On Tue, 16 Jan 2024 at 07:17, Krishna Chaitanya Chundru <quic_krichai@xxxxxxxxxxx> wrote: > > > > On 1/12/2024 9:03 PM, Dmitry Baryshkov wrote: > > On Fri, 12 Jan 2024 at 16:25, Krishna chaitanya chundru > > <quic_krichai@xxxxxxxxxxx> wrote: > >> > >> QCOM Resource Power Manager-hardened (RPMh) is a hardware block which > >> maintains hardware state of a regulator by performing max aggregation of > >> the requests made by all of the processors. > >> > >> PCIe controller can operate on different RPMh performance state of power > >> domain based up on the speed of the link. And this performance state varies > >> from target to target. > >> > >> It is manadate to scale the performance state based up on the PCIe speed > >> link operates so that SoC can run under optimum power conditions. > >> > >> Add Operating Performance Points(OPP) support to vote for RPMh state based > >> upon GEN speed link is operating. > >> > >> OPP can handle ICC bw voting also, so move icc bw voting through opp > >> framework if opp entries are present. > >> > >> In PCIe certain gen speeds like GEN1x2 & GEN2X1 or GEN3x2 & GEN4x1 use > >> same icc bw and has frequency, so use frequency based search to reduce > >> number of entries in the opp table. > >> > >> Don't initialize icc if opp is supported. > >> > >> Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx> > >> --- > >> drivers/pci/controller/dwc/pcie-qcom.c | 83 ++++++++++++++++++++++++++++------ > >> 1 file changed, 70 insertions(+), 13 deletions(-) > >> > >> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c > >> index 035953f0b6d8..31512dc9d6ff 100644 > >> --- a/drivers/pci/controller/dwc/pcie-qcom.c > >> +++ b/drivers/pci/controller/dwc/pcie-qcom.c > >> @@ -22,6 +22,7 @@ > >> #include <linux/of.h> > >> #include <linux/of_gpio.h> > >> #include <linux/pci.h> > >> +#include <linux/pm_opp.h> > >> #include <linux/pm_runtime.h> > >> #include <linux/platform_device.h> > >> #include <linux/phy/pcie.h> > >> @@ -244,6 +245,7 @@ struct qcom_pcie { > >> const struct qcom_pcie_cfg *cfg; > >> struct dentry *debugfs; > >> bool suspended; > >> + bool opp_supported; > >> }; > >> > >> #define to_qcom_pcie(x) dev_get_drvdata((x)->dev) > >> @@ -1404,16 +1406,14 @@ static int qcom_pcie_icc_init(struct qcom_pcie *pcie) > >> return 0; > >> } > >> > >> -static void qcom_pcie_icc_update(struct qcom_pcie *pcie) > >> +static void qcom_pcie_icc_opp_update(struct qcom_pcie *pcie) > >> { > >> struct dw_pcie *pci = pcie->pci; > >> - u32 offset, status; > >> + u32 offset, status, freq; > >> + struct dev_pm_opp *opp; > >> int speed, width; > >> int ret; > >> > >> - if (!pcie->icc_mem) > >> - return; > >> - > >> offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > >> status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA); > >> > >> @@ -1424,11 +1424,42 @@ static void qcom_pcie_icc_update(struct qcom_pcie *pcie) > >> speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status); > >> width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status); > >> > >> - ret = icc_set_bw(pcie->icc_mem, 0, width * QCOM_PCIE_LINK_SPEED_TO_BW(speed)); > >> - if (ret) { > >> - dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n", > >> - ret); > >> + if (pcie->opp_supported) { > >> + switch (speed) { > >> + case 1: > >> + freq = 2500000; > >> + break; > >> + case 2: > >> + freq = 5000000; > >> + break; > >> + case 3: > >> + freq = 8000000; > >> + break; > >> + default: > >> + WARN_ON_ONCE(1); > >> + fallthrough; > >> + case 4: > >> + freq = 16000000; > > > > I expected that this kind of detail goes to the OPP table itself. Can > > we index the table using the generation instead of frequency? > > > In the previous patch also we tried to use index only, but problem using > index is we can define only GEN speed. As we are voting for the ICC BW > voting also we need to consider for lane width while configuring this > path. It is difficult to use