[PATCH V7 02/11] PCI: generic, thunder: update to use generic ECAM API

From: Tomasz Nowicki
Date: Tue May 10 2016 - 11:20:24 EST

From: Jayachandran C <jchandra@xxxxxxxxxxxx>

Use functions provided by drivers/pci/ecam.h for mapping the config
space in drivers/pci/host/pci-host-common.c, and update its users to
use 'struct pci_config_window' and 'struct pci_ecam_ops'

The changes are mostly to use 'struct pci_config_window' in place of
'struct gen_pci'. Some of the fields of gen_pci were only used
temporarily and can be eliminated by using local variables or function
arguments, these are not carried over to struct pci_config_window.

pci-thunder-ecam.c and pci-thunder-pem.c are the only users of the
pci_host_common_probe function and the gen_pci structure, these have
been updated to use the new API as well.

The patch does not introduce any functional changes other than a very
minor one: with the new code, on 64-bit platforms, we do just a single
ioremap for the whole config space.

Signed-off-by: Jayachandran C <jchandra@xxxxxxxxxxxx>
---
drivers/pci/ecam.h | 5 ++
drivers/pci/host/Kconfig | 1 +
drivers/pci/host/pci-host-common.c | 114 +++++++++++++++---------------------
drivers/pci/host/pci-host-common.h | 47 ---------------
drivers/pci/host/pci-host-generic.c | 52 ++++------------
drivers/pci/host/pci-thunder-ecam.c | 39 +++---------
drivers/pci/host/pci-thunder-pem.c | 92 ++++++++++++++---------------
7 files changed, 113 insertions(+), 237 deletions(-)
delete mode 100644 drivers/pci/host/pci-host-common.h

diff --git a/drivers/pci/ecam.h b/drivers/pci/ecam.h
index 57de00d..1ad2176 100644
--- a/drivers/pci/ecam.h
+++ b/drivers/pci/ecam.h
@@ -59,4 +59,9 @@ void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
/* default ECAM ops, bus shift 20, generic read and write */
extern struct pci_ecam_ops pci_generic_ecam_ops;

+#ifdef CONFIG_PCI_HOST_GENERIC
+/* for DT based pci controllers that support ECAM */
+int pci_host_common_probe(struct platform_device *pdev,
+ struct pci_ecam_ops *ops);
+#endif
#endif
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 7a0780d..963300d 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -77,6 +77,7 @@ config PCI_RCAR_GEN2_PCIE

config PCI_HOST_COMMON
bool
+ select PCI_ECAM

config PCI_HOST_GENERIC
bool "Generic PCI host controller"
diff --git a/drivers/pci/host/pci-host-common.c b/drivers/pci/host/pci-host-common.c
index e9f850f..8cba7ab 100644
--- a/drivers/pci/host/pci-host-common.c
+++ b/drivers/pci/host/pci-host-common.c
@@ -22,27 +22,21 @@
#include <linux/of_pci.h>
#include <linux/platform_device.h>

-#include "pci-host-common.h"
+#include "../ecam.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)
+static int gen_pci_parse_request_of_pci_ranges(struct device *dev,
+ struct list_head *resources, struct resource **bus_range)
{
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);
+ err = of_pci_get_host_bridge_resources(np, 0, 0xff, resources, &iobase);
if (err)
return err;

- resource_list_for_each_entry(win, &pci->resources) {
+ resource_list_for_each_entry(win, resources) {
struct resource *parent, *res = win->res;

switch (resource_type(res)) {
@@ -60,7 +54,7 @@ static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
res_valid |= !(res->flags & IORESOURCE_PREFETCH);
break;
case IORESOURCE_BUS:
- pci->cfg.bus_range = res;
+ *bus_range = res;
default:
continue;
}
@@ -79,65 +73,60 @@ static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
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)
+static void gen_pci_unmap_cfg(void *ptr)
+{
+ pci_ecam_free((struct pci_config_window *)ptr);
+}
+
+static struct pci_config_window *gen_pci_init(struct device *dev,
+ struct list_head *resources, struct pci_ecam_ops *ops)
{
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;
+ struct resource cfgres;
+ struct resource *bus_range = NULL;
+ struct pci_config_window *cfg;

- err = of_address_to_resource(np, 0, &pci->cfg.res);
+ /* Parse our PCI ranges and request their resources */
+ err = gen_pci_parse_request_of_pci_ranges(dev, resources, &bus_range);
+ if (err)
+ goto err_out;
+
+ err = of_address_to_resource(dev->of_node, 0, &cfgres);
if (err) {
dev_err(dev, "missing \"reg\" property\n");
- return err;
+ goto err_out;
}

