driver's id table.
+ */
+struct dfl_device {
+	struct device dev;
+	int id;
+	u8 type;
+	u16 feature_id;
+	struct resource mmio_res;
+	int *irqs;
+	unsigned int num_irqs;
+	struct dfl_fpga_cdev *cdev;
+	const struct dfl_device_id *id_entry;
+};
+
+/**
+ * struct dfl_driver - represent an dfl device driver
+ *
+ * @drv: Driver model structure.
+ * @id_table: Pointer to table of device IDs the driver is interested in.
+ *	      { } member terminated.
+ * @probe: Mandatory callback for device binding.
+ * @remove: Callback for device unbinding.
+ */
+struct dfl_driver {
+	struct device_driver drv;
+	const struct dfl_device_id *id_table;
+
+	int (*probe)(struct dfl_device *dfl_dev);
+	void (*remove)(struct dfl_device *dfl_dev);
+};
+
+#define to_dfl_dev(d) container_of(d, struct dfl_device, dev)
+#define to_dfl_drv(d) container_of(d, struct dfl_driver, drv)
+
+/*
+ * use a macro to avoid include chaining to get THIS_MODULE
+ */
+#define dfl_driver_register(drv) \
+	__dfl_driver_register(drv, THIS_MODULE)
+int __dfl_driver_register(struct dfl_driver *dfl_drv, struct module *owner);
+void dfl_driver_unregister(struct dfl_driver *dfl_drv);
+
+/*
+ * module_dfl_driver() - Helper macro for drivers that don't do
+ * anything special in module init/exit.  This eliminates a lot of
+ * boilerplate.  Each module may only use this macro once, and
+ * calling it replaces module_init() and module_exit()
+ */
+#define module_dfl_driver(__dfl_driver) \
+	module_driver(__dfl_driver, dfl_driver_register, \
+		      dfl_driver_unregister)
+
 #endif /* __FPGA_DFL_H */
-- 
2.7.4

RE: [PATCH v4 3/4] fpga: dfl: create a dfl bus type to support DFL devices

[Wu, Hao]

> 
> A new bus type "dfl" is introduced for private features which are not
> initialized by DFL feature drivers (dfl-fme & dfl-afu drivers). So these
> private features could be handled by separate driver modules.
> 
> DFL feature drivers (dfl-fme, dfl-port) will create DFL devices on
> enumeration. DFL drivers could be registered on this bus to match these
> DFL devices. They are matched by dfl type & feature_id.
> 
> Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> Signed-off-by: Wu Hao <hao.wu@intel.com>
> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> Reviewed-by: Tom Rix <trix@redhat.com>
> ---
> v2: change the bus uevent format.
>     change the dfl device's sysfs name format.
>     refactor dfl_dev_add().
>     minor fixes for comments from Hao and Tom.
> v3: no change.
> v4: improve the uevent format, 4 bits for type & 12 bits for id.
>     change dfl_device->type to u8.
>     A dedicate field in struct dfl_feature for dfl device instance.
>     error out if dfl_device already exist on dfl_devs_init().
> ---
>  Documentation/ABI/testing/sysfs-bus-dfl |  15 ++
>  drivers/fpga/dfl.c                      | 263 +++++++++++++++++++++++++++++++-
>  drivers/fpga/dfl.h                      |  85 +++++++++++
>  3 files changed, 355 insertions(+), 8 deletions(-)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-dfl
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-dfl
> b/Documentation/ABI/testing/sysfs-bus-dfl
> new file mode 100644
> index 0000000..4d74cc0
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-dfl
> @@ -0,0 +1,15 @@
> +What:		/sys/bus/dfl/devices/dfl_dev.X/type
> +Date:		July 2020
> +KernelVersion:	5.10
> +Contact:	Xu Yilun <yilun.xu@intel.com>
> +Description:	Read-only. It returns type of DFL FIU of the device. Now DFL
> +		supports 2 FIU types, 0 for FME, 1 for PORT.
> +		Format: 0x%x
> +
> +What:		/sys/bus/dfl/devices/dfl_dev.X/feature_id
> +Date:		July 2020
> +KernelVersion:	5.10
> +Contact:	Xu Yilun <yilun.xu@intel.com>
> +Description:	Read-only. It returns feature identifier local to its DFL FIU
> +		type.
> +		Format: 0x%x
> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> index b5257d7..51cef85 100644
> --- a/drivers/fpga/dfl.c
> +++ b/drivers/fpga/dfl.c
> @@ -30,12 +30,6 @@ static DEFINE_MUTEX(dfl_id_mutex);
>   * index to dfl_chardevs table. If no chardev support just set devt_type
>   * as one invalid index (DFL_FPGA_DEVT_MAX).
>   */
> -enum dfl_id_type {
> -	FME_ID,		/* fme id allocation and mapping */
> -	PORT_ID,	/* port id allocation and mapping */
> -	DFL_ID_MAX,
> -};
> -
>  enum dfl_fpga_devt_type {
>  	DFL_FPGA_DEVT_FME,
>  	DFL_FPGA_DEVT_PORT,
> @@ -250,6 +244,245 @@ int dfl_fpga_check_port_id(struct platform_device
> *pdev, void *pport_id)
>  }
>  EXPORT_SYMBOL_GPL(dfl_fpga_check_port_id);
> 
> +static DEFINE_IDA(dfl_device_ida);
> +
> +static const struct dfl_device_id *
> +dfl_match_one_device(const struct dfl_device_id *id, struct dfl_device
> *ddev)
> +{
> +	if (id->type == ddev->type && id->feature_id == ddev->feature_id)
> +		return id;
> +
> +	return NULL;
> +}
> +
> +static int dfl_bus_match(struct device *dev, struct device_driver *drv)
> +{
> +	struct dfl_device *ddev = to_dfl_dev(dev);
> +	struct dfl_driver *ddrv = to_dfl_drv(drv);
> +	const struct dfl_device_id *id_entry = ddrv->id_table;
> +
> +	if (id_entry) {
> +		while (id_entry->feature_id) {
> +			if (dfl_match_one_device(id_entry, ddev)) {
> +				ddev->id_entry = id_entry;
> +				return 1;
> +			}
> +			id_entry++;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int dfl_bus_probe(struct device *dev)
> +{
> +	struct dfl_device *ddev = to_dfl_dev(dev);
> +	struct dfl_driver *ddrv = to_dfl_drv(dev->driver);
> +
> +	return ddrv->probe(ddev);
> +}
> +
> +static int dfl_bus_remove(struct device *dev)
> +{
> +	struct dfl_device *ddev = to_dfl_dev(dev);
> +	struct dfl_driver *ddrv = to_dfl_drv(dev->driver);
> +
> +	if (ddrv->remove)
> +		ddrv->remove(ddev);
> +
> +	return 0;
> +}
> +
> +static int dfl_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
> +{
> +	struct dfl_device *ddev = to_dfl_dev(dev);
> +
> +	/* The type has 4 valid bits and feature_id has 12 valid bits */
> +	return add_uevent_var(env, "MODALIAS=dfl:t%01Xf%03X",
> +			      ddev->type, ddev->feature_id);
> +}
> +
> +/* show dfl info fields */
> +#define dfl_info_attr(field, format_string)				\
> +static ssize_t								\
> +field##_show(struct device *dev, struct device_attribute *attr,
> 	\
> +	     char *buf)							\
> +{									\
> +	struct dfl_device *ddev = to_dfl_dev(dev);			\
> +									\
> +	return sprintf(buf, format_string, ddev->field);		\
> +}									\
> +static DEVICE_ATTR_RO(field)
> +
> +dfl_info_attr(type, "0x%x\n");
> +dfl_info_attr(feature_id, "0x%x\n");
> +
> +static struct attribute *dfl_dev_attrs[] = {
> +	&dev_attr_type.attr,
> +	&dev_attr_feature_id.attr,
> +	NULL,
> +};
> +
> +ATTRIBUTE_GROUPS(dfl_dev);
> +
> +static struct bus_type dfl_bus_type = {
> +	.name		= "dfl",
> +	.match		= dfl_bus_match,
> +	.probe		= dfl_bus_probe,
> +	.remove		= dfl_bus_remove,
> +	.uevent		= dfl_bus_uevent,
> +	.dev_groups	= dfl_dev_groups,
> +};
> +
> +static void release_dfl_dev(struct device *dev)
> +{
> +	struct dfl_device *ddev = to_dfl_dev(dev);
> +
> +	if (ddev->mmio_res.parent)
> +		release_resource(&ddev->mmio_res);
> +
> +	ida_simple_remove(&dfl_device_ida, ddev->id);
> +	kfree(ddev->irqs);
> +	kfree(ddev);
> +}
> +
> +static struct dfl_device *
> +dfl_dev_add(struct dfl_feature_platform_data *pdata,
> +	    struct dfl_feature *feature)
> +{
> +	struct platform_device *pdev = pdata->dev;
> +	struct resource *parent_res;
> +	struct dfl_device *ddev;
> +	int id, i, ret;
> +
> +	ddev = kzalloc(sizeof(*ddev), GFP_KERNEL);
> +	if (!ddev)
> +		return ERR_PTR(-ENOMEM);
> +
> +	id = ida_simple_get(&dfl_device_ida, 0, 0, GFP_KERNEL);
> +	if (id < 0) {
> +		dev_err(&pdev->dev, "unable to get id\n");
> +		kfree(ddev);
> +		return ERR_PTR(id);
> +	}
> +
> +	/* freeing resources by put_device() after device_initialize() */
> +	device_initialize(&ddev->dev);
> +	ddev->dev.parent = &pdev->dev;
> +	ddev->dev.bus = &dfl_bus_type;
> +	ddev->dev.release = release_dfl_dev;
> +	ddev->id = id;
> +	ret = dev_set_name(&ddev->dev, "dfl_dev.%d", id);
> +	if (ret)
> +		goto put_dev;
> +
> +	ddev->type = feature_dev_id_type(pdev);
> +	ddev->feature_id = feature->id;
> +	ddev->cdev = pdata->dfl_cdev;
> +
> +	/* add mmio resource */
> +	parent_res = &pdev->resource[feature->resource_index];
> +	ddev->mmio_res.flags = IORESOURCE_MEM;
> +	ddev->mmio_res.start = parent_res->start;
> +	ddev->mmio_res.end = parent_res->end;
> +	ddev->mmio_res.name = dev_name(&ddev->dev);

It doesn't reuse the pdev->resource only because it wants a more proper name
here?

> +	ret = insert_resource(parent_res, &ddev->mmio_res);
> +	if (ret) {
> +		dev_err(&pdev->dev, "%s failed to claim resource: %pR\n",
> +			dev_name(&ddev->dev), &ddev->mmio_res);
> +		goto put_dev;
> +	}
> +
> +	/* then add irq resource */
> +	if (feature->nr_irqs) {
> +		ddev->irqs = kcalloc(feature->nr_irqs,
> +				     sizeof(*ddev->irqs), GFP_KERNEL);
> +		if (!ddev->irqs) {
> +			ret = -ENOMEM;
> +			goto put_dev;
> +		}
> +
> +		for (i = 0; i < feature->nr_irqs; i++)
> +			ddev->irqs[i] = feature->irq_ctx[i].irq;
> +
> +		ddev->num_irqs = feature->nr_irqs;
> +	}
> +
> +	ret = device_add(&ddev->dev);
> +	if (ret)
> +		goto put_dev;
> +
> +	dev_info(&pdev->dev, "add dfl_dev: %s\n", dev_name(&ddev->dev));
> +	return ddev;
> +
> +put_dev:
> +	/* calls release_dfl_dev() which does the clean up  */
> +	put_device(&ddev->dev);
> +	return ERR_PTR(ret);
> +}
> +
> +static void dfl_devs_uinit(struct dfl_feature_platform_data *pdata)
> +{
> +	struct dfl_feature *feature;
> +
> +	dfl_fpga_dev_for_each_feature(pdata, feature) {
> +		if (feature->ddev) {
> +			device_unregister(&feature->ddev->dev);
> +			feature->ddev = NULL;
> +		}
> +	}
> +}
> +
> +static int dfl_devs_init(struct platform_device *pdev)
> +{
> +	struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev-
> >dev);
> +	struct dfl_feature *feature;
> +	struct dfl_device *ddev;
> +	int ret;
> +
> +	dfl_fpga_dev_for_each_feature(pdata, feature) {
> +		if (feature->ioaddr)
> +			continue;
> +
> +		if (feature->ddev) {
> +			ret = -EBUSY;

or -EEXIST

> +			goto err;
> +		}
> +
> +		ddev = dfl_dev_add(pdata, feature);
> +		if (IS_ERR(ddev)) {
> +			ret = PTR_ERR(ddev);
> +			goto err;
> +		}
> +
> +		feature->ddev = ddev;
> +	}
> +
> +	return 0;
> +
> +err:
> +	dfl_devs_uinit(pdata);
> +	return ret;
> +}
> +
> +int __dfl_driver_register(struct dfl_driver *dfl_drv, struct module *owner)
> +{
> +	if (!dfl_drv || !dfl_drv->probe || !dfl_drv->id_table)
> +		return -EINVAL;
> +
> +	dfl_drv->drv.owner = owner;
> +	dfl_drv->drv.bus = &dfl_bus_type;
> +
> +	return driver_register(&dfl_drv->drv);
> +}
> +EXPORT_SYMBOL(__dfl_driver_register);
> +
> +void dfl_driver_unregister(struct dfl_driver *dfl_drv)
> +{
> +	driver_unregister(&dfl_drv->drv);
> +}
> +EXPORT_SYMBOL(dfl_driver_unregister);
> +
>  #define is_header_feature(feature) ((feature)->id ==
> FEATURE_ID_FIU_HEADER)
> 
>  /**
> @@ -261,12 +494,15 @@ void dfl_fpga_dev_feature_uinit(struct
> platform_device *pdev)
>  	struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev-
> >dev);
>  	struct dfl_feature *feature;
> 
> -	dfl_fpga_dev_for_each_feature(pdata, feature)
> +	dfl_devs_uinit(pdata);

Or it's better to rename as dfl_devs_remove(pdata) or something?

> +
> +	dfl_fpga_dev_for_each_feature(pdata, feature) {
>  		if (feature->ops) {
>  			if (feature->ops->uinit)
>  				feature->ops->uinit(pdev, feature);
>  			feature->ops = NULL;
>  		}
> +	}
>  }
>  EXPORT_SYMBOL_GPL(dfl_fpga_dev_feature_uinit);
> 
> @@ -347,6 +583,10 @@ int dfl_fpga_dev_feature_init(struct
> platform_device *pdev,
>  		drv++;
>  	}
> 
> +	ret = dfl_devs_init(pdev);
> +	if (ret)
> +		goto exit;
> +
>  	return 0;
>  exit:
>  	dfl_fpga_dev_feature_uinit(pdev);
> @@ -1282,11 +1522,17 @@ static int __init dfl_fpga_init(void)
>  {
>  	int ret;
> 
> +	ret = bus_register(&dfl_bus_type);
> +	if (ret)
> +		return ret;
> +
>  	dfl_ids_init();
> 
>  	ret = dfl_chardev_init();
> -	if (ret)
> +	if (ret) {
>  		dfl_ids_destroy();
> +		bus_unregister(&dfl_bus_type);
> +	}
> 
>  	return ret;
>  }
> @@ -1624,6 +1870,7 @@ static void __exit dfl_fpga_exit(void)
>  {
>  	dfl_chardev_uinit();
>  	dfl_ids_destroy();
> +	bus_unregister(&dfl_bus_type);
>  }
> 
>  module_init(dfl_fpga_init);
> diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
> index 5973769..d7fd03a 100644
> --- a/drivers/fpga/dfl.h
> +++ b/drivers/fpga/dfl.h
> @@ -246,6 +246,7 @@ struct dfl_feature {
>  	struct dfl_feature_irq_ctx *irq_ctx;
>  	unsigned int nr_irqs;
>  	const struct dfl_feature_ops *ops;
> +	struct dfl_device *ddev;

Add some description please.

