[PATCH v3 1/2] PCI: generic: Refactor code to enable reuse by other drivers.

David Daney
2016-01-08T23:59:23Z

No change in functionality.

Move structure definitions into a separate header file. Move common
code to new file with Kconfig machinery to build it. Split probe
function in to two parts:

- a small driver specific probe function (gen_pci_probe)

- a common probe that can be used by other drivers
(pci_host_common_probe)

Signed-off-by: David Daney <david.daney@cavium.com>
---
MAINTAINERS | 1 +
drivers/pci/host/Kconfig | 4 +
drivers/pci/host/Makefile | 1 +
drivers/pci/host/pci-host-common.c | 194 ++++++++++++++++++++++++++++++++++++
drivers/pci/host/pci-host-common.h | 56 +++++++++++
drivers/pci/host/pci-host-generic.c | 190 +----------------------------------
6 files changed, 260 insertions(+), 186 deletions(-)
create mode 100644 drivers/pci/host/pci-host-common.c
create mode 100644 drivers/pci/host/pci-host-common.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 233f834..a3fc8b4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8217,6 +8217,7 @@ L: linux-pci@vger.kernel.org
L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
S: Maintained
F: Documentation/devicetree/bindings/pci/host-generic-pci.txt
+F: drivers/pci/host/pci-host-common.c
F: drivers/pci/host/pci-host-generic.c

PCIE DRIVER FOR ST SPEAR13XX
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index f131ba9..f171459 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -53,9 +53,13 @@ config PCI_RCAR_GEN2_PCIE
help
Say Y here if you want PCIe controller support on R-Car Gen2 SoCs.