index now as we need to consider both gen > speed and lane width. > For that reason we moved to frequencies to reduce number of entries in > OPP table. > for example if my controller supports GEN1 & GEN2 and MAX lane width is > 2. > > for GEN1x1 > opp-2500000 { > }; > > for GEN2x1 & GEN1x2 as both use same frequiences and bandwidth. > opp-5000000 { > }; > > for GEN2x2 > opp-10000000 { > > }; Ack. It would be nice to add this as a comment. Something as simple as 'gen1x2 and gen2x1 share the bandwidth value and thus the opp entry' > > - Krishna chaitanya. > >> + break; > >> + } > >> + > >> + opp = dev_pm_opp_find_freq_exact(pci->dev, freq * width, true); > >> + if (!IS_ERR(opp)) { > >> + ret = dev_pm_opp_set_opp(pci->dev, opp); > >> + if (ret) > >> + dev_err(pci->dev, "Failed to set opp: freq %ld ret %d\n", > >> + dev_pm_opp_get_freq(opp), ret); > >> + dev_pm_opp_put(opp); > >> + } > >> + } else { > >> + ret = icc_set_bw(pcie->icc_mem, 0, width * QCOM_PCIE_LINK_SPEED_TO_BW(speed)); > >> + if (ret) { > >> + dev_err(pci->dev, "failed to set interconnect bandwidth for pcie-mem: %d\n", > >> + ret); > >> + } > >> } > >> + > >> + return; > >> } > >> > >> static int qcom_pcie_link_transition_count(struct seq_file *s, void *data) > >> @@ -1471,8 +1502,10 @@ static void qcom_pcie_init_debugfs(struct qcom_pcie *pcie) > >> static int qcom_pcie_probe(struct platform_device *pdev) > >> { > >> const struct qcom_pcie_cfg *pcie_cfg; > >> + unsigned long max_freq = INT_MAX; > >> struct device *dev = &pdev->dev; > >> struct qcom_pcie *pcie; > >> + struct dev_pm_opp *opp; > >> struct dw_pcie_rp *pp; > >> struct resource *res; > >> struct dw_pcie *pci; > >> @@ -1539,9 +1572,33 @@ static int qcom_pcie_probe(struct platform_device *pdev) > >> goto err_pm_runtime_put; > >> } > >> > >> - ret = qcom_pcie_icc_init(pcie); > >> - if (ret) > >> + /* OPP table is optional */ > >> + ret = devm_pm_opp_of_add_table(dev); > >> + if (ret && ret != -ENODEV) { > >> + dev_err_probe(dev, ret, "Failed to add OPP table\n"); > >> goto err_pm_runtime_put; > >> + } > > > > Can we initialise the table from the driver if it is not found? This > > will help us by having the common code later on. > > > we already icc voting if there is no opp table present in the dts. Yes. So later we have two different code paths: one for the OPP table being present and another one for the absent OPP table. My suggestion is to initialise minimal OPP table by hand and then have a common code path in qcom_pcie_icc_update(). > So I think this might not be needed. > Please let me know if you want to use for some other use case. > > - Krishna Chaitanya. > >> + > >> + /* vote for max freq in the opp table if opp table is present */ > >> + if (ret != -ENODEV) { > >> + opp = dev_pm_opp_find_freq_floor(dev, &max_freq); > >> + if (!IS_ERR(opp)) { > >> + ret = dev_pm_opp_set_opp(dev, opp); > >> + if (ret) > >> + dev_err_probe(pci->dev, ret, > >> + "Failed to set opp: freq %ld\n", > >> + dev_pm_opp_get_freq(opp)); > >> + dev_pm_opp_put(opp); > >> + } > >> + pcie->opp_supported = true; > >> + } > >> + > >> + /* Skip icc init if opp is supported as icc bw vote is handled by opp framework */ > >> + if (!pcie->opp_supported) { > >> + ret = qcom_pcie_icc_init(pcie); > >> + if (ret) > >> + goto err_pm_runtime_put; > >> + } > >> > >> ret = pcie->cfg->ops->get_resources(pcie); > >> if (ret) > >> @@ -1561,7 +1618,7 @@ static int qcom_pcie_probe(struct platform_device *pdev) > >> goto err_phy_exit; > >> } > >> > >> - qcom_pcie_icc_update(pcie); > >> + qcom_pcie_icc_opp_update(pcie); > >> > >> if (pcie->mhi) > >> qcom_pcie_init_debugfs(pcie); > >> @@ -1640,7 +1697,7 @@ static int qcom_pcie_resume_noirq(struct device *dev) > >> pcie->suspended = false; > >> } > >> > >> - qcom_pcie_icc_update(pcie); > >> + qcom_pcie_icc_opp_update(pcie); > >> > >> return 0; > >> } > >> > >> -- > >> 2.42.0 > >> > >> > > > > -- With best wishes Dmitry