- /* 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;
+ cfg = pci_ecam_create(dev, &cfgres, bus_range, ops);
+ if (IS_ERR(cfg)) {
+ err = PTR_ERR(cfg);
+ goto err_out;
}

- return 0;
+ err = devm_add_action(dev, gen_pci_unmap_cfg, cfg);
+ if (err) {
+ gen_pci_unmap_cfg(cfg);
+ goto err_out;
+ }
+ return cfg;
+
+err_out:
+ pci_free_resource_list(resources);
+ return ERR_PTR(err);
}

int pci_host_common_probe(struct platform_device *pdev,
- struct gen_pci *pci)
+ struct pci_ecam_ops *ops)
{
- int err;
const char *type;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct pci_bus *bus, *child;
+ struct pci_config_window *cfg;
+ struct list_head resources;

type = of_get_property(np, "device_type", NULL);
if (!type || strcmp(type, "pci")) {
@@ -147,29 +136,18 @@ int pci_host_common_probe(struct platform_device *pdev,

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;
- }
+ INIT_LIST_HEAD(&resources);
+ cfg = gen_pci_init(dev, &resources, ops);
+ if (IS_ERR(cfg))
+ return PTR_ERR(cfg);

/* 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);
+ bus = pci_scan_root_bus(dev, cfg->busr.start, &ops->pci_ops, cfg,
+ &resources);
if (!bus) {
dev_err(dev, "Scanning rootbus failed");
return -ENODEV;
diff --git a/drivers/pci/host/pci-host-common.h b/drivers/pci/host/pci-host-common.h
deleted file mode 100644
index 09f3fa0..0000000
--- a/drivers/pci/host/pci-host-common.h
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * 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@xxxxxxx>
- */
-
-#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;
-};
-
-struct gen_pci {
- 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 e8aa78f..6eaceab 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -25,41 +25,12 @@
#include <linux/of_pci.h>
#include <linux/platform_device.h>

-#include "pci-host-common.h"
+#include "../ecam.h"

-static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
- unsigned int devfn,
- int where)
-{
- struct gen_pci *pci = bus->sysdata;
- resource_size_t idx = bus->number - pci->cfg.bus_range->start;
-
- return pci->cfg.win[idx] + ((devfn << 8) | where);
-}
-
-static struct gen_pci_cfg_bus_ops gen_pci_cfg_cam_bus_ops = {
+static struct pci_ecam_ops gen_pci_cfg_cam_bus_ops = {
.bus_shift = 16,
- .ops = {
- .map_bus = gen_pci_map_cfg_bus_cam,
- .read = pci_generic_config_read,
- .write = pci_generic_config_write,
- }
-};
-
-static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
- unsigned int devfn,
- int where)
-{
- struct gen_pci *pci = bus->sysdata;
- resource_size_t idx = bus->number - pci->cfg.bus_range->start;
-
- return pci->cfg.win[idx] + ((devfn << 12) | where);
-}
-
-static struct gen_pci_cfg_bus_ops gen_pci_cfg_ecam_bus_ops = {
- .bus_shift = 20,
- .ops = {
- .map_bus = gen_pci_map_cfg_bus_ecam,
+ .pci_ops = {
+ .map_bus = pci_ecam_map_bus,
.read = pci_generic_config_read,
.write = pci_generic_config_write,
}
@@ -70,25 +41,22 @@ static const struct of_device_id gen_pci_of_match[] = {
.data = &gen_pci_cfg_cam_bus_ops },

{ .compatible = "pci-host-ecam-generic",
- .data = &gen_pci_cfg_ecam_bus_ops },
+ .data = &pci_generic_ecam_ops },

{ },
};
+
MODULE_DEVICE_TABLE(of, gen_pci_of_match);

static int gen_pci_probe(struct platform_device *pdev)
{
- struct device *dev = &pdev->dev;
const struct of_device_id *of_id;
- struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
-
- if (!pci)
- return -ENOMEM;
+ struct pci_ecam_ops *ops;

- of_id = of_match_node(gen_pci_of_match, dev->of_node);
- pci->cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
+ of_id = of_match_node(gen_pci_of_match, pdev->dev.of_node);
+ ops = (struct pci_ecam_ops *)of_id->data;

- return pci_host_common_probe(pdev, pci);
+ return pci_host_common_probe(pdev, ops);
}

static struct platform_driver gen_pci_driver = {
diff --git a/drivers/pci/host/pci-thunder-ecam.c b/drivers/pci/host/pci-thunder-ecam.c
index d71935cb..540d030 100644
--- a/drivers/pci/host/pci-thunder-ecam.c
+++ b/drivers/pci/host/pci-thunder-ecam.c
@@ -13,18 +13,7 @@
#include <linux/of.h>
#include <linux/platform_device.h>

