[RFC PATCH 2/4] PCI: generic,thunder: Use generic config functions

From: Jayachandran C
Date: Thu Mar 17 2016 - 16:34:48 EST

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Use functions provided by pci/ecam.c for mapping config space. The
gen_pci structure is updated to store a pointer to the mapping.

'struct gen_pci_cfg_windows' is no longer needed since the mapping
is handled by generic code and 'struct gen_pci_cfg_bus_ops' can be
removed since bus shift is handled by generic code. The rest of the
data related to generic host controller are moved into 'struct gen_pci'
itself.

The generic code handles the bus and devfn shifts, so a common
function gen_pci_map_cfg_bus() has been added which can be used
as ->map_bus by all users.

With the updated interface, the users have to allocate a gen_pci
instance and setup the bus_shift and pci_ops fields in the structure
before calling pci_host_common_probe().

Update pci-host-common.c, pci-host-generic.c, pci-thunder-ecam.c
and pci-thunder-pem.c to use the new interface.

Also add dependency of PCI_GENERIC_ECAM for PCI_HOST_GENERIC
in Kconfig

Signed-off-by: Jayachandran C <jchandra@xxxxxxxxxxxx>
---
drivers/pci/host/Kconfig | 1 +
drivers/pci/host/pci-host-common.c | 68 +++++++++++++++++++------------------
drivers/pci/host/pci-host-common.h | 25 +++++---------
drivers/pci/host/pci-host-generic.c | 51 +++++-----------------------
drivers/pci/host/pci-thunder-ecam.c | 33 +++++-------------
drivers/pci/host/pci-thunder-pem.c | 41 +++++++---------------
6 files changed, 74 insertions(+), 145 deletions(-)

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index da61fa77..d27b989 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -82,6 +82,7 @@ config PCI_HOST_GENERIC
bool "Generic PCI host controller"
depends on (ARM || ARM64) && OF
select PCI_HOST_COMMON
+ select PCI_GENERIC_ECAM
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/pci-host-common.c b/drivers/pci/host/pci-host-common.c
index e9f850f..d3b0664 100644
--- a/drivers/pci/host/pci-host-common.c
+++ b/drivers/pci/host/pci-host-common.c
@@ -24,6 +24,14 @@

#include "pci-host-common.h"

+void __iomem *gen_pci_map_cfg_bus(struct pci_bus *bus,
+ unsigned int devfn, int where)
+{
+ struct gen_pci *pci = bus->sysdata;
+
+ return pci_generic_map_bus(pci->cfg, bus->number, devfn, where);
+}
+
static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
{
pci_free_resource_list(&pci->resources);
@@ -60,7 +68,7 @@ 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;
+ pci->bus_range = res;
default:
continue;
}
@@ -83,50 +91,44 @@ out_release_res:
return err;
}

+static void gen_pci_generic_unmap_cfg(void *ptr)
+{
+ pci_generic_unmap_config((struct pci_config_window *)ptr);
+}
+
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 resource *cfgres = &pci->cfgres;
+ struct resource *bus_range = pci->bus_range;
+ unsigned int bus_shift = pci->bus_shift;
struct device *dev = pci->host.dev.parent;
struct device_node *np = dev->of_node;
- u32 sz = 1 << pci->cfg.ops->bus_shift;
+ struct pci_config_window *cfg;

- err = of_address_to_resource(np, 0, &pci->cfg.res);
+ err = of_address_to_resource(np, 0, cfgres);
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;
+ bus_range->end = min(bus_range->end,
+ bus_range->start + (resource_size(cfgres) >> bus_shift) - 1);
+
+ cfg = pci_generic_map_config(cfgres->start, bus_range->start,
+ bus_range->end, bus_shift, bus_shift - 8);
+
+ if (IS_ERR(cfg))
+ return PTR_ERR(cfg);
+
+ err = devm_add_action(dev, gen_pci_generic_unmap_cfg, cfg);
+ if (err) {
+ gen_pci_generic_unmap_cfg(cfg);
+ return err;
}

+ pci->cfg = cfg;
return 0;
}

@@ -168,8 +170,8 @@ int pci_host_common_probe(struct platform_device *pdev,
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, pci->bus_range->start,
+ pci->ops, pci, &pci->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
index 09f3fa0..4eb2ff0 100644
--- a/drivers/pci/host/pci-host-common.h
+++ b/drivers/pci/host/pci-host-common.h
@@ -22,26 +22,19 @@
#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;
+ struct pci_host_bridge host;
+ struct resource *bus_range;
+ unsigned int bus_shift;
+ struct resource cfgres;
+ struct pci_config_window *cfg;
+ struct pci_ops *ops;
+ struct list_head resources;
};

int pci_host_common_probe(struct platform_device *pdev,
struct gen_pci *pci);
+void __iomem *gen_pci_map_cfg_bus(struct pci_bus *bus,
+ unsigned int devfn, int where);

