Hi Krishna,
Thanks for the patch!
On 6.06.23 8:49, Krishna chaitanya chundru wrote:
Add support to vote for ICC bandwidth based up on the link
speed and width.
Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
---
drivers/pci/controller/dwc/pcie-qcom-ep.c | 73 +++++++++++++++++++++++++++++++
1 file changed, 73 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 19b3283..79e7559 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -17,6 +17,7 @@
#include <linux/phy/pcie.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
+#include <linux/interconnect.h>
#include <linux/pm_domain.h>
#include <linux/regmap.h>
#include <linux/reset.h>
@@ -28,6 +29,7 @@
#define PARF_SYS_CTRL 0x00
#define PARF_DB_CTRL 0x10
#define PARF_PM_CTRL 0x20
+#define PARF_PM_STTS 0x24
#define PARF_MHI_CLOCK_RESET_CTRL 0x174
#define PARF_MHI_BASE_ADDR_LOWER 0x178
#define PARF_MHI_BASE_ADDR_UPPER 0x17c
@@ -128,6 +130,9 @@
/* DBI register fields */
#define DBI_CON_STATUS_POWER_STATE_MASK GENMASK(1, 0)
+#define DBI_LINKCTRLSTATUS 0x80
+#define DBI_LINKCTRKSTATUS_SHIFT 16
+
#define XMLH_LINK_UP 0x400
#define CORE_RESET_TIME_US_MIN 1000
#define CORE_RESET_TIME_US_MAX 1005
@@ -187,6 +192,8 @@ struct qcom_pcie_ep {
enum qcom_pcie_ep_link_status link_status;
int global_irq;
int perst_irq;
+
+ struct icc_path *icc;
};
static int qcom_pcie_ep_core_reset(struct qcom_pcie_ep *pcie_ep)
@@ -253,9 +260,56 @@ static void qcom_pcie_dw_stop_link(struct dw_pcie *pci)
disable_irq(pcie_ep->perst_irq);
}
+static void qcom_pcie_icc_update(struct qcom_pcie_ep *pcie_ep)
+{
+ struct dw_pcie *pci = &pcie_ep->pci;
+ u32 val, bw;
+ int speed, width;
+ int ret;
+
+ if (!pcie_ep->icc)
+ return;
+
+ val = dw_pcie_readl_dbi(pci, DBI_LINKCTRLSTATUS);
+ val = val >> DBI_LINKCTRKSTATUS_SHIFT;
+
+ speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, val);
+ width = FIELD_GET(PCI_EXP_LNKSTA_NLW, val);
+
+ /*
+ * ICC needs avg bw in KBps.
+ *
+ * For example for 2Gbps the avg BW = 2x1000x1000x1000/8*1000 = 250000
+ */
+ switch (speed) {
+ case 1:
+ bw = 250000; /* avg bw for GEN1 per lane: 2Gbps, peak bw: no vote */
+ break;
+ case 2:
+ bw = 500000; /* avg bw for GEN2 per lane: 4Gbps, peak bw no vote */
+ break;
+ case 3:
+ bw = 1000000; /* avg bw for GEN3 per lane: 8Gbps, peak bw no vote */
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ fallthrough;
+ case 4:
+ bw = 2000000; /* avg bw for GEN4 per lane: 16Gbps, peak bw no vote */
+ break;
+ }
+
+ ret = icc_set_bw(pcie_ep->icc, width * bw, 0);
Here you should use a non-zero value for peak bandwidth. You can use the average value also as peak.
There are some existing macros like GBps_to_icc(). Please use them.
+ if (ret) {
+ dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
+ ret);
+ }
+}
+
static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
{
int ret;
+ struct dw_pcie *pci = &pcie_ep->pci;
ret = clk_bulk_prepare_enable(pcie_ep->num_clks, pcie_ep->clks);
if (ret)
@@ -277,6 +331,20 @@ static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
if (ret)
goto err_phy_exit;
+ /*
+ * Some Qualcomm platforms require interconnect bandwidth constraints
+ * to be set before enabling interconnect clocks.
+ *
+ * Set an initial average bandwidth corresponding to single-lane Gen 1
+ * for the pcie to mem path.
+ */
+ ret = icc_set_bw(pcie_ep->icc, 250000, 0); /* avg bw: 2Gbps, peak bw: no vote */
Ditto.
+ if (ret) {
+ dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
+ ret);
+ goto err_phy_exit;
+ }
+
return 0;
err_phy_exit:
@@ -550,6 +618,10 @@ static int qcom_pcie_ep_get_resources(struct platform_device *pdev,
if (IS_ERR(pcie_ep->phy))
ret = PTR_ERR(pcie_ep->phy);
+ pcie_ep->icc = devm_of_icc_get(dev, "pci");
Is this "pci" path documented in the bindings?
Thanks,
Georgi
+ if (IS_ERR(pcie_ep->icc))
+ ret = PTR_ERR(pcie_ep->icc);
+
return ret;
}
@@ -572,6 +644,7 @@ static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data)
} else if (FIELD_GET(PARF_INT_ALL_BME, status)) {
dev_dbg(dev, "Received BME event. Link is enabled!\n");
pcie_ep->link_status = QCOM_PCIE_EP_LINK_ENABLED;
+ qcom_pcie_icc_update(pcie_ep);
} else if (FIELD_GET(PARF_INT_ALL_PM_TURNOFF, status)) {
dev_dbg(dev, "Received PM Turn-off event! Entering L23\n");
val = readl_relaxed(pcie_ep->parf + PARF_PM_CTRL);
