Re: [PATCH v2] PCI: cadence: Refactor driver to use as a core library

From: Kishon Vijay Abraham I
Date: Mon Oct 21 2019 - 08:13:45 EST


Tom,

On 17/10/19 12:38 AM, Tom Joseph wrote:
> All the platform related APIs/Structures in the driver is extracted
> out to a separate file (pcie-cadence-plat.c). This enables the
> driver to be used as a core library, which could now be used by
> other platform drivers. Testing done using simulation environment.

Bjorn has given a list of guidelines to follow while posting the patch. Please
see if you meet all of them for the change log.

https://lore.kernel.org/linux-pci/20171026223701.GA25649@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
>
> Signed-off-by: Tom Joseph <tjoseph@xxxxxxxxxxx>
> ---
> drivers/pci/controller/Kconfig | 28 +++++
> drivers/pci/controller/Makefile | 1 +
> drivers/pci/controller/pcie-cadence-ep.c | 96 +---------------
> drivers/pci/controller/pcie-cadence-host.c | 96 ++--------------
> drivers/pci/controller/pcie-cadence-plat.c | 174 +++++++++++++++++++++++++++++
> drivers/pci/controller/pcie-cadence.h | 82 ++++++++++++++
> 6 files changed, 297 insertions(+), 180 deletions(-)
> create mode 100644 drivers/pci/controller/pcie-cadence-plat.c
>
> diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> index fe9f9f1..cafbed0 100644
> --- a/drivers/pci/controller/Kconfig
> +++ b/drivers/pci/controller/Kconfig
> @@ -48,6 +48,34 @@ config PCIE_CADENCE_EP
> endpoint mode. This PCIe controller may be embedded into many
> different vendors SoCs.
>
> +config PCIE_CADENCE_PLAT
> + bool
> +
> +config PCIE_CADENCE_PLAT_HOST
> + bool "Cadence PCIe platform host controller"
> + depends on OF
> + depends on PCI
> + select IRQ_DOMAIN
> + select PCIE_CADENCE
> + select PCIE_CADENCE_HOST
> + select PCIE_CADENCE_PLAT
> + help
> + Say Y here if you want to support the Cadence PCIe platform controller in
> + host mode. This PCIe controller may be embedded into many different
> + vendors SoCs.
> +
> +config PCIE_CADENCE_PLAT_EP
> + bool "Cadence PCIe platform endpoint controller"
> + depends on OF
> + depends on PCI_ENDPOINT
> + select PCIE_CADENCE
> + select PCIE_CADENCE_EP
> + select PCIE_CADENCE_PLAT
> + help
> + Say Y here if you want to support the Cadence PCIe platform controller in
> + endpoint mode. This PCIe controller may be embedded into many
> + different vendors SoCs.
> +
> endmenu
>
> config PCIE_XILINX_NWL
> diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
> index d56a507..676a41e 100644
> --- a/drivers/pci/controller/Makefile
> +++ b/drivers/pci/controller/Makefile
> @@ -2,6 +2,7 @@
> obj-$(CONFIG_PCIE_CADENCE) += pcie-cadence.o
> obj-$(CONFIG_PCIE_CADENCE_HOST) += pcie-cadence-host.o
> obj-$(CONFIG_PCIE_CADENCE_EP) += pcie-cadence-ep.o
> +obj-$(CONFIG_PCIE_CADENCE_PLAT) += pcie-cadence-plat.o
> obj-$(CONFIG_PCI_FTPCI100) += pci-ftpci100.o
> obj-$(CONFIG_PCI_HYPERV) += pci-hyperv.o
> obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
> diff --git a/drivers/pci/controller/pcie-cadence-ep.c b/drivers/pci/controller/pcie-cadence-ep.c
> index def7820..1c173da 100644
> --- a/drivers/pci/controller/pcie-cadence-ep.c
> +++ b/drivers/pci/controller/pcie-cadence-ep.c
> @@ -17,35 +17,6 @@
> #define CDNS_PCIE_EP_IRQ_PCI_ADDR_NONE 0x1
> #define CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY 0x3
>
> -/**
> - * struct cdns_pcie_ep - private data for this PCIe endpoint controller driver
> - * @pcie: Cadence PCIe controller
> - * @max_regions: maximum number of regions supported by hardware
> - * @ob_region_map: bitmask of mapped outbound regions
> - * @ob_addr: base addresses in the AXI bus where the outbound regions start
> - * @irq_phys_addr: base address on the AXI bus where the MSI/legacy IRQ
> - * dedicated outbound regions is mapped.