#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..7b6cee1 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -27,51 +27,15 @@

#include "pci-host-common.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 = {
- .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,
- .read = pci_generic_config_read,
- .write = pci_generic_config_write,
- }
+static struct pci_ops gen_pci_ops = {
+ .map_bus = gen_pci_map_cfg_bus,
+ .read = pci_generic_config_read,
+ .write = pci_generic_config_write,
};

static const struct of_device_id gen_pci_of_match[] = {
- { .compatible = "pci-host-cam-generic",
- .data = &gen_pci_cfg_cam_bus_ops },
-
- { .compatible = "pci-host-ecam-generic",
- .data = &gen_pci_cfg_ecam_bus_ops },
-
+ { .compatible = "pci-host-cam-generic", .data = (void *)16},
+ { .compatible = "pci-host-ecam-generic", .data = (void *)20},
{ },
};
MODULE_DEVICE_TABLE(of, gen_pci_of_match);
@@ -86,7 +50,8 @@ static int gen_pci_probe(struct platform_device *pdev)
return -ENOMEM;

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->bus_shift = (unsigned long)of_id->data;
+ pci->ops = &gen_pci_ops;

return pci_host_common_probe(pdev, pci);
}
diff --git a/drivers/pci/host/pci-thunder-ecam.c b/drivers/pci/host/pci-thunder-ecam.c
index d71935cb..34714df 100644
--- a/drivers/pci/host/pci-thunder-ecam.c
+++ b/drivers/pci/host/pci-thunder-ecam.c
@@ -15,17 +15,6 @@

#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);
-}
-
static void set_val(u32 v, int where, int size, u32 *val)
{
int shift = (where & 3) * 8;
@@ -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 = (pci->cfgres.start >> 32) & (1 << 12);

v |= node_bits;
set_val(v, where, size, val);
@@ -358,19 +347,14 @@ 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 = {
- .bus_shift = 20,
- .ops = {
- .map_bus = thunder_ecam_map_bus,
- .read = thunder_ecam_config_read,
- .write = thunder_ecam_config_write,
- }
+static struct pci_ops thunder_ecam_pci_ops = {
+ .map_bus = gen_pci_map_cfg_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);
@@ -378,14 +362,13 @@ 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;
+ pci->ops = &thunder_ecam_pci_ops;
+ pci->bus_shift = 20;

return pci_host_common_probe(pdev, pci);
}
diff --git a/drivers/pci/host/pci-thunder-pem.c b/drivers/pci/host/pci-thunder-pem.c
index cabb92a..eb248c1 100644
--- a/drivers/pci/host/pci-thunder-pem.c
+++ b/drivers/pci/host/pci-thunder-pem.c
@@ -31,15 +31,6 @@ struct thunder_pem_pci {
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)
{
@@ -134,15 +125,15 @@ static int thunder_pem_config_read(struct pci_bus *bus, unsigned int devfn,
{
struct gen_pci *pci = bus->sysdata;

- if (bus->number < pci->cfg.bus_range->start ||
- bus->number > pci->cfg.bus_range->end)
+ if (bus->number < pci->bus_range->start ||
+ bus->number > pci->bus_range->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 == pci->bus_range->start)
return thunder_pem_bridge_read(bus, devfn, where, size, val);

return pci_generic_config_read(bus, devfn, where, size, val);
@@ -258,33 +249,28 @@ static int thunder_pem_config_write(struct pci_bus *bus, unsigned int devfn,
{
struct gen_pci *pci = bus->sysdata;

- if (bus->number < pci->cfg.bus_range->start ||
- bus->number > pci->cfg.bus_range->end)
+ if (bus->number < pci->bus_range->start ||
+ bus->number > pci->bus_range->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 == pci->bus_range->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 struct pci_ops thunder_pem_pci_ops = {
+ .map_bus = gen_pci_map_cfg_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 },
-
+ { .compatible = "cavium,pci-host-thunder-pem" },
{ },
};
MODULE_DEVICE_TABLE(of, thunder_pem_of_match);
@@ -292,7 +278,6 @@ MODULE_DEVICE_TABLE(of, thunder_pem_of_match);
static int thunder_pem_probe(struct platform_device *pdev)
{
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;
@@ -301,8 +286,8 @@ static int thunder_pem_probe(struct platform_device *pdev)
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;
+ pem_pci->gen_pci.ops = &thunder_pem_pci_ops;
+ pem_pci->gen_pci.bus_shift = 24;

/*
* The second register range is the PEM bridge to the PCIe
--
1.9.1

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