>  	void *priv;
>  };
> 
> @@ -514,4 +515,88 @@ long dfl_feature_ioctl_set_irq(struct
> platform_device *pdev,
>  			       struct dfl_feature *feature,
>  			       unsigned long arg);
> 
> +/**
> + * enum dfl_id_type - define the DFL FIU types
> + */
> +enum dfl_id_type {
> +	FME_ID,
> +	PORT_ID,
> +	DFL_ID_MAX,
> +};
> +
> +/**
> + * struct dfl_device_id -  dfl device identifier
> + * @type: Type of DFL FIU of the device. See enum dfl_id_type.

Only 4 bits used.

Hao

> + * @feature_id: contains 12 bits feature identifier local to its DFL FIU type.
> + * @driver_data: Driver specific data
> + */
> +struct dfl_device_id {
> +	u8 type;
> +	u16 feature_id;
> +	unsigned long driver_data;
> +};
> +
> +/**
> + * struct dfl_device - represent an dfl device on dfl bus
> + *
> + * @dev: Generic device interface.
> + * @id: id of the dfl device
> + * @type: Type of DFL FIU of the device. See enum dfl_id_type.
> + * @feature_id: 16 bits feature identifier local to its DFL FIU type.
> + * @mmio_res: MMIO resource of this dfl device.
> + * @irqs: List of Linux IRQ numbers of this dfl device.
> + * @num_irqs: number of IRQs supported by this dfl device.
> + * @cdev: pointer to DFL FPGA container device this dfl device belongs to.
> + * @id_entry: matched id entry in dfl driver's id table.
> + */
> +struct dfl_device {
> +	struct device dev;
> +	int id;
> +	u8 type;
> +	u16 feature_id;
> +	struct resource mmio_res;
> +	int *irqs;
> +	unsigned int num_irqs;
> +	struct dfl_fpga_cdev *cdev;
> +	const struct dfl_device_id *id_entry;
> +};
> +
> +/**
> + * struct dfl_driver - represent an dfl device driver
> + *
> + * @drv: Driver model structure.
> + * @id_table: Pointer to table of device IDs the driver is interested in.
> + *	      { } member terminated.
> + * @probe: Mandatory callback for device binding.
> + * @remove: Callback for device unbinding.
> + */
> +struct dfl_driver {
> +	struct device_driver drv;
> +	const struct dfl_device_id *id_table;
> +
> +	int (*probe)(struct dfl_device *dfl_dev);
> +	void (*remove)(struct dfl_device *dfl_dev);
> +};
> +
> +#define to_dfl_dev(d) container_of(d, struct dfl_device, dev)
> +#define to_dfl_drv(d) container_of(d, struct dfl_driver, drv)
> +
> +/*
> + * use a macro to avoid include chaining to get THIS_MODULE
> + */
> +#define dfl_driver_register(drv) \
> +	__dfl_driver_register(drv, THIS_MODULE)
> +int __dfl_driver_register(struct dfl_driver *dfl_drv, struct module *owner);
> +void dfl_driver_unregister(struct dfl_driver *dfl_drv);
> +
> +/*
> + * module_dfl_driver() - Helper macro for drivers that don't do
> + * anything special in module init/exit.  This eliminates a lot of
> + * boilerplate.  Each module may only use this macro once, and
> + * calling it replaces module_init() and module_exit()
> + */
> +#define module_dfl_driver(__dfl_driver) \
> +	module_driver(__dfl_driver, dfl_driver_register, \
> +		      dfl_driver_unregister)
> +
>  #endif /* __FPGA_DFL_H */
> --
> 2.7.4

Re: [PATCH v4 3/4] fpga: dfl: create a dfl bus type to support DFL devices

[Xu Yilun]

On Mon, Aug 10, 2020 at 02:36:44PM +0800, Wu, Hao wrote:
> >
> > A new bus type "dfl" is introduced for private features which are not
> > initialized by DFL feature drivers (dfl-fme & dfl-afu drivers). So these
> > private features could be handled by separate driver modules.
> >
> > DFL feature drivers (dfl-fme, dfl-port) will create DFL devices on
> > enumeration. DFL drivers could be registered on this bus to match these
> > DFL devices. They are matched by dfl type & feature_id.
> >
> > Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> > Signed-off-by: Wu Hao <hao.wu@intel.com>
> > Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> > Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> > Reviewed-by: Tom Rix <trix@redhat.com>
> > ---
> > v2: change the bus uevent format.
> >     change the dfl device's sysfs name format.
> >     refactor dfl_dev_add().
> >     minor fixes for comments from Hao and Tom.
> > v3: no change.
> > v4: improve the uevent format, 4 bits for type & 12 bits for id.
> >     change dfl_device->type to u8.
> >     A dedicate field in struct dfl_feature for dfl device instance.
> >     error out if dfl_device already exist on dfl_devs_init().
> > ---
> >  Documentation/ABI/testing/sysfs-bus-dfl |  15 ++
> >  drivers/fpga/dfl.c                      | 263 +++++++++++++++++++++++++++++++-
> >  drivers/fpga/dfl.h                      |  85 +++++++++++
> >  3 files changed, 355 insertions(+), 8 deletions(-)
> >  create mode 100644 Documentation/ABI/testing/sysfs-bus-dfl
> >
> > diff --git a/Documentation/ABI/testing/sysfs-bus-dfl
> > b/Documentation/ABI/testing/sysfs-bus-dfl
> > new file mode 100644
> > index 0000000..4d74cc0
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/sysfs-bus-dfl
> > @@ -0,0 +1,15 @@
> > +What:/sys/bus/dfl/devices/dfl_dev.X/type
> > +Date:July 2020
> > +KernelVersion:5.10
> > +Contact:Xu Yilun <yilun.xu@intel.com>
> > +Description:Read-only. It returns type of DFL FIU of the device. Now DFL
> > +supports 2 FIU types, 0 for FME, 1 for PORT.
> > +Format: 0x%x
> > +
> > +What:/sys/bus/dfl/devices/dfl_dev.X/feature_id
> > +Date:July 2020
> > +KernelVersion:5.10
> > +Contact:Xu Yilun <yilun.xu@intel.com>
> > +Description:Read-only. It returns feature identifier local to its DFL FIU
> > +type.
> > +Format: 0x%x
> > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> > index b5257d7..51cef85 100644
> > --- a/drivers/fpga/dfl.c
> > +++ b/drivers/fpga/dfl.c
> > @@ -30,12 +30,6 @@ static DEFINE_MUTEX(dfl_id_mutex);
> >   * index to dfl_chardevs table. If no chardev support just set devt_type
> >   * as one invalid index (DFL_FPGA_DEVT_MAX).
> >   */
> > -enum dfl_id_type {
> > -FME_ID,/* fme id allocation and mapping */
> > -PORT_ID,/* port id allocation and mapping */
> > -DFL_ID_MAX,
> > -};
> > -
> >  enum dfl_fpga_devt_type {
> >  DFL_FPGA_DEVT_FME,
> >  DFL_FPGA_DEVT_PORT,
> > @@ -250,6 +244,245 @@ int dfl_fpga_check_port_id(struct platform_device
> > *pdev, void *pport_id)
> >  }
> >  EXPORT_SYMBOL_GPL(dfl_fpga_check_port_id);
> >
> > +static DEFINE_IDA(dfl_device_ida);
> > +
> > +static const struct dfl_device_id *
> > +dfl_match_one_device(const struct dfl_device_id *id, struct dfl_device
> > *ddev)
> > +{
> > +if (id->type == ddev->type && id->feature_id == ddev->feature_id)
> > +return id;
> > +
> > +return NULL;
> > +}
> > +
> > +static int dfl_bus_match(struct device *dev, struct device_driver *drv)
> > +{
> > +struct dfl_device *ddev = to_dfl_dev(dev);
> > +struct dfl_driver *ddrv = to_dfl_drv(drv);
> > +const struct dfl_device_id *id_entry = ddrv->id_table;
> > +
> > +if (id_entry) {
> > +while (id_entry->feature_id) {
> > +if (dfl_match_one_device(id_entry, ddev)) {
> > +ddev->id_entry = id_entry;
> > +return 1;
> > +}
> > +id_entry++;
> > +}
> > +}
> > +
> > +return 0;
> > +}
> > +
> > +static int dfl_bus_probe(struct device *dev)
> > +{
> > +struct dfl_device *ddev = to_dfl_dev(dev);
> > +struct dfl_driver *ddrv = to_dfl_drv(dev->driver);
> > +
> > +return ddrv->probe(ddev);
> > +}
> > +
> > +static int dfl_bus_remove(struct device *dev)
> > +{
> > +struct dfl_device *ddev = to_dfl_dev(dev);
> > +struct dfl_driver *ddrv = to_dfl_drv(dev->driver);
> > +
> > +if (ddrv->remove)
> > +ddrv->remove(ddev);
> > +
> > +return 0;
> > +}
> > +
> > +static int dfl_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
> > +{
> > +struct dfl_device *ddev = to_dfl_dev(dev);
> > +
> > +/* The type has 4 valid bits and feature_id has 12 valid bits */
> > +return add_uevent_var(env, "MODALIAS=dfl:t%01Xf%03X",
> > +      ddev->type, ddev->feature_id);
> > +}
> > +
> > +/* show dfl info fields */
> > +#define dfl_info_attr(field, format_string)\
> > +static ssize_t\
> > +field##_show(struct device *dev, struct device_attribute *attr,
> > \
> > +     char *buf)\
> > +{\
> > +struct dfl_device *ddev = to_dfl_dev(dev);\
> > +\
> > +return sprintf(buf, format_string, ddev->field);\
> > +}\
> > +static DEVICE_ATTR_RO(field)
> > +
> > +dfl_info_attr(type, "0x%x\n");
> > +dfl_info_attr(feature_id, "0x%x\n");
> > +
> > +static struct attribute *dfl_dev_attrs[] = {
> > +&dev_attr_type.attr,
> > +&dev_attr_feature_id.attr,
> > +NULL,
> > +};
> > +
> > +ATTRIBUTE_GROUPS(dfl_dev);
> > +
> > +static struct bus_type dfl_bus_type = {
> > +.name= "dfl",
> > +.match= dfl_bus_match,
> > +.probe= dfl_bus_probe,
> > +.remove= dfl_bus_remove,
> > +.uevent= dfl_bus_uevent,
> > +.dev_groups= dfl_dev_groups,
> > +};
> > +
> > +static void release_dfl_dev(struct device *dev)
> > +{
> > +struct dfl_device *ddev = to_dfl_dev(dev);
> > +
> > +if (ddev->mmio_res.parent)
> > +release_resource(&ddev->mmio_res);
> > +
> > +ida_simple_remove(&dfl_device_ida, ddev->id);
> > +kfree(ddev->irqs);
> > +kfree(ddev);
> > +}
> > +
> > +static struct dfl_device *
> > +dfl_dev_add(struct dfl_feature_platform_data *pdata,
> > +    struct dfl_feature *feature)
> > +{
> > +struct platform_device *pdev = pdata->dev;
> > +struct resource *parent_res;
> > +struct dfl_device *ddev;
> > +int id, i, ret;
> > +
> > +ddev = kzalloc(sizeof(*ddev), GFP_KERNEL);
> > +if (!ddev)
> > +return ERR_PTR(-ENOMEM);
> > +
> > +id = ida_simple_get(&dfl_device_ida, 0, 0, GFP_KERNEL);
> > +if (id < 0) {
> > +dev_err(&pdev->dev, "unable to get id\n");
> > +kfree(ddev);
> > +return ERR_PTR(id);
> > +}
> > +
> > +/* freeing resources by put_device() after device_initialize() */
> > +device_initialize(&ddev->dev);
> > +ddev->dev.parent = &pdev->dev;
> > +ddev->dev.bus = &dfl_bus_type;
> > +ddev->dev.release = release_dfl_dev;
> > +ddev->id = id;
> > +ret = dev_set_name(&ddev->dev, "dfl_dev.%d", id);
> > +if (ret)
> > +goto put_dev;
> > +
> > +ddev->type = feature_dev_id_type(pdev);
> > +ddev->feature_id = feature->id;
> > +ddev->cdev = pdata->dfl_cdev;
> > +
> > +/* add mmio resource */
> > +parent_res = &pdev->resource[feature->resource_index];
> > +ddev->mmio_res.flags = IORESOURCE_MEM;
> > +ddev->mmio_res.start = parent_res->start;
> > +ddev->mmio_res.end = parent_res->end;
> > +ddev->mmio_res.name = dev_name(&ddev->dev);
> 
> It doesn't reuse the pdev->resource only because it wants a more proper name
> here?

I think yes. To be more precise, this mmio resource is another resource region
owned by the dfl device, although its range is the same as the parent
resource. It is the child of the parent resource. And we could see the
relationship from /proc/iomem. Also we could know exactly from
/proc/iomem which module owns the mem region.

> 
> > +ret = insert_resource(parent_res, &ddev->mmio_res);
> > +if (ret) {
> > +dev_err(&pdev->dev, "%s failed to claim resource: %pR\n",
> > +dev_name(&ddev->dev), &ddev->mmio_res);
> > +goto put_dev;
> > +}
> > +
> > +/* then add irq resource */
> > +if (feature->nr_irqs) {
> > +ddev->irqs = kcalloc(feature->nr_irqs,
> > +     sizeof(*ddev->irqs), GFP_KERNEL);
> > +if (!ddev->irqs) {
> > +ret = -ENOMEM;
> > +goto put_dev;
> > +}
> > +
> > +for (i = 0; i < feature->nr_irqs; i++)
> > +ddev->irqs[i] = feature->irq_ctx[i].irq;
> > +
> > +ddev->num_irqs = feature->nr_irqs;
> > +}
> > +
> > +ret = device_add(&ddev->dev);
> > +if (ret)
> > +goto put_dev;
> > +
> > +dev_info(&pdev->dev, "add dfl_dev: %s\n", dev_name(&ddev->dev));
> > +return ddev;
> > +
> > +put_dev:
> > +/* calls release_dfl_dev() which does the clean up  */
> > +put_device(&ddev->dev);
> > +return ERR_PTR(ret);
> > +}
> > +
> > +static void dfl_devs_uinit(struct dfl_feature_platform_data *pdata)
> > +{
> > +struct dfl_feature *feature;
> > +
> > +dfl_fpga_dev_for_each_feature(pdata, feature) {
> > +if (feature->ddev) {
> > +device_unregister(&feature->ddev->dev);
> > +feature->ddev = NULL;
> > +}
> > +}
> > +}
> > +
> > +static int dfl_devs_init(struct platform_device *pdev)
> > +{
> > +struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev-
> > >dev);
> > +struct dfl_feature *feature;
> > +struct dfl_device *ddev;
> > +int ret;
> > +
> > +dfl_fpga_dev_for_each_feature(pdata, feature) {
> > +if (feature->ioaddr)
> > +continue;
> > +
> > +if (feature->ddev) {
> > +ret = -EBUSY;
> 
> or -EEXIST

Yes, I could change it.