+config PCI_HOST_COMMON
+ bool
+
config PCI_HOST_GENERIC
bool "Generic PCI host controller"
depends on (ARM || ARM64) && OF
+ select PCI_HOST_COMMON
help
Say Y here if you want to support a simple generic PCI host
controller, such as the one emulated by kvmtool.
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 9d4d3c6..ba2c51f 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o
obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o
obj-$(CONFIG_PCI_RCAR_GEN2_PCIE) += pcie-rcar.o
+obj-$(CONFIG_PCI_HOST_COMMON) += pci-host-common.o
obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone-dw.o pci-keystone.o
diff --git a/drivers/pci/host/pci-host-common.c b/drivers/pci/host/pci-host-common.c
new file mode 100644
index 0000000..e9f850f
--- /dev/null
+++ b/drivers/pci/host/pci-host-common.c
@@ -0,0 +1,194 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright (C) 2014 ARM Limited
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/platform_device.h>
+
+#include "pci-host-common.h"
+
+static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
+{
+ pci_free_resource_list(&pci->resources);
+}
+
+static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
+{
+ int err, res_valid = 0;
+ struct device *dev = pci->host.dev.parent;
+ struct device_node *np = dev->of_node;
+ resource_size_t iobase;
+ struct resource_entry *win;
+
+ err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources,
+ &iobase);
+ if (err)
+ return err;
+
+ resource_list_for_each_entry(win, &pci->resources) {
+ struct resource *parent, *res = win->res;
+
+ switch (resource_type(res)) {
+ case IORESOURCE_IO:
+ parent = &ioport_resource;
+ err = pci_remap_iospace(res, iobase);
+ if (err) {
+ dev_warn(dev, "error %d: failed to map resource %pR\n",
+ err, res);
+ continue;
+ }
+ break;
+ case IORESOURCE_MEM:
+ parent = &iomem_resource;
+ res_valid |= !(res->flags & IORESOURCE_PREFETCH);
+ break;
+ case IORESOURCE_BUS:
+ pci->cfg.bus_range = res;
+ default:
+ continue;
+ }
+
+ err = devm_request_resource(dev, parent, res);
+ if (err)
+ goto out_release_res;
+ }
+
+ if (!res_valid) {
+ dev_err(dev, "non-prefetchable memory resource required\n");
+ err = -EINVAL;
+ goto out_release_res;
+ }
+
+ return 0;
+
+out_release_res:
+ gen_pci_release_of_pci_ranges(pci);
+ return err;
+}
+
+static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
+{
+ int err;
+ u8 bus_max;
+ resource_size_t busn;
+ struct resource *bus_range;
+ struct device *dev = pci->host.dev.parent;
+ struct device_node *np = dev->of_node;
+ u32 sz = 1 << pci->cfg.ops->bus_shift;
+
+ err = of_address_to_resource(np, 0, &pci->cfg.res);
+ if (err) {
+ dev_err(dev, "missing \"reg\" property\n");
+ return err;
+ }
+
+ /* Limit the bus-range to fit within reg */
+ bus_max = pci->cfg.bus_range->start +
+ (resource_size(&pci->cfg.res) >> pci->cfg.ops->bus_shift) - 1;
+ pci->cfg.bus_range->end = min_t(resource_size_t,
+ pci->cfg.bus_range->end, bus_max);
+
+ pci->cfg.win = devm_kcalloc(dev, resource_size(pci->cfg.bus_range),
+ sizeof(*pci->cfg.win), GFP_KERNEL);
+ if (!pci->cfg.win)
+ return -ENOMEM;
+
+ /* Map our Configuration Space windows */
+ if (!devm_request_mem_region(dev, pci->cfg.res.start,
+ resource_size(&pci->cfg.res),
+ "Configuration Space"))
