[PATCH RFC 2/2] drivers: pci: convert generic host controller to DT resource parsing API
Will Deacon
will.deacon at arm.com
Mon Oct 27 05:03:35 PDT 2014
On Thu, Oct 23, 2014 at 04:23:07PM +0100, Lorenzo Pieralisi wrote:
> In order to consolidate DT configuration for PCI host controllers in the
> kernel, a new API (ie of_pci_get_host_bridge_resources()) was developed
> to allow parsing and assigning IO/BUS/MEM resources from DT, removing
> duplicated code present in the majority of pci host driver implementations.
>
> This patch converts the existing PCI generic host controller driver to
> the new API. Most of the code parsing ranges and creating resources is
> now delegated to of_pci_get_host_bridge_resources() API.
>
> The PCI host controller code carries out resources filtering on the
> resulting resource list and maps IO space by using the newly introduced
> pci_ioremap_iospace() API.
>
> New code supports only one IO resource per generic host controller, which
> should cater for all existing host controller configurations.
>
> Cc: Arnd Bergmann <arnd at arndb.de>
> Cc: Will Deacon <will.deacon at arm.com>
> Cc: Bjorn Helgaas <bhelgaas at google.com>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
> ---
> drivers/pci/host/pci-host-generic.c | 120 ++++++++----------------------------
> 1 file changed, 27 insertions(+), 93 deletions(-)
Looks fine to me -- I assume you tested this under a 32-bit kernel?
Acked-by: Will Deacon <will.deacon at arm.com>
Will
> diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
> index 1e1a80f..1895907 100644
> --- a/drivers/pci/host/pci-host-generic.c
> +++ b/drivers/pci/host/pci-host-generic.c
> @@ -32,7 +32,7 @@ struct gen_pci_cfg_bus_ops {
>
> struct gen_pci_cfg_windows {
> struct resource res;
> - struct resource bus_range;
> + struct resource *bus_range;
> void __iomem **win;
>
> const struct gen_pci_cfg_bus_ops *ops;
> @@ -50,7 +50,7 @@ static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
> {
> struct pci_sys_data *sys = bus->sysdata;
> struct gen_pci *pci = sys->private_data;
> - resource_size_t idx = bus->number - pci->cfg.bus_range.start;
> + resource_size_t idx = bus->number - pci->cfg.bus_range->start;
>
> return pci->cfg.win[idx] + ((devfn << 8) | where);
> }
> @@ -66,7 +66,7 @@ static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
> {
> struct pci_sys_data *sys = bus->sysdata;
> struct gen_pci *pci = sys->private_data;
> - resource_size_t idx = bus->number - pci->cfg.bus_range.start;
> + resource_size_t idx = bus->number - pci->cfg.bus_range->start;
>
> return pci->cfg.win[idx] + ((devfn << 12) | where);
> }
> @@ -138,106 +138,50 @@ static const struct of_device_id gen_pci_of_match[] = {
> };
> MODULE_DEVICE_TABLE(of, gen_pci_of_match);
>
> -static int gen_pci_calc_io_offset(struct device *dev,
> - struct of_pci_range *range,
> - struct resource *res,
> - resource_size_t *offset)
> -{
> - static atomic_t wins = ATOMIC_INIT(0);
> - int err, idx, max_win;
> - unsigned int window;
> -
> - if (!PAGE_ALIGNED(range->cpu_addr))
> - return -EINVAL;
> -
> - max_win = (IO_SPACE_LIMIT + 1) / SZ_64K;
> - idx = atomic_inc_return(&wins);
> - if (idx > max_win)
> - return -ENOSPC;
> -
> - window = (idx - 1) * SZ_64K;
> - err = pci_ioremap_io(window, range->cpu_addr);
> - if (err)
> - return err;
> -
> - of_pci_range_to_resource(range, dev->of_node, res);
> - res->start = window;
> - res->end = res->start + range->size - 1;
> - *offset = window - range->pci_addr;
> - return 0;
> -}
> -
> -static int gen_pci_calc_mem_offset(struct device *dev,
> - struct of_pci_range *range,
> - struct resource *res,
> - resource_size_t *offset)
> -{
> - of_pci_range_to_resource(range, dev->of_node, res);