> 
> > +goto err;
> > +}
> > +
> > +ddev = dfl_dev_add(pdata, feature);
> > +if (IS_ERR(ddev)) {
> > +ret = PTR_ERR(ddev);
> > +goto err;
> > +}
> > +
> > +feature->ddev = ddev;
> > +}
> > +
> > +return 0;
> > +
> > +err:
> > +dfl_devs_uinit(pdata);
> > +return ret;
> > +}
> > +
> > +int __dfl_driver_register(struct dfl_driver *dfl_drv, struct module *owner)
> > +{
> > +if (!dfl_drv || !dfl_drv->probe || !dfl_drv->id_table)
> > +return -EINVAL;
> > +
> > +dfl_drv->drv.owner = owner;
> > +dfl_drv->drv.bus = &dfl_bus_type;
> > +
> > +return driver_register(&dfl_drv->drv);
> > +}
> > +EXPORT_SYMBOL(__dfl_driver_register);
> > +
> > +void dfl_driver_unregister(struct dfl_driver *dfl_drv)
> > +{
> > +driver_unregister(&dfl_drv->drv);
> > +}
> > +EXPORT_SYMBOL(dfl_driver_unregister);
> > +
> >  #define is_header_feature(feature) ((feature)->id ==
> > FEATURE_ID_FIU_HEADER)
> >
> >  /**
> > @@ -261,12 +494,15 @@ void dfl_fpga_dev_feature_uinit(struct
> > platform_device *pdev)
> >  struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev-
> > >dev);
> >  struct dfl_feature *feature;
> >
> > -dfl_fpga_dev_for_each_feature(pdata, feature)
> > +dfl_devs_uinit(pdata);
> 
> Or it's better to rename as dfl_devs_remove(pdata) or something?

I could change it.

> 
> > +
> > +dfl_fpga_dev_for_each_feature(pdata, feature) {
> >  if (feature->ops) {
> >  if (feature->ops->uinit)
> >  feature->ops->uinit(pdev, feature);
> >  feature->ops = NULL;
> >  }
> > +}
> >  }
> >  EXPORT_SYMBOL_GPL(dfl_fpga_dev_feature_uinit);
> >
> > @@ -347,6 +583,10 @@ int dfl_fpga_dev_feature_init(struct
> > platform_device *pdev,
> >  drv++;
> >  }
> >
> > +ret = dfl_devs_init(pdev);
> > +if (ret)
> > +goto exit;
> > +
> >  return 0;
> >  exit:
> >  dfl_fpga_dev_feature_uinit(pdev);
> > @@ -1282,11 +1522,17 @@ static int __init dfl_fpga_init(void)
> >  {
> >  int ret;
> >
> > +ret = bus_register(&dfl_bus_type);
> > +if (ret)
> > +return ret;
> > +
> >  dfl_ids_init();
> >
> >  ret = dfl_chardev_init();
> > -if (ret)
> > +if (ret) {
> >  dfl_ids_destroy();
> > +bus_unregister(&dfl_bus_type);
> > +}
> >
> >  return ret;
> >  }
> > @@ -1624,6 +1870,7 @@ static void __exit dfl_fpga_exit(void)
> >  {
> >  dfl_chardev_uinit();
> >  dfl_ids_destroy();
> > +bus_unregister(&dfl_bus_type);
> >  }
> >
> >  module_init(dfl_fpga_init);
> > diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
> > index 5973769..d7fd03a 100644
> > --- a/drivers/fpga/dfl.h
> > +++ b/drivers/fpga/dfl.h
> > @@ -246,6 +246,7 @@ struct dfl_feature {
> >  struct dfl_feature_irq_ctx *irq_ctx;
> >  unsigned int nr_irqs;
> >  const struct dfl_feature_ops *ops;
> > +struct dfl_device *ddev;
> 
> Add some description please.

Yes.

> 
> >  void *priv;
> >  };
> >
> > @@ -514,4 +515,88 @@ long dfl_feature_ioctl_set_irq(struct
> > platform_device *pdev,
> >         struct dfl_feature *feature,
> >         unsigned long arg);
> >
> > +/**
> > + * enum dfl_id_type - define the DFL FIU types
> > + */
> > +enum dfl_id_type {
> > +FME_ID,
> > +PORT_ID,
> > +DFL_ID_MAX,
> > +};
> > +
> > +/**
> > + * struct dfl_device_id -  dfl device identifier
> > + * @type: Type of DFL FIU of the device. See enum dfl_id_type.
> 
> Only 4 bits used.

I could make the comments more precise.

Thanks,
Yilun.

> 
> Hao
> 
> > + * @feature_id: contains 12 bits feature identifier local to its DFL FIU type.
> > + * @driver_data: Driver specific data
> > + */
> > +struct dfl_device_id {
> > +u8 type;
> > +u16 feature_id;
> > +unsigned long driver_data;
> > +};
> > +
> > +/**
> > + * struct dfl_device - represent an dfl device on dfl bus
> > + *
> > + * @dev: Generic device interface.
> > + * @id: id of the dfl device
> > + * @type: Type of DFL FIU of the device. See enum dfl_id_type.
> > + * @feature_id: 16 bits feature identifier local to its DFL FIU type.
> > + * @mmio_res: MMIO resource of this dfl device.
> > + * @irqs: List of Linux IRQ numbers of this dfl device.
> > + * @num_irqs: number of IRQs supported by this dfl device.
> > + * @cdev: pointer to DFL FPGA container device this dfl device belongs to.
> > + * @id_entry: matched id entry in dfl driver's id table.
> > + */
> > +struct dfl_device {
> > +struct device dev;
> > +int id;
> > +u8 type;
> > +u16 feature_id;
> > +struct resource mmio_res;
> > +int *irqs;
> > +unsigned int num_irqs;
> > +struct dfl_fpga_cdev *cdev;
> > +const struct dfl_device_id *id_entry;
> > +};
> > +
> > +/**
> > + * struct dfl_driver - represent an dfl device driver
> > + *
> > + * @drv: Driver model structure.
> > + * @id_table: Pointer to table of device IDs the driver is interested in.
> > + *      { } member terminated.
> > + * @probe: Mandatory callback for device binding.
> > + * @remove: Callback for device unbinding.
> > + */
> > +struct dfl_driver {
> > +struct device_driver drv;
> > +const struct dfl_device_id *id_table;
> > +
> > +int (*probe)(struct dfl_device *dfl_dev);
> > +void (*remove)(struct dfl_device *dfl_dev);
> > +};
> > +
> > +#define to_dfl_dev(d) container_of(d, struct dfl_device, dev)
> > +#define to_dfl_drv(d) container_of(d, struct dfl_driver, drv)
> > +
> > +/*
> > + * use a macro to avoid include chaining to get THIS_MODULE
> > + */
> > +#define dfl_driver_register(drv) \
> > +__dfl_driver_register(drv, THIS_MODULE)
> > +int __dfl_driver_register(struct dfl_driver *dfl_drv, struct module *owner);
> > +void dfl_driver_unregister(struct dfl_driver *dfl_drv);
> > +
> > +/*
> > + * module_dfl_driver() - Helper macro for drivers that don't do
> > + * anything special in module init/exit.  This eliminates a lot of
> > + * boilerplate.  Each module may only use this macro once, and
> > + * calling it replaces module_init() and module_exit()
> > + */
> > +#define module_dfl_driver(__dfl_driver) \
> > +module_driver(__dfl_driver, dfl_driver_register, \
> > +      dfl_driver_unregister)
> > +
> >  #endif /* __FPGA_DFL_H */
> > --
> > 2.7.4

[PATCH v4 4/4] fpga: dfl: add support for N3000 Nios private feature

[Xu Yilun]

This patch adds support for the Nios handshake private feature on Intel
N3000 FPGA Card.

The terminology "Nios" stands for the NIOS II - 32 bit embedded soft
processor designed for FPGAs. This private feature provides a handshake
interface to FPGA Nois firmware, which receives retimer configuration
command from host and executes via an internal SPI master. When Nios
finishes the configuration, host takes over the ownership of the SPI
master to control an Intel MAX10 BMC Chip on the SPI bus.

For Nios firmware handshake part, this driver requests the retimer
configuration for Nios with parameters from module param, and adds some
sysfs nodes for user to query Nios state.

For SPI part, this driver adds a spi-altera platform device as well as
the MAX10 BMC spi slave info. A spi-altera driver will be matched to
handle following the SPI work.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Tom Rix <trix@redhat.com>
---
v3: Add the doc for this driver
    Minor fixes for comments from Tom
v4: Move the err log in regmap implementation, and delete
     n3000_nios_writel/readl(), they have nothing to wrapper now.
    Some minor fixes and comments improvement.
---
 .../ABI/testing/sysfs-bus-dfl-devices-n3000-nios   |  18 +
 Documentation/fpga/dfl-n3000-nios.rst              |  41 ++
 Documentation/fpga/index.rst                       |   1 +
 drivers/fpga/Kconfig                               |  12 +
 drivers/fpga/Makefile                              |   2 +
 drivers/fpga/dfl-n3000-nios.c                      | 475 +++++++++++++++++++++
 6 files changed, 549 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
 create mode 100644 Documentation/fpga/dfl-n3000-nios.rst
 create mode 100644 drivers/fpga/dfl-n3000-nios.c

diff --git a/Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios b/Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
new file mode 100644
index 0000000..4b2b9c5
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
@@ -0,0 +1,18 @@
+What:		/sys/bus/dfl/devices/dfl_dev.X/fec_mode
+Date:		July 2020
+KernelVersion:	5.10
+Contact:	Xu Yilun <yilun.xu@intel.com>
+Description:	Read-only. It returns the FEC mode of the ethernet retimer
+		configured by NIOS firmware. "rs" for RS FEC mode, "kr" for
+		KR FEC mode, "no" FOR NO FEC mode. The FEC mode could be set
+		by module parameters, but it could only be set once after the
+		board powers up.
+		Format: string
+
+What:		/sys/bus/dfl/devices/dfl_dev.X/nios_fw_version
+Date:		July 2020
+KernelVersion:	5.10
+Contact:	Xu Yilun <yilun.xu@intel.com>
+Description:	Read-only. It returns the NIOS firmware version in FPGA. Its
+		format is "major.minor.patch".
+		Format: %x.%x.%x
diff --git a/Documentation/fpga/dfl-n3000-nios.rst b/Documentation/fpga/dfl-n3000-nios.rst
new file mode 100644
index 0000000..ecc14e3
--- /dev/null
+++ b/Documentation/fpga/dfl-n3000-nios.rst
@@ -0,0 +1,41 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================================
+DFL N3000 Nios Private Feature Driver
+=====================================
+
+The dfl N3000 Nios driver supports for the Nios handshake private feature on
+Intel N3000 FPGA Card.
+
+The terminology "Nios" stands for the NIOS II - 32 bit embedded soft processor
+designed for FPGAs. This private feature provides a handshake interface to FPGA
+Nios firmware, which receives the ethernet retimer configuration command from
+host and does the configuration via an internal SPI master. When Nios finishes
+the configuration, host takes over the ownership of the SPI master to control
+an Intel MAX10 BMC Chip on the SPI bus.
+
+So the driver does 2 major tasks on probe, uses the Nios firmware to configure
+the ethernet retimer, and then creates a spi master platform device with the
+MAX10 device info in spi_board_info.
+
+Module Parameters
+=================
+
+The dfl N3000 Nios driver supports the following module parameters:
+
+* fec_mode: string
+  Require the Nios firmware to set the FEC (Forward Error Correction) mode of
+  the ethernet retimer on the PAC N3000 FPGA card. The possible values could
+  be:
+
+  - "rs": Reed Solomon FEC (default)
+  - "kr": Fire Code FEC
+  - "no": No FEC
+
+  The configuration can only be set once after the board powers up, the
+  firmware will not accept second configuration afterward. So the fec mode
+  will not be changed if the module is reloaded with a different param value.
+
+  The configured value of the fec mode could be queried from sysfs node:
+
+  /sys/bus/dfl/devices/dfl_dev.X/fec_mode
diff --git a/Documentation/fpga/index.rst b/Documentation/fpga/index.rst
index f80f956..5fd3c37 100644
--- a/Documentation/fpga/index.rst
+++ b/Documentation/fpga/index.rst
@@ -8,6 +8,7 @@ fpga
     :maxdepth: 1
 
     dfl
+    dfl-n3000-nios
 
 .. only::  subproject and html
 
diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index 7cd5a29..f820142 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -191,6 +191,18 @@ config FPGA_DFL_AFU
 	  to the FPGA infrastructure via a Port. There may be more than one
 	  Port/AFU per DFL based FPGA device.
 