+ return -ENOMEM;
+
+ bus_range = pci->cfg.bus_range;
+ for (busn = bus_range->start; busn <= bus_range->end; ++busn) {
+ u32 idx = busn - bus_range->start;
+
+ pci->cfg.win[idx] = devm_ioremap(dev,
+ pci->cfg.res.start + idx * sz,
+ sz);
+ if (!pci->cfg.win[idx])
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+int pci_host_common_probe(struct platform_device *pdev,
+ struct gen_pci *pci)
+{
+ int err;
+ const char *type;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct pci_bus *bus, *child;
+
+ type = of_get_property(np, "device_type", NULL);
+ if (!type || strcmp(type, "pci")) {
+ dev_err(dev, "invalid \"device_type\" %s\n", type);
+ return -EINVAL;
+ }
+
+ of_pci_check_probe_only();
+
+ pci->host.dev.parent = dev;
+ INIT_LIST_HEAD(&pci->host.windows);
+ INIT_LIST_HEAD(&pci->resources);
+
+ /* Parse our PCI ranges and request their resources */
+ err = gen_pci_parse_request_of_pci_ranges(pci);
+ if (err)
+ return err;
+
+ /* Parse and map our Configuration Space windows */
+ err = gen_pci_parse_map_cfg_windows(pci);
+ if (err) {
+ gen_pci_release_of_pci_ranges(pci);
+ return err;
+ }
+
+ /* Do not reassign resources if probe only */
+ if (!pci_has_flag(PCI_PROBE_ONLY))
+ pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
+
+
+ bus = pci_scan_root_bus(dev, pci->cfg.bus_range->start,
+ &pci->cfg.ops->ops, pci, &pci->resources);
+ if (!bus) {
+ dev_err(dev, "Scanning rootbus failed");
+ return -ENODEV;
+ }
+
+ pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
+
+ if (!pci_has_flag(PCI_PROBE_ONLY)) {
+ pci_bus_size_bridges(bus);
+ pci_bus_assign_resources(bus);
+
+ list_for_each_entry(child, &bus->children, node)
+ pcie_bus_configure_settings(child);
+ }
+
+ pci_bus_add_devices(bus);
+ return 0;
+}
+
+MODULE_DESCRIPTION("Generic PCI host driver common code");
+MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/pci/host/pci-host-common.h b/drivers/pci/host/pci-host-common.h
new file mode 100644
index 0000000..9423808
--- /dev/null
+++ b/drivers/pci/host/pci-host-common.h
@@ -0,0 +1,56 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright (C) 2014 ARM Limited
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#ifndef _PCI_HOST_COMMON_H
+#define _PCI_HOST_COMMON_H
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+
+struct gen_pci_cfg_bus_ops {
+ u32 bus_shift;
+ struct pci_ops ops;
+};
+
+struct gen_pci_cfg_windows {
+ struct resource res;
+ struct resource *bus_range;
+ void __iomem **win;
+
+ struct gen_pci_cfg_bus_ops *ops;
+};
+
+/*
+ * ARM pcibios functions expect the ARM struct pci_sys_data as the PCI
+ * sysdata. Add pci_sys_data as the first element in struct gen_pci so
+ * that when we use a gen_pci pointer as sysdata, it is also a pointer to
+ * a struct pci_sys_data.
+ */
+struct gen_pci {
+#ifdef CONFIG_ARM
+ struct pci_sys_data sys;
+#endif
+ struct pci_host_bridge host;
+ struct gen_pci_cfg_windows cfg;
+ struct list_head resources;
+};
+
+int pci_host_common_probe(struct platform_device *pdev,
+ struct gen_pci *pci);
+
+#endif /* _PCI_HOST_COMMON_H */
diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
index 5434c90..e8aa78f 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -25,33 +25,7 @@
#include <linux/of_pci.h>
#include <linux/platform_device.h>

