[PATCH v2 0/9] Designware EP support and code clean up

[PATCH v2 0/9] Designware EP support and code clean up

[Gustavo Pimentel]

The patch set was made against the Bjorn's next branch.

Adds support Designware EP support.

Increases the maximum number of interrupts allowed for Designware IP
controller.

Does a code cleanup on Designware driver:
 - Replaces magic numbers without a easy meaning by a well known define
   that helps the human compreension.
 - Replaces a division by 2 by a simple right shift rotation of 1 bit.
 - Fixes all first letter characters on comments and debug messages to
   upper case to maintain coherency.

Gustavo Pimentel (9):
  bindings: PCI: designware: Example update
  PCI: dwc: Add support for endpoint mode
  bindings: PCI: designware: Add support for the EP in Designware driver
  PCI: Adds device ID for Synopsys Sample Endpoint.
  misc: pci_endpoint_test: Add designware EP entry
  PCI: dwc: Define maximum number of vectors
  PCI: dwc: Replace lower into upper case characters
  PCI: dwc: Small computation improvement
  PCI: dwc: Replace magic number by defines

 .../devicetree/bindings/pci/designware-pcie.txt    |  27 +++-
 drivers/misc/pci_endpoint_test.c                   |   1 +
 drivers/pci/dwc/Kconfig                            |  45 ++++--
 drivers/pci/dwc/pcie-designware-ep.c               |  20 +--
 drivers/pci/dwc/pcie-designware-host.c             |  77 +++++-----
 drivers/pci/dwc/pcie-designware-plat.c             | 159 +++++++++++++++++++--
 drivers/pci/dwc/pcie-designware.c                  |  22 +--
 drivers/pci/dwc/pcie-designware.h                  |   1 +
 drivers/pci/endpoint/functions/pci-epf-test.c      |   9 ++
 include/linux/pci_ids.h                            |   1 +
 10 files changed, 281 insertions(+), 81 deletions(-)

-- 
2.7.4

[PATCH v2 1/9] bindings: PCI: designware: Example update

[Gustavo Pimentel]

Replaces "ctrlreg" reg-name by "dbi" to be coherent with similar drivers,
however it still be compatible with any previous DT that uses the old
reg-name.

Replaces the PCIe base address example by a real PCIe base address in use.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
Changes v1->v2:
 - Removed any iATU reference or changes to avoid confusion.
 - Add "snps,dw-pcie" compatible string following Kishon's suggestion.

 Documentation/devicetree/bindings/pci/designware-pcie.txt | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/designware-pcie.txt b/Documentation/devicetree/bindings/pci/designware-pcie.txt
index 1da7ade..f02cd20 100644
--- a/Documentation/devicetree/bindings/pci/designware-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/designware-pcie.txt
@@ -1,7 +1,8 @@
 * Synopsys DesignWare PCIe interface
 
 Required properties:
-- compatible: should contain "snps,dw-pcie" to identify the core.
+- compatible:
+	"snps,dw-pcie-rc", "snps,dw-pcie" for RC mode;
 - reg: Should contain the configuration address space.
 - reg-names: Must be "config" for the PCIe configuration space.
     (The old way of getting the configuration address space from "ranges"
@@ -41,11 +42,11 @@ EP mode:
 
 Example configuration:
 
-	pcie: pcie@dffff000 {
-		compatible = "snps,dw-pcie";
-		reg = <0xdffff000 0x1000>, /* Controller registers */
-		      <0xd0000000 0x2000>; /* PCI config space */
-		reg-names = "ctrlreg", "config";
+	pcie: pcie@dfc00000 {
+		compatible = "snps,dw-pcie-rc", "snps,dw-pcie";
+		reg = <0xdfc00000 0x0001000>, /* IP registers */
+		      <0xd0000000 0x0002000>; /* Configuration space */
+		reg-names = "dbi", "config";
 		#address-cells = <3>;
 		#size-cells = <2>;
 		device_type = "pci";
@@ -54,5 +55,4 @@ Example configuration:
 		interrupts = <25>, <24>;
 		#interrupt-cells = <1>;
 		num-lanes = <1>;
-		num-viewport = <3>;
 	};
-- 
2.7.4

[PATCH v2 2/9] PCI: dwc: Add support for endpoint mode

[Gustavo Pimentel]

The PCIe controller dual mode is capable of operating in host mode as well
as endpoint mode by configuration, therefore this patch aims to add
endpoint mode support to the designware driver.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
Change v1->v2:
 - Removed dw_plat_pcie_stop_link empty function.
 - Implemented Kishon's suggestions about dw-pcie-rc and dw-pcie strings.
compatibility.
 - Added second entry on pci_epf_test_ids structure.

 drivers/pci/dwc/Kconfig                       |  45 ++++++--
 drivers/pci/dwc/pcie-designware-ep.c          |   4 +-
 drivers/pci/dwc/pcie-designware-plat.c        | 153 ++++++++++++++++++++++++--
 drivers/pci/endpoint/functions/pci-epf-test.c |   9 ++
 4 files changed, 190 insertions(+), 21 deletions(-)

diff --git a/drivers/pci/dwc/Kconfig b/drivers/pci/dwc/Kconfig
index 2f3f5c5..3fd7daf 100644
--- a/drivers/pci/dwc/Kconfig
+++ b/drivers/pci/dwc/Kconfig
@@ -7,8 +7,7 @@ config PCIE_DW
 
 config PCIE_DW_HOST
         bool
-	depends on PCI
-	depends on PCI_MSI_IRQ_DOMAIN
+	depends on PCI && PCI_MSI_IRQ_DOMAIN
         select PCIE_DW
 
 config PCIE_DW_EP
@@ -52,16 +51,42 @@ config PCI_DRA7XX_EP
 
 config PCIE_DW_PLAT
 	bool "Platform bus based DesignWare PCIe Controller"
-	depends on PCI
-	depends on PCI_MSI_IRQ_DOMAIN
-	select PCIE_DW_HOST
-	---help---
-	 This selects the DesignWare PCIe controller support. Select this if
-	 you have a PCIe controller on Platform bus.
+	help
+	  There are two instances of PCIe controller in Designware IP.
+	  This controller can work either as EP or RC. In order to enable
+	  host-specific features PCIE_DW_PLAT_HOST must be selected and in
+	  order to enable device-specific features PCIE_DW_PLAT_EP must be
+	  selected.
 
-	 If you have a controller with this interface, say Y or M here.
+config PCIE_DW_PLAT_HOST
+	bool "Platform bus based DesignWare PCIe Controller - Host mode"
+	depends on PCI && PCI_MSI_IRQ_DOMAIN
+	select PCIE_DW_HOST
+	select PCIE_DW_PLAT
+	default y
+	help
+	  Enables support for the PCIe controller in the Designware IP to
+	  work in host mode. There are two instances of PCIe controller in
+	  Designware IP.
+	  This controller can work either as EP or RC. In order to enable
+	  host-specific features PCIE_DW_PLAT_HOST must be selected and in
+	  order to enable device-specific features PCI_DW_PLAT_EP must be
+	  selected.
 
-	 If unsure, say N.
+config PCIE_DW_PLAT_EP
+	bool "Platform bus based DesignWare PCIe Controller - Endpoint mode"
+	depends on PCI && PCI_MSI_IRQ_DOMAIN
+	depends on PCI_ENDPOINT
+	select PCIE_DW_EP
+	select PCIE_DW_PLAT
+	help
+	  Enables support for the PCIe controller in the Designware IP to
+	  work in endpoint mode. There are two instances of PCIe controller
+	  in Designware IP.
+	  This controller can work either as EP or RC. In order to enable
+	  host-specific features PCIE_DW_PLAT_HOST must be selected and in
+	  order to enable device-specific features PCI_DW_PLAT_EP must be
+	  selected.
 
 config PCI_EXYNOS
 	bool "Samsung Exynos PCIe controller"
diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
index f07678b..4ac135a 100644
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -15,8 +15,10 @@
 void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
 {
 	struct pci_epc *epc = ep->epc;
+	struct pci_epf *epf;
 
-	pci_epc_linkup(epc);
+	list_for_each_entry(epf, &epc->pci_epf, list)
+		pci_epf_linkup(epf);
 }
 
 static void __dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar,
diff --git a/drivers/pci/dwc/pcie-designware-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
index 5416aa8..5382a7a 100644
--- a/drivers/pci/dwc/pcie-designware-plat.c
+++ b/drivers/pci/dwc/pcie-designware-plat.c
@@ -12,19 +12,29 @@
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
+#include <linux/of_device.h>
 #include <linux/of_gpio.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/resource.h>
 #include <linux/signal.h>
 #include <linux/types.h>
+#include <linux/regmap.h>
 
 #include "pcie-designware.h"
 
 struct dw_plat_pcie {
-	struct dw_pcie		*pci;
+	struct dw_pcie			*pci;
+	struct regmap			*regmap;
+	enum dw_pcie_device_mode	mode;
 };
 
+struct dw_plat_pcie_of_data {
+	enum dw_pcie_device_mode	mode;
+};
+
+static const struct of_device_id dw_plat_pcie_of_match[];
+
 static int dw_plat_pcie_host_init(struct pcie_port *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
@@ -42,9 +52,53 @@ static const struct dw_pcie_host_ops dw_plat_pcie_host_ops = {
 	.host_init = dw_plat_pcie_host_init,
 };
 
-static int dw_plat_add_pcie_port(struct pcie_port *pp,
+static int dw_plat_pcie_establish_link(struct dw_pcie *pci)
+{
+	return 0;
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+	.start_link = dw_plat_pcie_establish_link,
+};
+
+static void dw_plat_pcie_ep_init(struct dw_pcie_ep *ep)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	enum pci_barno bar;
+
+	for (bar = BAR_0; bar <= BAR_5; bar++)
+		dw_pcie_ep_reset_bar(pci, bar);
+}
+
+static int dw_plat_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
+				     enum pci_epc_irq_type type,
+				     u8 interrupt_num)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	switch (type) {
+	case PCI_EPC_IRQ_LEGACY:
+		dev_err(pci->dev, "EP cannot trigger legacy IRQs\n");
+		return -EINVAL;
+	case PCI_EPC_IRQ_MSI:
+		return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
+	default:
+		dev_err(pci->dev, "UNKNOWN IRQ type\n");
+	}
+
+	return 0;
+}
+
+static struct dw_pcie_ep_ops pcie_ep_ops = {
+	.ep_init = dw_plat_pcie_ep_init,
+	.raise_irq = dw_plat_pcie_ep_raise_irq,
+};
+
+static int dw_plat_add_pcie_port(struct dw_plat_pcie *dw_plat_pcie,
 				 struct platform_device *pdev)
 {
+	struct dw_pcie *pci = dw_plat_pcie->pci;
+	struct pcie_port *pp = &pci->pp;
 	struct device *dev = &pdev->dev;
 	int ret;
 
@@ -63,15 +117,44 @@ static int dw_plat_add_pcie_port(struct pcie_port *pp,
 
 	ret = dw_pcie_host_init(pp);
 	if (ret) {
-		dev_err(dev, "failed to initialize host\n");
+		dev_err(dev, "Failed to initialize host\n");
 		return ret;
 	}
 
 	return 0;
 }
 
-static const struct dw_pcie_ops dw_pcie_ops = {
-};
+static int dw_plat_add_pcie_ep(struct dw_plat_pcie *dw_plat_pcie,
+			       struct platform_device *pdev)
+{
+	int ret;
+	struct dw_pcie_ep *ep;
+	struct resource *res;
+	struct device *dev = &pdev->dev;
+	struct dw_pcie *pci = dw_plat_pcie->pci;
+
+	ep = &pci->ep;
+	ep->ops = &pcie_ep_ops;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi2");
+	pci->dbi_base2 = devm_ioremap(dev, res->start, resource_size(res));
+	if (IS_ERR(pci->dbi_base2))
+		return PTR_ERR(pci->dbi_base2);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "addr_space");
+	if (!res)
+		return -EINVAL;
+
+	ep->phys_base = res->start;
+	ep->addr_size = resource_size(res);
+
+	ret = dw_pcie_ep_init(ep);
+	if (ret) {
+		dev_err(dev, "Failed to initialize endpoint\n");
+		return ret;
+	}
+	return 0;
+}
 
 static int dw_plat_pcie_probe(struct platform_device *pdev)
 {
@@ -80,6 +163,16 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
 	struct dw_pcie *pci;
 	struct resource *res;  /* Resource from DT */
 	int ret;
+	const struct of_device_id *match;
+	const struct dw_plat_pcie_of_data *data;
+	enum dw_pcie_device_mode mode;
+
+	match = of_match_device(dw_plat_pcie_of_match, dev);
+	if (!match)
+		return -EINVAL;
+
+	data = (struct dw_plat_pcie_of_data *)match->data;
+	mode = (enum dw_pcie_device_mode)data->mode;
 
 	dw_plat_pcie = devm_kzalloc(dev, sizeof(*dw_plat_pcie), GFP_KERNEL);
 	if (!dw_plat_pcie)
@@ -93,23 +186,63 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
 	pci->ops = &dw_pcie_ops;
 
 	dw_plat_pcie->pci = pci;
+	dw_plat_pcie->mode = mode;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
+	if (!res)
+		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	pci->dbi_base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(pci->dbi_base))
 		return PTR_ERR(pci->dbi_base);
 
 	platform_set_drvdata(pdev, dw_plat_pcie);
 