+config FPGA_DFL_N3000_NIOS
+        tristate "FPGA DFL N3000 NIOS Driver"
+        depends on FPGA_DFL
+        select REGMAP
+        help
+	  This is the driver for the nios handshake private feature on Intel
+	  N3000 FPGA Card. This private feature provides a handshake interface
+	  to FPGA NIOS firmware, which receives retimer configuration command
+	  from host and executes via an internal SPI master. When nios finished
+	  the configuration, host takes over the ownership of the SPI master to
+	  control an Intel MAX10 BMC Chip on the SPI bus.
+
 config FPGA_DFL_PCI
 	tristate "FPGA DFL PCIe Device Driver"
 	depends on PCI && FPGA_DFL
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index d8e21df..27f20f2 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -44,5 +44,7 @@ dfl-fme-objs += dfl-fme-perf.o
 dfl-afu-objs := dfl-afu-main.o dfl-afu-region.o dfl-afu-dma-region.o
 dfl-afu-objs += dfl-afu-error.o
 
+obj-$(CONFIG_FPGA_DFL_N3000_NIOS)      += dfl-n3000-nios.o
+
 # Drivers for FPGAs which implement DFL
 obj-$(CONFIG_FPGA_DFL_PCI)		+= dfl-pci.o
diff --git a/drivers/fpga/dfl-n3000-nios.c b/drivers/fpga/dfl-n3000-nios.c
new file mode 100644
index 0000000..b3093a2
--- /dev/null
+++ b/drivers/fpga/dfl-n3000-nios.c
@@ -0,0 +1,475 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DFL device driver for Nios private feature on Intel PAC N3000
+ *
+ * Copyright (C) 2019-2020 Intel Corporation, Inc.
+ *
+ * Authors:
+ *   Wu Hao <hao.wu@intel.com>
+ *   Xu Yilun <yilun.xu@intel.com>
+ */
+#include <linux/bitfield.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/stddef.h>
+#include <linux/spi/altera.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+
+#include "dfl.h"
+
+static char *fec_mode = "rs";
+module_param(fec_mode, charp, 0444);
+MODULE_PARM_DESC(fec_mode, "FEC mode of the ethernet retimer on PAC N3000 FPGA card");
+
+/* N3000 Nios private feature registers */
+#define NIOS_SPI_PARAM			0x8
+#define PARAM_SHIFT_MODE_MSK		BIT_ULL(1)
+#define PARAM_SHIFT_MODE_MSB		0
+#define PARAM_SHIFT_MODE_LSB		1
+#define PARAM_DATA_WIDTH		GENMASK_ULL(7, 2)
+#define PARAM_NUM_CS			GENMASK_ULL(13, 8)
+#define PARAM_CLK_POL			BIT_ULL(14)
+#define PARAM_CLK_PHASE			BIT_ULL(15)
+#define PARAM_PERIPHERAL_ID		GENMASK_ULL(47, 32)
+
+#define NIOS_SPI_CTRL			0x10
+#define CTRL_WR_DATA			GENMASK_ULL(31, 0)
+#define CTRL_ADDR			GENMASK_ULL(44, 32)
+#define CTRL_CMD_MSK			GENMASK_ULL(63, 62)
+#define CTRL_CMD_NOP			0
+#define CTRL_CMD_RD			1
+#define CTRL_CMD_WR			2
+
+#define NIOS_SPI_STAT			0x18
+#define STAT_RD_DATA			GENMASK_ULL(31, 0)
+#define STAT_RW_VAL			BIT_ULL(32)
+
+/* Nios handshake registers, indirect access */
+#define NIOS_INIT			0x1000
+#define NIOS_INIT_DONE			BIT(0)
+#define NIOS_INIT_START			BIT(1)
+/* Mode for PKVL A, link 0, the same below */
+#define REQ_FEC_MODE_A0_MSK		GENMASK(9, 8)
+#define REQ_FEC_MODE_A1_MSK		GENMASK(11, 10)
+#define REQ_FEC_MODE_A2_MSK		GENMASK(13, 12)
+#define REQ_FEC_MODE_A3_MSK		GENMASK(15, 14)
+#define REQ_FEC_MODE_B0_MSK		GENMASK(17, 16)
+#define REQ_FEC_MODE_B1_MSK		GENMASK(19, 18)
+#define REQ_FEC_MODE_B2_MSK		GENMASK(21, 20)
+#define REQ_FEC_MODE_B3_MSK		GENMASK(23, 22)
+#define REQ_FEC_MODE_NO			0x0
+#define REQ_FEC_MODE_KR			0x1
+#define REQ_FEC_MODE_RS			0x2
+
+#define NIOS_FW_VERSION			0x1004
+#define NIOS_FW_VERSION_PATCH		GENMASK(23, 20)
+#define NIOS_FW_VERSION_MINOR		GENMASK(27, 24)
+#define NIOS_FW_VERSION_MAJOR		GENMASK(31, 28)
+
+#define PKVL_A_MODE_STS			0x1020
+#define PKVL_B_MODE_STS			0x1024
+#define PKVL_MODE_STS_GROUP_MSK		GENMASK(15, 8)
+#define PKVL_MODE_STS_GROUP_OK		0x0
+#define PKVL_MODE_STS_ID_MSK		GENMASK(7, 0)
+
+#define NS_REGBUS_WAIT_TIMEOUT	10000		/* loop count */
+#define NIOS_INIT_TIMEOUT		10000000	/* usec */
+#define NIOS_INIT_TIME_INTV		100000		/* usec */
+
+struct dfl_n3000_nios {
+	void __iomem *base;
+	struct regmap *regmap;
+	struct device *dev;
+	struct platform_device *altera_spi;
+};
+
+static ssize_t nios_fw_version_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct dfl_n3000_nios *ns = dev_get_drvdata(dev);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(ns->regmap, NIOS_FW_VERSION, &val);
+	if (ret)
+		return ret;
+
+	return sprintf(buf, "%x.%x.%x\n",
+		       (u8)FIELD_GET(NIOS_FW_VERSION_MAJOR, val),
+		       (u8)FIELD_GET(NIOS_FW_VERSION_MINOR, val),
+		       (u8)FIELD_GET(NIOS_FW_VERSION_PATCH, val));
+}
+static DEVICE_ATTR_RO(nios_fw_version);
+
+static ssize_t fec_mode_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct dfl_n3000_nios *ns = dev_get_drvdata(dev);
+	unsigned int val, mode;
+	int ret;
+
+	ret = regmap_read(ns->regmap, NIOS_INIT, &val);
+	if (ret)
+		return ret;
+
+	/*
+	 * FEC mode should always be the same for all links, as we set them
+	 * in this way.
+	 */
+	mode = FIELD_GET(REQ_FEC_MODE_A0_MSK, val);
+	if (mode != FIELD_GET(REQ_FEC_MODE_A1_MSK, val) ||
+	    mode != FIELD_GET(REQ_FEC_MODE_A2_MSK, val) ||
+	    mode != FIELD_GET(REQ_FEC_MODE_A3_MSK, val) ||
+	    mode != FIELD_GET(REQ_FEC_MODE_B0_MSK, val) ||
+	    mode != FIELD_GET(REQ_FEC_MODE_B1_MSK, val) ||
+	    mode != FIELD_GET(REQ_FEC_MODE_B2_MSK, val) ||
+	    mode != FIELD_GET(REQ_FEC_MODE_B3_MSK, val))
+		return -EFAULT;
+
+	switch (mode) {
+	case REQ_FEC_MODE_NO:
+		return sprintf(buf, "no\n");
+	case REQ_FEC_MODE_KR:
+		return sprintf(buf, "kr\n");
+	case REQ_FEC_MODE_RS:
+		return sprintf(buf, "rs\n");
+	}
+
+	return -EFAULT;
+}
+static DEVICE_ATTR_RO(fec_mode);
+
+static struct attribute *n3000_nios_attrs[] = {
+	&dev_attr_nios_fw_version.attr,
+	&dev_attr_fec_mode.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(n3000_nios);
+
+static bool init_error_detected(struct dfl_n3000_nios *ns)
+{
+	unsigned int val;
+
+	if (regmap_read(ns->regmap, PKVL_A_MODE_STS, &val))
+		return true;
+
+	if (FIELD_GET(PKVL_MODE_STS_GROUP_MSK, val) == PKVL_MODE_STS_GROUP_OK)
+		return true;
+
+	if (regmap_read(ns->regmap, PKVL_B_MODE_STS, &val))
+		return true;
+
+	if (FIELD_GET(PKVL_MODE_STS_GROUP_MSK, val) == PKVL_MODE_STS_GROUP_OK)
+		return true;
+
+	return false;
+}
+
+static void dump_error_stat(struct dfl_n3000_nios *ns)
+{
+	unsigned int val;
+
+	if (regmap_read(ns->regmap, PKVL_A_MODE_STS, &val))
+		return;
+
+	dev_info(ns->dev, "PKVL_A_MODE_STS %x\n", val);
+
+	if (regmap_read(ns->regmap, PKVL_B_MODE_STS, &val))
+		return;
+
+	dev_info(ns->dev, "PKVL_B_MODE_STS %x\n", val);
+}
+
+static int n3000_nios_init_done_check(struct dfl_n3000_nios *ns)
+{
+	struct device *dev = ns->dev;
+	unsigned int val, mode;
+	int ret;
+
+	/*
+	 * this SPI is shared by Nios core inside FPGA, Nios will use this SPI
+	 * master to do some one time initialization after power up, and then
+	 * release the control to OS. driver needs to poll on INIT_DONE to
+	 * see when driver could take the control.
+	 *
+	 * Please note that after 3.x.x version, INIT_START is introduced, so
+	 * driver needs to trigger START firstly and then check INIT_DONE.
+	 */
+
+	ret = regmap_read(ns->regmap, NIOS_FW_VERSION, &val);
+	if (ret)
+		return ret;
+
+	/*
+	 * If Nios version register is totally uninitialized(== 0x0), then the
+	 * Nios firmware is missing. So host could take control of SPI master
+	 * safely, but initialization work for Nios is not done. This is an
+	 * issue of FPGA image. We didn't error out because we need SPI master
+	 * to reprogram a new image.
+	 */
+	if (val == 0) {
+		dev_warn(dev, "Nios version reg = 0x%x, skip INIT_DONE check, but PKVL may be uninitialized\n",
+			 val);
+		return 0;
+	}
+
+	if (FIELD_GET(NIOS_FW_VERSION_MAJOR, val) >= 3) {
+		/* read NIOS_INIT to check if PKVL INIT done or not */
+		ret = regmap_read(ns->regmap, NIOS_INIT, &val);
+		if (ret)
+			return ret;
+
+		/* check if PKVLs are initialized already */
+		if (val & NIOS_INIT_DONE || val & NIOS_INIT_START)
+			goto nios_init_done;
+
+		/* configure FEC mode per module param */
+		val = NIOS_INIT_START;
+
+		/* FEC mode will be ignored by hardware in 10G mode */
+		if (!strcmp(fec_mode, "no"))
+			mode = REQ_FEC_MODE_NO;
+		else if (!strcmp(fec_mode, "kr"))
+			mode = REQ_FEC_MODE_KR;
+		else if (!strcmp(fec_mode, "rs"))
+			mode = REQ_FEC_MODE_RS;
+		else
+			return -EINVAL;
+
+		/* set the same FEC mode for all links */
+		val |= FIELD_PREP(REQ_FEC_MODE_A0_MSK, mode) |
+		       FIELD_PREP(REQ_FEC_MODE_A1_MSK, mode) |
+		       FIELD_PREP(REQ_FEC_MODE_A2_MSK, mode) |
+		       FIELD_PREP(REQ_FEC_MODE_A3_MSK, mode) |
+		       FIELD_PREP(REQ_FEC_MODE_B0_MSK, mode) |
+		       FIELD_PREP(REQ_FEC_MODE_B1_MSK, mode) |
+		       FIELD_PREP(REQ_FEC_MODE_B2_MSK, mode) |
+		       FIELD_PREP(REQ_FEC_MODE_B3_MSK, mode);
+
+		ret = regmap_write(ns->regmap, NIOS_INIT, val);
+		if (ret)
+			return ret;
+	}
+
+nios_init_done:
+	/* polls on NIOS_INIT_DONE */
+	ret = regmap_read_poll_timeout(ns->regmap, NIOS_INIT, val,
+				       val & NIOS_INIT_DONE,
+				       NIOS_INIT_TIME_INTV,
+				       NIOS_INIT_TIMEOUT);
+	if (ret) {
+		dev_err(dev, "NIOS_INIT_DONE %s\n",
+			(ret == -ETIMEDOUT) ? "timed out" : "check error");
+		goto dump_sts;
+	}
+
+	/*
+	 * after INIT_DONE is detected, it still needs to check if any ERR
+	 * detected.
+	 * We won't error out here even if error detected. Nios will release
+	 * spi controller when INIT_DONE is set, so driver could continue to
+	 * initialize spi controller device.
+	 */
+	if (init_error_detected(ns)) {
+		dev_warn(dev, "NIOS_INIT_DONE OK, but err found during init\n");
+		goto dump_sts;
+	}
+	return 0;
+
+dump_sts:
+	dump_error_stat(ns);
+
+	return ret;
+}
+
+struct spi_board_info m10_n3000_info = {
+	.modalias = "m10-n3000",
+	.max_speed_hz = 12500000,
+	.bus_num = 0,
+	.chip_select = 0,
+};
+
+static int create_altera_spi_controller(struct dfl_n3000_nios *ns)
+{
+	struct altera_spi_platform_data pdata = { 0 };
+	struct platform_device_info pdevinfo = { 0 };
+	void __iomem *base = ns->base;
+	u64 v;
+
+	v = readq(base + NIOS_SPI_PARAM);
+
+	pdata.mode_bits = SPI_CS_HIGH;
+	if (FIELD_GET(PARAM_CLK_POL, v))
+		pdata.mode_bits |= SPI_CPOL;
+	if (FIELD_GET(PARAM_CLK_PHASE, v))
+		pdata.mode_bits |= SPI_CPHA;
+
+	pdata.num_chipselect = FIELD_GET(PARAM_NUM_CS, v);
+	pdata.bits_per_word_mask =
+		SPI_BPW_RANGE_MASK(1, FIELD_GET(PARAM_DATA_WIDTH, v));
+
+	pdata.num_devices = 1;
+	pdata.devices = &m10_n3000_info;
+
+	dev_dbg(ns->dev, "%s cs %u bpm 0x%x mode 0x%x\n", __func__,
+		pdata.num_chipselect, pdata.bits_per_word_mask,
+		pdata.mode_bits);
+
+	pdevinfo.name = "subdev_spi_altera";
+	pdevinfo.id = PLATFORM_DEVID_AUTO;
+	pdevinfo.parent = ns->dev;
+	pdevinfo.data = &pdata;
+	pdevinfo.size_data = sizeof(pdata);
+
+	ns->altera_spi = platform_device_register_full(&pdevinfo);
+	return PTR_ERR_OR_ZERO(ns->altera_spi);
+}
+
+static void destroy_altera_spi_controller(struct dfl_n3000_nios *ns)
+{
+	platform_device_unregister(ns->altera_spi);
+}
+
+/* ns is the abbreviation of nios_spi */
+static int ns_poll_stat_timeout(void __iomem *base, u64 *v)
+{
+	int loops = NS_REGBUS_WAIT_TIMEOUT;
+
+	/*
+	 * We don't use the time based timeout here for performance.
+	 *
+	 * The image reprograming engine is on max10 bmc chip, which is the spi
+	 * device connected to altera spi controller. So the regbus read/write
+	 * is on the critical path of PAC N3000 image reprograming. And usually
+	 * the state changes in few loops, the time based timeout checking will
+	 * add too much overhead on it.
+	 *
+	 * Anyway, 10000 times loop is large enough.
+	 */
+	do {
+		*v = readq(base + NIOS_SPI_STAT);
+		if (*v & STAT_RW_VAL)
+			break;
+		cpu_relax();
+	} while (--loops);
+
+	return loops ? 0 : -ETIMEDOUT;
+}
+
+static int ns_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct dfl_n3000_nios *ns = context;
+	u64 v = 0;
+	int ret;
+
+	v |= FIELD_PREP(CTRL_CMD_MSK, CTRL_CMD_WR);
+	v |= FIELD_PREP(CTRL_ADDR, reg);
+	v |= FIELD_PREP(CTRL_WR_DATA, val);
+	writeq(v, ns->base + NIOS_SPI_CTRL);
+
+	ret = ns_poll_stat_timeout(ns->base, &v);
+	if (ret)
+		dev_err(ns->dev, "fail to write reg 0x%x val 0x%x: %d\n",
+			reg, val, ret);
+
+	return ret;
+}
+
+static int ns_reg_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct dfl_n3000_nios *ns = context;
+	u64 v = 0;
+	int ret;
+
+	v |= FIELD_PREP(CTRL_CMD_MSK, CTRL_CMD_RD);
+	v |= FIELD_PREP(CTRL_ADDR, reg);
+	writeq(v, ns->base + NIOS_SPI_CTRL);
+
+	ret = ns_poll_stat_timeout(ns->base, &v);
+	if (ret)
+		dev_err(ns->dev, "fail to read reg 0x%x: %d\n", reg, ret);
+	else
+		*val = FIELD_GET(STAT_RD_DATA, v);
+
+	return ret;
+}
+
+static const struct regmap_config ns_regbus_cfg = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.fast_io = true,
+
+	.reg_write = ns_reg_write,
+	.reg_read = ns_reg_read,
+};
+
+static int dfl_n3000_nios_probe(struct dfl_device *dfl_dev)
+{
+	struct device *dev = &dfl_dev->dev;
+	struct dfl_n3000_nios *ns;
+	int ret;
+
+	ns = devm_kzalloc(dev, sizeof(*ns), GFP_KERNEL);
+	if (!ns)
+		return -ENOMEM;
+
+	dev_set_drvdata(&dfl_dev->dev, ns);
+
+	ns->dev = dev;
+
+	ns->base = devm_ioremap_resource(&dfl_dev->dev, &dfl_dev->mmio_res);
+	if (IS_ERR(ns->base))
+		return PTR_ERR(ns->base);
+
+	ns->regmap = devm_regmap_init(dev, NULL, ns, &ns_regbus_cfg);
+	if (IS_ERR(ns->regmap))
+		return PTR_ERR(ns->regmap);
+
+	ret = n3000_nios_init_done_check(ns);
+	if (ret)
+		return ret;
+
+	ret = create_altera_spi_controller(ns);
+	if (ret)
+		dev_err(dev, "altera spi controller create failed: %d\n", ret);
+
+	return ret;
+}
+
+static void dfl_n3000_nios_remove(struct dfl_device *dfl_dev)
+{
+	struct dfl_n3000_nios *ns = dev_get_drvdata(&dfl_dev->dev);
+
+	destroy_altera_spi_controller(ns);
+}
+
+#define FME_FEATURE_ID_N3000_NIOS	0xd
+
+static const struct dfl_device_id dfl_n3000_nios_ids[] = {
+	{ FME_ID, FME_FEATURE_ID_N3000_NIOS },
+	{ }
+};
+
+static struct dfl_driver dfl_n3000_nios_driver = {
+	.drv	= {
+		.name       = "dfl-n3000-nios",
+		.dev_groups = n3000_nios_groups,
+	},
+	.id_table = dfl_n3000_nios_ids,
+	.probe   = dfl_n3000_nios_probe,
+	.remove  = dfl_n3000_nios_remove,
+};
+
+module_dfl_driver(dfl_n3000_nios_driver);
+
+MODULE_DEVICE_TABLE(dfl, dfl_n3000_nios_ids);
+MODULE_DESCRIPTION("DFL N3000 Nios private feature driver");
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

