Re: [PATCH V7 03/11] pci, of: Move the PCI I/O space management to PCI core code.

["Rafael J. Wysocki" <rafael@kernel.org>]

On Tue, May 10, 2016 at 5:19 PM, Tomasz Nowicki <tn@semihalf.com> wrote:
> No functional changes in this patch.
>
> PCI I/O space mapping code does not depend on OF, therefore it can be
> moved to PCI core code. This way we will be able to use it
> e.g. in ACPI PCI code.
>
> Suggested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
> CC: Arnd Bergmann <arnd@arndb.de>
> CC: Liviu Dudau <Liviu.Dudau@arm.com>
> ---
>  drivers/of/address.c       | 116 +--------------------------------------------
>  drivers/pci/pci.c          | 115 ++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/of_address.h |   9 ----
>  include/linux/pci.h        |   5 ++
>  4 files changed, 121 insertions(+), 124 deletions(-)
>
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 91a469d..0a553c0 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -4,6 +4,7 @@
>  #include <linux/ioport.h>
>  #include <linux/module.h>
>  #include <linux/of_address.h>
> +#include <linux/pci.h>
>  #include <linux/pci_regs.h>
>  #include <linux/sizes.h>
>  #include <linux/slab.h>
> @@ -673,121 +674,6 @@ const __be32 *of_get_address(struct device_node *dev, int index, u64 *size,
>  }
>  EXPORT_SYMBOL(of_get_address);
>
> -#ifdef PCI_IOBASE
> -struct io_range {
> -       struct list_head list;
> -       phys_addr_t start;
> -       resource_size_t size;
> -};
> -
> -static LIST_HEAD(io_range_list);
> -static DEFINE_SPINLOCK(io_range_lock);
> -#endif
> -
> -/*
> - * Record the PCI IO range (expressed as CPU physical address + size).
> - * Return a negative value if an error has occured, zero otherwise
> - */
> -int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
> -{
> -       int err = 0;
> -
> -#ifdef PCI_IOBASE
> -       struct io_range *range;
> -       resource_size_t allocated_size = 0;
> -
> -       /* check if the range hasn't been previously recorded */
> -       spin_lock(&io_range_lock);
> -       list_for_each_entry(range, &io_range_list, list) {
> -               if (addr >= range->start && addr + size <= range->start + size) {
> -                       /* range already registered, bail out */
> -                       goto end_register;
> -               }
> -               allocated_size += range->size;
> -       }
> -
> -       /* range not registed yet, check for available space */
> -       if (allocated_size + size - 1 > IO_SPACE_LIMIT) {
> -               /* if it's too big check if 64K space can be reserved */
> -               if (allocated_size + SZ_64K - 1 > IO_SPACE_LIMIT) {
> -                       err = -E2BIG;
> -                       goto end_register;
> -               }
> -
> -               size = SZ_64K;
> -               pr_warn("Requested IO range too big, new size set to 64K\n");
> -       }
> -
> -       /* add the range to the list */
> -       range = kzalloc(sizeof(*range), GFP_ATOMIC);
> -       if (!range) {
> -               err = -ENOMEM;
> -               goto end_register;
> -       }
> -
> -       range->start = addr;
> -       range->size = size;
> -
> -       list_add_tail(&range->list, &io_range_list);
> -
> -end_register:
> -       spin_unlock(&io_range_lock);
> -#endif
> -
> -       return err;
> -}
> -
> -phys_addr_t pci_pio_to_address(unsigned long pio)
> -{
> -       phys_addr_t address = (phys_addr_t)OF_BAD_ADDR;
> -
> -#ifdef PCI_IOBASE
> -       struct io_range *range;
> -       resource_size_t allocated_size = 0;
> -
> -       if (pio > IO_SPACE_LIMIT)
> -               return address;
> -
> -       spin_lock(&io_range_lock);
> -       list_for_each_entry(range, &io_range_list, list) {
> -               if (pio >= allocated_size && pio < allocated_size + range->size) {
> -                       address = range->start + pio - allocated_size;
> -                       break;
> -               }
> -               allocated_size += range->size;
> -       }
> -       spin_unlock(&io_range_lock);
> -#endif
> -
> -       return address;
> -}
> -
> -unsigned long __weak pci_address_to_pio(phys_addr_t address)
> -{
> -#ifdef PCI_IOBASE
> -       struct io_range *res;
> -       resource_size_t offset = 0;
> -       unsigned long addr = -1;
> -
> -       spin_lock(&io_range_lock);
> -       list_for_each_entry(res, &io_range_list, list) {
> -               if (address >= res->start && address < res->start + res->size) {
> -                       addr = address - res->start + offset;
> -                       break;
> -               }
> -               offset += res->size;
> -       }
> -       spin_unlock(&io_range_lock);
> -
> -       return addr;
> -#else
> -       if (address > IO_SPACE_LIMIT)
> -               return (unsigned long)-1;
> -
> -       return (unsigned long) address;
> -#endif
> -}
> -
>  static int __of_address_to_resource(struct device_node *dev,
>                 const __be32 *addrp, u64 size, unsigned int flags,
>                 const char *name, struct resource *r)
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 25e0327..bc0c914 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -3021,6 +3021,121 @@ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
>  }
>  EXPORT_SYMBOL(pci_request_regions_exclusive);
>
> +#ifdef PCI_IOBASE
> +struct io_range {
> +       struct list_head list;
> +       phys_addr_t start;
> +       resource_size_t size;
> +};
> +
> +static LIST_HEAD(io_range_list);
> +static DEFINE_SPINLOCK(io_range_lock);
> +#endif
> +
> +/*
> + * Record the PCI IO range (expressed as CPU physical address + size).
> + * Return a negative value if an error has occured, zero otherwise
> + */
> +int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
> +{
> +       int err = 0;
> +
> +#ifdef PCI_IOBASE

I understand that this moves code around, but those in-function
#ifdefs aren't nice.  Any chance to get rid of them but putting whole
functions under the #ifdef?