-	ret = dw_plat_add_pcie_port(&pci->pp, pdev);
-	if (ret < 0)
-		return ret;
+	switch (dw_plat_pcie->mode) {
+	case DW_PCIE_RC_TYPE:
+		if (!IS_ENABLED(CONFIG_PCIE_DW_PLAT_HOST))
+			return -ENODEV;
+
+		ret = dw_plat_add_pcie_port(dw_plat_pcie, pdev);
+		if (ret < 0)
+			return ret;
+		break;
+	case DW_PCIE_EP_TYPE:
+		if (!IS_ENABLED(CONFIG_PCIE_DW_PLAT_EP))
+			return -ENODEV;
+
+		ret = dw_plat_add_pcie_ep(dw_plat_pcie, pdev);
+		if (ret < 0)
+			return ret;
+		break;
+	default:
+		dev_err(dev, "INVALID device type %d\n", dw_plat_pcie->mode);
+	}
 
 	return 0;
 }
 
+static const struct dw_plat_pcie_of_data dw_plat_pcie_rc_of_data = {
+	.mode = DW_PCIE_RC_TYPE,
+};
+
+static const struct dw_plat_pcie_of_data dw_plat_pcie_ep_of_data = {
+	.mode = DW_PCIE_EP_TYPE,
+};
+
 static const struct of_device_id dw_plat_pcie_of_match[] = {
-	{ .compatible = "snps,dw-pcie", },
+	{
+		.compatible = "snps,dw-pcie",
+		.data = &dw_plat_pcie_rc_of_data,
+	},
+	{
+		.compatible = "snps,dw-pcie-rc",
+		.data = &dw_plat_pcie_rc_of_data,
+	},
+	{
+		.compatible = "snps,dw-pcie-ep",
+		.data = &dw_plat_pcie_ep_of_data,
+	},
 	{},
 };
 
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 7cef851..45d1c63 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -459,10 +459,19 @@ static int pci_epf_test_bind(struct pci_epf *epf)
 	return 0;
 }
 
+static const struct pci_epf_test_data data_cfg2 = {
+	.test_reg_bar = BAR_0,
+	.linkup_notifier = false
+};
+
 static const struct pci_epf_device_id pci_epf_test_ids[] = {
 	{
 		.name = "pci_epf_test",
 	},
+	{
+		.name = "pci_epf_test_cfg2",
+		.driver_data = (kernel_ulong_t)&data_cfg2,
+	},
 	{},
 };
 
-- 
2.7.4

Re: [PATCH v2 2/9] PCI: dwc: Add support for endpoint mode

[Kishon Vijay Abraham I]

Hi,

On Monday 09 April 2018 03:11 PM, Gustavo Pimentel wrote:
> The PCIe controller dual mode is capable of operating in host mode as well
> as endpoint mode by configuration, therefore this patch aims to add
> endpoint mode support to the designware driver.
> 
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
> ---
> Change v1->v2:
>  - Removed dw_plat_pcie_stop_link empty function.
>  - Implemented Kishon's suggestions about dw-pcie-rc and dw-pcie strings.
> compatibility.
>  - Added second entry on pci_epf_test_ids structure.
> 
>  drivers/pci/dwc/Kconfig                       |  45 ++++++--
>  drivers/pci/dwc/pcie-designware-ep.c          |   4 +-
>  drivers/pci/dwc/pcie-designware-plat.c        | 153 ++++++++++++++++++++++++--
>  drivers/pci/endpoint/functions/pci-epf-test.c |   9 ++
>  4 files changed, 190 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/pci/dwc/Kconfig b/drivers/pci/dwc/Kconfig
> index 2f3f5c5..3fd7daf 100644
> --- a/drivers/pci/dwc/Kconfig
> +++ b/drivers/pci/dwc/Kconfig
> @@ -7,8 +7,7 @@ config PCIE_DW
>  
>  config PCIE_DW_HOST
>          bool
> -	depends on PCI
> -	depends on PCI_MSI_IRQ_DOMAIN
> +	depends on PCI && PCI_MSI_IRQ_DOMAIN
>          select PCIE_DW
>  
>  config PCIE_DW_EP
> @@ -52,16 +51,42 @@ config PCI_DRA7XX_EP
>  
>  config PCIE_DW_PLAT
>  	bool "Platform bus based DesignWare PCIe Controller"
> -	depends on PCI
> -	depends on PCI_MSI_IRQ_DOMAIN
> -	select PCIE_DW_HOST
> -	---help---
> -	 This selects the DesignWare PCIe controller support. Select this if
> -	 you have a PCIe controller on Platform bus.
> +	help
> +	  There are two instances of PCIe controller in Designware IP.
> +	  This controller can work either as EP or RC. In order to enable
> +	  host-specific features PCIE_DW_PLAT_HOST must be selected and in
> +	  order to enable device-specific features PCIE_DW_PLAT_EP must be
> +	  selected.
>  
> -	 If you have a controller with this interface, say Y or M here.
> +config PCIE_DW_PLAT_HOST
> +	bool "Platform bus based DesignWare PCIe Controller - Host mode"
> +	depends on PCI && PCI_MSI_IRQ_DOMAIN
> +	select PCIE_DW_HOST
> +	select PCIE_DW_PLAT
> +	default y
> +	help
> +	  Enables support for the PCIe controller in the Designware IP to
> +	  work in host mode. There are two instances of PCIe controller in
> +	  Designware IP.
> +	  This controller can work either as EP or RC. In order to enable
> +	  host-specific features PCIE_DW_PLAT_HOST must be selected and in
> +	  order to enable device-specific features PCI_DW_PLAT_EP must be
> +	  selected.
>  
> -	 If unsure, say N.
> +config PCIE_DW_PLAT_EP
> +	bool "Platform bus based DesignWare PCIe Controller - Endpoint mode"
> +	depends on PCI && PCI_MSI_IRQ_DOMAIN
> +	depends on PCI_ENDPOINT
> +	select PCIE_DW_EP
> +	select PCIE_DW_PLAT
> +	help
> +	  Enables support for the PCIe controller in the Designware IP to
> +	  work in endpoint mode. There are two instances of PCIe controller
> +	  in Designware IP.
> +	  This controller can work either as EP or RC. In order to enable
> +	  host-specific features PCIE_DW_PLAT_HOST must be selected and in
> +	  order to enable device-specific features PCI_DW_PLAT_EP must be
> +	  selected.
>  
>  config PCI_EXYNOS
>  	bool "Samsung Exynos PCIe controller"
> diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
> index f07678b..4ac135a 100644
> --- a/drivers/pci/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/dwc/pcie-designware-ep.c
> @@ -15,8 +15,10 @@
>  void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
>  {
>  	struct pci_epc *epc = ep->epc;
> +	struct pci_epf *epf;
>  
> -	pci_epc_linkup(epc);
> +	list_for_each_entry(epf, &epc->pci_epf, list)
> +		pci_epf_linkup(epf);
>  }

This shouldn't be required anymore.
>  
>  static void __dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar,
> diff --git a/drivers/pci/dwc/pcie-designware-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
> index 5416aa8..5382a7a 100644
> --- a/drivers/pci/dwc/pcie-designware-plat.c
> +++ b/drivers/pci/dwc/pcie-designware-plat.c
> @@ -12,19 +12,29 @@
>  #include <linux/interrupt.h>
>  #include <linux/kernel.h>
>  #include <linux/init.h>
> +#include <linux/of_device.h>
>  #include <linux/of_gpio.h>
>  #include <linux/pci.h>
>  #include <linux/platform_device.h>
>  #include <linux/resource.h>
>  #include <linux/signal.h>
>  #include <linux/types.h>
> +#include <linux/regmap.h>
>  
>  #include "pcie-designware.h"
>  
>  struct dw_plat_pcie {
> -	struct dw_pcie		*pci;
> +	struct dw_pcie			*pci;
> +	struct regmap			*regmap;
> +	enum dw_pcie_device_mode	mode;
>  };
>  
> +struct dw_plat_pcie_of_data {
> +	enum dw_pcie_device_mode	mode;
> +};
> +
> +static const struct of_device_id dw_plat_pcie_of_match[];
> +
>  static int dw_plat_pcie_host_init(struct pcie_port *pp)
>  {
>  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> @@ -42,9 +52,53 @@ static const struct dw_pcie_host_ops dw_plat_pcie_host_ops = {
>  	.host_init = dw_plat_pcie_host_init,
>  };
>  
> -static int dw_plat_add_pcie_port(struct pcie_port *pp,
> +static int dw_plat_pcie_establish_link(struct dw_pcie *pci)
> +{
> +	return 0;
> +}
> +
> +static const struct dw_pcie_ops dw_pcie_ops = {
> +	.start_link = dw_plat_pcie_establish_link,
> +};
> +
> +static void dw_plat_pcie_ep_init(struct dw_pcie_ep *ep)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +	enum pci_barno bar;
> +
> +	for (bar = BAR_0; bar <= BAR_5; bar++)
> +		dw_pcie_ep_reset_bar(pci, bar);
> +}
> +
> +static int dw_plat_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
> +				     enum pci_epc_irq_type type,
> +				     u8 interrupt_num)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +
> +	switch (type) {
> +	case PCI_EPC_IRQ_LEGACY:
> +		dev_err(pci->dev, "EP cannot trigger legacy IRQs\n");
> +		return -EINVAL;
> +	case PCI_EPC_IRQ_MSI:
> +		return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
> +	default:
> +		dev_err(pci->dev, "UNKNOWN IRQ type\n");
> +	}
> +
> +	return 0;
> +}
> +
> +static struct dw_pcie_ep_ops pcie_ep_ops = {
> +	.ep_init = dw_plat_pcie_ep_init,
> +	.raise_irq = dw_plat_pcie_ep_raise_irq,
> +};
> +
> +static int dw_plat_add_pcie_port(struct dw_plat_pcie *dw_plat_pcie,
>  				 struct platform_device *pdev)
>  {
> +	struct dw_pcie *pci = dw_plat_pcie->pci;
> +	struct pcie_port *pp = &pci->pp;
>  	struct device *dev = &pdev->dev;
>  	int ret;
>  
> @@ -63,15 +117,44 @@ static int dw_plat_add_pcie_port(struct pcie_port *pp,
>  
>  	ret = dw_pcie_host_init(pp);
>  	if (ret) {
> -		dev_err(dev, "failed to initialize host\n");
> +		dev_err(dev, "Failed to initialize host\n");
>  		return ret;
>  	}
>  
>  	return 0;
>  }
>  
> -static const struct dw_pcie_ops dw_pcie_ops = {
> -};
> +static int dw_plat_add_pcie_ep(struct dw_plat_pcie *dw_plat_pcie,
> +			       struct platform_device *pdev)
> +{
> +	int ret;
> +	struct dw_pcie_ep *ep;
> +	struct resource *res;
> +	struct device *dev = &pdev->dev;
> +	struct dw_pcie *pci = dw_plat_pcie->pci;
> +
> +	ep = &pci->ep;
> +	ep->ops = &pcie_ep_ops;
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi2");
> +	pci->dbi_base2 = devm_ioremap(dev, res->start, resource_size(res));

This can throw up a NULL pointer dereferencing error. Use devm_ioremap_resource
instead.