RE: [PATCH v4 4/4] fpga: dfl: add support for N3000 Nios private feature

[Wu, Hao]

> Subject: [PATCH v4 4/4] fpga: dfl: add support for N3000 Nios private feature
> 
> This patch adds support for the Nios handshake private feature on Intel
> N3000 FPGA Card.
> 
> The terminology "Nios" stands for the NIOS II - 32 bit embedded soft
> processor designed for FPGAs. This private feature provides a handshake
> interface to FPGA Nois firmware, which receives retimer configuration
> command from host and executes via an internal SPI master. When Nios
> finishes the configuration, host takes over the ownership of the SPI
> master to control an Intel MAX10 BMC Chip on the SPI bus.
> 
> For Nios firmware handshake part, this driver requests the retimer
> configuration for Nios with parameters from module param, and adds some
> sysfs nodes for user to query Nios state.
> 
> For SPI part, this driver adds a spi-altera platform device as well as
> the MAX10 BMC spi slave info. A spi-altera driver will be matched to
> handle following the SPI work.
> 
> Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> Signed-off-by: Wu Hao <hao.wu@intel.com>
> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> Reviewed-by: Tom Rix <trix@redhat.com>
> ---
> v3: Add the doc for this driver
>     Minor fixes for comments from Tom
> v4: Move the err log in regmap implementation, and delete
>      n3000_nios_writel/readl(), they have nothing to wrapper now.
>     Some minor fixes and comments improvement.
> ---
>  .../ABI/testing/sysfs-bus-dfl-devices-n3000-nios   |  18 +
>  Documentation/fpga/dfl-n3000-nios.rst              |  41 ++
>  Documentation/fpga/index.rst                       |   1 +
>  drivers/fpga/Kconfig                               |  12 +
>  drivers/fpga/Makefile                              |   2 +
>  drivers/fpga/dfl-n3000-nios.c                      | 475 +++++++++++++++++++++
>  6 files changed, 549 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-dfl-devices-
> n3000-nios
>  create mode 100644 Documentation/fpga/dfl-n3000-nios.rst
>  create mode 100644 drivers/fpga/dfl-n3000-nios.c
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
> b/Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
> new file mode 100644
> index 0000000..4b2b9c5
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
> @@ -0,0 +1,18 @@
> +What:		/sys/bus/dfl/devices/dfl_dev.X/fec_mode
> +Date:		July 2020
> +KernelVersion:	5.10
> +Contact:	Xu Yilun <yilun.xu@intel.com>
> +Description:	Read-only. It returns the FEC mode of the ethernet retimer
> +		configured by NIOS firmware. "rs" for RS FEC mode, "kr" for
> +		KR FEC mode, "no" FOR NO FEC mode. The FEC mode could
> be set
> +		by module parameters, but it could only be set once after the
> +		board powers up.
> +		Format: string
> +
> +What:		/sys/bus/dfl/devices/dfl_dev.X/nios_fw_version
> +Date:		July 2020
> +KernelVersion:	5.10
> +Contact:	Xu Yilun <yilun.xu@intel.com>
> +Description:	Read-only. It returns the NIOS firmware version in FPGA. Its
> +		format is "major.minor.patch".
> +		Format: %x.%x.%x
> diff --git a/Documentation/fpga/dfl-n3000-nios.rst
> b/Documentation/fpga/dfl-n3000-nios.rst
> new file mode 100644
> index 0000000..ecc14e3
> --- /dev/null
> +++ b/Documentation/fpga/dfl-n3000-nios.rst
> @@ -0,0 +1,41 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +=====================================
> +DFL N3000 Nios Private Feature Driver
> +=====================================
> +
> +The dfl N3000 Nios driver supports for the Nios handshake private feature
> on
> +Intel N3000 FPGA Card.
> +
> +The terminology "Nios" stands for the NIOS II - 32 bit embedded soft
> processor
> +designed for FPGAs. This private feature provides a handshake interface to
> FPGA
> +Nios firmware, which receives the ethernet retimer configuration command
> from
> +host and does the configuration via an internal SPI master. When Nios
> finishes
> +the configuration, host takes over the ownership of the SPI master to
> control
> +an Intel MAX10 BMC Chip on the SPI bus.
> +
> +So the driver does 2 major tasks on probe, uses the Nios firmware to
> configure
> +the ethernet retimer, and then creates a spi master platform device with
> the
> +MAX10 device info in spi_board_info.
> +
> +Module Parameters
> +=================
> +
> +The dfl N3000 Nios driver supports the following module parameters:
> +
> +* fec_mode: string
> +  Require the Nios firmware to set the FEC (Forward Error Correction) mode
> of
> +  the ethernet retimer on the PAC N3000 FPGA card. The possible values
> could
> +  be:
> +
> +  - "rs": Reed Solomon FEC (default)
> +  - "kr": Fire Code FEC
> +  - "no": No FEC
> +
> +  The configuration can only be set once after the board powers up, the
> +  firmware will not accept second configuration afterward. So the fec mode
> +  will not be changed if the module is reloaded with a different param value.
> +
> +  The configured value of the fec mode could be queried from sysfs node:
> +
> +  /sys/bus/dfl/devices/dfl_dev.X/fec_mode
> diff --git a/Documentation/fpga/index.rst b/Documentation/fpga/index.rst
> index f80f956..5fd3c37 100644
> --- a/Documentation/fpga/index.rst
> +++ b/Documentation/fpga/index.rst
> @@ -8,6 +8,7 @@ fpga
>      :maxdepth: 1
> 
>      dfl
> +    dfl-n3000-nios
> 
>  .. only::  subproject and html
> 
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index 7cd5a29..f820142 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -191,6 +191,18 @@ config FPGA_DFL_AFU
>  	  to the FPGA infrastructure via a Port. There may be more than one
>  	  Port/AFU per DFL based FPGA device.
> 
> +config FPGA_DFL_N3000_NIOS
> +        tristate "FPGA DFL N3000 NIOS Driver"
> +        depends on FPGA_DFL
> +        select REGMAP
> +        help
> +	  This is the driver for the nios handshake private feature on Intel
> +	  N3000 FPGA Card. This private feature provides a handshake
> interface
> +	  to FPGA NIOS firmware, which receives retimer configuration
> command
> +	  from host and executes via an internal SPI master. When nios
> finished
> +	  the configuration, host takes over the ownership of the SPI master
> to
> +	  control an Intel MAX10 BMC Chip on the SPI bus.
> +
>  config FPGA_DFL_PCI
>  	tristate "FPGA DFL PCIe Device Driver"
>  	depends on PCI && FPGA_DFL
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index d8e21df..27f20f2 100644
> --- a/drivers/fpga/Makefile
> +++ b/drivers/fpga/Makefile
> @@ -44,5 +44,7 @@ dfl-fme-objs += dfl-fme-perf.o
>  dfl-afu-objs := dfl-afu-main.o dfl-afu-region.o dfl-afu-dma-region.o
>  dfl-afu-objs += dfl-afu-error.o
> 
> +obj-$(CONFIG_FPGA_DFL_N3000_NIOS)      += dfl-n3000-nios.o
> +
>  # Drivers for FPGAs which implement DFL
>  obj-$(CONFIG_FPGA_DFL_PCI)		+= dfl-pci.o
> diff --git a/drivers/fpga/dfl-n3000-nios.c b/drivers/fpga/dfl-n3000-nios.c
> new file mode 100644
> index 0000000..b3093a2
> --- /dev/null
> +++ b/drivers/fpga/dfl-n3000-nios.c
> @@ -0,0 +1,475 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * DFL device driver for Nios private feature on Intel PAC N3000
> + *
> + * Copyright (C) 2019-2020 Intel Corporation, Inc.
> + *
> + * Authors:
> + *   Wu Hao <hao.wu@intel.com>
> + *   Xu Yilun <yilun.xu@intel.com>
> + */
> +#include <linux/bitfield.h>
> +#include <linux/errno.h>
> +#include <linux/io.h>
> +#include <linux/io-64-nonatomic-lo-hi.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/stddef.h>
> +#include <linux/spi/altera.h>
> +#include <linux/spi/spi.h>
> +#include <linux/types.h>
> +
> +#include "dfl.h"
> +
> +static char *fec_mode = "rs";
> +module_param(fec_mode, charp, 0444);
> +MODULE_PARM_DESC(fec_mode, "FEC mode of the ethernet retimer on
> PAC N3000 FPGA card");

