[PATCH v5 08/12] PCI: imx6: Config look up table(LUT) to support MSI ITS and IOMMU for i.MX95

Frank Li
2024-05-28T19:40:15Z

For the i.MX95, configuration of a LUT is necessary to convert Bus Device
Function (BDF) to stream IDs, which are utilized by both IOMMU and ITS.
This involves examining the msi-map and smmu-map to ensure consistent
mapping of PCI BDF to the same stream IDs. Subsequently, LUT-related
registers are configured. In the absence of an msi-map, the built-in MSI
controller is utilized as a fallback.

Additionally, register a PCI bus notifier to trigger imx_pcie_add_device()
upon the appearance of a new PCI device and when the bus is an iMX6 PCI
controller. This function configures the correct LUT based on Device Tree
Settings (DTS).

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
drivers/pci/controller/dwc/pci-imx6.c | 175 +++++++++++++++++++++++++++++++++-
1 file changed, 174 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 29309ad0e352b..8ecc00049e20b 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -54,6 +54,22 @@
#define IMX95_PE0_GEN_CTRL_3 0x1058
#define IMX95_PCIE_LTSSM_EN BIT(0)

+#define IMX95_PE0_LUT_ACSCTRL 0x1008
+#define IMX95_PEO_LUT_RWA BIT(16)
+#define IMX95_PE0_LUT_ENLOC GENMASK(4, 0)
+
+#define IMX95_PE0_LUT_DATA1 0x100c
+#define IMX95_PE0_LUT_VLD BIT(31)
+#define IMX95_PE0_LUT_DAC_ID GENMASK(10, 8)
+#define IMX95_PE0_LUT_STREAM_ID GENMASK(5, 0)
+
+#define IMX95_PE0_LUT_DATA2 0x1010
+#define IMX95_PE0_LUT_REQID GENMASK(31, 16)
+#define IMX95_PE0_LUT_MASK GENMASK(15, 0)
+
+#define IMX95_SID_MASK GENMASK(5, 0)
+#define IMX95_MAX_LUT 32
+
#define to_imx_pcie(x) dev_get_drvdata((x)->dev)

enum imx_pcie_variants {
@@ -79,6 +95,7 @@ enum imx_pcie_variants {
#define IMX_PCIE_FLAG_HAS_PHY_RESET BIT(5)
#define IMX_PCIE_FLAG_HAS_SERDES BIT(6)
#define IMX_PCIE_FLAG_SUPPORT_64BIT BIT(7)
+#define IMX_PCIE_FLAG_MONITOR_DEV BIT(8)

#define imx_check_flag(pci, val) (pci->drvdata->flags & val)

@@ -132,6 +149,8 @@ struct imx_pcie {
struct device *pd_pcie_phy;
struct phy *phy;
const struct imx_pcie_drvdata *drvdata;
+
+ struct mutex lock;
};

/* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
@@ -215,6 +234,66 @@ static int imx95_pcie_init_phy(struct imx_pcie *imx_pcie)
return 0;
}

+static int imx_pcie_config_lut(struct imx_pcie *imx_pcie, u16 reqid, u8 sid)
+{
+ struct dw_pcie *pci = imx_pcie->pci;
+ struct device *dev = pci->dev;
+ u32 data1, data2;
+ int i;
+
+ if (sid >= 64) {
+ dev_err(dev, "Invalid SID for index %d\n", sid);
+ return -EINVAL;
+ }
+
+ guard(mutex)(&imx_pcie->lock);
+
+ for (i = 0; i < IMX95_MAX_LUT; i++) {
+ regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_ACSCTRL, IMX95_PEO_LUT_RWA | i);
+
+ regmap_read(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA1, &data1);
+ if (data1 & IMX95_PE0_LUT_VLD)
+ continue;
+
+ data1 = FIELD_PREP(IMX95_PE0_LUT_DAC_ID, 0);
+ data1 |= FIELD_PREP(IMX95_PE0_LUT_STREAM_ID, sid);
+ data1 |= IMX95_PE0_LUT_VLD;
+
+ regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA1, data1);
+
+ data2 = 0xffff;
+ data2 |= FIELD_PREP(IMX95_PE0_LUT_REQID, reqid);
+
+ regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA2, data2);
+
+ regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_ACSCTRL, i);
+
+ return 0;
+ }
+
+ dev_err(dev, "All lut already used\n");
+ return -EINVAL;
+}
+
+static void imx_pcie_remove_lut(struct imx_pcie *imx_pcie, u16 reqid)
+{
+ u32 data2 = 0;
+ int i;
+
+ guard(mutex)(&imx_pcie->lock);
+
+ for (i = 0; i < IMX95_MAX_LUT; i++) {
+ regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_ACSCTRL, IMX95_PEO_LUT_RWA | i);
+
+ regmap_read(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA2, &data2);
+ if (FIELD_GET(IMX95_PE0_LUT_REQID, data2) == reqid) {
+ regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA1, 0);
+ regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA2, 0);
+ regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_ACSCTRL, i);
+ }
+ }
+}
+
static void imx_pcie_configure_type(struct imx_pcie *imx_pcie)
{
const struct imx_pcie_drvdata *drvdata = imx_pcie->drvdata;
@@ -1232,6 +1311,85 @@ static int imx_pcie_resume_noirq(struct device *dev)
return 0;
}