> +	if (IS_ERR(pci->dbi_base2))
> +		return PTR_ERR(pci->dbi_base2);
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "addr_space");
> +	if (!res)
> +		return -EINVAL;
> +
> +	ep->phys_base = res->start;
> +	ep->addr_size = resource_size(res);
> +
> +	ret = dw_pcie_ep_init(ep);
> +	if (ret) {
> +		dev_err(dev, "Failed to initialize endpoint\n");
> +		return ret;
> +	}
> +	return 0;
> +}
>  
>  static int dw_plat_pcie_probe(struct platform_device *pdev)
>  {
> @@ -80,6 +163,16 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
>  	struct dw_pcie *pci;
>  	struct resource *res;  /* Resource from DT */
>  	int ret;
> +	const struct of_device_id *match;
> +	const struct dw_plat_pcie_of_data *data;
> +	enum dw_pcie_device_mode mode;
> +
> +	match = of_match_device(dw_plat_pcie_of_match, dev);
> +	if (!match)
> +		return -EINVAL;
> +
> +	data = (struct dw_plat_pcie_of_data *)match->data;
> +	mode = (enum dw_pcie_device_mode)data->mode;
>  
>  	dw_plat_pcie = devm_kzalloc(dev, sizeof(*dw_plat_pcie), GFP_KERNEL);
>  	if (!dw_plat_pcie)
> @@ -93,23 +186,63 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
>  	pci->ops = &dw_pcie_ops;
>  
>  	dw_plat_pcie->pci = pci;
> +	dw_plat_pcie->mode = mode;
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
> +	if (!res)
> +		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  
> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	pci->dbi_base = devm_ioremap_resource(dev, res);
>  	if (IS_ERR(pci->dbi_base))
>  		return PTR_ERR(pci->dbi_base);
>  
>  	platform_set_drvdata(pdev, dw_plat_pcie);
>  
> -	ret = dw_plat_add_pcie_port(&pci->pp, pdev);
> -	if (ret < 0)
> -		return ret;
> +	switch (dw_plat_pcie->mode) {
> +	case DW_PCIE_RC_TYPE:
> +		if (!IS_ENABLED(CONFIG_PCIE_DW_PLAT_HOST))
> +			return -ENODEV;
> +
> +		ret = dw_plat_add_pcie_port(dw_plat_pcie, pdev);
> +		if (ret < 0)
> +			return ret;
> +		break;
> +	case DW_PCIE_EP_TYPE:
> +		if (!IS_ENABLED(CONFIG_PCIE_DW_PLAT_EP))
> +			return -ENODEV;
> +
> +		ret = dw_plat_add_pcie_ep(dw_plat_pcie, pdev);
> +		if (ret < 0)
> +			return ret;
> +		break;
> +	default:
> +		dev_err(dev, "INVALID device type %d\n", dw_plat_pcie->mode);
> +	}
>  
>  	return 0;
>  }
>  
> +static const struct dw_plat_pcie_of_data dw_plat_pcie_rc_of_data = {
> +	.mode = DW_PCIE_RC_TYPE,
> +};
> +
> +static const struct dw_plat_pcie_of_data dw_plat_pcie_ep_of_data = {
> +	.mode = DW_PCIE_EP_TYPE,
> +};
> +
>  static const struct of_device_id dw_plat_pcie_of_match[] = {
> -	{ .compatible = "snps,dw-pcie", },
> +	{
> +		.compatible = "snps,dw-pcie",
> +		.data = &dw_plat_pcie_rc_of_data,
> +	},
> +	{
> +		.compatible = "snps,dw-pcie-rc",
> +		.data = &dw_plat_pcie_rc_of_data,
> +	},
> +	{
> +		.compatible = "snps,dw-pcie-ep",
> +		.data = &dw_plat_pcie_ep_of_data,
> +	},
>  	{},
>  };
>  
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 7cef851..45d1c63 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c

have a separate patch for this.
> @@ -459,10 +459,19 @@ static int pci_epf_test_bind(struct pci_epf *epf)
>  	return 0;
>  }
>  
> +static const struct pci_epf_test_data data_cfg2 = {
> +	.test_reg_bar = BAR_0,

default test_reg_bar is BAR_0. So you can skip this.
> +	.linkup_notifier = false
> +};
> +

Thanks
Kishon

Re: [PATCH v2 2/9] PCI: dwc: Add support for endpoint mode

[Gustavo Pimentel]

Hi Kishon,

On 10/04/2018 06:12, Kishon Vijay Abraham I wrote:
> Hi,
> 
> On Monday 09 April 2018 03:11 PM, Gustavo Pimentel wrote:
>> The PCIe controller dual mode is capable of operating in host mode as well
>> as endpoint mode by configuration, therefore this patch aims to add
>> endpoint mode support to the designware driver.
>>
>> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
>> ---
>> Change v1->v2:
>>  - Removed dw_plat_pcie_stop_link empty function.
>>  - Implemented Kishon's suggestions about dw-pcie-rc and dw-pcie strings.
>> compatibility.
>>  - Added second entry on pci_epf_test_ids structure.
>>
>>  drivers/pci/dwc/Kconfig                       |  45 ++++++--
>>  drivers/pci/dwc/pcie-designware-ep.c          |   4 +-
>>  drivers/pci/dwc/pcie-designware-plat.c        | 153 ++++++++++++++++++++++++--
>>  drivers/pci/endpoint/functions/pci-epf-test.c |   9 ++
>>  4 files changed, 190 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/pci/dwc/Kconfig b/drivers/pci/dwc/Kconfig
>> index 2f3f5c5..3fd7daf 100644
>> --- a/drivers/pci/dwc/Kconfig
>> +++ b/drivers/pci/dwc/Kconfig
>> @@ -7,8 +7,7 @@ config PCIE_DW
>>  
>>  config PCIE_DW_HOST
>>          bool
>> -	depends on PCI
>> -	depends on PCI_MSI_IRQ_DOMAIN
>> +	depends on PCI && PCI_MSI_IRQ_DOMAIN
>>          select PCIE_DW
>>  
>>  config PCIE_DW_EP
>> @@ -52,16 +51,42 @@ config PCI_DRA7XX_EP
>>  
>>  config PCIE_DW_PLAT
>>  	bool "Platform bus based DesignWare PCIe Controller"
>> -	depends on PCI
>> -	depends on PCI_MSI_IRQ_DOMAIN
>> -	select PCIE_DW_HOST
>> -	---help---
>> -	 This selects the DesignWare PCIe controller support. Select this if
>> -	 you have a PCIe controller on Platform bus.
>> +	help
>> +	  There are two instances of PCIe controller in Designware IP.
>> +	  This controller can work either as EP or RC. In order to enable
>> +	  host-specific features PCIE_DW_PLAT_HOST must be selected and in
>> +	  order to enable device-specific features PCIE_DW_PLAT_EP must be
>> +	  selected.
>>  
>> -	 If you have a controller with this interface, say Y or M here.
>> +config PCIE_DW_PLAT_HOST
>> +	bool "Platform bus based DesignWare PCIe Controller - Host mode"
>> +	depends on PCI && PCI_MSI_IRQ_DOMAIN
>> +	select PCIE_DW_HOST
>> +	select PCIE_DW_PLAT
>> +	default y
>> +	help
>> +	  Enables support for the PCIe controller in the Designware IP to
>> +	  work in host mode. There are two instances of PCIe controller in
>> +	  Designware IP.
>> +	  This controller can work either as EP or RC. In order to enable
>> +	  host-specific features PCIE_DW_PLAT_HOST must be selected and in
>> +	  order to enable device-specific features PCI_DW_PLAT_EP must be
>> +	  selected.
>>  
>> -	 If unsure, say N.
>> +config PCIE_DW_PLAT_EP
>> +	bool "Platform bus based DesignWare PCIe Controller - Endpoint mode"
>> +	depends on PCI && PCI_MSI_IRQ_DOMAIN
>> +	depends on PCI_ENDPOINT
>> +	select PCIE_DW_EP
>> +	select PCIE_DW_PLAT
>> +	help
>> +	  Enables support for the PCIe controller in the Designware IP to
>> +	  work in endpoint mode. There are two instances of PCIe controller
>> +	  in Designware IP.
>> +	  This controller can work either as EP or RC. In order to enable
>> +	  host-specific features PCIE_DW_PLAT_HOST must be selected and in
>> +	  order to enable device-specific features PCI_DW_PLAT_EP must be
>> +	  selected.
>>  
>>  config PCI_EXYNOS
>>  	bool "Samsung Exynos PCIe controller"
>> diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
>> index f07678b..4ac135a 100644
>> --- a/drivers/pci/dwc/pcie-designware-ep.c
>> +++ b/drivers/pci/dwc/pcie-designware-ep.c
>> @@ -15,8 +15,10 @@
>>  void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
>>  {
>>  	struct pci_epc *epc = ep->epc;
>> +	struct pci_epf *epf;
>>  
>> -	pci_epc_linkup(epc);
>> +	list_for_each_entry(epf, &epc->pci_epf, list)
>> +		pci_epf_linkup(epf);
>>  }
> 
> This shouldn't be required anymore.

Ok. I'll revert it.

>>  
>>  static void __dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar,
>> diff --git a/drivers/pci/dwc/pcie-designware-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
>> index 5416aa8..5382a7a 100644
>> --- a/drivers/pci/dwc/pcie-designware-plat.c
>> +++ b/drivers/pci/dwc/pcie-designware-plat.c
>> @@ -12,19 +12,29 @@
>>  #include <linux/interrupt.h>
>>  #include <linux/kernel.h>
>>  #include <linux/init.h>
>> +#include <linux/of_device.h>
>>  #include <linux/of_gpio.h>
>>  #include <linux/pci.h>
>>  #include <linux/platform_device.h>
>>  #include <linux/resource.h>
>>  #include <linux/signal.h>
>>  #include <linux/types.h>
>> +#include <linux/regmap.h>
>>  
>>  #include "pcie-designware.h"
>>  
>>  struct dw_plat_pcie {
>> -	struct dw_pcie		*pci;
>> +	struct dw_pcie			*pci;
>> +	struct regmap			*regmap;
>> +	enum dw_pcie_device_mode	mode;
>>  };
>>  
>> +struct dw_plat_pcie_of_data {
>> +	enum dw_pcie_device_mode	mode;
>> +};
>> +
>> +static const struct of_device_id dw_plat_pcie_of_match[];
>> +
>>  static int dw_plat_pcie_host_init(struct pcie_port *pp)
>>  {
>>  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> @@ -42,9 +52,53 @@ static const struct dw_pcie_host_ops dw_plat_pcie_host_ops = {
>>  	.host_init = dw_plat_pcie_host_init,
>>  };
>>  
>> -static int dw_plat_add_pcie_port(struct pcie_port *pp,
>> +static int dw_plat_pcie_establish_link(struct dw_pcie *pci)
>> +{
>> +	return 0;
>> +}
>> +
>> +static const struct dw_pcie_ops dw_pcie_ops = {
>> +	.start_link = dw_plat_pcie_establish_link,
>> +};
>> +
>> +static void dw_plat_pcie_ep_init(struct dw_pcie_ep *ep)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
>> +	enum pci_barno bar;
>> +
>> +	for (bar = BAR_0; bar <= BAR_5; bar++)
>> +		dw_pcie_ep_reset_bar(pci, bar);
>> +}
>> +
>> +static int dw_plat_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
>> +				     enum pci_epc_irq_type type,
>> +				     u8 interrupt_num)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
>> +
>> +	switch (type) {
>> +	case PCI_EPC_IRQ_LEGACY:
>> +		dev_err(pci->dev, "EP cannot trigger legacy IRQs\n");
>> +		return -EINVAL;
>> +	case PCI_EPC_IRQ_MSI:
>> +		return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
>> +	default:
>> +		dev_err(pci->dev, "UNKNOWN IRQ type\n");
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static struct dw_pcie_ep_ops pcie_ep_ops = {
>> +	.ep_init = dw_plat_pcie_ep_init,
>> +	.raise_irq = dw_plat_pcie_ep_raise_irq,
>> +};
>> +
>> +static int dw_plat_add_pcie_port(struct dw_plat_pcie *dw_plat_pcie,
>>  				 struct platform_device *pdev)
>>  {
>> +	struct dw_pcie *pci = dw_plat_pcie->pci;
>> +	struct pcie_port *pp = &pci->pp;
>>  	struct device *dev = &pdev->dev;
>>  	int ret;
>>  
>> @@ -63,15 +117,44 @@ static int dw_plat_add_pcie_port(struct pcie_port *pp,
>>  
>>  	ret = dw_pcie_host_init(pp);
>>  	if (ret) {
>> -		dev_err(dev, "failed to initialize host\n");
>> +		dev_err(dev, "Failed to initialize host\n");
>>  		return ret;
>>  	}
>>  
>>  	return 0;
>>  }
>>  
>> -static const struct dw_pcie_ops dw_pcie_ops = {
>> -};
>> +static int dw_plat_add_pcie_ep(struct dw_plat_pcie *dw_plat_pcie,
>> +			       struct platform_device *pdev)
>> +{
>> +	int ret;
>> +	struct dw_pcie_ep *ep;
>> +	struct resource *res;
>> +	struct device *dev = &pdev->dev;
>> +	struct dw_pcie *pci = dw_plat_pcie->pci;
>> +
>> +	ep = &pci->ep;
>> +	ep->ops = &pcie_ep_ops;
>> +
>> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi2");
>> +	pci->dbi_base2 = devm_ioremap(dev, res->start, resource_size(res));
> 
> This can throw up a NULL pointer dereferencing error. Use devm_ioremap_resource
> instead.