> - * @irq_cpu_addr: base address in the CPU space where a write access triggers
> - * the sending of a memory write (MSI) / normal message (legacy
> - * IRQ) TLP through the PCIe bus.
> - * @irq_pci_addr: used to save the current mapping of the MSI/legacy IRQ
> - * dedicated outbound region.
> - * @irq_pci_fn: the latest PCI function that has updated the mapping of
> - * the MSI/legacy IRQ dedicated outbound region.
> - * @irq_pending: bitmask of asserted legacy IRQs.
> - */
> -struct cdns_pcie_ep {
> - struct cdns_pcie pcie;
> - u32 max_regions;
> - unsigned long ob_region_map;
> - phys_addr_t *ob_addr;
> - phys_addr_t irq_phys_addr;
> - void __iomem *irq_cpu_addr;
> - u64 irq_pci_addr;
> - u8 irq_pci_fn;
> - u8 irq_pending;
> -};
> -
> static int cdns_pcie_ep_write_header(struct pci_epc *epc, u8 fn,
> struct pci_epf_header *hdr)
> {
> @@ -424,28 +395,17 @@ static const struct pci_epc_ops cdns_pcie_epc_ops = {
> .get_features = cdns_pcie_ep_get_features,
> };
>
> -static const struct of_device_id cdns_pcie_ep_of_match[] = {
> - { .compatible = "cdns,cdns-pcie-ep" },
> -
> - { },
> -};
>
> -static int cdns_pcie_ep_probe(struct platform_device *pdev)
> +int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
> {
> - struct device *dev = &pdev->dev;
> + struct device *dev = ep->pcie.dev;
> + struct platform_device *pdev = to_platform_device(dev);
> struct device_node *np = dev->of_node;
> - struct cdns_pcie_ep *ep;
> - struct cdns_pcie *pcie;
> - struct pci_epc *epc;
> + struct cdns_pcie *pcie = &ep->pcie;
> struct resource *res;
> + struct pci_epc *epc;
> int ret;
> - int phy_count;
> -
> - ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
> - if (!ep)
> - return -ENOMEM;
>
> - pcie = &ep->pcie;
> pcie->is_rc = false;
>
> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg");
> @@ -474,19 +434,6 @@ static int cdns_pcie_ep_probe(struct platform_device *pdev)
> if (!ep->ob_addr)
> return -ENOMEM;
>
> - ret = cdns_pcie_init_phy(dev, pcie);
> - if (ret) {
> - dev_err(dev, "failed to init phy\n");
> - return ret;
> - }
> - platform_set_drvdata(pdev, pcie);
> - pm_runtime_enable(dev);
> - ret = pm_runtime_get_sync(dev);
> - if (ret < 0) {
> - dev_err(dev, "pm_runtime_get_sync() failed\n");
> - goto err_get_sync;
> - }
> -
> /* Disable all but function 0 (anyway BIT(0) is hardwired to 1). */
> cdns_pcie_writel(pcie, CDNS_PCIE_LM_EP_FUNC_CFG, BIT(0));
>
> @@ -528,38 +475,5 @@ static int cdns_pcie_ep_probe(struct platform_device *pdev)
> err_init:
> pm_runtime_put_sync(dev);
>
> - err_get_sync:
> - pm_runtime_disable(dev);
> - cdns_pcie_disable_phy(pcie);
> - phy_count = pcie->phy_count;
> - while (phy_count--)
> - device_link_del(pcie->link[phy_count]);
> -
> return ret;
> }
> -
> -static void cdns_pcie_ep_shutdown(struct platform_device *pdev)
> -{
> - struct device *dev = &pdev->dev;
> - struct cdns_pcie *pcie = dev_get_drvdata(dev);
> - int ret;
> -
> - ret = pm_runtime_put_sync(dev);
> - if (ret < 0)
> - dev_dbg(dev, "pm_runtime_put_sync failed\n");
> -
> - pm_runtime_disable(dev);
> -
> - cdns_pcie_disable_phy(pcie);
> -}
> -
> -static struct platform_driver cdns_pcie_ep_driver = {
> - .driver = {
> - .name = "cdns-pcie-ep",
> - .of_match_table = cdns_pcie_ep_of_match,
