On Sat, Apr 27, 2024 at 05:06:43PM +0530, Manivannan Sadhasivam wrote:
> PCI: imx6: Add support for configuring BDF to SID mapping for i.MX95
>
> On Tue, Apr 02, 2024 at 10:33:44AM -0400, Frank Li wrote:
> > i.MX95 need config LUT to convert bpf to stream id. IOMMU and ITS use the
>
> Did you mean BDF? Here and everywhere.
>
> > same stream id. Check msi-map and smmu-map and make sure the same PCI bpf
> > map to the same stream id. Then config LUT related registers.
> >
>
> These DT properties not documented in the binding.
>
> > Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> > ---
> > drivers/pci/controller/dwc/pcie-imx.c | 175 ++++++++++++++++++++++++++++++++++
> > 1 file changed, 175 insertions(+)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-imx.c b/drivers/pci/controller/dwc/pcie-imx.c
> > index af0f960f28757..653d8e8ee1abc 100644
> > --- a/drivers/pci/controller/dwc/pcie-imx.c
> > +++ b/drivers/pci/controller/dwc/pcie-imx.c
> > @@ -55,6 +55,22 @@
> > #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 {
> > @@ -217,6 +233,159 @@ static int imx95_pcie_init_phy(struct imx_pcie *imx_pcie)
> > return 0;
> > }
> >
> > +static int imx_pcie_update_lut(struct imx_pcie *imx_pcie, int index, u16 reqid, u16 mask, u8 sid)
> > +{
> > + struct dw_pcie *pci = imx_pcie->pci;
> > + struct device *dev = pci->dev;
> > + u32 data1, data2;
> > +
> > + if (sid >= 64) {
> > + dev_err(dev, "Too big stream id: %d\n", sid);
>
> 'Invalid SID for index (%d): %d\n', index, sid
>
> > + return -EINVAL;
> > + }
> > +
> > + 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 = mask;
> > + 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, index);
> > +
> > + return 0;
> > +}
> > +
> > +struct imx_of_map {
>
> imx_iommu_map
>
> > + u32 bdf;
> > + u32 phandle;
> > + u32 sid;
> > + u32 sid_len;
> > +};
> > +
> > +static int imx_check_msi_and_smmmu(struct imx_pcie *imx_pcie,
> > + struct imx_of_map *msi_map, u32 msi_size, u32 msi_map_mask,
> > + struct imx_of_map *smmu_map, u32 smmu_size, u32 smmu_map_mask)
> > +{
> > + struct dw_pcie *pci = imx_pcie->pci;
> > + struct device *dev = pci->dev;
> > + int i;
> > +
>
> if (!msi_map || !smmu_map)
> return 0;
>
> > + if (msi_map && smmu_map) {
> > + if (msi_size != smmu_size)
> > + return -EINVAL;
> > + if (msi_map_mask != smmu_map_mask)
> > + return -EINVAL;
>
> if (msi_size != smmu_size || msi_map_mask != smmu_map_mask)
> return -EINVAL;
>
> > +
> > + for (i = 0; i < msi_size / sizeof(*msi_map); i++) {
> > + if (msi_map->bdf != smmu_map->bdf) {
> > + dev_err(dev, "bdf setting is not match\n");
>
> 'BDF mismatch between msi-map and iommu-map'
>
> > + return -EINVAL;
> > + }
> > + if ((msi_map->sid & IMX95_SID_MASK) != smmu_map->sid) {
> > + dev_err(dev, "sid setting is not match\n");
>
> 'SID mismatch between msi-map and iommu-map'
>
> > + return -EINVAL;
> > + }
> > + if ((msi_map->sid_len & IMX95_SID_MASK) != smmu_map->sid_len) {
> > + dev_err(dev, "sid_len setting is not match\n");
>
> 'SID length mismatch between msi-map and iommu-map'
>
> > + return -EINVAL;
> > + }
> > + }
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/*
> > + * Simple static config lut according to dts settings DAC index and stream ID used as a match result
> > + * of LUT pre-allocated and used by PCIes.
> > + *
>
> Please reword the above sentence.
How about:
"A straightforward static configuration lookup table (LUT) is established
based on the stream ID specified in the DTS settings."
>
> > + * Currently stream ID from 32-64 for PCIe.
> > + * 32-40: first PCI bus.
> > + * 40-48: second PCI bus.
>
> I believe this is an SoC specific info. So better not add it here. It belongs to
> DT.
>
> > + *
> > + * DAC_ID is index of TRDC.DAC index, start from 2 at iMX95.