I have looked on [1] and [2] and both implementations uses devm_ioremap
function, they are also wrong?

[1] -> https://elixir.bootlin.com/linux/latest/source/drivers/pci/dwc/pcie-artpec6.c
[2] -> https://elixir.bootlin.com/linux/latest/source/drivers/pci/dwc/pci-dra7xx.c

> 
>> +	if (IS_ERR(pci->dbi_base2))
>> +		return PTR_ERR(pci->dbi_base2);

However this validation is wrong. By using the devm_ioremap function the correct
validation should be like this:

if (!pci->dbi_base2)
	return -ENOMEM;

like exists on [1] and [2]. Can I maintain the coherency with [1] and [2]?

>> +
>> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "addr_space");
>> +	if (!res)
>> +		return -EINVAL;
>> +
>> +	ep->phys_base = res->start;
>> +	ep->addr_size = resource_size(res);
>> +
>> +	ret = dw_pcie_ep_init(ep);
>> +	if (ret) {
>> +		dev_err(dev, "Failed to initialize endpoint\n");
>> +		return ret;
>> +	}
>> +	return 0;
>> +}
>>  
>>  static int dw_plat_pcie_probe(struct platform_device *pdev)
>>  {
>> @@ -80,6 +163,16 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
>>  	struct dw_pcie *pci;
>>  	struct resource *res;  /* Resource from DT */
>>  	int ret;
>> +	const struct of_device_id *match;
>> +	const struct dw_plat_pcie_of_data *data;
>> +	enum dw_pcie_device_mode mode;
>> +
>> +	match = of_match_device(dw_plat_pcie_of_match, dev);
>> +	if (!match)
>> +		return -EINVAL;
>> +
>> +	data = (struct dw_plat_pcie_of_data *)match->data;
>> +	mode = (enum dw_pcie_device_mode)data->mode;
>>  
>>  	dw_plat_pcie = devm_kzalloc(dev, sizeof(*dw_plat_pcie), GFP_KERNEL);
>>  	if (!dw_plat_pcie)
>> @@ -93,23 +186,63 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
>>  	pci->ops = &dw_pcie_ops;
>>  
>>  	dw_plat_pcie->pci = pci;
>> +	dw_plat_pcie->mode = mode;
>> +
>> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
>> +	if (!res)
>> +		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>  
>> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>  	pci->dbi_base = devm_ioremap_resource(dev, res);
>>  	if (IS_ERR(pci->dbi_base))
>>  		return PTR_ERR(pci->dbi_base);
>>  
>>  	platform_set_drvdata(pdev, dw_plat_pcie);
>>  
>> -	ret = dw_plat_add_pcie_port(&pci->pp, pdev);
>> -	if (ret < 0)
>> -		return ret;
>> +	switch (dw_plat_pcie->mode) {
>> +	case DW_PCIE_RC_TYPE:
>> +		if (!IS_ENABLED(CONFIG_PCIE_DW_PLAT_HOST))
>> +			return -ENODEV;
>> +
>> +		ret = dw_plat_add_pcie_port(dw_plat_pcie, pdev);
>> +		if (ret < 0)
>> +			return ret;
>> +		break;
>> +	case DW_PCIE_EP_TYPE:
>> +		if (!IS_ENABLED(CONFIG_PCIE_DW_PLAT_EP))
>> +			return -ENODEV;
>> +
>> +		ret = dw_plat_add_pcie_ep(dw_plat_pcie, pdev);
>> +		if (ret < 0)
>> +			return ret;
>> +		break;
>> +	default:
>> +		dev_err(dev, "INVALID device type %d\n", dw_plat_pcie->mode);
>> +	}
>>  
>>  	return 0;
>>  }
>>  
>> +static const struct dw_plat_pcie_of_data dw_plat_pcie_rc_of_data = {
>> +	.mode = DW_PCIE_RC_TYPE,
>> +};
>> +
>> +static const struct dw_plat_pcie_of_data dw_plat_pcie_ep_of_data = {
>> +	.mode = DW_PCIE_EP_TYPE,
>> +};
>> +
>>  static const struct of_device_id dw_plat_pcie_of_match[] = {
>> -	{ .compatible = "snps,dw-pcie", },
>> +	{
>> +		.compatible = "snps,dw-pcie",
>> +		.data = &dw_plat_pcie_rc_of_data,
>> +	},
>> +	{
>> +		.compatible = "snps,dw-pcie-rc",
>> +		.data = &dw_plat_pcie_rc_of_data,
>> +	},
>> +	{
>> +		.compatible = "snps,dw-pcie-ep",
>> +		.data = &dw_plat_pcie_ep_of_data,
>> +	},
>>  	{},
>>  };
>>  
>> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
>> index 7cef851..45d1c63 100644
>> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
>> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> 
> have a separate patch for this.

Ok.

>> @@ -459,10 +459,19 @@ static int pci_epf_test_bind(struct pci_epf *epf)
>>  	return 0;
>>  }
>>  
>> +static const struct pci_epf_test_data data_cfg2 = {
>> +	.test_reg_bar = BAR_0,
> 
> default test_reg_bar is BAR_0. So you can skip this.

Ok, I'll remove it.

>> +	.linkup_notifier = false
>> +};
>> +
> 
> Thanks
> Kishon
> 

Regards,
Gustavo

Re: [PATCH v2 2/9] PCI: dwc: Add support for endpoint mode

[Kishon Vijay Abraham I]

Hi,

On Tuesday 10 April 2018 04:06 PM, Gustavo Pimentel wrote:
> Hi Kishon,
> 
> On 10/04/2018 06:12, Kishon Vijay Abraham I wrote:
>> Hi,
>>
>> On Monday 09 April 2018 03:11 PM, Gustavo Pimentel wrote:
>>> The PCIe controller dual mode is capable of operating in host mode as well
>>> as endpoint mode by configuration, therefore this patch aims to add
>>> endpoint mode support to the designware driver.
>>>
>>> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
>>> ---
>>> Change v1->v2:
>>>  - Removed dw_plat_pcie_stop_link empty function.
>>>  - Implemented Kishon's suggestions about dw-pcie-rc and dw-pcie strings.
>>> compatibility.
>>>  - Added second entry on pci_epf_test_ids structure.
>>>
>>>  drivers/pci/dwc/Kconfig                       |  45 ++++++--
>>>  drivers/pci/dwc/pcie-designware-ep.c          |   4 +-
>>>  drivers/pci/dwc/pcie-designware-plat.c        | 153 ++++++++++++++++++++++++--
>>>  drivers/pci/endpoint/functions/pci-epf-test.c |   9 ++
>>>  4 files changed, 190 insertions(+), 21 deletions(-)
>>>
>>> diff --git a/drivers/pci/dwc/Kconfig b/drivers/pci/dwc/Kconfig
>>> index 2f3f5c5..3fd7daf 100644
>>> --- a/drivers/pci/dwc/Kconfig
>>> +++ b/drivers/pci/dwc/Kconfig
>>> @@ -7,8 +7,7 @@ config PCIE_DW
>>>  
>>>  config PCIE_DW_HOST
>>>          bool
>>> -	depends on PCI
>>> -	depends on PCI_MSI_IRQ_DOMAIN
>>> +	depends on PCI && PCI_MSI_IRQ_DOMAIN
>>>          select PCIE_DW
>>>  
>>>  config PCIE_DW_EP
>>> @@ -52,16 +51,42 @@ config PCI_DRA7XX_EP
>>>  
>>>  config PCIE_DW_PLAT
>>>  	bool "Platform bus based DesignWare PCIe Controller"
>>> -	depends on PCI
>>> -	depends on PCI_MSI_IRQ_DOMAIN
>>> -	select PCIE_DW_HOST
>>> -	---help---
>>> -	 This selects the DesignWare PCIe controller support. Select this if
>>> -	 you have a PCIe controller on Platform bus.
>>> +	help
>>> +	  There are two instances of PCIe controller in Designware IP.
>>> +	  This controller can work either as EP or RC. In order to enable
>>> +	  host-specific features PCIE_DW_PLAT_HOST must be selected and in
>>> +	  order to enable device-specific features PCIE_DW_PLAT_EP must be
>>> +	  selected.
>>>  
>>> -	 If you have a controller with this interface, say Y or M here.
>>> +config PCIE_DW_PLAT_HOST
>>> +	bool "Platform bus based DesignWare PCIe Controller - Host mode"
>>> +	depends on PCI && PCI_MSI_IRQ_DOMAIN
>>> +	select PCIE_DW_HOST
>>> +	select PCIE_DW_PLAT
>>> +	default y
>>> +	help
>>> +	  Enables support for the PCIe controller in the Designware IP to
>>> +	  work in host mode. There are two instances of PCIe controller in
>>> +	  Designware IP.
>>> +	  This controller can work either as EP or RC. In order to enable
>>> +	  host-specific features PCIE_DW_PLAT_HOST must be selected and in
>>> +	  order to enable device-specific features PCI_DW_PLAT_EP must be
>>> +	  selected.
>>>  
>>> -	 If unsure, say N.
>>> +config PCIE_DW_PLAT_EP
>>> +	bool "Platform bus based DesignWare PCIe Controller - Endpoint mode"
>>> +	depends on PCI && PCI_MSI_IRQ_DOMAIN
>>> +	depends on PCI_ENDPOINT
>>> +	select PCIE_DW_EP
>>> +	select PCIE_DW_PLAT
>>> +	help
>>> +	  Enables support for the PCIe controller in the Designware IP to
>>> +	  work in endpoint mode. There are two instances of PCIe controller
>>> +	  in Designware IP.
>>> +	  This controller can work either as EP or RC. In order to enable
>>> +	  host-specific features PCIE_DW_PLAT_HOST must be selected and in
>>> +	  order to enable device-specific features PCI_DW_PLAT_EP must be
>>> +	  selected.
>>>  
>>>  config PCI_EXYNOS
>>>  	bool "Samsung Exynos PCIe controller"
>>> diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
>>> index f07678b..4ac135a 100644
>>> --- a/drivers/pci/dwc/pcie-designware-ep.c
>>> +++ b/drivers/pci/dwc/pcie-designware-ep.c
>>> @@ -15,8 +15,10 @@
>>>  void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
>>>  {
>>>  	struct pci_epc *epc = ep->epc;
>>> +	struct pci_epf *epf;
>>>  
>>> -	pci_epc_linkup(epc);
>>> +	list_for_each_entry(epf, &epc->pci_epf, list)
>>> +		pci_epf_linkup(epf);
>>>  }
>>
>> This shouldn't be required anymore.
> 
> Ok. I'll revert it.
> 
>>>  
>>>  static void __dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar,
>>> diff --git a/drivers/pci/dwc/pcie-designware-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
>>> index 5416aa8..5382a7a 100644
>>> --- a/drivers/pci/dwc/pcie-designware-plat.c
>>> +++ b/drivers/pci/dwc/pcie-designware-plat.c
>>> @@ -12,19 +12,29 @@
>>>  #include <linux/interrupt.h>
>>>  #include <linux/kernel.h>
>>>  #include <linux/init.h>
>>> +#include <linux/of_device.h>
>>>  #include <linux/of_gpio.h>
>>>  #include <linux/pci.h>
>>>  #include <linux/platform_device.h>
>>>  #include <linux/resource.h>
>>>  #include <linux/signal.h>
>>>  #include <linux/types.h>
>>> +#include <linux/regmap.h>
>>>  
>>>  #include "pcie-designware.h"
>>>  
>>>  struct dw_plat_pcie {
>>> -	struct dw_pcie		*pci;
>>> +	struct dw_pcie			*pci;
>>> +	struct regmap			*regmap;
>>> +	enum dw_pcie_device_mode	mode;
>>>  };
>>>  
>>> +struct dw_plat_pcie_of_data {
>>> +	enum dw_pcie_device_mode	mode;
>>> +};
>>> +
>>> +static const struct of_device_id dw_plat_pcie_of_match[];
>>> +
>>>  static int dw_plat_pcie_host_init(struct pcie_port *pp)
>>>  {
>>>  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>>> @@ -42,9 +52,53 @@ static const struct dw_pcie_host_ops dw_plat_pcie_host_ops = {
>>>  	.host_init = dw_plat_pcie_host_init,
>>>  };
>>>  
>>> -static int dw_plat_add_pcie_port(struct pcie_port *pp,
>>> +static int dw_plat_pcie_establish_link(struct dw_pcie *pci)
>>> +{
>>> +	return 0;
>>> +}
>>> +
>>> +static const struct dw_pcie_ops dw_pcie_ops = {
>>> +	.start_link = dw_plat_pcie_establish_link,
>>> +};
>>> +
>>> +static void dw_plat_pcie_ep_init(struct dw_pcie_ep *ep)
>>> +{
>>> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
>>> +	enum pci_barno bar;
>>> +
>>> +	for (bar = BAR_0; bar <= BAR_5; bar++)
>>> +		dw_pcie_ep_reset_bar(pci, bar);
>>> +}
>>> +
>>> +static int dw_plat_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
>>> +				     enum pci_epc_irq_type type,
>>> +				     u8 interrupt_num)
>>> +{
>>> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
>>> +
>>> +	switch (type) {
>>> +	case PCI_EPC_IRQ_LEGACY:
>>> +		dev_err(pci->dev, "EP cannot trigger legacy IRQs\n");
>>> +		return -EINVAL;
>>> +	case PCI_EPC_IRQ_MSI:
>>> +		return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
>>> +	default:
>>> +		dev_err(pci->dev, "UNKNOWN IRQ type\n");
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static struct dw_pcie_ep_ops pcie_ep_ops = {
>>> +	.ep_init = dw_plat_pcie_ep_init,
>>> +	.raise_irq = dw_plat_pcie_ep_raise_irq,
>>> +};
>>> +
>>> +static int dw_plat_add_pcie_port(struct dw_plat_pcie *dw_plat_pcie,
>>>  				 struct platform_device *pdev)
>>>  {
>>> +	struct dw_pcie *pci = dw_plat_pcie->pci;
>>> +	struct pcie_port *pp = &pci->pp;
>>>  	struct device *dev = &pdev->dev;
>>>  	int ret;
>>>  
>>> @@ -63,15 +117,44 @@ static int dw_plat_add_pcie_port(struct pcie_port *pp,
>>>  
>>>  	ret = dw_pcie_host_init(pp);
>>>  	if (ret) {
>>> -		dev_err(dev, "failed to initialize host\n");
>>> +		dev_err(dev, "Failed to initialize host\n");
>>>  		return ret;
>>>  	}
>>>  
>>>  	return 0;
>>>  }
>>>  
>>> -static const struct dw_pcie_ops dw_pcie_ops = {
>>> -};
>>> +static int dw_plat_add_pcie_ep(struct dw_plat_pcie *dw_plat_pcie,
>>> +			       struct platform_device *pdev)
>>> +{
>>> +	int ret;
>>> +	struct dw_pcie_ep *ep;
>>> +	struct resource *res;
>>> +	struct device *dev = &pdev->dev;
>>> +	struct dw_pcie *pci = dw_plat_pcie->pci;
>>> +
>>> +	ep = &pci->ep;
>>> +	ep->ops = &pcie_ep_ops;
>>> +
>>> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi2");
>>> +	pci->dbi_base2 = devm_ioremap(dev, res->start, resource_size(res));
>>
>> This can throw up a NULL pointer dereferencing error. Use devm_ioremap_resource
>> instead.
> 
> I have looked on [1] and [2] and both implementations uses devm_ioremap
> function, they are also wrong?
> 
> [1] -> https://elixir.bootlin.com/linux/latest/source/drivers/pci/dwc/pcie-artpec6.c
> [2] -> https://elixir.bootlin.com/linux/latest/source/drivers/pci/dwc/pci-dra7xx.c

