[PATCH v3 05/11] PCI: brcmstb: Enable external MSI-X if available

Stanimir Varbanov
2024-10-14T14:39:26Z

On RPi5 there is an external MIP MSI-X interrupt controller
which can handle up to 64 interrupts.

Signed-off-by: Stanimir Varbanov <svarbanov@suse.de>
---
v2 -> v3:
- No changes

drivers/pci/controller/pcie-brcmstb.c | 63 +++++++++++++++++++++++++--
1 file changed, 59 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index b0ef2f31914d..b76c16287f37 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -1323,6 +1323,52 @@ static int brcm_pcie_start_link(struct brcm_pcie *pcie)
return 0;
}

+static int brcm_pcie_enable_external_msix(struct brcm_pcie *pcie,
+ struct device_node *msi_np)
+{
+ struct inbound_win inbound_wins[PCIE_BRCM_MAX_INBOUND_WINS];
+ u64 msi_pci_addr, msi_phys_addr;
+ struct resource r;
+ int mip_bar, ret;
+ u32 val, reg;
+
+ ret = of_property_read_reg(msi_np, 1, &msi_pci_addr, NULL);
+ if (ret)
+ return ret;
+
+ ret = of_address_to_resource(msi_np, 0, &r);
+ if (ret)
+ return ret;
+
+ msi_phys_addr = r.start;
+
+ /* Find free inbound window for MIP access */
+ mip_bar = brcm_pcie_get_inbound_wins(pcie, inbound_wins);
+ if (mip_bar < 0)
+ return mip_bar;
+
+ mip_bar += 1;
+ reg = brcm_bar_reg_offset(mip_bar);
+
+ val = lower_32_bits(msi_pci_addr);
+ val |= brcm_pcie_encode_ibar_size(SZ_4K);
+ writel(val, pcie->base + reg);
+
+ val = upper_32_bits(msi_pci_addr);
+ writel(val, pcie->base + reg + 4);
+
+ reg = brcm_ubus_reg_offset(mip_bar);
+
+ val = lower_32_bits(msi_phys_addr);
+ val |= PCIE_MISC_UBUS_BAR1_CONFIG_REMAP_ACCESS_EN_MASK;
+ writel(val, pcie->base + reg);
+
+ val = upper_32_bits(msi_phys_addr);
+ writel(val, pcie->base + reg + 4);
+
+ return 0;
+}
+
static const char * const supplies[] = {
"vpcie3v3",
"vpcie3v3aux",
@@ -1888,11 +1934,20 @@ static int brcm_pcie_probe(struct platform_device *pdev)
goto fail;
}

- msi_np = of_parse_phandle(pcie->np, "msi-parent", 0);
- if (pci_msi_enabled() && msi_np == pcie->np) {
- ret = brcm_pcie_enable_msi(pcie);
+ if (pci_msi_enabled()) {
+ msi_np = of_parse_phandle(pcie->np, "msi-parent", 0);
+ const char *str;
+
+ if (msi_np == pcie->np) {
+ str = "internal MSI";
+ ret = brcm_pcie_enable_msi(pcie);
+ } else {
+ str = "external MSI-X";
+ ret = brcm_pcie_enable_external_msix(pcie, msi_np);
+ }
+
if (ret) {
- dev_err(pcie->dev, "probe of internal MSI failed");
+ dev_err(pcie->dev, "enable of %s failed\n", str);
goto fail;
}
}
--
2.43.0