Re: [PATCH V6 2/5] PCI: Adapt pci_register_io_range() for indirect-IO and PCI I/O translation

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

On Thu, Feb 2, 2017 at 6:36 PM, John Garry <john.garry@huawei.com> wrote:
> Hi Rafael,
>
> Could you kindly check the minor changes to drivers/acpi/pci_root.c?  It
> would also be appreciated if you could review the ACPI-relevant parts in
> lib/extio.c, in [PATCH V5 5/5] LPC: Add the ACPI LPC support

If you want patches to be reviewed from the ACPI perspective, please
CC them to linux-acpi.  I'm not the only person who may be interested
in them.

The change is pci_root.c looks OK to me, but it's Bjorn's call anyway.

Thanks,
Rafael



> On 24/01/2017 07:05, zhichang.yuan wrote:
>>
>> After indirect-IO is introduced, system must can assigned indirect-IO
>> devices
>> with logical I/O ranges which are different from those for PCI I/O
>> devices.
>> Otherwise, I/O accessors can't identify whether the I/O port is for memory
>> mapped I/O or indirect-IO.
>> As current helper, pci_register_io_range(), is used for PCI I/O ranges
>> registration and translation, indirect-IO devices should also apply these
>> helpers to manage the I/O ranges. It will be easy to ensure the assigned
>> logical I/O ranges unique.
>> But for indirect-IO devices, there is no cpu address. The current
>> pci_register_io_range() can not work for this case.
>>
>> This patch makes some changes on the pci_register_io_range() to support
>> the
>> I/O range registration with device's fwnode also. After this, the
>> indirect-IO
>> devices can register the device-local I/O range to system logical I/O and
>> easily perform the translation between device-local I/O range and sytem
>> logical I/O range.
>>
>> Signed-off-by: zhichang.yuan <yuanzhichang@hisilicon.com>
>> Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.com>
>> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>> ---
>>  drivers/acpi/pci_root.c | 12 +++++-------
>>  drivers/of/address.c    |  8 ++------
>>  drivers/pci/pci.c       | 44 ++++++++++++++++++++++++++++++++++++++++----
>>  include/linux/pci.h     |  7 +++++--
>>  4 files changed, 52 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
>> index bf601d4..6cadf05 100644
>> --- a/drivers/acpi/pci_root.c
>> +++ b/drivers/acpi/pci_root.c
>> @@ -730,7 +730,8 @@ static void acpi_pci_root_validate_resources(struct
>> device *dev,
>>         }
>>  }
>>
>> -static void acpi_pci_root_remap_iospace(struct resource_entry *entry)
>> +static void acpi_pci_root_remap_iospace(struct fwnode_handle *node,
>> +                                       struct resource_entry *entry)
>>  {
>>  #ifdef PCI_IOBASE
>>         struct resource *res = entry->res;
>> @@ -739,11 +740,7 @@ static void acpi_pci_root_remap_iospace(struct
>> resource_entry *entry)
>>         resource_size_t length = resource_size(res);
>>         unsigned long port;
>>
>> -       if (pci_register_io_range(cpu_addr, length))
>> -               goto err;
>> -
>> -       port = pci_address_to_pio(cpu_addr);
>> -       if (port == (unsigned long)-1)
>> +       if (pci_register_io_range(node, cpu_addr, length, &port))
>>                 goto err;
>>
>>         res->start = port;
>> @@ -781,7 +778,8 @@ int acpi_pci_probe_root_resources(struct
>> acpi_pci_root_info *info)
>>         else {
>>                 resource_list_for_each_entry_safe(entry, tmp, list) {
>>                         if (entry->res->flags & IORESOURCE_IO)
>> -                               acpi_pci_root_remap_iospace(entry);
>> +
>> acpi_pci_root_remap_iospace(&device->fwnode,
>> +                                                           entry);
>>
>>                         if (entry->res->flags & IORESOURCE_DISABLED)
>>                                 resource_list_destroy_entry(entry);
>> diff --git a/drivers/of/address.c b/drivers/of/address.c
>> index 02b2903..d85d228 100644
>> --- a/drivers/of/address.c
>> +++ b/drivers/of/address.c
>> @@ -2,6 +2,7 @@
>>  #define pr_fmt(fmt)    "OF: " fmt
>>
>>  #include <linux/device.h>
>> +#include <linux/fwnode.h>
>>  #include <linux/io.h>
>>  #include <linux/ioport.h>
>>  #include <linux/module.h>
>> @@ -323,14 +324,9 @@ int of_pci_range_to_resource(struct of_pci_range
>> *range,
>>
>>         if (res->flags & IORESOURCE_IO) {
>>                 unsigned long port;
>> -               err = pci_register_io_range(range->cpu_addr, range->size);
>> +               err = pci_register_io_range(&np->fwnode, range->cpu_addr,
>> range->size, &port);
>>                 if (err)
>>                         goto invalid_range;
>> -               port = pci_address_to_pio(range->cpu_addr);
>> -               if (port == (unsigned long)-1) {
>> -                       err = -EINVAL;
>> -                       goto invalid_range;
>> -               }
>>                 res->start = port;
>>         } else {
>>                 if ((sizeof(resource_size_t) < 8) &&
>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>> index a881c0d..5289221 100644
