Hi Bjorn,

On 17/08/21 9:08 pm, Bjorn Helgaas wrote:

On Wed, Aug 11, 2021 at 12:16:54PM +0530, Kishon Vijay Abraham I wrote:

quoted

Now that support for SR-IOV is added in PCIe endpoint core, add support
to configure virtual functions in the Cadence PCIe EP driver.

Signed-off-by: Kishon Vijay Abraham I <redacted>
---
 .../pci/controller/cadence/pcie-cadence-ep.c  | 136 +++++++++++++++---
 drivers/pci/controller/cadence/pcie-cadence.h |   9 ++
 2 files changed, 125 insertions(+), 20 deletions(-)

quoted

@@ -92,21 +118,29 @@ static int cdns_pcie_ep_set_bar(struct pci_epc *epc, u8 fn, u8 vfn,
 
 	addr0 = lower_32_bits(bar_phys);
 	addr1 = upper_32_bits(bar_phys);
-	cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar),
-			 addr0);
-	cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar),
-			 addr1);
 
 	reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG(bar, fn);
+	if (vfn == 1)
+		reg = CDNS_PCIE_LM_EP_VFUNC_BAR_CFG(bar, fn);

Seems sort of weird to compute "reg", then sometimes overwrite it, as
opposed to:

  if (vfn == 1)
    reg = CDNS_PCIE_LM_EP_VFUNC_BAR_CFG(bar, fn);
  else
    reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG(bar, fn);

I tried to write it without "else". But I can change it back.

Also slightly weird that "vfn" is basically used as a boolean, but
it's actually a u8 virtual function number.  I guess VF 1 is special
and not like the other VFs?

VF1 is special in that it's enough for configuring the SR-IOV capability
but below the "vfn" is used for configuring inbound window.

Thanks
Kishon

quoted

 	b = (bar < BAR_4) ? bar : bar - BAR_4;
 
-	cfg = cdns_pcie_readl(pcie, reg);
-	cfg &= ~(CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) |
-		 CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b));
-	cfg |= (CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE(b, aperture) |
-		CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl));
-	cdns_pcie_writel(pcie, reg, cfg);
+	if (vfn == 0 || vfn == 1) {
+		cfg = cdns_pcie_readl(pcie, reg);
+		cfg &= ~(CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) |
+			 CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b));
+		cfg |= (CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE(b, aperture) |
+			CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl));
+		cdns_pcie_writel(pcie, reg, cfg);
+	}
 
+	fn = cdns_pcie_get_fn_from_vfn(pcie, fn, vfn);
+	cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar),
+			 addr0);
+	cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar),
+			 addr1);
+
+	if (vfn > 0)
+		epf = &epf->epf[vfn - 1];
 	epf->epf_bar[bar] = epf_bar;
 
 	return 0;

@@ -122,18 +156,25 @@ static void cdns_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn, u8 vfn,
 	u32 reg, cfg, b, ctrl;
 
 	reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG(bar, fn);
+	if (vfn == 1)
+		reg = CDNS_PCIE_LM_EP_VFUNC_BAR_CFG(bar, fn);

Similar recomputation of "reg".

quoted

 	b = (bar < BAR_4) ? bar : bar - BAR_4;
 
-	ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED;
-	cfg = cdns_pcie_readl(pcie, reg);
-	cfg &= ~(CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) |
-		 CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b));
-	cfg |= CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl);
-	cdns_pcie_writel(pcie, reg, cfg);
+	if (vfn == 0 || vfn == 1) {
+		ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED;
+		cfg = cdns_pcie_readl(pcie, reg);
+		cfg &= ~(CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) |
+			 CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b));
+		cfg |= CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl);
+		cdns_pcie_writel(pcie, reg, cfg);
+	}