Re: [v3 3/6] PCI: endpoint: Add support to handle multiple base for mapping outbound memory

["Lad, Prabhakar" <prabhakar.csengg@gmail.com>]

Hi Kishon,

On Mon, Jan 13, 2020 at 8:56 AM Kishon Vijay Abraham I <kishon@ti.com> wrote:
>
> Hi Prabhakar,
>
> On 10/01/20 11:38 PM, Lad, Prabhakar wrote:
> > Hi Kishon,
> >
> > Thank you for the review.
> >
> > On Thu, Jan 9, 2020 at 6:25 AM Kishon Vijay Abraham I <kishon@ti.com> wrote:
> >>
> >> Hi Prabhakar,
> >>
> >> On 08/01/20 9:52 PM, Lad Prabhakar wrote:
> >>> R-Car PCIe controller has support to map multiple memory regions for
> >>> mapping the outbound memory in local system also the controller limits
> >>> single allocation for each region (that is, once a chunk is used from the
> >>> region it cannot be used to allocate a new one). This features inspires to
> >>> add support for handling multiple memory bases in endpoint framework.
> >>>
> >>> With this patch pci_epc_mem_init() now accepts multiple regions, also
> >>> page_size for each memory region is passed during initialization so as
> >>> to handle single allocation for each region by setting the page_size to
> >>> window_size.
> >>>
> >>> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >>> ---
> >>>  .../pci/controller/cadence/pcie-cadence-ep.c  |  12 +-
> >>>  .../pci/controller/dwc/pcie-designware-ep.c   |  31 ++-
> >>>  drivers/pci/controller/pcie-rockchip-ep.c     |  14 +-
> >>>  drivers/pci/endpoint/functions/pci-epf-test.c |  29 +--
> >>>  drivers/pci/endpoint/pci-epc-core.c           |   7 +-
> >>>  drivers/pci/endpoint/pci-epc-mem.c            | 199 ++++++++++++++----
> >>>  include/linux/pci-epc.h                       |  46 ++--
> >>>  7 files changed, 245 insertions(+), 93 deletions(-)
> >>>
> >> .
> >> .
> >> <snip>
> >> .
> >> .
> >>> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> >>> index 2091508c1620..289c266c2d90 100644
> >>> --- a/drivers/pci/endpoint/pci-epc-core.c
> >>> +++ b/drivers/pci/endpoint/pci-epc-core.c
> >>> @@ -358,13 +358,15 @@ EXPORT_SYMBOL_GPL(pci_epc_unmap_addr);
> >>>   * @epc: the EPC device on which address is allocated
> >>>   * @func_no: the endpoint function number in the EPC device
> >>>   * @phys_addr: physical address of the local system
> >>> + * @window: index to the window region where PCI address will be mapped
> >>>   * @pci_addr: PCI address to which the physical address should be mapped
> >>>   * @size: the size of the allocation
> >>>   *
> >>>   * Invoke to map CPU address with PCI address.
> >>>   */
> >>>  int pci_epc_map_addr(struct pci_epc *epc, u8 func_no,
> >>> -                  phys_addr_t phys_addr, u64 pci_addr, size_t size)
> >>> +                  phys_addr_t phys_addr, int window,
> >>> +                  u64 pci_addr, size_t size)
> >>>  {
> >>>       int ret;
> >>>       unsigned long flags;
> >>> @@ -376,7 +378,8 @@ int pci_epc_map_addr(struct pci_epc *epc, u8 func_no,
> >>>               return 0;
> >>>
> >>>       spin_lock_irqsave(&epc->lock, flags);
> >>> -     ret = epc->ops->map_addr(epc, func_no, phys_addr, pci_addr, size);
> >>> +     ret = epc->ops->map_addr(epc, func_no, phys_addr,
> >>> +                              window, pci_addr, size);
> >>>       spin_unlock_irqrestore(&epc->lock, flags);
> >>>
> >>>       return ret;
> >>> diff --git a/drivers/pci/endpoint/pci-epc-mem.c b/drivers/pci/endpoint/pci-epc-mem.c
> >>> index d2b174ce15de..f205f7819292 100644
> >>> --- a/drivers/pci/endpoint/pci-epc-mem.c
> >>> +++ b/drivers/pci/endpoint/pci-epc-mem.c
> >>> @@ -38,57 +38,77 @@ static int pci_epc_mem_get_order(struct pci_epc_mem *mem, size_t size)
> >>>  /**
> >>>   * __pci_epc_mem_init() - initialize the pci_epc_mem structure
> >>>   * @epc: the EPC device that invoked pci_epc_mem_init
> >>> - * @phys_base: the physical address of the base
> >>> - * @size: the size of the address space
> >>> - * @page_size: size of each page
> >>> + * @windows: pointer to windows supported by the device
> >>> + * @num_windows: number of windows device supports
> >>>   *
> >>>   * Invoke to initialize the pci_epc_mem structure used by the
> >>>   * endpoint functions to allocate mapped PCI address.
> >>>   */
> >>> -int __pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_base, size_t size,