> - .pm = &cdns_pcie_pm_ops,
> - },
> - .probe = cdns_pcie_ep_probe,
> - .shutdown = cdns_pcie_ep_shutdown,
> -};
> -builtin_platform_driver(cdns_pcie_ep_driver);
> diff --git a/drivers/pci/controller/pcie-cadence-host.c b/drivers/pci/controller/pcie-cadence-host.c
> index 97e2510..5081908 100644
> --- a/drivers/pci/controller/pcie-cadence-host.c
> +++ b/drivers/pci/controller/pcie-cadence-host.c
> @@ -11,33 +11,6 @@
>
> #include "pcie-cadence.h"
>
> -/**
> - * struct cdns_pcie_rc - private data for this PCIe Root Complex driver
> - * @pcie: Cadence PCIe controller
> - * @dev: pointer to PCIe device
> - * @cfg_res: start/end offsets in the physical system memory to map PCI
> - * configuration space accesses
> - * @bus_range: first/last buses behind the PCIe host controller
> - * @cfg_base: IO mapped window to access the PCI configuration space of a
> - * single function at a time
> - * @max_regions: maximum number of regions supported by the hardware
> - * @no_bar_nbits: Number of bits to keep for inbound (PCIe -> CPU) address
> - * translation (nbits sets into the "no BAR match" register)
> - * @vendor_id: PCI vendor ID
> - * @device_id: PCI device ID
> - */
> -struct cdns_pcie_rc {
> - struct cdns_pcie pcie;
> - struct device *dev;
> - struct resource *cfg_res;
> - struct resource *bus_range;
> - void __iomem *cfg_base;
> - u32 max_regions;
> - u32 no_bar_nbits;
> - u16 vendor_id;
> - u16 device_id;
> -};
> -
> static void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
> int where)
> {
> @@ -92,11 +65,6 @@ static struct pci_ops cdns_pcie_host_ops = {
> .write = pci_generic_config_write,
> };
>
> -static const struct of_device_id cdns_pcie_host_of_match[] = {
> - { .compatible = "cdns,cdns-pcie-host" },
> -
> - { },
> -};
>
> static int cdns_pcie_host_init_root_port(struct cdns_pcie_rc *rc)
> {
> @@ -136,10 +104,10 @@ static int cdns_pcie_host_init_root_port(struct cdns_pcie_rc *rc)
> static int cdns_pcie_host_init_address_translation(struct cdns_pcie_rc *rc)
> {
> struct cdns_pcie *pcie = &rc->pcie;
> - struct resource *cfg_res = rc->cfg_res;
> struct resource *mem_res = pcie->mem_res;
> struct resource *bus_range = rc->bus_range;
> - struct device *dev = rc->dev;
> + struct resource *cfg_res = rc->cfg_res;
> + struct device *dev = pcie->dev;
> struct device_node *np = dev->of_node;
> struct of_pci_range_parser parser;
> struct of_pci_range range;
> @@ -233,27 +201,22 @@ static int cdns_pcie_host_init(struct device *dev,
> return err;
> }
>
> -static int cdns_pcie_host_probe(struct platform_device *pdev)
> +int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
> {
> - struct device *dev = &pdev->dev;
> + struct device *dev = rc->pcie.dev;
> + struct platform_device *pdev = to_platform_device(dev);
> struct device_node *np = dev->of_node;
> struct pci_host_bridge *bridge;
> struct list_head resources;
> - struct cdns_pcie_rc *rc;
> struct cdns_pcie *pcie;
> struct resource *res;
> int ret;
> - int phy_count;
>
> - bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc));
> + bridge = pci_host_bridge_from_priv(rc);
> if (!bridge)
> return -ENOMEM;
>
> - rc = pci_host_bridge_priv(bridge);
> - rc->dev = dev;
> -
> pcie = &rc->pcie;
> - pcie->is_rc = true;

is_rc can be left in host_setup.