+static bool imx_pcie_match_device(struct pci_bus *bus);
+
+static int imx_pcie_add_device(struct imx_pcie *imx_pcie, struct pci_dev *pdev)
+{
+ u32 sid_i = 0, sid_m = 0, rid = pci_dev_id(pdev);
+ struct device *dev = imx_pcie->pci->dev;
+ int err;
+
+ err = of_map_id(dev->of_node, rid, "iommu-map", "iommu-map-mask", NULL, &sid_i);
+ if (err)
+ return err;
+
+ err = of_map_id(dev->of_node, rid, "msi-map", "msi-map-mask", NULL, &sid_m);
+ if (err)
+ return err;
+
+ if (sid_i != rid && sid_m != rid)
+ if ((sid_i & IMX95_SID_MASK) != (sid_m & IMX95_SID_MASK)) {
+ dev_err(dev, "its and iommu stream id miss match, please check dts file\n");
+ return -EINVAL;
+ }
+
+ /* if iommu-map is not existed then use msi-map's stream id*/
+ if (sid_i == rid)
+ sid_i = sid_m;
+
+ sid_i &= IMX95_SID_MASK;
+
+ if (sid_i != rid)
+ return imx_pcie_config_lut(imx_pcie, rid, sid_i);
+
+ /* Use dwc built-in MSI controller */
+ return 0;
+}
+
+static void imx_pcie_del_device(struct imx_pcie *imx_pcie, struct pci_dev *pdev)
+{
+ imx_pcie_remove_lut(imx_pcie, pci_dev_id(pdev));
+}
+
+
+static int imx_pcie_bus_notifier(struct notifier_block *nb, unsigned long action, void *data)
+{
+ struct pci_host_bridge *host;
+ struct imx_pcie *imx_pcie;
+ struct pci_dev *pdev;
+ int err;
+
+ pdev = to_pci_dev(data);
+ host = pci_find_host_bridge(pdev->bus);
+
+ if (!imx_pcie_match_device(host->bus))
+ return NOTIFY_OK;
+
+ imx_pcie = to_imx_pcie(to_dw_pcie_from_pp(host->sysdata));
+
+ if (!imx_check_flag(imx_pcie, IMX_PCIE_FLAG_MONITOR_DEV))
+ return NOTIFY_OK;
+
+ switch (action) {
+ case BUS_NOTIFY_ADD_DEVICE:
+ err = imx_pcie_add_device(imx_pcie, pdev);
+ if (err)
+ return notifier_from_errno(err);
+ break;
+ case BUS_NOTIFY_DEL_DEVICE:
+ imx_pcie_del_device(imx_pcie, pdev);
+ break;
+ default:
+ return NOTIFY_DONE;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block imx_pcie_nb = {
+ .notifier_call = imx_pcie_bus_notifier,
+};
+
static const struct dev_pm_ops imx_pcie_pm_ops = {
NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_pcie_suspend_noirq,
imx_pcie_resume_noirq)
@@ -1264,6 +1422,8 @@ static int imx_pcie_probe(struct platform_device *pdev)
imx_pcie->pci = pci;
imx_pcie->drvdata = of_device_get_match_data(dev);

+ mutex_init(&imx_pcie->lock);
+
/* Find the PHY if one is defined, only imx7d uses it */
np = of_parse_phandle(node, "fsl,imx7d-pcie-phy", 0);
if (np) {
@@ -1551,7 +1711,8 @@ static const struct imx_pcie_drvdata drvdata[] = {
},
[IMX95] = {
.variant = IMX95,
- .flags = IMX_PCIE_FLAG_HAS_SERDES,
+ .flags = IMX_PCIE_FLAG_HAS_SERDES |
+ IMX_PCIE_FLAG_MONITOR_DEV,
.clk_names = imx8mq_clks,
.clks_cnt = ARRAY_SIZE(imx8mq_clks),
.ltssm_off = IMX95_PE0_GEN_CTRL_3,
@@ -1687,6 +1848,8 @@ DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_SYNOPSYS, 0xabcd,

static int __init imx_pcie_init(void)
{
+ int ret;
+
#ifdef CONFIG_ARM
struct device_node *np;

@@ -1705,7 +1868,17 @@ static int __init imx_pcie_init(void)
hook_fault_code(8, imx6q_pcie_abort_handler, SIGBUS, 0,
"external abort on non-linefetch");
#endif
+ ret = bus_register_notifier(&pci_bus_type, &imx_pcie_nb);
+ if (ret)
+ return ret;

return platform_driver_register(&imx_pcie_driver);
}
+
+static void __exit imx_pcie_exit(void)
+{
+ bus_unregister_notifier(&pci_bus_type, &imx_pcie_nb);
+}
+
device_initcall(imx_pcie_init);
+__exitcall(imx_pcie_exit);

--
2.34.1