Intel PAC..
> +
> +/* N3000 Nios private feature registers */
> +#define NIOS_SPI_PARAM			0x8
> +#define PARAM_SHIFT_MODE_MSK		BIT_ULL(1)
> +#define PARAM_SHIFT_MODE_MSB		0
> +#define PARAM_SHIFT_MODE_LSB		1
> +#define PARAM_DATA_WIDTH		GENMASK_ULL(7, 2)
> +#define PARAM_NUM_CS			GENMASK_ULL(13, 8)
> +#define PARAM_CLK_POL			BIT_ULL(14)
> +#define PARAM_CLK_PHASE			BIT_ULL(15)
> +#define PARAM_PERIPHERAL_ID		GENMASK_ULL(47, 32)
> +
> +#define NIOS_SPI_CTRL			0x10
> +#define CTRL_WR_DATA			GENMASK_ULL(31, 0)
> +#define CTRL_ADDR			GENMASK_ULL(44, 32)
> +#define CTRL_CMD_MSK			GENMASK_ULL(63, 62)
> +#define CTRL_CMD_NOP			0
> +#define CTRL_CMD_RD			1
> +#define CTRL_CMD_WR			2
> +
> +#define NIOS_SPI_STAT			0x18
> +#define STAT_RD_DATA			GENMASK_ULL(31, 0)
> +#define STAT_RW_VAL			BIT_ULL(32)
> +
> +/* Nios handshake registers, indirect access */
> +#define NIOS_INIT			0x1000
> +#define NIOS_INIT_DONE			BIT(0)
> +#define NIOS_INIT_START			BIT(1)
> +/* Mode for PKVL A, link 0, the same below */
> +#define REQ_FEC_MODE_A0_MSK		GENMASK(9, 8)
> +#define REQ_FEC_MODE_A1_MSK		GENMASK(11, 10)
> +#define REQ_FEC_MODE_A2_MSK		GENMASK(13, 12)
> +#define REQ_FEC_MODE_A3_MSK		GENMASK(15, 14)
> +#define REQ_FEC_MODE_B0_MSK		GENMASK(17, 16)
> +#define REQ_FEC_MODE_B1_MSK		GENMASK(19, 18)
> +#define REQ_FEC_MODE_B2_MSK		GENMASK(21, 20)
> +#define REQ_FEC_MODE_B3_MSK		GENMASK(23, 22)
> +#define REQ_FEC_MODE_NO			0x0
> +#define REQ_FEC_MODE_KR			0x1
> +#define REQ_FEC_MODE_RS			0x2
> +
> +#define NIOS_FW_VERSION			0x1004
> +#define NIOS_FW_VERSION_PATCH		GENMASK(23, 20)
> +#define NIOS_FW_VERSION_MINOR		GENMASK(27, 24)
> +#define NIOS_FW_VERSION_MAJOR		GENMASK(31, 28)
> +
> +#define PKVL_A_MODE_STS			0x1020
> +#define PKVL_B_MODE_STS			0x1024
> +#define PKVL_MODE_STS_GROUP_MSK		GENMASK(15, 8)
> +#define PKVL_MODE_STS_GROUP_OK		0x0
> +#define PKVL_MODE_STS_ID_MSK		GENMASK(7, 0)
> +
> +#define NS_REGBUS_WAIT_TIMEOUT	10000		/* loop count */
> +#define NIOS_INIT_TIMEOUT		10000000	/* usec */
> +#define NIOS_INIT_TIME_INTV		100000		/* usec */
> +
> +struct dfl_n3000_nios {
> +	void __iomem *base;
> +	struct regmap *regmap;
> +	struct device *dev;
> +	struct platform_device *altera_spi;
> +};
> +
> +static ssize_t nios_fw_version_show(struct device *dev,
> +				    struct device_attribute *attr, char *buf)
> +{
> +	struct dfl_n3000_nios *ns = dev_get_drvdata(dev);
> +	unsigned int val;
> +	int ret;
> +
> +	ret = regmap_read(ns->regmap, NIOS_FW_VERSION, &val);
> +	if (ret)
> +		return ret;
> +
> +	return sprintf(buf, "%x.%x.%x\n",
> +		       (u8)FIELD_GET(NIOS_FW_VERSION_MAJOR, val),
> +		       (u8)FIELD_GET(NIOS_FW_VERSION_MINOR, val),
> +		       (u8)FIELD_GET(NIOS_FW_VERSION_PATCH, val));
> +}
> +static DEVICE_ATTR_RO(nios_fw_version);
> +
> +static ssize_t fec_mode_show(struct device *dev,
> +			     struct device_attribute *attr, char *buf)
> +{
> +	struct dfl_n3000_nios *ns = dev_get_drvdata(dev);
> +	unsigned int val, mode;
> +	int ret;
> +
> +	ret = regmap_read(ns->regmap, NIOS_INIT, &val);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * FEC mode should always be the same for all links, as we set them
> +	 * in this way.
> +	 */
> +	mode = FIELD_GET(REQ_FEC_MODE_A0_MSK, val);
> +	if (mode != FIELD_GET(REQ_FEC_MODE_A1_MSK, val) ||
> +	    mode != FIELD_GET(REQ_FEC_MODE_A2_MSK, val) ||
> +	    mode != FIELD_GET(REQ_FEC_MODE_A3_MSK, val) ||
> +	    mode != FIELD_GET(REQ_FEC_MODE_B0_MSK, val) ||
> +	    mode != FIELD_GET(REQ_FEC_MODE_B1_MSK, val) ||
> +	    mode != FIELD_GET(REQ_FEC_MODE_B2_MSK, val) ||
> +	    mode != FIELD_GET(REQ_FEC_MODE_B3_MSK, val))
> +		return -EFAULT;
> +
> +	switch (mode) {
> +	case REQ_FEC_MODE_NO:
> +		return sprintf(buf, "no\n");
> +	case REQ_FEC_MODE_KR:
> +		return sprintf(buf, "kr\n");
> +	case REQ_FEC_MODE_RS:
> +		return sprintf(buf, "rs\n");
> +	}
> +
> +	return -EFAULT;
> +}
> +static DEVICE_ATTR_RO(fec_mode);
> +
> +static struct attribute *n3000_nios_attrs[] = {
> +	&dev_attr_nios_fw_version.attr,
> +	&dev_attr_fec_mode.attr,
> +	NULL,
> +};
> +ATTRIBUTE_GROUPS(n3000_nios);
> +
> +static bool init_error_detected(struct dfl_n3000_nios *ns)
> +{
> +	unsigned int val;
> +
> +	if (regmap_read(ns->regmap, PKVL_A_MODE_STS, &val))
> +		return true;
> +
> +	if (FIELD_GET(PKVL_MODE_STS_GROUP_MSK, val) ==
> PKVL_MODE_STS_GROUP_OK)
> +		return true;
> +
> +	if (regmap_read(ns->regmap, PKVL_B_MODE_STS, &val))
> +		return true;
> +
> +	if (FIELD_GET(PKVL_MODE_STS_GROUP_MSK, val) ==
> PKVL_MODE_STS_GROUP_OK)
> +		return true;
> +
> +	return false;
> +}
> +
> +static void dump_error_stat(struct dfl_n3000_nios *ns)
> +{
> +	unsigned int val;
> +
> +	if (regmap_read(ns->regmap, PKVL_A_MODE_STS, &val))
> +		return;
> +
> +	dev_info(ns->dev, "PKVL_A_MODE_STS %x\n", val);
> +
> +	if (regmap_read(ns->regmap, PKVL_B_MODE_STS, &val))
> +		return;
> +
> +	dev_info(ns->dev, "PKVL_B_MODE_STS %x\n", val);
> +}
> +
> +static int n3000_nios_init_done_check(struct dfl_n3000_nios *ns)
> +{
> +	struct device *dev = ns->dev;
> +	unsigned int val, mode;
> +	int ret;
> +
> +	/*
> +	 * this SPI is shared by Nios core inside FPGA, Nios will use this SPI
> +	 * master to do some one time initialization after power up, and then
> +	 * release the control to OS. driver needs to poll on INIT_DONE to
> +	 * see when driver could take the control.
> +	 *
> +	 * Please note that after 3.x.x version, INIT_START is introduced, so
> +	 * driver needs to trigger START firstly and then check INIT_DONE.
> +	 */
> +
> +	ret = regmap_read(ns->regmap, NIOS_FW_VERSION, &val);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * If Nios version register is totally uninitialized(== 0x0), then the
> +	 * Nios firmware is missing. So host could take control of SPI master
> +	 * safely, but initialization work for Nios is not done. This is an
> +	 * issue of FPGA image. We didn't error out because we need SPI
> master
> +	 * to reprogram a new image.
> +	 */
> +	if (val == 0) {
> +		dev_warn(dev, "Nios version reg = 0x%x, skip INIT_DONE
> check, but PKVL may be uninitialized\n",

Seems no place introduced the PKVL or just use retimer to replace PKVL?

Thanks
Hao

> +			 val);
> +		return 0;
> +	}
> +
> +	if (FIELD_GET(NIOS_FW_VERSION_MAJOR, val) >= 3) {
> +		/* read NIOS_INIT to check if PKVL INIT done or not */
> +		ret = regmap_read(ns->regmap, NIOS_INIT, &val);
> +		if (ret)
> +			return ret;
> +
> +		/* check if PKVLs are initialized already */
> +		if (val & NIOS_INIT_DONE || val & NIOS_INIT_START)
> +			goto nios_init_done;
> +
> +		/* configure FEC mode per module param */
> +		val = NIOS_INIT_START;
> +
> +		/* FEC mode will be ignored by hardware in 10G mode */

So always no fec mode from hardware? Or software should force it
in 10G mode? Or 10G mode, below code can be skipped?

> +		if (!strcmp(fec_mode, "no"))
> +			mode = REQ_FEC_MODE_NO;
> +		else if (!strcmp(fec_mode, "kr"))
> +			mode = REQ_FEC_MODE_KR;
> +		else if (!strcmp(fec_mode, "rs"))
> +			mode = REQ_FEC_MODE_RS;
> +		else
> +			return -EINVAL;
> +
> +		/* set the same FEC mode for all links */
> +		val |= FIELD_PREP(REQ_FEC_MODE_A0_MSK, mode) |
> +		       FIELD_PREP(REQ_FEC_MODE_A1_MSK, mode) |
> +		       FIELD_PREP(REQ_FEC_MODE_A2_MSK, mode) |
> +		       FIELD_PREP(REQ_FEC_MODE_A3_MSK, mode) |
> +		       FIELD_PREP(REQ_FEC_MODE_B0_MSK, mode) |
> +		       FIELD_PREP(REQ_FEC_MODE_B1_MSK, mode) |
> +		       FIELD_PREP(REQ_FEC_MODE_B2_MSK, mode) |
> +		       FIELD_PREP(REQ_FEC_MODE_B3_MSK, mode);
> +
> +		ret = regmap_write(ns->regmap, NIOS_INIT, val);
> +		if (ret)
> +			return ret;
> +	}
> +
> +nios_init_done:
> +	/* polls on NIOS_INIT_DONE */
> +	ret = regmap_read_poll_timeout(ns->regmap, NIOS_INIT, val,
> +				       val & NIOS_INIT_DONE,
> +				       NIOS_INIT_TIME_INTV,
> +				       NIOS_INIT_TIMEOUT);
> +	if (ret) {
> +		dev_err(dev, "NIOS_INIT_DONE %s\n",
> +			(ret == -ETIMEDOUT) ? "timed out" : "check error");
> +		goto dump_sts;
> +	}
> +
> +	/*
> +	 * after INIT_DONE is detected, it still needs to check if any ERR
> +	 * detected.
> +	 * We won't error out here even if error detected. Nios will release
> +	 * spi controller when INIT_DONE is set, so driver could continue to
> +	 * initialize spi controller device.
> +	 */
> +	if (init_error_detected(ns)) {
> +		dev_warn(dev, "NIOS_INIT_DONE OK, but err found during
> init\n");
> +		goto dump_sts;
> +	}
> +	return 0;
> +
> +dump_sts:
> +	dump_error_stat(ns);
> +
> +	return ret;
> +}
> +
> +struct spi_board_info m10_n3000_info = {
> +	.modalias = "m10-n3000",
> +	.max_speed_hz = 12500000,
> +	.bus_num = 0,
> +	.chip_select = 0,
> +};
> +
> +static int create_altera_spi_controller(struct dfl_n3000_nios *ns)
> +{
> +	struct altera_spi_platform_data pdata = { 0 };
> +	struct platform_device_info pdevinfo = { 0 };
> +	void __iomem *base = ns->base;
> +	u64 v;
> +
> +	v = readq(base + NIOS_SPI_PARAM);
> +
> +	pdata.mode_bits = SPI_CS_HIGH;
> +	if (FIELD_GET(PARAM_CLK_POL, v))
> +		pdata.mode_bits |= SPI_CPOL;
> +	if (FIELD_GET(PARAM_CLK_PHASE, v))
> +		pdata.mode_bits |= SPI_CPHA;
> +
> +	pdata.num_chipselect = FIELD_GET(PARAM_NUM_CS, v);
> +	pdata.bits_per_word_mask =
> +		SPI_BPW_RANGE_MASK(1, FIELD_GET(PARAM_DATA_WIDTH,
> v));
> +
> +	pdata.num_devices = 1;
> +	pdata.devices = &m10_n3000_info;
> +
> +	dev_dbg(ns->dev, "%s cs %u bpm 0x%x mode 0x%x\n", __func__,
> +		pdata.num_chipselect, pdata.bits_per_word_mask,
> +		pdata.mode_bits);
> +
> +	pdevinfo.name = "subdev_spi_altera";
> +	pdevinfo.id = PLATFORM_DEVID_AUTO;
> +	pdevinfo.parent = ns->dev;
> +	pdevinfo.data = &pdata;
> +	pdevinfo.size_data = sizeof(pdata);
> +
> +	ns->altera_spi = platform_device_register_full(&pdevinfo);
> +	return PTR_ERR_OR_ZERO(ns->altera_spi);
> +}
> +
> +static void destroy_altera_spi_controller(struct dfl_n3000_nios *ns)
> +{
> +	platform_device_unregister(ns->altera_spi);
> +}
> +
> +/* ns is the abbreviation of nios_spi */
> +static int ns_poll_stat_timeout(void __iomem *base, u64 *v)
> +{
> +	int loops = NS_REGBUS_WAIT_TIMEOUT;
> +
> +	/*
> +	 * We don't use the time based timeout here for performance.
> +	 *
> +	 * The image reprograming engine is on max10 bmc chip, which is the
> spi
> +	 * device connected to altera spi controller. So the regbus read/write
> +	 * is on the critical path of PAC N3000 image reprograming. And
> usually
> +	 * the state changes in few loops, the time based timeout checking
> will
> +	 * add too much overhead on it.
> +	 *
> +	 * Anyway, 10000 times loop is large enough.
> +	 */
> +	do {
> +		*v = readq(base + NIOS_SPI_STAT);
> +		if (*v & STAT_RW_VAL)
> +			break;
> +		cpu_relax();
> +	} while (--loops);
> +
> +	return loops ? 0 : -ETIMEDOUT;
> +}
> +
> +static int ns_reg_write(void *context, unsigned int reg, unsigned int val)
> +{
> +	struct dfl_n3000_nios *ns = context;
> +	u64 v = 0;
> +	int ret;
> +
> +	v |= FIELD_PREP(CTRL_CMD_MSK, CTRL_CMD_WR);
> +	v |= FIELD_PREP(CTRL_ADDR, reg);
> +	v |= FIELD_PREP(CTRL_WR_DATA, val);
> +	writeq(v, ns->base + NIOS_SPI_CTRL);
> +
> +	ret = ns_poll_stat_timeout(ns->base, &v);
> +	if (ret)
> +		dev_err(ns->dev, "fail to write reg 0x%x val 0x%x: %d\n",
> +			reg, val, ret);
> +
> +	return ret;
> +}
> +
> +static int ns_reg_read(void *context, unsigned int reg, unsigned int *val)
> +{
> +	struct dfl_n3000_nios *ns = context;
> +	u64 v = 0;
> +	int ret;
> +
> +	v |= FIELD_PREP(CTRL_CMD_MSK, CTRL_CMD_RD);
> +	v |= FIELD_PREP(CTRL_ADDR, reg);
> +	writeq(v, ns->base + NIOS_SPI_CTRL);
> +
> +	ret = ns_poll_stat_timeout(ns->base, &v);
> +	if (ret)
> +		dev_err(ns->dev, "fail to read reg 0x%x: %d\n", reg, ret);
> +	else
> +		*val = FIELD_GET(STAT_RD_DATA, v);
> +
> +	return ret;
> +}
> +
> +static const struct regmap_config ns_regbus_cfg = {
> +	.reg_bits = 32,
> +	.reg_stride = 4,
> +	.val_bits = 32,
> +	.fast_io = true,
> +
> +	.reg_write = ns_reg_write,
> +	.reg_read = ns_reg_read,
> +};
> +
> +static int dfl_n3000_nios_probe(struct dfl_device *dfl_dev)
> +{
> +	struct device *dev = &dfl_dev->dev;
> +	struct dfl_n3000_nios *ns;
> +	int ret;
> +
> +	ns = devm_kzalloc(dev, sizeof(*ns), GFP_KERNEL);
> +	if (!ns)
> +		return -ENOMEM;
> +
> +	dev_set_drvdata(&dfl_dev->dev, ns);
> +
> +	ns->dev = dev;
> +
> +	ns->base = devm_ioremap_resource(&dfl_dev->dev, &dfl_dev-
> >mmio_res);
> +	if (IS_ERR(ns->base))
> +		return PTR_ERR(ns->base);
> +
> +	ns->regmap = devm_regmap_init(dev, NULL, ns, &ns_regbus_cfg);
> +	if (IS_ERR(ns->regmap))
> +		return PTR_ERR(ns->regmap);
> +
> +	ret = n3000_nios_init_done_check(ns);
> +	if (ret)
> +		return ret;
> +
> +	ret = create_altera_spi_controller(ns);
> +	if (ret)
> +		dev_err(dev, "altera spi controller create failed: %d\n", ret);
> +
> +	return ret;
> +}
> +
> +static void dfl_n3000_nios_remove(struct dfl_device *dfl_dev)
> +{
> +	struct dfl_n3000_nios *ns = dev_get_drvdata(&dfl_dev->dev);
> +
> +	destroy_altera_spi_controller(ns);
> +}
> +
> +#define FME_FEATURE_ID_N3000_NIOS	0xd
> +
> +static const struct dfl_device_id dfl_n3000_nios_ids[] = {
> +	{ FME_ID, FME_FEATURE_ID_N3000_NIOS },
> +	{ }
> +};
> +
> +static struct dfl_driver dfl_n3000_nios_driver = {
> +	.drv	= {
> +		.name       = "dfl-n3000-nios",
> +		.dev_groups = n3000_nios_groups,
> +	},
> +	.id_table = dfl_n3000_nios_ids,
> +	.probe   = dfl_n3000_nios_probe,
> +	.remove  = dfl_n3000_nios_remove,
> +};
> +
> +module_dfl_driver(dfl_n3000_nios_driver);
> +
> +MODULE_DEVICE_TABLE(dfl, dfl_n3000_nios_ids);
> +MODULE_DESCRIPTION("DFL N3000 Nios private feature driver");
> +MODULE_AUTHOR("Intel Corporation");
> +MODULE_LICENSE("GPL v2");
> --
> 2.7.4

