Designware EP support and code clean up

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 <[email protected]>

---
Changes v1->v2:
- Removed any iATU reference or changes to avoid confusion.
- Add "snps,dw-pcie" compatible string following Kishon's suggestion.
Changes v2->v3:
- Nothing changed, just to follow the patch set version.
Changes v3->v4:
- Reverted "snps,dw-pcie-rc" compatible string requested by Rob Herring.
Changes v4->v5:
- Nothing changed, just to follow the patch set version.

 Documentation/devicetree/bindings/pci/designware-pcie.txt | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

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 <[email protected]>

Acked-by Kishon Vijay Abraham I <[email protected]>

---
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.
Changes v2->v3:
- Reverted additions in dw_pcie_ep_linkup function.
- Replaced devm_ioremap by devm_ioremap_resource function.
- Moved second entry in pci_epf_test_ids structure into a new patch file.
Changes v3->v4:
- Reverted "snps,dw-pcie-rc" compatible string requested by Rob Herring.
Changes v4->v5:
- Nothing changed, just to follow the patch set version.

 drivers/pci/dwc/Kconfig                |  45 +++++++---
 drivers/pci/dwc/pcie-designware-plat.c | 149 ++++++++++++++++++++++++++++++---
 2 files changed, 174 insertions(+), 20 deletions(-)

drivers/pci/dwc/Kconfig +1 -4

index 2f3f5c5..3fd7daf 100644
@@ -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

drivers/pci/dwc/Kconfig +28 -2

-	 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"

drivers/pci/dwc/pcie-designware-plat.c +139 -10

index 5416aa8..efc315c 100644
@@ -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_resource(dev, 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 +186,59 @@ 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-ep",
+		.data = &dw_plat_pcie_ep_of_data,
+	},
 	{},
 };
 

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

Signed-off-by Gustavo Pimentel <[email protected]>

---
Change v1->v2:
- Register new device id following Kishon's suggestion.
Change v2->v3:
- Nothing changed, just to follow the patch set version.
Changes v3->v4:
- Nothing changed, just to follow the patch set version.
Changes v4->v5:
- Nothing changed, just to follow the patch set version.

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

include/linux/pci_ids.h +0 -0

index cc608fc5..22b1c1b 100644

include/linux/pci_ids.h +0 -0

 #define PCI_VENDOR_ID_VITESSE		0x1725
 #define PCI_DEVICE_ID_VITESSE_VSC7174	0x7174

Signature · 1 line

2.7.4

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 <[email protected]>

---
Change v1->v2:
- Nothing changed, just to follow the patch set version.
Change v2->v3:
- Nothing changed, just to follow the patch set version.
Changes v3->v4:
- Nothing changed, just to follow the patch set version.
Changes v4->v5:
- Nothing changed, just to follow the patch set version.

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

drivers/pci/dwc/pcie-designware-plat.c +1 -0

index efc315c..5937fed 100644
@@ -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)

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 <[email protected]>

Acked-by Jingoo Han <[email protected]>

---
Change v1->v2:
- Added an extra log description line about code style following Fabio
Estevam suggestion.
Change v2->v3:
- Nothing changed, just to follow the patch set version.
Changes v3->v4:
- Nothing changed, just to follow the patch set version.
Changes v4->v5:
- Nothing changed, just to follow the patch set version.

 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(-)

drivers/pci/dwc/pcie-designware-ep.c +8 -8

index f07678b..15b22a6 100644
@@ -75,7 +75,7 @@ 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;
 	}
 

@@ -100,7 +100,7 @@ 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;
 	}
 

@@ -204,7 +204,7 @@ 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;
 	}
 

@@ -348,21 +348,21 @@ 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;
 	}
 

@@ -389,7 +389,7 @@ 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);
 	}
 

drivers/pci/dwc/pcie-designware-host.c +19 -16

index 6c409079..5a23f78 100644
@@ -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 |= 0x00ff0100;
 	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);

drivers/pci/dwc/pcie-designware.c +10 -10

index 1b7282e..778c4f7 100644
@@ -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) {

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

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.

Signed-off-by Gustavo Pimentel <[email protected]>

---
Change v1->v2:
- Nothing changed, just to follow the patch set version.
Change v2->v3:
- Nothing changed, just to follow the patch set version.
Changes v3->v4:
- Added a small explication to the log description.
Changes v4->v5:
- Nothing changed, just to follow the patch set version.

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

drivers/pci/dwc/pcie-designware-host.c +2 -2

index 5a23f78..fc55fde 100644
@@ -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;

drivers/pci/dwc/pcie-designware-host.c +2 -3

 	} 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

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

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.

Signed-off-by Gustavo Pimentel <[email protected]>

---
Change v1->v2:
- Nothing changed, just to follow the patch set version.
Change v2->v3:
- Nothing changed, just to follow the patch set version.
Changes v3->v4:
- Added a small explication to the log description.
Changes v4->v5:
- Nothing changed, just to follow the patch set version.

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

drivers/pci/dwc/pcie-designware-host.c +2 -2

index 5a23f78..fc55fde 100644
@@ -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) {