>
> rc->max_regions = 32;
> of_property_read_u32(np, "cdns,max-outbound-regions", &rc->max_regions);
> @@ -287,21 +250,8 @@ static int cdns_pcie_host_probe(struct platform_device *pdev)
> dev_err(dev, "missing \"mem\"\n");
> return -EINVAL;
> }
> - pcie->mem_res = res;
>
> - ret = cdns_pcie_init_phy(dev, pcie);
> - if (ret) {
> - dev_err(dev, "failed to init phy\n");
> - return ret;
> - }
> - platform_set_drvdata(pdev, pcie);
> -
> - pm_runtime_enable(dev);
> - ret = pm_runtime_get_sync(dev);
> - if (ret < 0) {
> - dev_err(dev, "pm_runtime_get_sync() failed\n");
> - goto err_get_sync;
> - }
> + pcie->mem_res = res;
>
> ret = cdns_pcie_host_init(dev, &resources, rc);
> if (ret)
> @@ -326,37 +276,5 @@ static int cdns_pcie_host_probe(struct platform_device *pdev)
> err_init:
> pm_runtime_put_sync(dev);
>
> - err_get_sync:
> - pm_runtime_disable(dev);
> - cdns_pcie_disable_phy(pcie);
> - phy_count = pcie->phy_count;
> - while (phy_count--)
> - device_link_del(pcie->link[phy_count]);
> -
> return ret;
> }
> -
> -static void cdns_pcie_shutdown(struct platform_device *pdev)
> -{
> - struct device *dev = &pdev->dev;
> - struct cdns_pcie *pcie = dev_get_drvdata(dev);
> - int ret;
> -
> - ret = pm_runtime_put_sync(dev);
> - if (ret < 0)
> - dev_dbg(dev, "pm_runtime_put_sync failed\n");
> -
> - pm_runtime_disable(dev);
> - cdns_pcie_disable_phy(pcie);
> -}
> -
> -static struct platform_driver cdns_pcie_host_driver = {
> - .driver = {
> - .name = "cdns-pcie-host",
> - .of_match_table = cdns_pcie_host_of_match,
> - .pm = &cdns_pcie_pm_ops,
> - },
> - .probe = cdns_pcie_host_probe,
> - .shutdown = cdns_pcie_shutdown,
> -};
> -builtin_platform_driver(cdns_pcie_host_driver);
> diff --git a/drivers/pci/controller/pcie-cadence-plat.c b/drivers/pci/controller/pcie-cadence-plat.c
> new file mode 100644
> index 0000000..f5c6bf6
> --- /dev/null
> +++ b/drivers/pci/controller/pcie-cadence-plat.c
> @@ -0,0 +1,174 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Cadence PCIe platform driver.
> + *
> + * Copyright (c) 2019, Cadence Design Systems
> + * Author: Tom Joseph <tjoseph@xxxxxxxxxxx>
> + */
> +#include <linux/kernel.h>
> +#include <linux/of_address.h>
> +#include <linux/of_pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/of_device.h>
> +#include "pcie-cadence.h"
> +
> +/**
> + * struct cdns_plat_pcie - private data for this PCIe platform driver
> + * @pcie: Cadence PCIe controller
> + * @is_rc: Set to 1 indicates the PCIe controller mode is Root Complex,
> + * if 0 it is in Endpoint mode.
> + */
> +struct cdns_plat_pcie {
> + struct cdns_pcie *pcie;
> + bool is_rc;
> +};
> +
> +struct cdns_plat_pcie_of_data {
> + bool is_rc;
> +};
> +
> +static const struct of_device_id cdns_plat_pcie_of_match[];
> +
> +static int cdns_plat_pcie_probe(struct platform_device *pdev)
> +{
> + const struct cdns_plat_pcie_of_data *data;
> + struct cdns_plat_pcie *cdns_plat_pcie;
> + const struct of_device_id *match;
> + struct device *dev = &pdev->dev;
> + struct pci_host_bridge *bridge;
> + struct cdns_pcie_ep *ep;
> + struct cdns_pcie_rc *rc;
> + int phy_count;
> + bool is_rc;
> + int ret;
> +
> + match = of_match_device(cdns_plat_pcie_of_match, dev);
> + if (!match)
> + return -EINVAL;
> +
> + data = (struct cdns_plat_pcie_of_data *)match->data;
> + is_rc = data->is_rc;
> +
> + pr_debug(" Started %s with is_rc: %d\n", __func__, is_rc);
> + cdns_plat_pcie = devm_kzalloc(dev, sizeof(*cdns_plat_pcie), GFP_KERNEL);
> + if (!cdns_plat_pcie)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, cdns_plat_pcie);
> + if (is_rc) {
> + if (!IS_ENABLED(CONFIG_PCIE_CADENCE_PLAT_HOST))