-#include "pci-host-common.h"
-
-/* Mapping is standard ECAM */
-static void __iomem *thunder_ecam_map_bus(struct pci_bus *bus,
- unsigned int devfn,
- int where)
-{
- struct gen_pci *pci = bus->sysdata;
- resource_size_t idx = bus->number - pci->cfg.bus_range->start;
-
- return pci->cfg.win[idx] + ((devfn << 12) | where);
-}
+#include "../ecam.h"

static void set_val(u32 v, int where, int size, u32 *val)
{
@@ -99,7 +88,7 @@ static int handle_ea_bar(u32 e0, int bar, struct pci_bus *bus,
static int thunder_ecam_p2_config_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
- struct gen_pci *pci = bus->sysdata;
+ struct pci_config_window *cfg = bus->sysdata;
int where_a = where & ~3;
void __iomem *addr;
u32 node_bits;
@@ -129,7 +118,7 @@ static int thunder_ecam_p2_config_read(struct pci_bus *bus, unsigned int devfn,
* the config space access window. Since we are working with
* the high-order 32 bits, shift everything down by 32 bits.
*/
- node_bits = (pci->cfg.res.start >> 32) & (1 << 12);
+ node_bits = (cfg->res.start >> 32) & (1 << 12);

v |= node_bits;
set_val(v, where, size, val);
@@ -358,36 +347,24 @@ static int thunder_ecam_config_write(struct pci_bus *bus, unsigned int devfn,
return pci_generic_config_write(bus, devfn, where, size, val);
}

-static struct gen_pci_cfg_bus_ops thunder_ecam_bus_ops = {
+static struct pci_ecam_ops pci_thunder_ecam_ops = {
.bus_shift = 20,
- .ops = {
- .map_bus = thunder_ecam_map_bus,
+ .pci_ops = {
+ .map_bus = pci_ecam_map_bus,
.read = thunder_ecam_config_read,
.write = thunder_ecam_config_write,
}
};

static const struct of_device_id thunder_ecam_of_match[] = {
- { .compatible = "cavium,pci-host-thunder-ecam",
- .data = &thunder_ecam_bus_ops },
-
+ { .compatible = "cavium,pci-host-thunder-ecam" },
{ },
};
MODULE_DEVICE_TABLE(of, thunder_ecam_of_match);

static int thunder_ecam_probe(struct platform_device *pdev)
{
- struct device *dev = &pdev->dev;
- const struct of_device_id *of_id;
- struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
-
- if (!pci)
- return -ENOMEM;
-
- of_id = of_match_node(thunder_ecam_of_match, dev->of_node);
- pci->cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
-
- return pci_host_common_probe(pdev, pci);
+ return pci_host_common_probe(pdev, &pci_thunder_ecam_ops);
}

static struct platform_driver thunder_ecam_driver = {
diff --git a/drivers/pci/host/pci-thunder-pem.c b/drivers/pci/host/pci-thunder-pem.c
index cabb92a..a7b61ce 100644
--- a/drivers/pci/host/pci-thunder-pem.c
+++ b/drivers/pci/host/pci-thunder-pem.c
@@ -20,34 +20,22 @@
#include <linux/of_pci.h>
#include <linux/platform_device.h>

-#include "pci-host-common.h"
+#include "../ecam.h"

#define PEM_CFG_WR 0x28
#define PEM_CFG_RD 0x30

struct thunder_pem_pci {
- struct gen_pci gen_pci;
u32 ea_entry[3];
void __iomem *pem_reg_base;
};

-static void __iomem *thunder_pem_map_bus(struct pci_bus *bus,
- unsigned int devfn, int where)
-{
- struct gen_pci *pci = bus->sysdata;
- resource_size_t idx = bus->number - pci->cfg.bus_range->start;
-
- return pci->cfg.win[idx] + ((devfn << 16) | where);
-}
-
static int thunder_pem_bridge_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
u64 read_val;
- struct thunder_pem_pci *pem_pci;
- struct gen_pci *pci = bus->sysdata;
-
- pem_pci = container_of(pci, struct thunder_pem_pci, gen_pci);
+ struct pci_config_window *cfg = bus->sysdata;
+ struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;

if (devfn != 0 || where >= 2048) {
*val = ~0;
@@ -132,17 +120,17 @@ static int thunder_pem_bridge_read(struct pci_bus *bus, unsigned int devfn,
static int thunder_pem_config_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
- struct gen_pci *pci = bus->sysdata;
+ struct pci_config_window *cfg = bus->sysdata;

