Re: [PATCH v9 2/7] PCI: Apply the new generic I/O management on PCI IO hosts

Bjorn Helgaas
2017-05-26T21:20:01Z

On Thu, May 25, 2017 at 12:37:23PM +0100, Gabriele Paoloni wrote:
> From: "zhichang.yuan" <yuanzhichang@hisilicon.com>
>
> After introducing the new generic I/O space management(LOGIC_IO), the
> original PCI MMIO relevant helpers need to be updated based on the new
> interfaces defined in LOGIC_IO.
> This patch adapts the corresponding code to match the changes introduced
> by LOGIC_IO.
>
> 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> #earlier draft

Not sure how you plan to merge this, but here's my ack:

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

If you split this as suggested below, add my ack to all three patches.

> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index b01bd5b..c9fe12b 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
>...

> -int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
> +int pci_register_io_range(struct fwnode_handle *fwnode, phys_addr_t addr,
> + resource_size_t size)

It's trivial and nit-picky, but I would do the __weak removal in its
own patch. It's obviously fine because there's only one
implementation, but it's unrelated to the main point of this patch.

I would split the signature change (fwnode addition) to a separate
patch, too, just to make the actual change more obvious, especially
since that's the only part that crosses subsystems (ACPI, PCI, OF).

> {
> - int err = 0;
> -
> + int ret = 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");
> - }
> + struct logic_pio_hwaddr *range;
>
> - /* add the range to the list */
> - range = kzalloc(sizeof(*range), GFP_ATOMIC);
> - if (!range) {
> - err = -ENOMEM;
> - goto end_register;
> - }
> + if (!size || addr + size < addr)
> + return -EINVAL;
>
> - range->start = addr;
> + range = kzalloc(sizeof(*range), GFP_KERNEL);
> + if (!range)
> + return -ENOMEM;

Add a blank line here.

> + range->fwnode = fwnode;
> range->size = size;
> + range->hw_start = addr;
> + range->flags = PIO_CPU_MMIO;
>
> - list_add_tail(&range->list, &io_range_list);
> -
> -end_register:
> - spin_unlock(&io_range_lock);
> + ret = logic_pio_register_range(range);
> + if (ret)
> + kfree(range);
> #endif
>
> - return err;
> + return ret;
> }