Re: [PATCH v4 4/4] fpga: dfl: add support for N3000 Nios private feature

[Xu Yilun]

On Mon, Aug 10, 2020 at 03:00:08PM +0800, Wu, Hao wrote:
> > Subject: [PATCH v4 4/4] fpga: dfl: add support for N3000 Nios private feature
> >
> > This patch adds support for the Nios handshake private feature on Intel
> > N3000 FPGA Card.
> >
> > The terminology "Nios" stands for the NIOS II - 32 bit embedded soft
> > processor designed for FPGAs. This private feature provides a handshake
> > interface to FPGA Nois firmware, which receives retimer configuration
> > command from host and executes via an internal SPI master. When Nios
> > finishes the configuration, host takes over the ownership of the SPI
> > master to control an Intel MAX10 BMC Chip on the SPI bus.
> >
> > For Nios firmware handshake part, this driver requests the retimer
> > configuration for Nios with parameters from module param, and adds some
> > sysfs nodes for user to query Nios state.
> >
> > For SPI part, this driver adds a spi-altera platform device as well as
> > the MAX10 BMC spi slave info. A spi-altera driver will be matched to
> > handle following the SPI work.
> >
> > Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> > Signed-off-by: Wu Hao <hao.wu@intel.com>
> > Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> > Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> > Reviewed-by: Tom Rix <trix@redhat.com>
> > ---
> > v3: Add the doc for this driver
> >     Minor fixes for comments from Tom
> > v4: Move the err log in regmap implementation, and delete
> >      n3000_nios_writel/readl(), they have nothing to wrapper now.
> >     Some minor fixes and comments improvement.
> > ---
> >  .../ABI/testing/sysfs-bus-dfl-devices-n3000-nios   |  18 +
> >  Documentation/fpga/dfl-n3000-nios.rst              |  41 ++
> >  Documentation/fpga/index.rst                       |   1 +
> >  drivers/fpga/Kconfig                               |  12 +
> >  drivers/fpga/Makefile                              |   2 +
> >  drivers/fpga/dfl-n3000-nios.c                      | 475 +++++++++++++++++++++
> >  6 files changed, 549 insertions(+)
> >  create mode 100644 Documentation/ABI/testing/sysfs-bus-dfl-devices-
> > n3000-nios
> >  create mode 100644 Documentation/fpga/dfl-n3000-nios.rst
> >  create mode 100644 drivers/fpga/dfl-n3000-nios.c
> >
> > diff --git a/Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
> > b/Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
> > new file mode 100644
> > index 0000000..4b2b9c5
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
> > @@ -0,0 +1,18 @@
> > +What:/sys/bus/dfl/devices/dfl_dev.X/fec_mode
> > +Date:July 2020
> > +KernelVersion:5.10
> > +Contact:Xu Yilun <yilun.xu@intel.com>
> > +Description:Read-only. It returns the FEC mode of the ethernet retimer
> > +configured by NIOS firmware. "rs" for RS FEC mode, "kr" for
> > +KR FEC mode, "no" FOR NO FEC mode. The FEC mode could
> > be set
> > +by module parameters, but it could only be set once after the
> > +board powers up.
> > +Format: string
> > +
> > +What:/sys/bus/dfl/devices/dfl_dev.X/nios_fw_version
> > +Date:July 2020
> > +KernelVersion:5.10
> > +Contact:Xu Yilun <yilun.xu@intel.com>
> > +Description:Read-only. It returns the NIOS firmware version in FPGA. Its
> > +format is "major.minor.patch".
> > +Format: %x.%x.%x
> > diff --git a/Documentation/fpga/dfl-n3000-nios.rst
> > b/Documentation/fpga/dfl-n3000-nios.rst
> > new file mode 100644
> > index 0000000..ecc14e3
> > --- /dev/null
> > +++ b/Documentation/fpga/dfl-n3000-nios.rst
> > @@ -0,0 +1,41 @@
> > +.. SPDX-License-Identifier: GPL-2.0
> > +
> > +=====================================
> > +DFL N3000 Nios Private Feature Driver
> > +=====================================
> > +
> > +The dfl N3000 Nios driver supports for the Nios handshake private feature
> > on
> > +Intel N3000 FPGA Card.
> > +
> > +The terminology "Nios" stands for the NIOS II - 32 bit embedded soft
> > processor
> > +designed for FPGAs. This private feature provides a handshake interface to
> > FPGA
> > +Nios firmware, which receives the ethernet retimer configuration command
> > from
> > +host and does the configuration via an internal SPI master. When Nios
> > finishes
> > +the configuration, host takes over the ownership of the SPI master to
> > control
> > +an Intel MAX10 BMC Chip on the SPI bus.
> > +
> > +So the driver does 2 major tasks on probe, uses the Nios firmware to
> > configure
> > +the ethernet retimer, and then creates a spi master platform device with
> > the
> > +MAX10 device info in spi_board_info.
> > +
> > +Module Parameters
> > +=================
> > +
> > +The dfl N3000 Nios driver supports the following module parameters:
> > +
> > +* fec_mode: string
> > +  Require the Nios firmware to set the FEC (Forward Error Correction) mode
> > of
> > +  the ethernet retimer on the PAC N3000 FPGA card. The possible values
> > could
> > +  be:
> > +
> > +  - "rs": Reed Solomon FEC (default)
> > +  - "kr": Fire Code FEC
> > +  - "no": No FEC
> > +
> > +  The configuration can only be set once after the board powers up, the
> > +  firmware will not accept second configuration afterward. So the fec mode
> > +  will not be changed if the module is reloaded with a different param value.
> > +
> > +  The configured value of the fec mode could be queried from sysfs node:
> > +
> > +  /sys/bus/dfl/devices/dfl_dev.X/fec_mode
> > diff --git a/Documentation/fpga/index.rst b/Documentation/fpga/index.rst
> > index f80f956..5fd3c37 100644
> > --- a/Documentation/fpga/index.rst
> > +++ b/Documentation/fpga/index.rst
> > @@ -8,6 +8,7 @@ fpga
> >      :maxdepth: 1
> >
> >      dfl
> > +    dfl-n3000-nios
> >
> >  .. only::  subproject and html
> >
> > diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> > index 7cd5a29..f820142 100644
> > --- a/drivers/fpga/Kconfig
> > +++ b/drivers/fpga/Kconfig
> > @@ -191,6 +191,18 @@ config FPGA_DFL_AFU
> >    to the FPGA infrastructure via a Port. There may be more than one
> >    Port/AFU per DFL based FPGA device.
> >
> > +config FPGA_DFL_N3000_NIOS
> > +        tristate "FPGA DFL N3000 NIOS Driver"
> > +        depends on FPGA_DFL
> > +        select REGMAP
> > +        help
> > +  This is the driver for the nios handshake private feature on Intel
> > +  N3000 FPGA Card. This private feature provides a handshake
> > interface
> > +  to FPGA NIOS firmware, which receives retimer configuration
> > command
> > +  from host and executes via an internal SPI master. When nios
> > finished
> > +  the configuration, host takes over the ownership of the SPI master
> > to
> > +  control an Intel MAX10 BMC Chip on the SPI bus.
> > +
> >  config FPGA_DFL_PCI
> >  tristate "FPGA DFL PCIe Device Driver"
> >  depends on PCI && FPGA_DFL
> > diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> > index d8e21df..27f20f2 100644
> > --- a/drivers/fpga/Makefile
> > +++ b/drivers/fpga/Makefile
> > @@ -44,5 +44,7 @@ dfl-fme-objs += dfl-fme-perf.o
> >  dfl-afu-objs := dfl-afu-main.o dfl-afu-region.o dfl-afu-dma-region.o
> >  dfl-afu-objs += dfl-afu-error.o
> >
> > +obj-$(CONFIG_FPGA_DFL_N3000_NIOS)      += dfl-n3000-nios.o
> > +
> >  # Drivers for FPGAs which implement DFL
> >  obj-$(CONFIG_FPGA_DFL_PCI)+= dfl-pci.o
> > diff --git a/drivers/fpga/dfl-n3000-nios.c b/drivers/fpga/dfl-n3000-nios.c
> > new file mode 100644
> > index 0000000..b3093a2
> > --- /dev/null
> > +++ b/drivers/fpga/dfl-n3000-nios.c
> > @@ -0,0 +1,475 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * DFL device driver for Nios private feature on Intel PAC N3000
> > + *
> > + * Copyright (C) 2019-2020 Intel Corporation, Inc.
> > + *
> > + * Authors:
> > + *   Wu Hao <hao.wu@intel.com>
> > + *   Xu Yilun <yilun.xu@intel.com>
> > + */
> > +#include <linux/bitfield.h>
> > +#include <linux/errno.h>
> > +#include <linux/io.h>
> > +#include <linux/io-64-nonatomic-lo-hi.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> > +#include <linux/stddef.h>
> > +#include <linux/spi/altera.h>
> > +#include <linux/spi/spi.h>
> > +#include <linux/types.h>
> > +
> > +#include "dfl.h"
> > +
> > +static char *fec_mode = "rs";
> > +module_param(fec_mode, charp, 0444);
> > +MODULE_PARM_DESC(fec_mode, "FEC mode of the ethernet retimer on
> > PAC N3000 FPGA card");
> 
> Intel PAC..

Yes.

> > +
> > +/* N3000 Nios private feature registers */
> > +#define NIOS_SPI_PARAM0x8
> > +#define PARAM_SHIFT_MODE_MSKBIT_ULL(1)
> > +#define PARAM_SHIFT_MODE_MSB0
> > +#define PARAM_SHIFT_MODE_LSB1
> > +#define PARAM_DATA_WIDTHGENMASK_ULL(7, 2)
> > +#define PARAM_NUM_CSGENMASK_ULL(13, 8)
> > +#define PARAM_CLK_POLBIT_ULL(14)
> > +#define PARAM_CLK_PHASEBIT_ULL(15)
> > +#define PARAM_PERIPHERAL_IDGENMASK_ULL(47, 32)
> > +
> > +#define NIOS_SPI_CTRL0x10
> > +#define CTRL_WR_DATAGENMASK_ULL(31, 0)
> > +#define CTRL_ADDRGENMASK_ULL(44, 32)
> > +#define CTRL_CMD_MSKGENMASK_ULL(63, 62)
> > +#define CTRL_CMD_NOP0
> > +#define CTRL_CMD_RD1
> > +#define CTRL_CMD_WR2
> > +
> > +#define NIOS_SPI_STAT0x18
> > +#define STAT_RD_DATAGENMASK_ULL(31, 0)
> > +#define STAT_RW_VALBIT_ULL(32)
> > +
> > +/* Nios handshake registers, indirect access */
> > +#define NIOS_INIT0x1000
> > +#define NIOS_INIT_DONEBIT(0)
> > +#define NIOS_INIT_STARTBIT(1)
> > +/* Mode for PKVL A, link 0, the same below */
> > +#define REQ_FEC_MODE_A0_MSKGENMASK(9, 8)
> > +#define REQ_FEC_MODE_A1_MSKGENMASK(11, 10)
> > +#define REQ_FEC_MODE_A2_MSKGENMASK(13, 12)
> > +#define REQ_FEC_MODE_A3_MSKGENMASK(15, 14)
> > +#define REQ_FEC_MODE_B0_MSKGENMASK(17, 16)
> > +#define REQ_FEC_MODE_B1_MSKGENMASK(19, 18)
> > +#define REQ_FEC_MODE_B2_MSKGENMASK(21, 20)
> > +#define REQ_FEC_MODE_B3_MSKGENMASK(23, 22)
> > +#define REQ_FEC_MODE_NO0x0
> > +#define REQ_FEC_MODE_KR0x1
> > +#define REQ_FEC_MODE_RS0x2
> > +
> > +#define NIOS_FW_VERSION0x1004
> > +#define NIOS_FW_VERSION_PATCHGENMASK(23, 20)
> > +#define NIOS_FW_VERSION_MINORGENMASK(27, 24)
> > +#define NIOS_FW_VERSION_MAJORGENMASK(31, 28)
> > +
> > +#define PKVL_A_MODE_STS0x1020
> > +#define PKVL_B_MODE_STS0x1024
> > +#define PKVL_MODE_STS_GROUP_MSKGENMASK(15, 8)
> > +#define PKVL_MODE_STS_GROUP_OK0x0
> > +#define PKVL_MODE_STS_ID_MSKGENMASK(7, 0)
> > +
> > +#define NS_REGBUS_WAIT_TIMEOUT10000/* loop count */
> > +#define NIOS_INIT_TIMEOUT10000000/* usec */
> > +#define NIOS_INIT_TIME_INTV100000/* usec */
> > +
> > +struct dfl_n3000_nios {
> > +void __iomem *base;
> > +struct regmap *regmap;
> > +struct device *dev;
> > +struct platform_device *altera_spi;
> > +};
> > +
> > +static ssize_t nios_fw_version_show(struct device *dev,
> > +    struct device_attribute *attr, char *buf)
> > +{
> > +struct dfl_n3000_nios *ns = dev_get_drvdata(dev);
> > +unsigned int val;
> > +int ret;
> > +
> > +ret = regmap_read(ns->regmap, NIOS_FW_VERSION, &val);
> > +if (ret)
> > +return ret;
> > +
> > +return sprintf(buf, "%x.%x.%x\n",
> > +       (u8)FIELD_GET(NIOS_FW_VERSION_MAJOR, val),
> > +       (u8)FIELD_GET(NIOS_FW_VERSION_MINOR, val),
> > +       (u8)FIELD_GET(NIOS_FW_VERSION_PATCH, val));
> > +}
> > +static DEVICE_ATTR_RO(nios_fw_version);
> > +
> > +static ssize_t fec_mode_show(struct device *dev,
> > +     struct device_attribute *attr, char *buf)
> > +{
> > +struct dfl_n3000_nios *ns = dev_get_drvdata(dev);
> > +unsigned int val, mode;
> > +int ret;
> > +
> > +ret = regmap_read(ns->regmap, NIOS_INIT, &val);
> > +if (ret)
> > +return ret;
> > +
> > +/*
> > + * FEC mode should always be the same for all links, as we set them
> > + * in this way.
> > + */
> > +mode = FIELD_GET(REQ_FEC_MODE_A0_MSK, val);
> > +if (mode != FIELD_GET(REQ_FEC_MODE_A1_MSK, val) ||
> > +    mode != FIELD_GET(REQ_FEC_MODE_A2_MSK, val) ||
> > +    mode != FIELD_GET(REQ_FEC_MODE_A3_MSK, val) ||
> > +    mode != FIELD_GET(REQ_FEC_MODE_B0_MSK, val) ||
> > +    mode != FIELD_GET(REQ_FEC_MODE_B1_MSK, val) ||
> > +    mode != FIELD_GET(REQ_FEC_MODE_B2_MSK, val) ||
> > +    mode != FIELD_GET(REQ_FEC_MODE_B3_MSK, val))
> > +return -EFAULT;
> > +
> > +switch (mode) {
> > +case REQ_FEC_MODE_NO:
> > +return sprintf(buf, "no\n");
> > +case REQ_FEC_MODE_KR:
> > +return sprintf(buf, "kr\n");
> > +case REQ_FEC_MODE_RS:
> > +return sprintf(buf, "rs\n");
> > +}
> > +
> > +return -EFAULT;
> > +}
> > +static DEVICE_ATTR_RO(fec_mode);
> > +
> > +static struct attribute *n3000_nios_attrs[] = {
> > +&dev_attr_nios_fw_version.attr,
> > +&dev_attr_fec_mode.attr,
> > +NULL,
> > +};
> > +ATTRIBUTE_GROUPS(n3000_nios);
> > +
> > +static bool init_error_detected(struct dfl_n3000_nios *ns)
> > +{
> > +unsigned int val;
> > +
> > +if (regmap_read(ns->regmap, PKVL_A_MODE_STS, &val))
> > +return true;
> > +
> > +if (FIELD_GET(PKVL_MODE_STS_GROUP_MSK, val) ==
> > PKVL_MODE_STS_GROUP_OK)
> > +return true;
> > +
> > +if (regmap_read(ns->regmap, PKVL_B_MODE_STS, &val))
> > +return true;
> > +
> > +if (FIELD_GET(PKVL_MODE_STS_GROUP_MSK, val) ==
> > PKVL_MODE_STS_GROUP_OK)
> > +return true;
> > +
> > +return false;
> > +}
> > +
> > +static void dump_error_stat(struct dfl_n3000_nios *ns)
> > +{
> > +unsigned int val;
> > +
> > +if (regmap_read(ns->regmap, PKVL_A_MODE_STS, &val))
> > +return;
> > +
> > +dev_info(ns->dev, "PKVL_A_MODE_STS %x\n", val);
> > +
> > +if (regmap_read(ns->regmap, PKVL_B_MODE_STS, &val))
> > +return;
> > +
> > +dev_info(ns->dev, "PKVL_B_MODE_STS %x\n", val);
> > +}
> > +
> > +static int n3000_nios_init_done_check(struct dfl_n3000_nios *ns)
> > +{
> > +struct device *dev = ns->dev;
> > +unsigned int val, mode;
> > +int ret;
> > +
> > +/*
> > + * this SPI is shared by Nios core inside FPGA, Nios will use this SPI
> > + * master to do some one time initialization after power up, and then
> > + * release the control to OS. driver needs to poll on INIT_DONE to
> > + * see when driver could take the control.
> > + *
> > + * Please note that after 3.x.x version, INIT_START is introduced, so
> > + * driver needs to trigger START firstly and then check INIT_DONE.
> > + */
> > +
> > +ret = regmap_read(ns->regmap, NIOS_FW_VERSION, &val);
> > +if (ret)
> > +return ret;
> > +
> > +/*
> > + * If Nios version register is totally uninitialized(== 0x0), then the
> > + * Nios firmware is missing. So host could take control of SPI master
> > + * safely, but initialization work for Nios is not done. This is an
> > + * issue of FPGA image. We didn't error out because we need SPI
> > master
> > + * to reprogram a new image.
> > + */
> > +if (val == 0) {
> > +dev_warn(dev, "Nios version reg = 0x%x, skip INIT_DONE
> > check, but PKVL may be uninitialized\n",
> 
> Seems no place introduced the PKVL or just use retimer to replace PKVL?