yes, they are wrong. There was a patch to fix it but somehow dropped
https://patchwork.kernel.org/patch/10173831/.

I'll resend them.

Thanks
Kishon

[PATCH v2 3/9] bindings: PCI: designware: Add support for the EP in Designware driver

[Gustavo Pimentel]

Add device tree binding documentation for the Endpoint in PCIe Designware
driver.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
Change v1->v2:
 - Add a missing log description.
 - Add "snps,dw-pcie" compatible string following Kishon's suggestion.

 Documentation/devicetree/bindings/pci/designware-pcie.txt | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Documentation/devicetree/bindings/pci/designware-pcie.txt b/Documentation/devicetree/bindings/pci/designware-pcie.txt
index f02cd20..f5da9cf 100644
--- a/Documentation/devicetree/bindings/pci/designware-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/designware-pcie.txt
@@ -3,6 +3,7 @@
 Required properties:
 - compatible:
 	"snps,dw-pcie-rc", "snps,dw-pcie" for RC mode;
+	"snps,dw-pcie-ep", "snps,dw-pcie" for EP mode;
 - reg: Should contain the configuration address space.
 - reg-names: Must be "config" for the PCIe configuration space.
     (The old way of getting the configuration address space from "ranges"
@@ -56,3 +57,15 @@ Example configuration:
 		#interrupt-cells = <1>;
 		num-lanes = <1>;
 	};
+or
+	pcie_ep: pcie_ep@dfc00000 {
+		compatible = "snps,dw-pcie-ep", "snps,dw_pcie";
+		reg = <0xdfc00000 0x0001000>, /* IP registers 1 */
+		      <0xdfc01000 0x0001000>, /* IP registers 2 */
+		      <0xd0000000 0x2000000>; /* Configuration space */
+		reg-names = "dbi", "dbi2", "addr_space";
+		device_type = "pci";
+		num-ib-windows = <6>;
+		num-ob-windows = <2>;
+		num-lanes = <1>;
+	};
-- 
2.7.4

[PATCH v2 4/9] PCI: Adds device ID for Synopsys Sample Endpoint.

[Gustavo Pimentel]

The PCIe controller dual mode is capable of operating in host mode as well
as endpoint mode by configuration.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
Change v1->v2:
- Register new device id following Kishon's suggestion.

 include/linux/pci_ids.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index f22124e..887c04e 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -2349,6 +2349,7 @@
 #define PCI_DEVICE_ID_CENATEK_IDE	0x0001
 
 #define PCI_VENDOR_ID_SYNOPSYS		0x16c3
+#define PCI_DEVICE_ID_SYNOPSYS_SMPL_EP	0xedda
 
 #define PCI_VENDOR_ID_VITESSE		0x1725
 #define PCI_DEVICE_ID_VITESSE_VSC7174	0x7174
-- 
2.7.4

[PATCH v2 5/9] misc: pci_endpoint_test: Add designware EP entry

[Gustavo Pimentel]

Adds the designware EP device ID entry to pci_endpoint_test driver table
to allow this device to be recognize and handle by the pci_endpoint_test
driver.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
Change v1->v2:
- Changed device id following Kishon's suggestion.

 drivers/misc/pci_endpoint_test.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
index fe8897e..37db0fc 100644
--- a/drivers/misc/pci_endpoint_test.c
+++ b/drivers/misc/pci_endpoint_test.c
@@ -634,6 +634,7 @@ static void pci_endpoint_test_remove(struct pci_dev *pdev)
 static const struct pci_device_id pci_endpoint_test_tbl[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_DRA74x) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_DRA72x) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_SYNOPSYS, PCI_DEVICE_ID_SYNOPSYS_SMPL_EP) },
 	{ }
 };
 MODULE_DEVICE_TABLE(pci, pci_endpoint_test_tbl);
-- 
2.7.4

[PATCH v2 6/9] PCI: dwc: Define maximum number of vectors

[Gustavo Pimentel]

Adds a callback that defines the maximum number of vectors that can be use
by the Root Complex.

Since this is a parameter associated to each SoC IP setting, makes sense to
be configurable and easily visible to future modifications.

The designware IP supports a maximum of 256 vectors.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
Change v1->v2:
- Nothing changed, just to follow the patch set version.

 drivers/pci/dwc/pcie-designware-plat.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/pci/dwc/pcie-designware-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
index 5382a7a..94da252 100644
--- a/drivers/pci/dwc/pcie-designware-plat.c
+++ b/drivers/pci/dwc/pcie-designware-plat.c
@@ -48,8 +48,14 @@ static int dw_plat_pcie_host_init(struct pcie_port *pp)
 	return 0;
 }
 
+static void dw_plat_set_num_vectors(struct pcie_port *pp)
+{
+	pp->num_vectors = MAX_MSI_IRQS;
+}
+
 static const struct dw_pcie_host_ops dw_plat_pcie_host_ops = {
 	.host_init = dw_plat_pcie_host_init,
+	.set_num_vectors = dw_plat_set_num_vectors,
 };
 
 static int dw_plat_pcie_establish_link(struct dw_pcie *pci)
-- 
2.7.4

Re: [PATCH v2 6/9] PCI: dwc: Define maximum number of vectors

[Lorenzo Pieralisi]

On Mon, Apr 09, 2018 at 10:41:15AM +0100, Gustavo Pimentel wrote:
> Adds a callback that defines the maximum number of vectors that can be use
> by the Root Complex.
> 
> Since this is a parameter associated to each SoC IP setting, makes sense to
> be configurable and easily visible to future modifications.
> 
> The designware IP supports a maximum of 256 vectors.

I think that a DT property instead of a callback would have made more
sense - I struggle to see the point in defining a callback to initialize
a variable, this can be done in the generic dwc code (and a DT binding).

Lorenzo

> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
> ---
> Change v1->v2:
> - Nothing changed, just to follow the patch set version.
> 
>  drivers/pci/dwc/pcie-designware-plat.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/pci/dwc/pcie-designware-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
> index 5382a7a..94da252 100644
> --- a/drivers/pci/dwc/pcie-designware-plat.c
> +++ b/drivers/pci/dwc/pcie-designware-plat.c
> @@ -48,8 +48,14 @@ static int dw_plat_pcie_host_init(struct pcie_port *pp)
>  	return 0;
>  }
>  
> +static void dw_plat_set_num_vectors(struct pcie_port *pp)
> +{
> +	pp->num_vectors = MAX_MSI_IRQS;
> +}
> +
>  static const struct dw_pcie_host_ops dw_plat_pcie_host_ops = {
>  	.host_init = dw_plat_pcie_host_init,
> +	.set_num_vectors = dw_plat_set_num_vectors,
>  };
>  
>  static int dw_plat_pcie_establish_link(struct dw_pcie *pci)
> -- 
> 2.7.4
> 
> 

Re: [PATCH v2 6/9] PCI: dwc: Define maximum number of vectors

[Gustavo Pimentel]

Hi Lorenzo,

On 09/04/2018 17:03, Lorenzo Pieralisi wrote:
> On Mon, Apr 09, 2018 at 10:41:15AM +0100, Gustavo Pimentel wrote:
>> Adds a callback that defines the maximum number of vectors that can be use
>> by the Root Complex.
>>
>> Since this is a parameter associated to each SoC IP setting, makes sense to
>> be configurable and easily visible to future modifications.
>>
>> The designware IP supports a maximum of 256 vectors.
> 
> I think that a DT property instead of a callback would have made more
> sense - I struggle to see the point in defining a callback to initialize
> a variable, this can be done in the generic dwc code (and a DT binding).

The addition of this callback was done in MSI-X patch series before I take over
the PCIe Designware driver responsibility. However I remember a thread in which
this subject was discussed (see [1]), maybe this could bring some light about
the motive why is was done like this. If you don't agree I can do patch after
this series only focusing on this topic in order to do like to suggested.

[1] -> https://www.spinics.net/lists/linux-pci/msg61835.html
> 
> Lorenzo
> 
>> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
>> ---
>> Change v1->v2:
>> - Nothing changed, just to follow the patch set version.
>>
>>  drivers/pci/dwc/pcie-designware-plat.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/pci/dwc/pcie-designware-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
>> index 5382a7a..94da252 100644
>> --- a/drivers/pci/dwc/pcie-designware-plat.c
>> +++ b/drivers/pci/dwc/pcie-designware-plat.c
>> @@ -48,8 +48,14 @@ static int dw_plat_pcie_host_init(struct pcie_port *pp)
>>  	return 0;
>>  }
>>  
>> +static void dw_plat_set_num_vectors(struct pcie_port *pp)
>> +{
>> +	pp->num_vectors = MAX_MSI_IRQS;
>> +}
>> +
>>  static const struct dw_pcie_host_ops dw_plat_pcie_host_ops = {
>>  	.host_init = dw_plat_pcie_host_init,
>> +	.set_num_vectors = dw_plat_set_num_vectors,
>>  };
>>  
>>  static int dw_plat_pcie_establish_link(struct dw_pcie *pci)
>> -- 
>> 2.7.4
>>
>>

Regards,
Gustavo

Re: [PATCH v2 6/9] PCI: dwc: Define maximum number of vectors

[Lorenzo Pieralisi]

On Tue, Apr 10, 2018 at 08:59:30AM +0100, Gustavo Pimentel wrote:
> Hi Lorenzo,
> 
> On 09/04/2018 17:03, Lorenzo Pieralisi wrote:
> > On Mon, Apr 09, 2018 at 10:41:15AM +0100, Gustavo Pimentel wrote:
> >> Adds a callback that defines the maximum number of vectors that can be use
> >> by the Root Complex.
> >>
> >> Since this is a parameter associated to each SoC IP setting, makes sense to
> >> be configurable and easily visible to future modifications.
> >>
> >> The designware IP supports a maximum of 256 vectors.
> > 
> > I think that a DT property instead of a callback would have made more
> > sense - I struggle to see the point in defining a callback to initialize
> > a variable, this can be done in the generic dwc code (and a DT binding).
> 
> The addition of this callback was done in MSI-X patch series before I take over
> the PCIe Designware driver responsibility. However I remember a thread in which
> this subject was discussed (see [1]), maybe this could bring some light about
> the motive why is was done like this. If you don't agree I can do patch after
> this series only focusing on this topic in order to do like to suggested.
> 
> [1] -> https://www.spinics.net/lists/linux-pci/msg61835.html

Lucas has a point - it is fine to handle them as you do in this patch,
it does not make much sense to add a property for something that
strictly depends on the compatible string.

