Re: [PATCH v4 3/5] PCI: generic: Quit clobbering our pci_ops.

From: Bjorn Helgaas
Date: Thu Oct 08 2015 - 11:02:23 EST


[+cc Arnd]

Arnd, you had comments on the previous version. What do you think of
this one?

On Fri, Oct 02, 2015 at 11:44:01AM -0700, David Daney wrote:
> From: David Daney <david.daney@xxxxxxxxxx>
>
> The pci-host-generic driver keeps a global struct pci_ops which it
> then patches with the .map_bus method appropriate for the bus device.
> A problem arises when the driver is used for two different types of
> bus devices, the .map_bus method for the last device probed clobbers
> the method for all previous devices. The result, only the last bus
> device probed has the proper .map_bus, and the others fail.
>
> Move the struct pci_ops into the bus specific structure, and
> initialize a pointer to it when the bus device is probed.
>
> Acked-by: Will Deacon <will.deacon@xxxxxxx>
> Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
> ---
> Change from v3: Use pointer to ops rather than make a copy.
>
> drivers/pci/host/pci-host-generic.c | 27 +++++++++++++++------------
> 1 file changed, 15 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
> index 9e9f1c3..216ded5 100644
> --- a/drivers/pci/host/pci-host-generic.c
> +++ b/drivers/pci/host/pci-host-generic.c
> @@ -27,7 +27,7 @@
>
> struct gen_pci_cfg_bus_ops {
> u32 bus_shift;
> - void __iomem *(*map_bus)(struct pci_bus *, unsigned int, int);
> + struct pci_ops ops;
> };
>
> struct gen_pci_cfg_windows {
> @@ -35,7 +35,7 @@ struct gen_pci_cfg_windows {
> struct resource *bus_range;
> void __iomem **win;
>
> - const struct gen_pci_cfg_bus_ops *ops;
> + struct gen_pci_cfg_bus_ops *ops;
> };
>
> /*
> @@ -65,7 +65,11 @@ static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
>
> static struct gen_pci_cfg_bus_ops gen_pci_cfg_cam_bus_ops = {
> .bus_shift = 16,
> - .map_bus = gen_pci_map_cfg_bus_cam,
> + .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,
> @@ -80,12 +84,11 @@ static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
>
> static struct gen_pci_cfg_bus_ops gen_pci_cfg_ecam_bus_ops = {
> .bus_shift = 20,
> - .map_bus = gen_pci_map_cfg_bus_ecam,
> -};
> -
> -static struct pci_ops gen_pci_ops = {
> - .read = pci_generic_config_read,
> - .write = pci_generic_config_write,
> + .ops = {
> + .map_bus = gen_pci_map_cfg_bus_ecam,
> + .read = pci_generic_config_read,
> + .write = pci_generic_config_write,
> + }
> };
>
> static const struct of_device_id gen_pci_of_match[] = {
> @@ -234,8 +237,7 @@ static int gen_pci_probe(struct platform_device *pdev)
> }
>
> of_id = of_match_node(gen_pci_of_match, np);
> - pci->cfg.ops = of_id->data;
> - gen_pci_ops.map_bus = pci->cfg.ops->map_bus;
> + 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);
> @@ -256,7 +258,8 @@ static int gen_pci_probe(struct platform_device *pdev)
> if (!pci_has_flag(PCI_PROBE_ONLY))
> pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
>
> - bus = pci_scan_root_bus(dev, 0, &gen_pci_ops, pci, &pci->resources);
> + bus = pci_scan_root_bus(dev, 0,
> + &pci->cfg.ops->ops, pci, &pci->resources);
> if (!bus) {
> dev_err(dev, "Scanning rootbus failed");
> return -ENODEV;
> --
> 1.9.1
>
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