Re: [PATCH V7 2/7] PCI: Apply the new generic I/O management on PCI IO hosts
From: dann frazier
Date: Mon Mar 27 2017 - 15:47:04 EST
On Sun, Mar 12, 2017 at 8:42 PM, zhichang.yuan
<yuanzhichang@xxxxxxxxxxxxx> wrote:
> After introducing the new generic I/O space management(LIBIO), the original PCI
> MMIO relevant helpers need to be updated based on the new interfaces defined in
> LIBIO.
> This patch adapts the corresponding code to match the changes introduced by
> LIBIO.
> Signed-off-by: zhichang.yuan <yuanzhichang@xxxxxxxxxxxxx>
> Signed-off-by: Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> #earlier draft
> Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> #drivers/pci parts
> ---
> drivers/acpi/pci_root.c | 8 +++--
> drivers/of/address.c | 4 ++-
> drivers/pci/pci.c | 96 +++++++++++--------------------------------------
> include/linux/pci.h | 3 +-
> 4 files changed, 30 insertions(+), 81 deletions(-)
>
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index 919be0a..4d8cc24 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 *fwnode,
> + struct resource_entry *entry)
> {
> #ifdef PCI_IOBASE
> struct resource *res = entry->res;
> @@ -739,7 +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))
> + if (pci_register_io_range(fwnode, cpu_addr, length))
> goto err;
>
> port = pci_address_to_pio(cpu_addr);
> @@ -781,7 +782,8 @@ 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..fb5d16a 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>
> @@ -323,7 +324,8 @@ 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);
> if (err)
> goto invalid_range;
> port = pci_address_to_pio(range->cpu_addr);
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 7904d02..079319f 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -3238,65 +3238,37 @@ 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 pci_register_io_range(struct fwnode_handle *fwnode, 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;
> - }
> + struct libio_range *range, *tmprange;
>
> - size = SZ_64K;
> - pr_warn("Requested IO range too big, new size set to 64K\n");
> - }
> + if (!size || addr + size < addr)
> + return -EINVAL;
>
> - /* add the range to the list */
> - range = kzalloc(sizeof(*range), GFP_ATOMIC);
> - if (!range) {
> - err = -ENOMEM;
> - goto end_register;
> - }
> + WARN_ON(!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(size));
>
> - range->start = addr;
> + range = kzalloc(sizeof(*range), GFP_KERNEL);
> + if (!range)
> + return -ENOMEM;
> + range->node = fwnode;
> + range->flags = IO_CPU_MMIO;
> range->size = size;
> + range->hw_start = addr;
>
> - list_add_tail(&range->list, &io_range_list);
> -
> -end_register:
> - spin_unlock(&io_range_lock);
> + tmprange = register_libio_range(range);
> + if (tmprange != range) {
> + kfree(range);
> + if (!IS_ERR(tmprange))
> + err = 0;
> + }
> #endif
>
> return err;
> @@ -3307,21 +3279,10 @@ 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);
> + address = libio_to_hwaddr(pio);
> #endif
>
> return address;
> @@ -3330,25 +3291,8 @@ phys_addr_t pci_pio_to_address(unsigned long pio)
> 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;
> + return libio_translate_cpuaddr(address);
> #else
> - if (address > IO_SPACE_LIMIT)
> - return (unsigned long)-1;
> -
> return (unsigned long) address;
> #endif
> }
fyi, this fails to build if PCI_IOBASE is defined and CONFIG_LIBIO=n:
drivers/built-in.o: In function `pci_register_io_range':
/home/ubuntu/linux-4.10.0/drivers/pci/pci.c:3266: undefined reference
to `register_libio_range'
drivers/built-in.o: In function `pci_pio_to_address':
/home/ubuntu/linux-4.10.0/drivers/pci/pci.c:3285: undefined reference
to `libio_to_hwaddr'
drivers/built-in.o: In function `pci_address_to_pio':
/home/ubuntu/linux-4.10.0/drivers/pci/pci.c:3294: undefined reference
to `libio_translate_cpuaddr'
-dann
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index eb3da1a..6401327 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1194,7 +1194,8 @@ int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
> void *alignf_data);
>
>
> -int 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);
> 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);
> --
> 1.9.1
>