> >>> -                    size_t page_size)
> >>> +int __pci_epc_mem_init(struct pci_epc *epc, struct pci_epc_mem_window *windows,
> >>> +                    int num_windows)
> >>>  {
> >>> -     int ret;
> >>> -     struct pci_epc_mem *mem;
> >>> -     unsigned long *bitmap;
> >>> +     struct pci_epc_mem *mem = NULL;
> >>> +     unsigned long *bitmap = NULL;
> >>>       unsigned int page_shift;
> >>> -     int pages;
> >>> +     size_t page_size;
> >>>       int bitmap_size;
> >>> +     int pages;
> >>> +     int ret;
> >>> +     int i;
> >>>
> >>> -     if (page_size < PAGE_SIZE)
> >>> -             page_size = PAGE_SIZE;
> >>> +     epc->mem_windows = 0;
> >>>
> >>> -     page_shift = ilog2(page_size);
> >>> -     pages = size >> page_shift;
> >>> -     bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
> >>> +     if (!windows)
> >>> +             return -EINVAL;
> >>>
> >>> -     mem = kzalloc(sizeof(*mem), GFP_KERNEL);
> >>> -     if (!mem) {
> >>> -             ret = -ENOMEM;
> >>> -             goto err;
> >>> -     }
> >>> +     if (num_windows <= 0)
> >>> +             return -EINVAL;
> >>>
> >>> -     bitmap = kzalloc(bitmap_size, GFP_KERNEL);
> >>> -     if (!bitmap) {
> >>> -             ret = -ENOMEM;
> >>> -             goto err_mem;
> >>> -     }
> >>> +     epc->mem = kcalloc(num_windows, sizeof(*mem), GFP_KERNEL);
> >>> +     if (!epc->mem)
> >>> +             return -EINVAL;
> >>> +
> >>> +     for (i = 0; i < num_windows; i++) {
> >>> +             page_size = windows[i].page_size;
> >>> +             if (page_size < PAGE_SIZE)
> >>> +                     page_size = PAGE_SIZE;
> >>> +             page_shift = ilog2(page_size);
> >>> +             pages = windows[i].size >> page_shift;
> >>> +             bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
> >>> +
> >>> +             mem = kzalloc(sizeof(*mem), GFP_KERNEL);
> >>> +             if (!mem) {
> >>> +                     ret = -ENOMEM;
> >>> +                     goto err_mem;
> >>> +             }
> >>>
> >>> -     mem->bitmap = bitmap;
> >>> -     mem->phys_base = phys_base;
> >>> -     mem->page_size = page_size;
> >>> -     mem->pages = pages;
> >>> -     mem->size = size;
> >>> +             bitmap = kzalloc(bitmap_size, GFP_KERNEL);
> >>> +             if (!bitmap) {
> >>> +                     ret = -ENOMEM;
> >>> +                     goto err_mem;
> >>> +             }
> >>>
> >>> -     epc->mem = mem;
> >>> +             mem->bitmap = bitmap;
> >>> +             mem->window.phys_base = windows[i].phys_base;
> >>> +             mem->page_size = page_size;
> >>> +             mem->pages = pages;
> >>> +             mem->window.size = windows[i].size;
> >>> +             mem->window.map_size = 0;
> >>> +
> >>> +             epc->mem[i] = mem;
> >>> +     }
> >>> +     epc->mem_windows = num_windows;
> >>>
> >>>       return 0;
> >>>
> >>>  err_mem:
> >>> -     kfree(mem);
> >>> +     for (; i >= 0; i--) {
> >>
> >> mem has to be reinitialized for every iteration of the loop.
> > not sure what exactly you mean here, could you please elaborate.
>
> You are invoking "kfree(mem->bitmap);" in a loop without re-initializing
> mem. Refer pci_epc_mem_exit() where you are doing the free properly.
>
good catch will fix that.

Cheers,
--Prabhakar

> >
> >>> +             kfree(mem->bitmap);
> >>> +             kfree(epc->mem[i]);
> >>> +     }
> >>> +     kfree(epc->mem);
> >>>
> >>> -err:
> >>> -return ret;
> >>> +     return ret;
> >>>  }
> >>>  EXPORT_SYMBOL_GPL(__pci_epc_mem_init);
> >>>
> >>> @@ -101,48 +121,127 @@ EXPORT_SYMBOL_GPL(__pci_epc_mem_init);
> >>>   */
> >>>  void pci_epc_mem_exit(struct pci_epc *epc)
> >>>  {
> >>> -     struct pci_epc_mem *mem = epc->mem;
> >>> +     struct pci_epc_mem *mem;
> >>> +     int i;
> >>> +
> >>> +     if (!epc->mem_windows)
> >>> +             return;
> >>> +
> >>> +     for (i = 0; i <= epc->mem_windows; i++) {
> >>> +             mem = epc->mem[i];
>
> Missing the above line in the error handling above.
>
>
> >>> +             kfree(mem->bitmap);
> >>> +             kfree(epc->mem[i]);
> >>> +     }
>
> Thanks
> Kishon

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