> - *offset = range->cpu_addr - range->pci_addr;
> - return 0;
> -}
> -
> static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
> {
> - struct pci_host_bridge_window *win;
> -
> - list_for_each_entry(win, &pci->resources, list)
> - release_resource(win->res);
> -
> pci_free_resource_list(&pci->resources);
> }
>
> static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
> {
> - struct of_pci_range range;
> - struct of_pci_range_parser parser;
> int err, res_valid = 0;
> struct device *dev = pci->host.dev.parent;
> struct device_node *np = dev->of_node;
> + resource_size_t iobase;
> + struct pci_host_bridge_window *win;
>
> - if (of_pci_range_parser_init(&parser, np)) {
> - dev_err(dev, "missing \"ranges\" property\n");
> - return -EINVAL;
> - }
> + err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources,
> + &iobase);
> + if (err)
> + return err;
>
> - for_each_of_pci_range(&parser, &range) {
> - struct resource *parent, *res;
> - resource_size_t offset;
> - u32 restype = range.flags & IORESOURCE_TYPE_BITS;
> + list_for_each_entry(win, &pci->resources, list) {
> + struct resource *parent, *res = win->res;
>
> - res = devm_kmalloc(dev, sizeof(*res), GFP_KERNEL);
> - if (!res) {
> - err = -ENOMEM;
> - goto out_release_res;
> - }
> -
> - switch (restype) {
> + switch (resource_type(res)) {
> case IORESOURCE_IO:
> parent = &ioport_resource;
> - err = gen_pci_calc_io_offset(dev, &range, res, &offset);
> + 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;
> - err = gen_pci_calc_mem_offset(dev, &range, res, &offset);
> - res_valid |= !(res->flags & IORESOURCE_PREFETCH || err);
> + res_valid |= !(res->flags & IORESOURCE_PREFETCH);
> break;
> + case IORESOURCE_BUS:
> + pci->cfg.bus_range = res;
> default:
> - err = -EINVAL;
> continue;
> }
>
> - if (err) {
> - dev_warn(dev,
> - "error %d: failed to add resource [type 0x%x, %lld bytes]\n",
> - err, restype, range.size);
> - continue;
> - }
> -
> - err = request_resource(parent, res);
> + err = devm_request_resource(dev, parent, res);
> if (err)
> goto out_release_res;
> -
> - pci_add_resource_offset(&pci->resources, res, offset);
> }
>
> if (!res_valid) {
> @@ -262,14 +206,6 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
> struct device *dev = pci->host.dev.parent;
> struct device_node *np = dev->of_node;
>
> - if (of_pci_parse_bus_range(np, &pci->cfg.bus_range))
> - pci->cfg.bus_range = (struct resource) {
> - .name = np->name,
> - .start = 0,
> - .end = 0xff,
> - .flags = IORESOURCE_BUS,
> - };
> -
> err = of_address_to_resource(np, 0, &pci->cfg.res);
> if (err) {
> dev_err(dev, "missing \"reg\" property\n");
> @@ -277,12 +213,12 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
> }
>
> /* Limit the bus-range to fit within reg */
> - bus_max = pci->cfg.bus_range.start +
> + 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.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),
> + pci->cfg.win = devm_kcalloc(dev, resource_size(pci->cfg.bus_range),
> sizeof(*pci->cfg.win), GFP_KERNEL);
> if (!pci->cfg.win)
> return -ENOMEM;
> @@ -293,7 +229,7 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
> "Configuration Space"))
> return -ENOMEM;
>
> - bus_range = &pci->cfg.bus_range;
> + bus_range = pci->cfg.bus_range;
> for (busn = bus_range->start; busn <= bus_range->end; ++busn) {
> u32 idx = busn - bus_range->start;
> u32 sz = 1 << pci->cfg.ops->bus_shift;
> @@ -305,8 +241,6 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
> return -ENOMEM;
> }
>
> - /* Register bus resource */
> - pci_add_resource(&pci->resources, bus_range);
> return 0;
> }
>
> --
> 2.1.2
>
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