> > + * ITS [pci(2bit): streamid(6bits)]
> > + * pci 0 is 0
> > + * pci 1 is 3
> > + */
> > +static int imx_pcie_config_sid(struct imx_pcie *imx_pcie)
> > +{
> > + struct imx_of_map *msi_map = NULL, *smmu_map = NULL, *cur;
> > + int i, j, lut_index, nr_map, msi_size = 0, smmu_size = 0;
> > + u32 msi_map_mask = 0xffff, smmu_map_mask = 0xffff;
> > + struct dw_pcie *pci = imx_pcie->pci;
> > + struct device *dev = pci->dev;
> > + u32 mask;
> > + int size;
> > +
> > + of_get_property(dev->of_node, "msi-map", &msi_size);
> > + if (msi_size) {
>
> You mentioned in the commit message that msi-map and iommu-map needs to be the
> same for this SoC. But here you are just ignoring the absence of 'msi-map'
> property.
If msi-map not exist, it will be fail back to use DWC's msi controller
insteand of ITS.
Do you think need comments here for that?
>
> > + msi_map = devm_kzalloc(dev, msi_size, GFP_KERNEL);
> > + if (!msi_map)
> > + return -ENOMEM;
> > +
> > + if (of_property_read_u32_array(dev->of_node, "msi-map", (u32 *)msi_map,
> > + msi_size / sizeof(u32)))
> > + return -EINVAL;
> > +
> > + of_property_read_u32(dev->of_node, "msi-map-mask", &msi_map_mask);
> > + }
> > +
> > + cur = msi_map;
> > + size = msi_size;
> > + mask = msi_map_mask;
> > +
> > + of_get_property(dev->of_node, "iommu-map", &smmu_size);
>
> Same comment as above.
If iommu-map was not exist, it will work without iommu. the combination
as below (4 cases).
not-exist exit
msi-map dw-msi its
iommu-map by-pass-mmu smmu
Require stream id must be the same only when both msi-map and iommu exist.
>
> > + if (smmu_size) {
> > + smmu_map = devm_kzalloc(dev, smmu_size, GFP_KERNEL);
> > + if (!smmu_map)
> > + return -ENOMEM;
> > +
> > + if (of_property_read_u32_array(dev->of_node, "iommu-map", (u32 *)smmu_map,
> > + smmu_size / sizeof(u32)))
> > + return -EINVAL;
> > +
> > + of_property_read_u32(dev->of_node, "iommu_map_mask", &smmu_map_mask);
> > + }
> > +
> > + if (imx_check_msi_and_smmmu(imx_pcie, msi_map, msi_size, msi_map_mask,
> > + smmu_map, smmu_size, smmu_map_mask))
> > + return -EINVAL;
> > +
>
> Hmm, so you want to continue even if the 'msi-map' and 'iommu-map' properties
> don't exist i.e., for old platforms?
imx_check_msi_and_smmmu() will return 0 when smmu_map is null.
>
> > + if (!cur) {
> > + cur = smmu_map;
> > + size = smmu_size;
> > + mask = smmu_map_mask;
> > + }
> > +
> > + nr_map = size / (sizeof(*cur));
> > +
> > + lut_index = 0;
>
> Just initialize it while defining itself.
>
> > + for (i = 0; i < nr_map; i++) {
> > + for (j = 0; j < cur->sid_len; j++) {
> > + imx_pcie_update_lut(imx_pcie, lut_index, cur->bdf + j, mask,
> > + (cur->sid + j) & IMX95_SID_MASK);
> > + lut_index++;
> > + }
> > + cur++;
> > +
> > + if (lut_index >= IMX95_MAX_LUT) {
> > + dev_err(dev, "its-map/iommu-map exceed HW limiation\n");
>
> 'Too many msi-map/iommu-map entries'
>
> But I think you can just continue to use the allowed entries.
>
> > + return -EINVAL;
> > + }
> > + }
> > +
> > + devm_kfree(dev, smmu_map);
> > + devm_kfree(dev, msi_map);
>
> Please don't explicitly free the devm_ managed resources unless really needed.
> Else don't use devm_ at all.
It'd better use auto clean up function __free(kfree) here.
>
> > +
> > + return 0;
> > +}
> > +
> > static void imx_pcie_configure_type(struct imx_pcie *imx_pcie)
> > {
> > const struct imx_pcie_drvdata *drvdata = imx_pcie->drvdata;
> > @@ -950,6 +1119,12 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp)
> > goto err_phy_off;
> > }
> >
> > + ret = imx_pcie_config_sid(imx_pcie);
> > + if (ret < 0) {
> > + dev_err(dev, "failed to config sid:%d\n", ret);
>
> 'Failed to config BDF to SID mapping: %d\n'
>
> - Mani
>
> --
> மணிவண்ணன் சதாசிவம்