Thanks,
Lorenzo

[PATCH v2 7/9] PCI: dwc: Replace lower into upper case characters

[Gustavo Pimentel]

Replaces lower into upper case characters in comments and debug printks.

This is an attempt to keep the messages coherent within the designware
driver.

Also fixed code style on dw_pcie_irq_domain_free function.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
Change v1->v2:
- Added an extra log description line about code style following Fabio
Estevam suggestion.

 drivers/pci/dwc/pcie-designware-ep.c   | 16 ++++++++--------
 drivers/pci/dwc/pcie-designware-host.c | 35 ++++++++++++++++++----------------
 drivers/pci/dwc/pcie-designware.c      | 22 ++++++++++-----------
 3 files changed, 38 insertions(+), 35 deletions(-)

diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
index 4ac135a..05515ca 100644
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -77,7 +77,7 @@ static int dw_pcie_ep_inbound_atu(struct dw_pcie_ep *ep, enum pci_barno bar,
 
 	free_win = find_first_zero_bit(ep->ib_window_map, ep->num_ib_windows);
 	if (free_win >= ep->num_ib_windows) {
-		dev_err(pci->dev, "no free inbound window\n");
+		dev_err(pci->dev, "No free inbound window\n");
 		return -EINVAL;
 	}
 
@@ -102,7 +102,7 @@ static int dw_pcie_ep_outbound_atu(struct dw_pcie_ep *ep, phys_addr_t phys_addr,
 
 	free_win = find_first_zero_bit(ep->ob_window_map, ep->num_ob_windows);
 	if (free_win >= ep->num_ob_windows) {
-		dev_err(pci->dev, "no free outbound window\n");
+		dev_err(pci->dev, "No free outbound window\n");
 		return -EINVAL;
 	}
 
@@ -206,7 +206,7 @@ static int dw_pcie_ep_map_addr(struct pci_epc *epc, u8 func_no,
 
 	ret = dw_pcie_ep_outbound_atu(ep, addr, pci_addr, size);
 	if (ret) {
-		dev_err(pci->dev, "failed to enable address\n");
+		dev_err(pci->dev, "Failed to enable address\n");
 		return ret;
 	}
 
@@ -350,21 +350,21 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 
 	ret = of_property_read_u32(np, "num-ib-windows", &ep->num_ib_windows);
 	if (ret < 0) {
-		dev_err(dev, "unable to read *num-ib-windows* property\n");
+		dev_err(dev, "Unable to read *num-ib-windows* property\n");
 		return ret;
 	}
 	if (ep->num_ib_windows > MAX_IATU_IN) {
-		dev_err(dev, "invalid *num-ib-windows*\n");
+		dev_err(dev, "Invalid *num-ib-windows*\n");
 		return -EINVAL;
 	}
 
 	ret = of_property_read_u32(np, "num-ob-windows", &ep->num_ob_windows);
 	if (ret < 0) {
-		dev_err(dev, "unable to read *num-ob-windows* property\n");
+		dev_err(dev, "Unable to read *num-ob-windows* property\n");
 		return ret;
 	}
 	if (ep->num_ob_windows > MAX_IATU_OUT) {
-		dev_err(dev, "invalid *num-ob-windows*\n");
+		dev_err(dev, "Invalid *num-ob-windows*\n");
 		return -EINVAL;
 	}
 
@@ -391,7 +391,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 
 	epc = devm_pci_epc_create(dev, &epc_ops);
 	if (IS_ERR(epc)) {
-		dev_err(dev, "failed to create epc device\n");
+		dev_err(dev, "Failed to create epc device\n");
 		return PTR_ERR(epc);
 	}
 
diff --git a/drivers/pci/dwc/pcie-designware-host.c b/drivers/pci/dwc/pcie-designware-host.c
index 550fdbb..03e9b82 100644
--- a/drivers/pci/dwc/pcie-designware-host.c
+++ b/drivers/pci/dwc/pcie-designware-host.c
@@ -248,8 +248,10 @@ static void dw_pcie_irq_domain_free(struct irq_domain *domain,
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&pp->lock, flags);
+
 	bitmap_release_region(pp->msi_irq_in_use, data->hwirq,
 			      order_base_2(nr_irqs));
+
 	raw_spin_unlock_irqrestore(&pp->lock, flags);
 }
 
@@ -266,7 +268,7 @@ int dw_pcie_allocate_domains(struct pcie_port *pp)
 	pp->irq_domain = irq_domain_create_linear(fwnode, pp->num_vectors,
 					       &dw_pcie_msi_domain_ops, pp);
 	if (!pp->irq_domain) {
-		dev_err(pci->dev, "failed to create IRQ domain\n");
+		dev_err(pci->dev, "Failed to create IRQ domain\n");
 		return -ENOMEM;
 	}
 
@@ -274,7 +276,7 @@ int dw_pcie_allocate_domains(struct pcie_port *pp)
 						   &dw_pcie_msi_domain_info,
 						   pp->irq_domain);
 	if (!pp->msi_domain) {
-		dev_err(pci->dev, "failed to create MSI domain\n");
+		dev_err(pci->dev, "Failed to create MSI domain\n");
 		irq_domain_remove(pp->irq_domain);
 		return -ENOMEM;
 	}
@@ -301,13 +303,13 @@ void dw_pcie_msi_init(struct pcie_port *pp)
 	page = alloc_page(GFP_KERNEL);
 	pp->msi_data = dma_map_page(dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE);
 	if (dma_mapping_error(dev, pp->msi_data)) {
-		dev_err(dev, "failed to map MSI data\n");
+		dev_err(dev, "Failed to map MSI data\n");
 		__free_page(page);
 		return;
 	}
 	msi_target = (u64)pp->msi_data;
 
-	/* program the msi_data */
+	/* Program the msi_data */
 	dw_pcie_wr_own_conf(pp, PCIE_MSI_ADDR_LO, 4,
 			    lower_32_bits(msi_target));
 	dw_pcie_wr_own_conf(pp, PCIE_MSI_ADDR_HI, 4,
@@ -335,7 +337,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
 		pp->cfg0_base = cfg_res->start;
 		pp->cfg1_base = cfg_res->start + pp->cfg0_size;
 	} else if (!pp->va_cfg0_base) {
-		dev_err(dev, "missing *config* reg space\n");
+		dev_err(dev, "Missing *config* reg space\n");
 	}
 
 	bridge = pci_alloc_host_bridge(0);
@@ -357,7 +359,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
 		case IORESOURCE_IO:
 			ret = pci_remap_iospace(win->res, pp->io_base);
 			if (ret) {
-				dev_warn(dev, "error %d: failed to map resource %pR\n",
+				dev_warn(dev, "Error %d: failed to map resource %pR\n",
 					 ret, win->res);
 				resource_list_destroy_entry(win);
 			} else {
@@ -391,7 +393,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
 						pp->cfg->start,
 						resource_size(pp->cfg));
 		if (!pci->dbi_base) {
-			dev_err(dev, "error with ioremap\n");
+			dev_err(dev, "Error with ioremap\n");
 			ret = -ENOMEM;
 			goto error;
 		}
@@ -403,7 +405,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
 		pp->va_cfg0_base = devm_pci_remap_cfgspace(dev,
 					pp->cfg0_base, pp->cfg0_size);
 		if (!pp->va_cfg0_base) {
-			dev_err(dev, "error with ioremap in function\n");
+			dev_err(dev, "Error with ioremap in function\n");
 			ret = -ENOMEM;
 			goto error;
 		}
@@ -414,7 +416,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
 						pp->cfg1_base,
 						pp->cfg1_size);
 		if (!pp->va_cfg1_base) {
-			dev_err(dev, "error with ioremap\n");
+			dev_err(dev, "Error with ioremap\n");
 			ret = -ENOMEM;
 			goto error;
 		}
@@ -586,7 +588,7 @@ static int dw_pcie_valid_device(struct pcie_port *pp, struct pci_bus *bus,
 			return 0;
 	}
 
-	/* access only one slot on each root port */
+	/* Access only one slot on each root port */
 	if (bus->number == pp->root_bus_nr && dev > 0)
 		return 0;
 
@@ -652,11 +654,12 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
 	for (ctrl = 0; ctrl < num_ctrls; ctrl++)
 		dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + (ctrl * 12), 4,
 				    &pp->irq_status[ctrl]);
-	/* setup RC BARs */
+
+	/* Setup RC BARs */
 	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, 0x00000004);
 	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_1, 0x00000000);
 
-	/* setup interrupt pins */
+	/* Setup interrupt pins */
 	dw_pcie_dbi_ro_wr_en(pci);
 	val = dw_pcie_readl_dbi(pci, PCI_INTERRUPT_LINE);
 	val &= 0xffff00ff;
@@ -664,13 +667,13 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
 	dw_pcie_writel_dbi(pci, PCI_INTERRUPT_LINE, val);
 	dw_pcie_dbi_ro_wr_dis(pci);
 
-	/* setup bus numbers */
+	/* Setup bus numbers */
 	val = dw_pcie_readl_dbi(pci, PCI_PRIMARY_BUS);
 	val &= 0xff000000;
 	val |= 0x00010100;
 	dw_pcie_writel_dbi(pci, PCI_PRIMARY_BUS, val);
 
-	/* setup command register */
+	/* Setup command register */
 	val = dw_pcie_readl_dbi(pci, PCI_COMMAND);
 	val &= 0xffff0000;
 	val |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
@@ -683,7 +686,7 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
 	 * we should not program the ATU here.
 	 */
 	if (!pp->ops->rd_other_conf) {
-		/* get iATU unroll support */
+		/* Get iATU unroll support */
 		pci->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pci);
 		dev_dbg(pci->dev, "iATU unroll: %s\n",
 			pci->iatu_unroll_enabled ? "enabled" : "disabled");
@@ -701,7 +704,7 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
 
 	/* Enable write permission for the DBI read-only register */
 	dw_pcie_dbi_ro_wr_en(pci);
-	/* program correct class for RC */
+	/* Program correct class for RC */
 	dw_pcie_wr_own_conf(pp, PCI_CLASS_DEVICE, 2, PCI_CLASS_BRIDGE_PCI);
 	/* Better disable write permission right after the update */
 	dw_pcie_dbi_ro_wr_dis(pci);
diff --git a/drivers/pci/dwc/pcie-designware.c b/drivers/pci/dwc/pcie-designware.c
index 1b7282e..778c4f7 100644
--- a/drivers/pci/dwc/pcie-designware.c
+++ b/drivers/pci/dwc/pcie-designware.c
@@ -69,7 +69,7 @@ u32 __dw_pcie_read_dbi(struct dw_pcie *pci, void __iomem *base, u32 reg,
 
 	ret = dw_pcie_read(base + reg, size, &val);
 	if (ret)
-		dev_err(pci->dev, "read DBI address failed\n");
+		dev_err(pci->dev, "Read DBI address failed\n");
 
 	return val;
 }
@@ -86,7 +86,7 @@ void __dw_pcie_write_dbi(struct dw_pcie *pci, void __iomem *base, u32 reg,
 
 	ret = dw_pcie_write(base + reg, size, val);
 	if (ret)
-		dev_err(pci->dev, "write DBI address failed\n");
+		dev_err(pci->dev, "Write DBI address failed\n");
 }
 
 static u32 dw_pcie_readl_ob_unroll(struct dw_pcie *pci, u32 index, u32 reg)
@@ -137,7 +137,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, int index,
 
 		usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
 	}
-	dev_err(pci->dev, "outbound iATU is not being enabled\n");
+	dev_err(pci->dev, "Outbound iATU is not being enabled\n");
 }
 
 void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
@@ -180,7 +180,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
 
 		usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
 	}
-	dev_err(pci->dev, "outbound iATU is not being enabled\n");
+	dev_err(pci->dev, "Outbound iATU is not being enabled\n");
 }
 
 static u32 dw_pcie_readl_ib_unroll(struct dw_pcie *pci, u32 index, u32 reg)
@@ -238,7 +238,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct dw_pcie *pci, int index,
 
 		usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
 	}
-	dev_err(pci->dev, "inbound iATU is not being enabled\n");
+	dev_err(pci->dev, "Inbound iATU is not being enabled\n");
 
 	return -EBUSY;
 }
@@ -284,7 +284,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int bar,
 
 		usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
 	}
-	dev_err(pci->dev, "inbound iATU is not being enabled\n");
+	dev_err(pci->dev, "Inbound iATU is not being enabled\n");
 
 	return -EBUSY;
 }
@@ -313,16 +313,16 @@ int dw_pcie_wait_for_link(struct dw_pcie *pci)
 {
 	int retries;
 