Yes.

> 
> Thanks
> Hao
> 
> > + val);
> > +return 0;
> > +}
> > +
> > +if (FIELD_GET(NIOS_FW_VERSION_MAJOR, val) >= 3) {
> > +/* read NIOS_INIT to check if PKVL INIT done or not */
> > +ret = regmap_read(ns->regmap, NIOS_INIT, &val);
> > +if (ret)
> > +return ret;
> > +
> > +/* check if PKVLs are initialized already */
> > +if (val & NIOS_INIT_DONE || val & NIOS_INIT_START)
> > +goto nios_init_done;
> > +
> > +/* configure FEC mode per module param */
> > +val = NIOS_INIT_START;
> > +
> > +/* FEC mode will be ignored by hardware in 10G mode */
> 
> So always no fec mode from hardware? Or software should force it
> in 10G mode? Or 10G mode, below code can be skipped?

I'm not sure about the 10G mode behavior since HW ignores the config in
this case. I'll check it.

Thanks
Yilun

> 
> > +if (!strcmp(fec_mode, "no"))
> > +mode = REQ_FEC_MODE_NO;
> > +else if (!strcmp(fec_mode, "kr"))
> > +mode = REQ_FEC_MODE_KR;
> > +else if (!strcmp(fec_mode, "rs"))
> > +mode = REQ_FEC_MODE_RS;
> > +else
> > +return -EINVAL;
> > +
> > +/* set the same FEC mode for all links */
> > +val |= FIELD_PREP(REQ_FEC_MODE_A0_MSK, mode) |
> > +       FIELD_PREP(REQ_FEC_MODE_A1_MSK, mode) |
> > +       FIELD_PREP(REQ_FEC_MODE_A2_MSK, mode) |
> > +       FIELD_PREP(REQ_FEC_MODE_A3_MSK, mode) |
> > +       FIELD_PREP(REQ_FEC_MODE_B0_MSK, mode) |
> > +       FIELD_PREP(REQ_FEC_MODE_B1_MSK, mode) |
> > +       FIELD_PREP(REQ_FEC_MODE_B2_MSK, mode) |
> > +       FIELD_PREP(REQ_FEC_MODE_B3_MSK, mode);
> > +
> > +ret = regmap_write(ns->regmap, NIOS_INIT, val);
> > +if (ret)
> > +return ret;
> > +}
> > +
> > +nios_init_done:
> > +/* polls on NIOS_INIT_DONE */
> > +ret = regmap_read_poll_timeout(ns->regmap, NIOS_INIT, val,
> > +       val & NIOS_INIT_DONE,
> > +       NIOS_INIT_TIME_INTV,
> > +       NIOS_INIT_TIMEOUT);
> > +if (ret) {
> > +dev_err(dev, "NIOS_INIT_DONE %s\n",
> > +(ret == -ETIMEDOUT) ? "timed out" : "check error");
> > +goto dump_sts;
> > +}
> > +
> > +/*
> > + * after INIT_DONE is detected, it still needs to check if any ERR
> > + * detected.
> > + * We won't error out here even if error detected. Nios will release
> > + * spi controller when INIT_DONE is set, so driver could continue to
> > + * initialize spi controller device.
> > + */
> > +if (init_error_detected(ns)) {
> > +dev_warn(dev, "NIOS_INIT_DONE OK, but err found during
> > init\n");
> > +goto dump_sts;
> > +}
> > +return 0;
> > +
> > +dump_sts:
> > +dump_error_stat(ns);
> > +
> > +return ret;
> > +}
> > +
> > +struct spi_board_info m10_n3000_info = {
> > +.modalias = "m10-n3000",
> > +.max_speed_hz = 12500000,
> > +.bus_num = 0,
> > +.chip_select = 0,
> > +};
> > +
> > +static int create_altera_spi_controller(struct dfl_n3000_nios *ns)
> > +{
> > +struct altera_spi_platform_data pdata = { 0 };
> > +struct platform_device_info pdevinfo = { 0 };
> > +void __iomem *base = ns->base;
> > +u64 v;
> > +
> > +v = readq(base + NIOS_SPI_PARAM);
> > +
> > +pdata.mode_bits = SPI_CS_HIGH;
> > +if (FIELD_GET(PARAM_CLK_POL, v))
> > +pdata.mode_bits |= SPI_CPOL;
> > +if (FIELD_GET(PARAM_CLK_PHASE, v))
> > +pdata.mode_bits |= SPI_CPHA;
> > +
> > +pdata.num_chipselect = FIELD_GET(PARAM_NUM_CS, v);
> > +pdata.bits_per_word_mask =
> > +SPI_BPW_RANGE_MASK(1, FIELD_GET(PARAM_DATA_WIDTH,
> > v));
> > +
> > +pdata.num_devices = 1;
> > +pdata.devices = &m10_n3000_info;
> > +
> > +dev_dbg(ns->dev, "%s cs %u bpm 0x%x mode 0x%x\n", __func__,
> > +pdata.num_chipselect, pdata.bits_per_word_mask,
> > +pdata.mode_bits);
> > +
> > +pdevinfo.name = "subdev_spi_altera";
> > +pdevinfo.id = PLATFORM_DEVID_AUTO;
> > +pdevinfo.parent = ns->dev;
> > +pdevinfo.data = &pdata;
> > +pdevinfo.size_data = sizeof(pdata);
> > +
> > +ns->altera_spi = platform_device_register_full(&pdevinfo);
> > +return PTR_ERR_OR_ZERO(ns->altera_spi);
> > +}
> > +
> > +static void destroy_altera_spi_controller(struct dfl_n3000_nios *ns)
> > +{
> > +platform_device_unregister(ns->altera_spi);
> > +}
> > +
> > +/* ns is the abbreviation of nios_spi */
> > +static int ns_poll_stat_timeout(void __iomem *base, u64 *v)
> > +{
> > +int loops = NS_REGBUS_WAIT_TIMEOUT;
> > +
> > +/*
> > + * We don't use the time based timeout here for performance.
> > + *
> > + * The image reprograming engine is on max10 bmc chip, which is the
> > spi
> > + * device connected to altera spi controller. So the regbus read/write
> > + * is on the critical path of PAC N3000 image reprograming. And
> > usually
> > + * the state changes in few loops, the time based timeout checking
> > will
> > + * add too much overhead on it.
> > + *
> > + * Anyway, 10000 times loop is large enough.
> > + */
> > +do {
> > +*v = readq(base + NIOS_SPI_STAT);
> > +if (*v & STAT_RW_VAL)
> > +break;
> > +cpu_relax();
> > +} while (--loops);
> > +
> > +return loops ? 0 : -ETIMEDOUT;
> > +}
> > +
> > +static int ns_reg_write(void *context, unsigned int reg, unsigned int val)
> > +{
> > +struct dfl_n3000_nios *ns = context;
> > +u64 v = 0;
> > +int ret;
> > +
> > +v |= FIELD_PREP(CTRL_CMD_MSK, CTRL_CMD_WR);
> > +v |= FIELD_PREP(CTRL_ADDR, reg);
> > +v |= FIELD_PREP(CTRL_WR_DATA, val);
> > +writeq(v, ns->base + NIOS_SPI_CTRL);
> > +
> > +ret = ns_poll_stat_timeout(ns->base, &v);
> > +if (ret)
> > +dev_err(ns->dev, "fail to write reg 0x%x val 0x%x: %d\n",
> > +reg, val, ret);
> > +
> > +return ret;
> > +}
> > +
> > +static int ns_reg_read(void *context, unsigned int reg, unsigned int *val)
> > +{
> > +struct dfl_n3000_nios *ns = context;
> > +u64 v = 0;
> > +int ret;
> > +
> > +v |= FIELD_PREP(CTRL_CMD_MSK, CTRL_CMD_RD);
> > +v |= FIELD_PREP(CTRL_ADDR, reg);
> > +writeq(v, ns->base + NIOS_SPI_CTRL);
> > +
> > +ret = ns_poll_stat_timeout(ns->base, &v);
> > +if (ret)
> > +dev_err(ns->dev, "fail to read reg 0x%x: %d\n", reg, ret);
> > +else
> > +*val = FIELD_GET(STAT_RD_DATA, v);
> > +
> > +return ret;
> > +}
> > +
> > +static const struct regmap_config ns_regbus_cfg = {
> > +.reg_bits = 32,
> > +.reg_stride = 4,
> > +.val_bits = 32,
> > +.fast_io = true,
> > +
> > +.reg_write = ns_reg_write,
> > +.reg_read = ns_reg_read,
> > +};
> > +
> > +static int dfl_n3000_nios_probe(struct dfl_device *dfl_dev)
> > +{
> > +struct device *dev = &dfl_dev->dev;
> > +struct dfl_n3000_nios *ns;
> > +int ret;
> > +
> > +ns = devm_kzalloc(dev, sizeof(*ns), GFP_KERNEL);
> > +if (!ns)
> > +return -ENOMEM;
> > +
> > +dev_set_drvdata(&dfl_dev->dev, ns);
> > +
> > +ns->dev = dev;
> > +
> > +ns->base = devm_ioremap_resource(&dfl_dev->dev, &dfl_dev-
> > >mmio_res);
> > +if (IS_ERR(ns->base))
> > +return PTR_ERR(ns->base);
> > +
> > +ns->regmap = devm_regmap_init(dev, NULL, ns, &ns_regbus_cfg);
> > +if (IS_ERR(ns->regmap))
> > +return PTR_ERR(ns->regmap);
> > +
> > +ret = n3000_nios_init_done_check(ns);
> > +if (ret)
> > +return ret;
> > +
> > +ret = create_altera_spi_controller(ns);
> > +if (ret)
> > +dev_err(dev, "altera spi controller create failed: %d\n", ret);
> > +
> > +return ret;
> > +}
> > +
> > +static void dfl_n3000_nios_remove(struct dfl_device *dfl_dev)
> > +{
> > +struct dfl_n3000_nios *ns = dev_get_drvdata(&dfl_dev->dev);
> > +
> > +destroy_altera_spi_controller(ns);
> > +}
> > +
> > +#define FME_FEATURE_ID_N3000_NIOS0xd
> > +
> > +static const struct dfl_device_id dfl_n3000_nios_ids[] = {
> > +{ FME_ID, FME_FEATURE_ID_N3000_NIOS },
> > +{ }
> > +};
> > +
> > +static struct dfl_driver dfl_n3000_nios_driver = {
> > +.drv= {
> > +.name       = "dfl-n3000-nios",
> > +.dev_groups = n3000_nios_groups,
> > +},
> > +.id_table = dfl_n3000_nios_ids,
> > +.probe   = dfl_n3000_nios_probe,
> > +.remove  = dfl_n3000_nios_remove,
> > +};
> > +
> > +module_dfl_driver(dfl_n3000_nios_driver);
> > +
> > +MODULE_DEVICE_TABLE(dfl, dfl_n3000_nios_ids);
> > +MODULE_DESCRIPTION("DFL N3000 Nios private feature driver");
> > +MODULE_AUTHOR("Intel Corporation");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 2.7.4