Re: [PATCH v4] PCI: endpoint: Add prefetch BAR support

[Li Chen]

ping. 

PS: this patch can be git am on 5.17-rc3 without confliction.

 ---- On Thu, 20 Jan 2022 23:12:56 -0500 Li Chen <lchen.firstlove@xxxxxxxxxxxx> wrote ----
 > From: Li Chen <lchen@xxxxxxxxxxxxx>
 > 
 > Before this commit, epf cannot set BAR to be prefetchable.
 > Prefetchable BAR can also help epf device to use bridge's
 > prefetch memory window.
 > 
 > Signed-off-by: Li Chen <lchen@xxxxxxxxxxxxx>
 > ---
 > Changes in v2:
 > Remove Gerrit Change-id
 > Changes in v3:
 > capitalize "BAR" in the subject and commit log as suggested by Bjorn.
 > Changes in v4:
 > This patch context doesn't change but resend with my Zoho mail account in that previous
 > company mail will contain un-removeable proprietary messages. 
 > Add "From:" to the first line of the message body.
 > 
 >  drivers/pci/endpoint/functions/pci-epf-test.c | 4 ++++
 >  include/linux/pci-epc.h                       | 2 ++
 >  2 files changed, 6 insertions(+)
 > 
 > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
 > index 90d84d3bc868..96489cfdf58d 100644
 > --- a/drivers/pci/endpoint/functions/pci-epf-test.c
 > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
 > @@ -817,15 +817,19 @@ static void pci_epf_configure_bar(struct pci_epf *epf,
 >  {
 >      struct pci_epf_bar *epf_bar;
 >      bool bar_fixed_64bit;
 > +    bool bar_prefetch;
 >      int i;
 >  
 >      for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 >          epf_bar = &epf->bar[i];
 >          bar_fixed_64bit = !!(epc_features->bar_fixed_64bit & (1 << i));
 > +        bar_prefetch = !!(epc_features->bar_prefetch & (1 << i));
 >          if (bar_fixed_64bit)
 >              epf_bar->flags |= PCI_BASE_ADDRESS_MEM_TYPE_64;
 >          if (epc_features->bar_fixed_size[i])
 >              bar_size[i] = epc_features->bar_fixed_size[i];
 > +        if (bar_prefetch)
 > +            epf_bar->flags |= PCI_BASE_ADDRESS_MEM_PREFETCH;
 >      }
 >  }
 >  
 > diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
 > index a48778e1a4ee..825632d581d0 100644
 > --- a/include/linux/pci-epc.h
 > +++ b/include/linux/pci-epc.h
 > @@ -161,6 +161,7 @@ struct pci_epc {
 >   * @msix_capable: indicate if the endpoint function has MSI-X capability
 >   * @reserved_bar: bitmap to indicate reserved BAR unavailable to function driver
 >   * @bar_fixed_64bit: bitmap to indicate fixed 64bit BARs
 > + * @bar_prefetch: bitmap to indicate prefetchable BARs
 >   * @bar_fixed_size: Array specifying the size supported by each BAR
 >   * @align: alignment size required for BAR buffer allocation
 >   */
 > @@ -171,6 +172,7 @@ struct pci_epc_features {
 >      unsigned int    msix_capable : 1;
 >      u8    reserved_bar;
 >      u8    bar_fixed_64bit;
 > +    u8    bar_prefetch;
 >      u64    bar_fixed_size[PCI_STD_NUM_BARS];
 >      size_t    align;
 >  };
 > -- 
 > 2.34.1
 > 
 > 
 >