-	/* check if the link is up or not */
+	/* Check if the link is up or not */
 	for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
 		if (dw_pcie_link_up(pci)) {
-			dev_info(pci->dev, "link up\n");
+			dev_info(pci->dev, "Link up\n");
 			return 0;
 		}
 		usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX);
 	}
 
-	dev_err(pci->dev, "phy link never came up\n");
+	dev_err(pci->dev, "Phy link never came up\n");
 
 	return -ETIMEDOUT;
 }
@@ -351,7 +351,7 @@ void dw_pcie_setup(struct dw_pcie *pci)
 	if (ret)
 		lanes = 0;
 
-	/* set the number of lanes */
+	/* Set the number of lanes */
 	val = dw_pcie_readl_dbi(pci, PCIE_PORT_LINK_CONTROL);
 	val &= ~PORT_LINK_MODE_MASK;
 	switch (lanes) {
@@ -373,7 +373,7 @@ void dw_pcie_setup(struct dw_pcie *pci)
 	}
 	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val);
 
-	/* set link width speed control register */
+	/* Set link width speed control register */
 	val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
 	val &= ~PORT_LOGIC_LINK_WIDTH_MASK;
 	switch (lanes) {
-- 
2.7.4

Re: [PATCH v2 7/9] PCI: dwc: Replace lower into upper case characters

[Joe Perches]

On Mon, 2018-04-09 at 10:41 +0100, Gustavo Pimentel wrote:
> Replaces lower into upper case characters in comments and debug printks.
> 
> This is an attempt to keep the messages coherent within the designware
> driver.

It'd be nice to make all the dwc drivers use the same
message wording.

For instance:

drivers/pci/dwc/pci-keystone.c: dev_err(dev, "phy link never came up\n");
drivers/pci/dwc/pcie-designware.c:      dev_err(pci->dev, "phy link never came up\n");
drivers/pci/host/pcie-xilinx-nwl.c:     dev_err(dev, "PHY link never came up\n");

Re: [PATCH v2 7/9] PCI: dwc: Replace lower into upper case characters

[Gustavo Pimentel]

Hi Joe,

On 09/04/2018 11:25, Joe Perches wrote:
> On Mon, 2018-04-09 at 10:41 +0100, Gustavo Pimentel wrote:
>> Replaces lower into upper case characters in comments and debug printks.
>>
>> This is an attempt to keep the messages coherent within the designware
>> driver.
> 
> It'd be nice to make all the dwc drivers use the same
> message wording.
> 
> For instance:
> 
> drivers/pci/dwc/pci-keystone.c: dev_err(dev, "phy link never came up\n");
> drivers/pci/dwc/pcie-designware.c:      dev_err(pci->dev, "phy link never came up\n");
> drivers/pci/host/pcie-xilinx-nwl.c:     dev_err(dev, "PHY link never came up\n");

I also agree, I added a task to my backlog to fix that. However, this task
shouldn't be done in this patch series since it's a more broader task involving
many drivers and different maintainers. Agree?

> 

Regards,
Gustavo

Re: [PATCH v2 7/9] PCI: dwc: Replace lower into upper case characters

[Joe Perches]

On Mon, 2018-04-09 at 14:10 +0100, Gustavo Pimentel wrote:
> Hi Joe,

Hello Gustavo.

> On 09/04/2018 11:25, Joe Perches wrote:
> > On Mon, 2018-04-09 at 10:41 +0100, Gustavo Pimentel wrote:
> > > Replaces lower into upper case characters in comments and debug printks.
> > > 
> > > This is an attempt to keep the messages coherent within the designware
> > > driver.
> > 
> > It'd be nice to make all the dwc drivers use the same
> > message wording.
> > 
> > For instance:
> > 
> > drivers/pci/dwc/pci-keystone.c: dev_err(dev, "phy link never came up\n");
> > drivers/pci/dwc/pcie-designware.c:      dev_err(pci->dev, "phy link never came up\n");
> > drivers/pci/host/pcie-xilinx-nwl.c:     dev_err(dev, "PHY link never came up\n");
> 
> I also agree, I added a task to my backlog to fix that. However, this task
> shouldn't be done in this patch series since it's a more broader task involving
> many drivers and different maintainers. Agree?

Right.

I was just highlighting the inconsistency.
So, no worries.  Whenever.

Re: [PATCH v2 7/9] PCI: dwc: Replace lower into upper case characters

[Jingoo Han]

On Monday, April 9, 2018 5:41 AM, Gustavo Pimentel wrote:
> 
> Replaces lower into upper case characters in comments and debug printks.
> 
> This is an attempt to keep the messages coherent within the designware
> driver.
> 
> Also fixed code style on dw_pcie_irq_domain_free function.
> 
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>

Acked-by: Jingoo Han <jingoohan1@gmail.com>


> ---
> Change v1->v2:
> - Added an extra log description line about code style following Fabio
> Estevam suggestion.
> 
>  drivers/pci/dwc/pcie-designware-ep.c   | 16 ++++++++--------
>  drivers/pci/dwc/pcie-designware-host.c | 35 ++++++++++++++++++-----------
> -----
>  drivers/pci/dwc/pcie-designware.c      | 22 ++++++++++-----------
>  3 files changed, 38 insertions(+), 35 deletions(-)
> 

[.....]

[PATCH v2 8/9] PCI: dwc: Small computation improvement

[Gustavo Pimentel]

Replaces a simple division by 2 to a right shift rotation of 1 bit.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
Change v1->v2:
- Nothing changed, just to follow the patch set version.

 drivers/pci/dwc/pcie-designware-host.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/dwc/pcie-designware-host.c b/drivers/pci/dwc/pcie-designware-host.c
index 03e9b82..8e6fed4 100644
--- a/drivers/pci/dwc/pcie-designware-host.c
+++ b/drivers/pci/dwc/pcie-designware-host.c
@@ -332,8 +332,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
 
 	cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
 	if (cfg_res) {
-		pp->cfg0_size = resource_size(cfg_res) / 2;
-		pp->cfg1_size = resource_size(cfg_res) / 2;
+		pp->cfg0_size = resource_size(cfg_res) >> 1;
+		pp->cfg1_size = resource_size(cfg_res) >> 1;
 		pp->cfg0_base = cfg_res->start;
 		pp->cfg1_base = cfg_res->start + pp->cfg0_size;
 	} else if (!pp->va_cfg0_base) {
@@ -377,8 +377,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
 			break;
 		case 0:
 			pp->cfg = win->res;
-			pp->cfg0_size = resource_size(pp->cfg) / 2;
-			pp->cfg1_size = resource_size(pp->cfg) / 2;
+			pp->cfg0_size = resource_size(pp->cfg) >> 1;
+			pp->cfg1_size = resource_size(pp->cfg) >> 1;
 			pp->cfg0_base = pp->cfg->start;
 			pp->cfg1_base = pp->cfg->start + pp->cfg0_size;
 			break;
-- 
2.7.4

Re: [PATCH v2 8/9] PCI: dwc: Small computation improvement

[Jingoo Han]

On Monday, April 9, 2018 5:41 AM, Gustavo Pimentel wrote:
> 
> Replaces a simple division by 2 to a right shift rotation of 1 bit.

It looks good. However, would you add a simple reason to the commit
message?

Best regards,
Jingoo Han

> 
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
> ---
> Change v1->v2:
> - Nothing changed, just to follow the patch set version.
> 
>  drivers/pci/dwc/pcie-designware-host.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/dwc/pcie-designware-host.c
> b/drivers/pci/dwc/pcie-designware-host.c
> index 03e9b82..8e6fed4 100644
> --- a/drivers/pci/dwc/pcie-designware-host.c
> +++ b/drivers/pci/dwc/pcie-designware-host.c
> @@ -332,8 +332,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
> 
>  	cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> "config");
>  	if (cfg_res) {
> -		pp->cfg0_size = resource_size(cfg_res) / 2;
> -		pp->cfg1_size = resource_size(cfg_res) / 2;
> +		pp->cfg0_size = resource_size(cfg_res) >> 1;
> +		pp->cfg1_size = resource_size(cfg_res) >> 1;
>  		pp->cfg0_base = cfg_res->start;
>  		pp->cfg1_base = cfg_res->start + pp->cfg0_size;
>  	} else if (!pp->va_cfg0_base) {
> @@ -377,8 +377,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
>  			break;
>  		case 0:
>  			pp->cfg = win->res;
> -			pp->cfg0_size = resource_size(pp->cfg) / 2;
> -			pp->cfg1_size = resource_size(pp->cfg) / 2;
> +			pp->cfg0_size = resource_size(pp->cfg) >> 1;
> +			pp->cfg1_size = resource_size(pp->cfg) >> 1;
>  			pp->cfg0_base = pp->cfg->start;
>  			pp->cfg1_base = pp->cfg->start + pp->cfg0_size;
>  			break;
> --
> 2.7.4
> 

Re: [PATCH v2 8/9] PCI: dwc: Small computation improvement

[Gustavo Pimentel]

Hi Jingoo,

On 11/04/2018 01:01, Jingoo Han wrote:
> On Monday, April 9, 2018 5:41 AM, Gustavo Pimentel wrote:
>>
>> Replaces a simple division by 2 to a right shift rotation of 1 bit.
> 
> It looks good. However, would you add a simple reason to the commit
> message?

Sure.

Can be this one?

Probably any recent and decent compiler does this kind of substitution
in order to improve code performance. Nevertheless it's a coding good
practice whenever there is a division / multiplication by multiple of 2
to replace it by the equivalent operation in this case, the shift
rotation.

> 
> Best regards,
> Jingoo Han
> 
>>
>> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
>> ---
>> Change v1->v2:
>> - Nothing changed, just to follow the patch set version.
>>
>>  drivers/pci/dwc/pcie-designware-host.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/pci/dwc/pcie-designware-host.c
>> b/drivers/pci/dwc/pcie-designware-host.c
>> index 03e9b82..8e6fed4 100644
>> --- a/drivers/pci/dwc/pcie-designware-host.c
>> +++ b/drivers/pci/dwc/pcie-designware-host.c
>> @@ -332,8 +332,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
>>
>>  	cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>> "config");
>>  	if (cfg_res) {
>> -		pp->cfg0_size = resource_size(cfg_res) / 2;
>> -		pp->cfg1_size = resource_size(cfg_res) / 2;
>> +		pp->cfg0_size = resource_size(cfg_res) >> 1;
>> +		pp->cfg1_size = resource_size(cfg_res) >> 1;
>>  		pp->cfg0_base = cfg_res->start;
>>  		pp->cfg1_base = cfg_res->start + pp->cfg0_size;
>>  	} else if (!pp->va_cfg0_base) {
>> @@ -377,8 +377,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
>>  			break;
>>  		case 0:
>>  			pp->cfg = win->res;
>> -			pp->cfg0_size = resource_size(pp->cfg) / 2;
>> -			pp->cfg1_size = resource_size(pp->cfg) / 2;
>> +			pp->cfg0_size = resource_size(pp->cfg) >> 1;
>> +			pp->cfg1_size = resource_size(pp->cfg) >> 1;
>>  			pp->cfg0_base = pp->cfg->start;
>>  			pp->cfg1_base = pp->cfg->start + pp->cfg0_size;
>>  			break;
>> --
>> 2.7.4
>>
> 
> 

Regards,
Gustavo

Re: [PATCH v2 8/9] PCI: dwc: Small computation improvement

[Jingoo Han]

On Wednesday, April 11, 2018 3:40 AM, Gustavo Pimentel wrote:
> 
> Hi Jingoo,
> 
> On 11/04/2018 01:01, Jingoo Han wrote:
> > On Monday, April 9, 2018 5:41 AM, Gustavo Pimentel wrote:
> >>
> >> Replaces a simple division by 2 to a right shift rotation of 1 bit.
> >
> > It looks good. However, would you add a simple reason to the commit
> > message?
> 
> Sure.
> 
> Can be this one?
> 
> Probably any recent and decent compiler does this kind of substitution
> in order to improve code performance. Nevertheless it's a coding good
> practice whenever there is a division / multiplication by multiple of 2
> to replace it by the equivalent operation in this case, the shift
> rotation.

Yes, that's what I wanted. The most platforms using 'dwc' are based on
ARM CPUs. So, the shift rotation can be better.
Thank you.

