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SubjectRe: [PATCH v4 4/5] PCI: endpoint: Make pci_epc_set_bar() return the BAR width that was set-up
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Hi Niklas,

On Thursday 08 March 2018 07:03 PM, Niklas Cassel wrote:
> In order to properly handle 64-bit BARs, we need to know what BAR width
> that was actually set-up by specific pci_epc_set_bar() implementations.
>
> This is done so that we can know if we need to skip a BAR,
> since a 64-bit BAR consists of a BAR pair.
>
> It is important to know the BAR width that was actually set-up,
> since some drivers, like the Cadence EP controller, does not
> simply look at PCI_BASE_ADDRESS_MEM_TYPE_64, as it configures
> all BARs larger than 2G as 64-bit.
>
> Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
> ---
> drivers/pci/cadence/pcie-cadence-ep.c | 2 +-
> drivers/pci/dwc/pcie-designware-ep.c | 4 ++--
> drivers/pci/endpoint/functions/pci-epf-test.c | 7 ++++++-
> 3 files changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/cadence/pcie-cadence-ep.c b/drivers/pci/cadence/pcie-cadence-ep.c
> index 3c3a97743453..0e4cc4cca56d 100644
> --- a/drivers/pci/cadence/pcie-cadence-ep.c
> +++ b/drivers/pci/cadence/pcie-cadence-ep.c
> @@ -135,7 +135,7 @@ static int cdns_pcie_ep_set_bar(struct pci_epc *epc, u8 fn, enum pci_barno bar,
> CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl));
> cdns_pcie_writel(pcie, reg, cfg);
>
> - return 0;
> + return is_64bits ? 1 : 0;
> }
>
> static void cdns_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn,
> diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
> index b20b2651caf9..f3c19f8ff8e5 100644
> --- a/drivers/pci/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/dwc/pcie-designware-ep.c
> @@ -139,7 +139,7 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no,
> as_type = DW_PCIE_AS_IO;
>
> ret = dw_pcie_ep_inbound_atu(ep, bar, bar_phys, as_type);
> - if (ret)
> + if (ret < 0)
> return ret;
>
> dw_pcie_dbi_ro_wr_en(pci);
> @@ -154,7 +154,7 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no,
> }
> dw_pcie_dbi_ro_wr_dis(pci);
>
> - return 0;
> + return (flags & PCI_BASE_ADDRESS_MEM_TYPE_64) ? 1 : 0;
> }
>
> static int dw_pcie_find_index(struct dw_pcie_ep *ep, phys_addr_t addr,
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 7c70433b11a7..09878e011284 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -379,12 +379,17 @@ static int pci_epf_test_set_bar(struct pci_epf *epf)
> ret = pci_epc_set_bar(epc, epf->func_no, bar,
> epf_bar->phys_addr,
> epf_bar->size, bar_flags[bar]);
> - if (ret) {
> + if (ret < 0) {
> pci_epf_free_space(epf, epf_test->reg[bar], bar);
> dev_err(dev, "failed to set BAR%d\n", bar);
> if (bar == test_reg_bar)
> return ret;
> }
> + /*
> + * pci_epc_set_bar() returns 1 if a 64-bit BAR was set-up,
> + * or 0 if a 32-bit BAR was set-up.
> + */
> + bar += ret;

I'd prefer having a new argument bool *is_64bit in set_bar rather than having
to work with return value of set_bar.

Even otherwise, can't we set PCI_BASE_ADDRESS_MEM_TYPE_64 based on size in
pci-epf-test itself?

Thanks
Kishon

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