-struct gen_pci_cfg_bus_ops {
- u32 bus_shift;
- struct pci_ops ops;
-};
-
-struct gen_pci_cfg_windows {
- struct resource res;
- struct resource *bus_range;
- void __iomem **win;
-
- struct gen_pci_cfg_bus_ops *ops;
-};
-
-/*
- * ARM pcibios functions expect the ARM struct pci_sys_data as the PCI
- * sysdata. Add pci_sys_data as the first element in struct gen_pci so
- * that when we use a gen_pci pointer as sysdata, it is also a pointer to
- * a struct pci_sys_data.
- */
-struct gen_pci {
-#ifdef CONFIG_ARM
- struct pci_sys_data sys;
-#endif
- struct pci_host_bridge host;
- struct gen_pci_cfg_windows cfg;
- struct list_head resources;
-};
+#include "pci-host-common.h"

static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
unsigned int devfn,
@@ -102,175 +76,19 @@ static const struct of_device_id gen_pci_of_match[] = {
};
MODULE_DEVICE_TABLE(of, gen_pci_of_match);

-static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
-{
- pci_free_resource_list(&pci->resources);
-}
-
-static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
-{
- int err, res_valid = 0;
- struct device *dev = pci->host.dev.parent;
- struct device_node *np = dev->of_node;
- resource_size_t iobase;
- struct resource_entry *win;
-
- err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources,
- &iobase);
- if (err)
- return err;
-
- resource_list_for_each_entry(win, &pci->resources) {
- struct resource *parent, *res = win->res;
-
- switch (resource_type(res)) {
- case IORESOURCE_IO:
- parent = &ioport_resource;
- err = pci_remap_iospace(res, iobase);
- if (err) {
- dev_warn(dev, "error %d: failed to map resource %pR\n",
- err, res);
- continue;
- }
- break;
- case IORESOURCE_MEM:
- parent = &iomem_resource;
- res_valid |= !(res->flags & IORESOURCE_PREFETCH);
- break;
- case IORESOURCE_BUS:
- pci->cfg.bus_range = res;
- default:
- continue;
- }
-
- err = devm_request_resource(dev, parent, res);
- if (err)
- goto out_release_res;
- }
-
- if (!res_valid) {
- dev_err(dev, "non-prefetchable memory resource required\n");
- err = -EINVAL;
- goto out_release_res;
- }
-
- return 0;
-
-out_release_res:
- gen_pci_release_of_pci_ranges(pci);
- return err;
-}
-
-static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
-{
- int err;
- u8 bus_max;
- resource_size_t busn;
- struct resource *bus_range;
- struct device *dev = pci->host.dev.parent;
- struct device_node *np = dev->of_node;
- u32 sz = 1 << pci->cfg.ops->bus_shift;
-
- err = of_address_to_resource(np, 0, &pci->cfg.res);
- if (err) {
- dev_err(dev, "missing \"reg\" property\n");
- return err;
- }
-
- /* Limit the bus-range to fit within reg */
- bus_max = pci->cfg.bus_range->start +
- (resource_size(&pci->cfg.res) >> pci->cfg.ops->bus_shift) - 1;
- pci->cfg.bus_range->end = min_t(resource_size_t,
- pci->cfg.bus_range->end, bus_max);
-
- pci->cfg.win = devm_kcalloc(dev, resource_size(pci->cfg.bus_range),
- sizeof(*pci->cfg.win), GFP_KERNEL);
- if (!pci->cfg.win)
- return -ENOMEM;
-
- /* Map our Configuration Space windows */
- if (!devm_request_mem_region(dev, pci->cfg.res.start,
- resource_size(&pci->cfg.res),
- "Configuration Space"))
- return -ENOMEM;
-
- bus_range = pci->cfg.bus_range;
- for (busn = bus_range->start; busn <= bus_range->end; ++busn) {
- u32 idx = busn - bus_range->start;
-
- pci->cfg.win[idx] = devm_ioremap(dev,
- pci->cfg.res.start + idx * sz,
- sz);
- if (!pci->cfg.win[idx])
- return -ENOMEM;
- }
-
- return 0;
-}
-
static int gen_pci_probe(struct platform_device *pdev)
{
- int err;
- const char *type;
- const struct of_device_id *of_id;
struct device *dev = &pdev->dev;
- struct device_node *np = dev->of_node;
+ const struct of_device_id *of_id;
struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
- struct pci_bus *bus, *child;

if (!pci)
return -ENOMEM;

- type = of_get_property(np, "device_type", NULL);
- if (!type || strcmp(type, "pci")) {
- dev_err(dev, "invalid \"device_type\" %s\n", type);
- return -EINVAL;
- }
-
- of_pci_check_probe_only();
-
- of_id = of_match_node(gen_pci_of_match, np);
+ of_id = of_match_node(gen_pci_of_match, dev->of_node);
pci->cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
- pci->host.dev.parent = dev;
- INIT_LIST_HEAD(&pci->host.windows);
- INIT_LIST_HEAD(&pci->resources);
-
- /* Parse our PCI ranges and request their resources */
- err = gen_pci_parse_request_of_pci_ranges(pci);
- if (err)
- return err;
-
- /* Parse and map our Configuration Space windows */
- err = gen_pci_parse_map_cfg_windows(pci);
- if (err) {
- gen_pci_release_of_pci_ranges(pci);
- return err;
- }
-
- /* Do not reassign resources if probe only */
- if (!pci_has_flag(PCI_PROBE_ONLY))
- pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
-
-
- bus = pci_scan_root_bus(dev, pci->cfg.bus_range->start,
- &pci->cfg.ops->ops, pci, &pci->resources);
- if (!bus) {
- dev_err(dev, "Scanning rootbus failed");
- return -ENODEV;
- }
-
- pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
-
- if (!pci_has_flag(PCI_PROBE_ONLY)) {
- pci_bus_size_bridges(bus);
- pci_bus_assign_resources(bus);
-
- list_for_each_entry(child, &bus->children, node)
- pcie_bus_configure_settings(child);
- }

- pci_bus_add_devices(bus);
- return 0;
+ return pci_host_common_probe(pdev, pci);
}

static struct platform_driver gen_pci_driver = {
--
1.8.3.1