[v4,2/5] PCI: designware-ep: Make dw_pcie_ep_set_bar() handle 64-bit BARs properly

Message ID 20180308133331.19464-3-niklas.cassel@axis.com
State Superseded
Delegated to: Lorenzo Pieralisi
Headers show
Series
  • PCI endpoint 64-bit BAR fixes
Related show

Commit Message

Niklas Cassel March 8, 2018, 1:33 p.m.
Since a 64-bit BAR consists of a BAR pair, we need to write to both
BARs in the BAR pair to setup the BAR properly.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
---
 drivers/pci/dwc/pcie-designware-ep.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

Comments

Kishon Vijay Abraham I March 21, 2018, 5:49 a.m. | #1
Hi Niklas,

On Thursday 08 March 2018 07:03 PM, Niklas Cassel wrote:
> Since a 64-bit BAR consists of a BAR pair, we need to write to both
> BARs in the BAR pair to setup the BAR properly.
> 
> Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
> ---
>  drivers/pci/dwc/pcie-designware-ep.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
> index 9236b998327f..946bbdf53c4d 100644
> --- a/drivers/pci/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/dwc/pcie-designware-ep.c
> @@ -136,8 +136,15 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no,
>  		return ret;
>  
>  	dw_pcie_dbi_ro_wr_en(pci);
> -	dw_pcie_writel_dbi2(pci, reg, size - 1);
> -	dw_pcie_writel_dbi(pci, reg, flags);
> +	if (flags & PCI_BASE_ADDRESS_MEM_TYPE_64) {
> +		dw_pcie_writel_dbi2(pci, reg, lower_32_bits(size - 1));
> +		dw_pcie_writel_dbi(pci, reg, flags);
> +		dw_pcie_writel_dbi2(pci, reg + 4, upper_32_bits(size - 1));
> +		dw_pcie_writel_dbi(pci, reg + 4, 0);

I think we should check in pci_epc_set_bar to make sure BAR_5 cannot have
PCI_BASE_ADDRESS_MEM_TYPE_64 flag set as this might lead undesired result.

Thanks
Kishon

Patch

diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
index 9236b998327f..946bbdf53c4d 100644
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -136,8 +136,15 @@  static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no,
 		return ret;
 
 	dw_pcie_dbi_ro_wr_en(pci);
-	dw_pcie_writel_dbi2(pci, reg, size - 1);
-	dw_pcie_writel_dbi(pci, reg, flags);
+	if (flags & PCI_BASE_ADDRESS_MEM_TYPE_64) {
+		dw_pcie_writel_dbi2(pci, reg, lower_32_bits(size - 1));
+		dw_pcie_writel_dbi(pci, reg, flags);
+		dw_pcie_writel_dbi2(pci, reg + 4, upper_32_bits(size - 1));
+		dw_pcie_writel_dbi(pci, reg + 4, 0);
+	} else {
+		dw_pcie_writel_dbi2(pci, reg, size - 1);
+		dw_pcie_writel_dbi(pci, reg, flags);
+	}
 	dw_pcie_dbi_ro_wr_dis(pci);
 
 	return 0;