>> --- a/drivers/pci/pci.c
>> +++ b/drivers/pci/pci.c
>> @@ -3241,6 +3241,7 @@ int pci_request_regions_exclusive(struct pci_dev
>> *pdev, const char *res_name)
>>  #ifdef PCI_IOBASE
>>  struct io_range {
>>         struct list_head list;
>> +       struct fwnode_handle *node;
>>         phys_addr_t start;
>>         resource_size_t size;
>>  };
>> @@ -3253,7 +3254,8 @@ struct io_range {
>>   * 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 __weak pci_register_io_range(struct fwnode_handle *node, phys_addr_t
>> addr,
>> +                                resource_size_t size, unsigned long
>> *port)
>>  {
>>         int err = 0;
>>
>> @@ -3261,10 +3263,31 @@ int __weak pci_register_io_range(phys_addr_t addr,
>> resource_size_t size)
>>         struct io_range *range;
>>         resource_size_t allocated_size = 0;
>>
>> +       /*
>> +        * As indirect-IO which support multiple bus instances is
>> introduced,
>> +        * the input 'addr' is probably not page-aligned. If the PCI I/O
>> +        * ranges are registered after indirect-IO, there is risk that the
>> +        * start logical PIO assigned to PCI I/O is not page-aligned.
>> +        * This will cause some I/O subranges are not remapped or
>> overlapped
>> +        * in pci_remap_iospace() handling.
>> +        */
>> +       WARN_ON(addr != IO_RANGE_IOEXT && !(addr & PAGE_MASK));
>> +       /*
>> +        * MMIO will call ioremap, it is better to align size with
>> PAGE_SIZE,
>> +        * then the return linux virtual PIO is page-aligned.
>> +        */
>> +       if (size & PAGE_MASK)
>> +               size = PAGE_ALIGN(size);
>> +
>>         /* 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) {
>> +               if (node == range->node)
>> +                       goto end_register;
>> +
>> +               if (addr != IO_RANGE_IOEXT &&
>> +                   addr >= range->start &&
>> +                   addr + size <= range->start + size) {
>>                         /* range already registered, bail out */
>>                         goto end_register;
>>                 }
>> @@ -3290,6 +3313,7 @@ int __weak pci_register_io_range(phys_addr_t addr,
>> resource_size_t size)
>>                 goto end_register;
>>         }
>>
>> +       range->node = node;
>>         range->start = addr;
>>         range->size = size;
>>
>> @@ -3297,6 +3321,14 @@ int __weak pci_register_io_range(phys_addr_t addr,
>> resource_size_t size)
>>
>>  end_register:
>>         spin_unlock(&io_range_lock);
>> +
>> +       *port = allocated_size;
>> +#else
>> +       /*
>> +        * powerpc and microblaze have their own registration,
>> +        * just look up the value here
>> +        */
>> +       *port = pci_address_to_pio(addr);
>>  #endif
>>
>>         return err;
>> @@ -3315,7 +3347,9 @@ phys_addr_t pci_pio_to_address(unsigned long pio)
>>
>>         spin_lock(&io_range_lock);
>>         list_for_each_entry(range, &io_range_list, list) {
>> -               if (pio >= allocated_size && pio < allocated_size +
>> range->size) {
>> +               if (range->start != IO_RANGE_IOEXT &&
>> +                       pio >= allocated_size &&
>> +                       pio < allocated_size + range->size) {
>>                         address = range->start + pio - allocated_size;
>>                         break;
>>                 }
>> @@ -3336,7 +3370,9 @@ unsigned long __weak pci_address_to_pio(phys_addr_t
>> address)
>>
>>         spin_lock(&io_range_lock);
>>         list_for_each_entry(res, &io_range_list, list) {
>> -               if (address >= res->start && address < res->start +
>> res->size) {
>> +               if (res->start != IO_RANGE_IOEXT &&
>> +                       address >= res->start &&
>> +                       address < res->start + res->size) {
>>                         addr = address - res->start + offset;
>>                         break;
>>                 }
>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>> index e2d1a12..8d91af8 100644
>> --- a/include/linux/pci.h
>> +++ b/include/linux/pci.h
>> @@ -34,6 +34,9 @@
>>
>>  #include <linux/pci_ids.h>
>>
>> +/* the macro below flags an invalid cpu address
>> + * and is used by IO special hosts              */
>> +#define IO_RANGE_IOEXT (resource_size_t)(-1ull)
>>  /*
>>   * The PCI interface treats multi-function devices as independent
>>   * devices.  The slot/function address of each device is encoded
>> @@ -1197,8 +1200,8 @@ int __must_check pci_bus_alloc_resource(struct
>> pci_bus *bus,
>>                                                   resource_size_t),
>>                         void *alignf_data);
>>
>> -
>> -int pci_register_io_range(phys_addr_t addr, resource_size_t size);
>> +int pci_register_io_range(struct fwnode_handle *node, phys_addr_t addr,
>> +                         resource_size_t size, unsigned long *port);
>>  unsigned long pci_address_to_pio(phys_addr_t addr);
>>  phys_addr_t pci_pio_to_address(unsigned long pio);
>>  int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr);
>>
>
>