- if (bus->number < pci->cfg.bus_range->start ||
- bus->number > pci->cfg.bus_range->end)
+ if (bus->number < cfg->busr.start ||
+ bus->number > cfg->busr.end)
return PCIBIOS_DEVICE_NOT_FOUND;

/*
* The first device on the bus is the PEM PCIe bridge.
* Special case its config access.
*/
- if (bus->number == pci->cfg.bus_range->start)
+ if (bus->number == cfg->busr.start)
return thunder_pem_bridge_read(bus, devfn, where, size, val);

return pci_generic_config_read(bus, devfn, where, size, val);
@@ -187,12 +175,11 @@ static u32 thunder_pem_bridge_w1c_bits(int where)
static int thunder_pem_bridge_write(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
- struct gen_pci *pci = bus->sysdata;
- struct thunder_pem_pci *pem_pci;
+ struct pci_config_window *cfg = bus->sysdata;
+ struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
u64 write_val, read_val;
u32 mask = 0;

- pem_pci = container_of(pci, struct thunder_pem_pci, gen_pci);

if (devfn != 0 || where >= 2048)
return PCIBIOS_DEVICE_NOT_FOUND;
@@ -256,53 +243,38 @@ static int thunder_pem_bridge_write(struct pci_bus *bus, unsigned int devfn,
static int thunder_pem_config_write(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
- struct gen_pci *pci = bus->sysdata;
+ struct pci_config_window *cfg = bus->sysdata;

- if (bus->number < pci->cfg.bus_range->start ||
- bus->number > pci->cfg.bus_range->end)
+ if (bus->number < cfg->busr.start ||
+ bus->number > cfg->busr.end)
return PCIBIOS_DEVICE_NOT_FOUND;
/*
* The first device on the bus is the PEM PCIe bridge.
* Special case its config access.
*/
- if (bus->number == pci->cfg.bus_range->start)
+ if (bus->number == cfg->busr.start)
return thunder_pem_bridge_write(bus, devfn, where, size, val);


return pci_generic_config_write(bus, devfn, where, size, val);
}

-static struct gen_pci_cfg_bus_ops thunder_pem_bus_ops = {
- .bus_shift = 24,
- .ops = {
- .map_bus = thunder_pem_map_bus,
- .read = thunder_pem_config_read,
- .write = thunder_pem_config_write,
- }
-};
-
-static const struct of_device_id thunder_pem_of_match[] = {
- { .compatible = "cavium,pci-host-thunder-pem",
- .data = &thunder_pem_bus_ops },
-
- { },
-};
-MODULE_DEVICE_TABLE(of, thunder_pem_of_match);
-
-static int thunder_pem_probe(struct platform_device *pdev)
+static int thunder_pem_init(struct device *dev, struct pci_config_window *cfg)
{
- struct device *dev = &pdev->dev;
- const struct of_device_id *of_id;
resource_size_t bar4_start;
struct resource *res_pem;
struct thunder_pem_pci *pem_pci;
+ struct platform_device *pdev;
+
+ /* Only OF support for now */
+ if (!dev->of_node)
+ return -EINVAL;

pem_pci = devm_kzalloc(dev, sizeof(*pem_pci), GFP_KERNEL);
if (!pem_pci)
return -ENOMEM;

- of_id = of_match_node(thunder_pem_of_match, dev->of_node);
- pem_pci->gen_pci.cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
+ pdev = to_platform_device(dev);

/*
* The second register range is the PEM bridge to the PCIe
@@ -330,7 +302,29 @@ static int thunder_pem_probe(struct platform_device *pdev)
pem_pci->ea_entry[1] = (u32)(res_pem->end - bar4_start) & ~3u;
pem_pci->ea_entry[2] = (u32)(bar4_start >> 32);

- return pci_host_common_probe(pdev, &pem_pci->gen_pci);
+ cfg->priv = pem_pci;
+ return 0;
+}
+
+static struct pci_ecam_ops pci_thunder_pem_ops = {
+ .bus_shift = 24,
+ .init = thunder_pem_init,
+ .pci_ops = {
+ .map_bus = pci_ecam_map_bus,
+ .read = thunder_pem_config_read,
+ .write = thunder_pem_config_write,
+ }
+};
+
+static const struct of_device_id thunder_pem_of_match[] = {
+ { .compatible = "cavium,pci-host-thunder-pem" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, thunder_pem_of_match);
+
+static int thunder_pem_probe(struct platform_device *pdev)
+{
+ return pci_host_common_probe(pdev, &pci_thunder_pem_ops);
}

static struct platform_driver thunder_pem_driver = {
--
1.9.1