On Mon, Mar 25, 2019 at 03:09:39PM +0530, Kishon Vijay Abraham I wrote: > Modify pci_epf_alloc_space API to take alignment size as argument in > order to argument in order to allocate aligned buffers to be mapped to > BARs. > > Add 'align' parameter to epc_features which can be used by platform > drivers to specifiy the BAR allocation alignment requirements and use > this while invoking pci_epf_alloc_space. > > This is mainly required for Synopsys Designware PCIe core which masks > the lower bits based on the BAR size (See "I/O and MEM Match Modes" > section in DesignWare Cores PCI Express Controller Databook version > 4.90a).
Hi Kishon, isn't this a generic PCI BAR requirement rather than a Designware specific one ? The patch is fine I just would like to understand the statement above. Thanks, Lorenzo > Signed-off-by: Kishon Vijay Abraham I <[email protected]> > --- > drivers/pci/endpoint/functions/pci-epf-test.c | 5 +++-- > drivers/pci/endpoint/pci-epf-core.c | 10 ++++++++-- > include/linux/pci-epc.h | 2 ++ > include/linux/pci-epf.h | 3 ++- > 4 files changed, 15 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c > b/drivers/pci/endpoint/functions/pci-epf-test.c > index d0b91da49bf4..c0786ca74312 100644 > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > @@ -438,7 +438,7 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) > epc_features = epf_test->epc_features; > > base = pci_epf_alloc_space(epf, sizeof(struct pci_epf_test_reg), > - test_reg_bar); > + test_reg_bar, epc_features->align); > if (!base) { > dev_err(dev, "Failed to allocated register space\n"); > return -ENOMEM; > @@ -453,7 +453,8 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) > if (!!(epc_features->reserved_bar & (1 << bar))) > continue; > > - base = pci_epf_alloc_space(epf, bar_size[bar], bar); > + base = pci_epf_alloc_space(epf, bar_size[bar], bar, > + epc_features->align); > if (!base) > dev_err(dev, "Failed to allocate space for BAR%d\n", > bar); > diff --git a/drivers/pci/endpoint/pci-epf-core.c > b/drivers/pci/endpoint/pci-epf-core.c > index 8bfdcd291196..fb1306de8f40 100644 > --- a/drivers/pci/endpoint/pci-epf-core.c > +++ b/drivers/pci/endpoint/pci-epf-core.c > @@ -109,10 +109,12 @@ EXPORT_SYMBOL_GPL(pci_epf_free_space); > * pci_epf_alloc_space() - allocate memory for the PCI EPF register space > * @size: the size of the memory that has to be allocated > * @bar: the BAR number corresponding to the allocated register space > + * @align: alignment size for the allocation region > * > * Invoke to allocate memory for the PCI EPF register space. > */ > -void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno > bar) > +void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno > bar, > + size_t align) > { > void *space; > struct device *dev = epf->epc->dev.parent; > @@ -120,7 +122,11 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t > size, enum pci_barno bar) > > if (size < 128) > size = 128; > - size = roundup_pow_of_two(size); > + > + if (align) > + size = ALIGN(size, align); > + else > + size = roundup_pow_of_two(size); > > space = dma_alloc_coherent(dev, size, &phys_addr, GFP_KERNEL); > if (!space) { > diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h > index c3ffa3917f88..f641badc2c61 100644 > --- a/include/linux/pci-epc.h > +++ b/include/linux/pci-epc.h > @@ -109,6 +109,7 @@ struct pci_epc { > * @reserved_bar: bitmap to indicate reserved BAR unavailable to function > driver > * @bar_fixed_64bit: bitmap to indicate fixed 64bit BARs > * @bar_fixed_size: Array specifying the size supported by each BAR > + * @align: alignment size required for BAR buffer allocation > */ > struct pci_epc_features { > unsigned int linkup_notifier : 1; > @@ -117,6 +118,7 @@ struct pci_epc_features { > u8 reserved_bar; > u8 bar_fixed_64bit; > u64 bar_fixed_size[BAR_5 + 1]; > + size_t align; > }; > > #define to_pci_epc(device) container_of((device), struct pci_epc, dev) > diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h > index ec02f58758c8..2d6f07556682 100644 > --- a/include/linux/pci-epf.h > +++ b/include/linux/pci-epf.h > @@ -149,7 +149,8 @@ void pci_epf_destroy(struct pci_epf *epf); > int __pci_epf_register_driver(struct pci_epf_driver *driver, > struct module *owner); > void pci_epf_unregister_driver(struct pci_epf_driver *driver); > -void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno > bar); > +void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno > bar, > + size_t align); > void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar); > int pci_epf_bind(struct pci_epf *epf); > void pci_epf_unbind(struct pci_epf *epf); > -- > 2.17.1 >