Best regards,
Jingoo Han

> 
> >
> > Best regards,
> > Jingoo Han
> >
> >>
> >> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
> >> ---
> >> Change v1->v2:
> >> - Nothing changed, just to follow the patch set version.
> >>
> >>  drivers/pci/dwc/pcie-designware-host.c | 8 ++++----
> >>  1 file changed, 4 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/pci/dwc/pcie-designware-host.c
> >> b/drivers/pci/dwc/pcie-designware-host.c
> >> index 03e9b82..8e6fed4 100644
> >> --- a/drivers/pci/dwc/pcie-designware-host.c
> >> +++ b/drivers/pci/dwc/pcie-designware-host.c
> >> @@ -332,8 +332,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
> >>
> >>  	cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> >> "config");
> >>  	if (cfg_res) {
> >> -		pp->cfg0_size = resource_size(cfg_res) / 2;
> >> -		pp->cfg1_size = resource_size(cfg_res) / 2;
> >> +		pp->cfg0_size = resource_size(cfg_res) >> 1;
> >> +		pp->cfg1_size = resource_size(cfg_res) >> 1;
> >>  		pp->cfg0_base = cfg_res->start;
> >>  		pp->cfg1_base = cfg_res->start + pp->cfg0_size;
> >>  	} else if (!pp->va_cfg0_base) {
> >> @@ -377,8 +377,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
> >>  			break;
> >>  		case 0:
> >>  			pp->cfg = win->res;
> >> -			pp->cfg0_size = resource_size(pp->cfg) / 2;
> >> -			pp->cfg1_size = resource_size(pp->cfg) / 2;
> >> +			pp->cfg0_size = resource_size(pp->cfg) >> 1;
> >> +			pp->cfg1_size = resource_size(pp->cfg) >> 1;
> >>  			pp->cfg0_base = pp->cfg->start;
> >>  			pp->cfg1_base = pp->cfg->start + pp->cfg0_size;
> >>  			break;
> >> --
> >> 2.7.4
> >>
> >
> >
> 
> Regards,
> Gustavo

Re: [PATCH v2 8/9] PCI: dwc: Small computation improvement

[Gustavo Pimentel]

Hi Jingoo,

On 11/04/2018 20:37, Jingoo Han wrote:
> On Wednesday, April 11, 2018 3:40 AM, Gustavo Pimentel wrote:
>>
>> Hi Jingoo,
>>
>> On 11/04/2018 01:01, Jingoo Han wrote:
>>> On Monday, April 9, 2018 5:41 AM, Gustavo Pimentel wrote:
>>>>
>>>> Replaces a simple division by 2 to a right shift rotation of 1 bit.
>>>
>>> It looks good. However, would you add a simple reason to the commit
>>> message?
>>
>> Sure.
>>
>> Can be this one?
>>
>> Probably any recent and decent compiler does this kind of substitution
>> in order to improve code performance. Nevertheless it's a coding good
>> practice whenever there is a division / multiplication by multiple of 2
>> to replace it by the equivalent operation in this case, the shift
>> rotation.
> 
> Yes, that's what I wanted. The most platforms using 'dwc' are based on
> ARM CPUs. So, the shift rotation can be better.
> Thank you.

Can I get your acked-by on this?

> 
> Best regards,
> Jingoo Han
> 
>>
>>>
>>> Best regards,
>>> Jingoo Han
>>>
>>>>
>>>> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
>>>> ---
>>>> Change v1->v2:
>>>> - Nothing changed, just to follow the patch set version.
>>>>
>>>>  drivers/pci/dwc/pcie-designware-host.c | 8 ++++----
>>>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/drivers/pci/dwc/pcie-designware-host.c
>>>> b/drivers/pci/dwc/pcie-designware-host.c
>>>> index 03e9b82..8e6fed4 100644
>>>> --- a/drivers/pci/dwc/pcie-designware-host.c
>>>> +++ b/drivers/pci/dwc/pcie-designware-host.c
>>>> @@ -332,8 +332,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
>>>>
>>>>  	cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>>>> "config");
>>>>  	if (cfg_res) {
>>>> -		pp->cfg0_size = resource_size(cfg_res) / 2;
>>>> -		pp->cfg1_size = resource_size(cfg_res) / 2;
>>>> +		pp->cfg0_size = resource_size(cfg_res) >> 1;
>>>> +		pp->cfg1_size = resource_size(cfg_res) >> 1;
>>>>  		pp->cfg0_base = cfg_res->start;
>>>>  		pp->cfg1_base = cfg_res->start + pp->cfg0_size;
>>>>  	} else if (!pp->va_cfg0_base) {
>>>> @@ -377,8 +377,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
>>>>  			break;
>>>>  		case 0:
>>>>  			pp->cfg = win->res;
>>>> -			pp->cfg0_size = resource_size(pp->cfg) / 2;
>>>> -			pp->cfg1_size = resource_size(pp->cfg) / 2;
>>>> +			pp->cfg0_size = resource_size(pp->cfg) >> 1;
>>>> +			pp->cfg1_size = resource_size(pp->cfg) >> 1;
>>>>  			pp->cfg0_base = pp->cfg->start;
>>>>  			pp->cfg1_base = pp->cfg->start + pp->cfg0_size;
>>>>  			break;
>>>> --
>>>> 2.7.4
>>>>
>>>
>>>
>>
>> Regards,
>> Gustavo
> 
> 

Regards,
Gustavo

Re: [PATCH v2 8/9] PCI: dwc: Small computation improvement

[Fabio Estevam]

Hi Gustavo,

On Wed, Apr 11, 2018 at 4:40 AM, Gustavo Pimentel
<gustavo.pimentel@synopsys.com> wrote:

> Can be this one?
>
> Probably any recent and decent compiler does this kind of substitution
> in order to improve code performance. Nevertheless it's a coding good
> practice whenever there is a division / multiplication by multiple of 2
> to replace it by the equivalent operation in this case, the shift
> rotation.

Subject says that this patch provides a computation improvement, but
as you said above the compiler
will perform the shift, so it doesn't seem we will get any benefit.

IMHO the original code has better readability as it makes easier to
understand that pp->cfg0_size will get the half of
resource_size(pp->cfg) size.

I would say it is better to drop this patch from the series.

Thanks

Re: [PATCH v2 8/9] PCI: dwc: Small computation improvement

[Gustavo Pimentel]

Hi Fabio,

On 15/04/2018 14:09, Fabio Estevam wrote:
> Hi Gustavo,
> 
> On Wed, Apr 11, 2018 at 4:40 AM, Gustavo Pimentel
> <gustavo.pimentel@synopsys.com> wrote:
> 
>> Can be this one?
>>
>> Probably any recent and decent compiler does this kind of substitution
>> in order to improve code performance. Nevertheless it's a coding good
>> practice whenever there is a division / multiplication by multiple of 2
>> to replace it by the equivalent operation in this case, the shift
>> rotation.
> 
> Subject says that this patch provides a computation improvement, but
> as you said above the compiler
> will perform the shift, so it doesn't seem we will get any benefit.

In the worth case there is no performance, so it will not hurt having it.
However depending the compiler and the platform this can bring some improvement.
For instance like Jingoo said: "The most platforms using 'dwc' are based on ARM
CPUs. So, the shift rotation can be better."

It's just a attempt to improve the code that doesn't bring any harm.

> 
> IMHO the original code has better readability as it makes easier to
> understand that pp->cfg0_size will get the half of
> resource_size(pp->cfg) size.

Personally I prefer the shift rotation rather the division by 2. But in my case
I'm used to use/see this type of operation, but it's like I said it's my
personal opinion.

> 
> I would say it is better to drop this patch from the series.

Let's see this patch inflicts pain on someone else, in that case I'll remove
from the series.

> 
> Thanks
> 

Regards,
Gustavo

[PATCH v2 9/9] PCI: dwc: Replace magic number by defines

[Gustavo Pimentel]

Replace magic numbers by a well known define in order to make the code
human readable and also facilitate the code reusability.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
Change v1->v2:
- Nothing changed, just to follow the patch set version.

 drivers/pci/dwc/pcie-designware-host.c | 34 ++++++++++++++++++++--------------
 drivers/pci/dwc/pcie-designware.h      |  1 +
 2 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/dwc/pcie-designware-host.c b/drivers/pci/dwc/pcie-designware-host.c
index 8e6fed4..ff43b0f 100644
--- a/drivers/pci/dwc/pcie-designware-host.c
+++ b/drivers/pci/dwc/pcie-designware-host.c
@@ -83,18 +83,23 @@ irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
 	num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
 
 	for (i = 0; i < num_ctrls; i++) {
-		dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS + i * 12, 4,
-				    &val);
+		dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS +
+					(i * MSI_REG_CTRL_BLOCK_SIZE),
+				    4, &val);
 		if (!val)
 			continue;
 
 		ret = IRQ_HANDLED;
 		pos = 0;
-		while ((pos = find_next_bit((unsigned long *) &val, 32,
-					    pos)) != 32) {
-			irq = irq_find_mapping(pp->irq_domain, i * 32 + pos);
+		while ((pos = find_next_bit((unsigned long *) &val,
+					    MAX_MSI_IRQS_PER_CTRL,
+					    pos)) != MAX_MSI_IRQS_PER_CTRL) {
+			irq = irq_find_mapping(pp->irq_domain,
+					       (i * MAX_MSI_IRQS_PER_CTRL) +
+					       pos);
 			generic_handle_irq(irq);
-			dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_STATUS + i * 12,
+			dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_STATUS +
+						(i * MSI_REG_CTRL_BLOCK_SIZE),
 					    4, 1 << pos);
 			pos++;
 		}
@@ -157,9 +162,9 @@ static void dw_pci_bottom_mask(struct irq_data *data)
 	if (pp->ops->msi_clear_irq) {
 		pp->ops->msi_clear_irq(pp, data->hwirq);
 	} else {
-		ctrl = data->hwirq / 32;
-		res = ctrl * 12;
-		bit = data->hwirq % 32;
+		ctrl = data->hwirq / MAX_MSI_IRQS_PER_CTRL;
+		res = ctrl * MSI_REG_CTRL_BLOCK_SIZE;
+		bit = data->hwirq % MAX_MSI_IRQS_PER_CTRL;
 
 		pp->irq_status[ctrl] &= ~(1 << bit);
 		dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4,
@@ -180,9 +185,9 @@ static void dw_pci_bottom_unmask(struct irq_data *data)
 	if (pp->ops->msi_set_irq) {
 		pp->ops->msi_set_irq(pp, data->hwirq);
 	} else {
-		ctrl = data->hwirq / 32;
-		res = ctrl * 12;
-		bit = data->hwirq % 32;
+		ctrl = data->hwirq / MAX_MSI_IRQS_PER_CTRL;
+		res = ctrl * MSI_REG_CTRL_BLOCK_SIZE;
+		bit = data->hwirq % MAX_MSI_IRQS_PER_CTRL;
 
 		pp->irq_status[ctrl] |= 1 << bit;
 		dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4,
@@ -652,8 +657,9 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
 
 	/* Initialize IRQ Status array */
 	for (ctrl = 0; ctrl < num_ctrls; ctrl++)
-		dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + (ctrl * 12), 4,
-				    &pp->irq_status[ctrl]);
+		dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE +
+					(ctrl * MSI_REG_CTRL_BLOCK_SIZE),
+				    4, &pp->irq_status[ctrl]);
 
 	/* Setup RC BARs */
 	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, 0x00000004);
diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index fe811db..bee4e25 100644
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -110,6 +110,7 @@
 #define MAX_MSI_IRQS			256
 #define MAX_MSI_IRQS_PER_CTRL		32
 #define MAX_MSI_CTRLS			(MAX_MSI_IRQS / MAX_MSI_IRQS_PER_CTRL)
+#define MSI_REG_CTRL_BLOCK_SIZE		12
 #define MSI_DEF_NUM_VECTORS		32
 
 /* Maximum number of inbound/outbound iATUs */
-- 
2.7.4

Re: [PATCH v2 9/9] PCI: dwc: Replace magic number by defines

[Jingoo Han]

On Monday, April 9, 2018 5:41 AM, Gustavo Pimentel wrote:
> 
> Replace magic numbers by a well known define in order to make the code
> human readable and also facilitate the code reusability.
> 
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>

Acked-by: Jingoo Han <jingoohan1@gmail.com>

> ---
> Change v1->v2:
> - Nothing changed, just to follow the patch set version.
> 
>  drivers/pci/dwc/pcie-designware-host.c | 34 ++++++++++++++++++++---------
> -----
>  drivers/pci/dwc/pcie-designware.h      |  1 +
>  2 files changed, 21 insertions(+), 14 deletions(-)
> 

[.....]