> + return -ENODEV;
> +
> + bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc));
> + if (!bridge)
> + return -ENOMEM;
> +
> + rc = pci_host_bridge_priv(bridge);
> + rc->pcie.dev = dev;
> + cdns_plat_pcie->pcie = &rc->pcie;
> + cdns_plat_pcie->is_rc = is_rc;
> +
> + ret = cdns_pcie_init_phy(dev, cdns_plat_pcie->pcie);
> + if (ret) {
> + dev_err(dev, "failed to init phy\n");
> + return ret;
> + }
> + pm_runtime_enable(dev);
> + ret = pm_runtime_get_sync(dev);
> + if (ret < 0) {
> + dev_err(dev, "pm_runtime_get_sync() failed\n");
> + goto err_get_sync;
> + }
> +
> + ret = cdns_pcie_host_setup(rc);
> + if (ret)
> + goto err_init;
> + } else {
> + if (!IS_ENABLED(CONFIG_PCIE_CADENCE_PLAT_EP))
> + return -ENODEV;
> +
> + ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
> + if (!ep)
> + return -ENOMEM;
> +
> + ep->pcie.dev = dev;
> + cdns_plat_pcie->pcie = &ep->pcie;
> + cdns_plat_pcie->is_rc = is_rc;
> +
> + ret = cdns_pcie_init_phy(dev, cdns_plat_pcie->pcie);
> + if (ret) {
> + dev_err(dev, "failed to init phy\n");
> + return ret;
> + }
> +
> + pm_runtime_enable(dev);
> + ret = pm_runtime_get_sync(dev);
> + if (ret < 0) {
> + dev_err(dev, "pm_runtime_get_sync() failed\n");
> + goto err_get_sync;
> + }
> +
> + ret = cdns_pcie_ep_setup(ep);
> + if (ret)
> + goto err_init;
> + }
> +
> + err_init:
> + pm_runtime_put_sync(dev);
> +
> + err_get_sync:
> + pm_runtime_disable(dev);
> + cdns_pcie_disable_phy(cdns_plat_pcie->pcie);
> + phy_count = cdns_plat_pcie->pcie->phy_count;
> + while (phy_count--)
> + device_link_del(cdns_plat_pcie->pcie->link[phy_count]);
> +
> + return 0;
> +}
> +
> +static void cdns_plat_pcie_shutdown(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct cdns_pcie *pcie = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = pm_runtime_put_sync(dev);
> + if (ret < 0)
> + dev_dbg(dev, "pm_runtime_put_sync failed\n");
> +
> + pm_runtime_disable(dev);
> +
> + cdns_pcie_disable_phy(pcie);
> +}
> +
> +static const struct cdns_plat_pcie_of_data cdns_plat_pcie_host_of_data = {
> + .is_rc = true,
> +};
> +
> +static const struct cdns_plat_pcie_of_data cdns_plat_pcie_ep_of_data = {
> + .is_rc = false,
> +};
> +
> +static const struct of_device_id cdns_plat_pcie_of_match[] = {
> + {
> + .compatible = "cdns,cdns-pcie-host",
> + .data = &cdns_plat_pcie_host_of_data,
> + },
> + {
> + .compatible = "cdns,cdns-pcie-ep",
> + .data = &cdns_plat_pcie_ep_of_data,
> + },
> + {},
> +};
> +
> +static struct platform_driver cdns_plat_pcie_driver = {
> + .driver = {
> + .name = "cdns-pcie",
> + .of_match_table = cdns_plat_pcie_of_match,
> + .pm = &cdns_pcie_pm_ops,
> + },
> + .probe = cdns_plat_pcie_probe,
> + .shutdown = cdns_plat_pcie_shutdown,
> +};
> +builtin_platform_driver(cdns_plat_pcie_driver);
> diff --git a/drivers/pci/controller/pcie-cadence.h b/drivers/pci/controller/pcie-cadence.h
> index ae6bf2a..62e9dcd 100644
> --- a/drivers/pci/controller/pcie-cadence.h
> +++ b/drivers/pci/controller/pcie-cadence.h
> @@ -190,6 +190,8 @@ enum cdns_pcie_rp_bar {
> (((code) << 8) & CDNS_PCIE_NORMAL_MSG_CODE_MASK)
> #define CDNS_PCIE_MSG_NO_DATA BIT(16)
>
> +struct cdns_pcie;
> +
> enum cdns_pcie_msg_code {
> MSG_CODE_ASSERT_INTA = 0x20,
> MSG_CODE_ASSERT_INTB = 0x21,
> @@ -221,6 +223,11 @@ enum cdns_pcie_msg_routing {
> MSG_ROUTING_GATHER,
> };
>
> +
> +struct cdns_pcie_common_ops {
> + int (*cdns_start_link)(struct cdns_pcie *pcie, bool start);
> + bool (*cdns_is_link_up)(struct cdns_pcie *pcie);
> +};

This structure is defined here and not used anywhere. You could create a new
patch to add this structure and use it in cadence core.

Thanks
Kishon