| Message ID | 20230927154603.172049-2-manivannan.sadhasivam@linaro.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Krzysztof Wilczyński |
| Headers | show |
| Series | [v3,1/3] PCI: qcom: Make use of PCIE_SPEED2MBS_ENC() macro for encoding link speed | expand |
On Wed, Sep 27, 2023 at 05:46:02PM +0200, Manivannan Sadhasivam wrote: > Instead of hardcoding the link speed in MBps, let's make use of the > existing PCIE_SPEED2MBS_ENC() macro that does the encoding of the > link speed for us. Also, let's Wrap it with QCOM_PCIE_LINK_SPEED_TO_BW() > macro to do the conversion to ICC speed. In subject, /Make use of/Use/ would make better use of the subject line. Lots of "uses" there :) Above, s/let's//, and also s/make use of/use/. > +#define QCOM_PCIE_LINK_SPEED_TO_BW(speed) \ > + Mbps_to_icc(PCIE_SPEED2MBS_ENC(pcie_link_speed[speed])) It's a shame to have to duplicate this macro in pcie-qcom.c and in pcie-qcom-ep.c, especially since there's nothing qcom-specific in it. Would a macro like this fit in interconnect.h? > - ret = icc_set_bw(pcie_ep->icc_mem, 0, MBps_to_icc(PCIE_GEN1_BW_MBPS)); > + ret = icc_set_bw(pcie_ep->icc_mem, 0, QCOM_PCIE_LINK_SPEED_TO_BW(1)); "1" is not very informative here. Maybe PCIE_SPEED_2_5GT? (I didn't completely verify that this is equivalent.) Bjorn
On Wed, Sep 27, 2023 at 12:55:42PM -0500, Bjorn Helgaas wrote: > On Wed, Sep 27, 2023 at 05:46:02PM +0200, Manivannan Sadhasivam wrote: > > Instead of hardcoding the link speed in MBps, let's make use of the > > existing PCIE_SPEED2MBS_ENC() macro that does the encoding of the > > link speed for us. Also, let's Wrap it with QCOM_PCIE_LINK_SPEED_TO_BW() > > macro to do the conversion to ICC speed. > > In subject, /Make use of/Use/ would make better use of the subject > line. Lots of "uses" there :) > > Above, s/let's//, and also s/make use of/use/. > Ok, I will reword accordingly. > > +#define QCOM_PCIE_LINK_SPEED_TO_BW(speed) \ > > + Mbps_to_icc(PCIE_SPEED2MBS_ENC(pcie_link_speed[speed])) > > It's a shame to have to duplicate this macro in pcie-qcom.c and in > pcie-qcom-ep.c, especially since there's nothing qcom-specific in it. > > Would a macro like this fit in interconnect.h? > Unfortunately, no. This macro is neither interconnect specific nor PCI, but a kind of both used by the driver. So it makes sense to keep it in the driver itself for now. If we happen to create a common header for host and ep drivers in the future, it can be moved to that. > > - ret = icc_set_bw(pcie_ep->icc_mem, 0, MBps_to_icc(PCIE_GEN1_BW_MBPS)); > > + ret = icc_set_bw(pcie_ep->icc_mem, 0, QCOM_PCIE_LINK_SPEED_TO_BW(1)); > > "1" is not very informative here. Maybe PCIE_SPEED_2_5GT? (I didn't > completely verify that this is equivalent.) > No. PCIE_SPEED_2_5GT is defined as 0x14 in pci.h. And I do not want to add a macro for just "1" here. - Mani > Bjorn
On Thu, Sep 28, 2023 at 08:48:08PM +0200, Manivannan Sadhasivam wrote: > On Wed, Sep 27, 2023 at 12:55:42PM -0500, Bjorn Helgaas wrote: > > On Wed, Sep 27, 2023 at 05:46:02PM +0200, Manivannan Sadhasivam wrote: > > > Instead of hardcoding the link speed in MBps, let's make use of the > > > existing PCIE_SPEED2MBS_ENC() macro that does the encoding of the > > > link speed for us. Also, let's Wrap it with QCOM_PCIE_LINK_SPEED_TO_BW() > > > macro to do the conversion to ICC speed. > > > - ret = icc_set_bw(pcie_ep->icc_mem, 0, MBps_to_icc(PCIE_GEN1_BW_MBPS)); > > > + ret = icc_set_bw(pcie_ep->icc_mem, 0, QCOM_PCIE_LINK_SPEED_TO_BW(1)); > > > > "1" is not very informative here. Maybe PCIE_SPEED_2_5GT? (I didn't > > completely verify that this is equivalent.) > > No. PCIE_SPEED_2_5GT is defined as 0x14 in pci.h. And I do not want to add a > macro for just "1" here. Is there no other existing macro that contains the 2.5GT/s hint?
On Thu, Sep 28, 2023 at 04:27:57PM -0500, Bjorn Helgaas wrote: > On Thu, Sep 28, 2023 at 08:48:08PM +0200, Manivannan Sadhasivam wrote: > > On Wed, Sep 27, 2023 at 12:55:42PM -0500, Bjorn Helgaas wrote: > > > On Wed, Sep 27, 2023 at 05:46:02PM +0200, Manivannan Sadhasivam wrote: > > > > Instead of hardcoding the link speed in MBps, let's make use of the > > > > existing PCIE_SPEED2MBS_ENC() macro that does the encoding of the > > > > link speed for us. Also, let's Wrap it with QCOM_PCIE_LINK_SPEED_TO_BW() > > > > macro to do the conversion to ICC speed. > > > > > - ret = icc_set_bw(pcie_ep->icc_mem, 0, MBps_to_icc(PCIE_GEN1_BW_MBPS)); > > > > + ret = icc_set_bw(pcie_ep->icc_mem, 0, QCOM_PCIE_LINK_SPEED_TO_BW(1)); > > > > > > "1" is not very informative here. Maybe PCIE_SPEED_2_5GT? (I didn't > > > completely verify that this is equivalent.) > > > > No. PCIE_SPEED_2_5GT is defined as 0x14 in pci.h. And I do not want to add a > > macro for just "1" here. > > Is there no other existing macro that contains the 2.5GT/s hint? I couldn't find any :/ Adding a new macro would collide with the existing one IMO. - Mani
diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c index 8bd8107690a6..32c8d9e37876 100644 --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c @@ -23,6 +23,7 @@ #include <linux/reset.h> #include <linux/module.h> +#include "../../pci.h" #include "pcie-designware.h" /* PARF registers */ @@ -135,10 +136,8 @@ #define CORE_RESET_TIME_US_MAX 1005 #define WAKE_DELAY_US 2000 /* 2 ms */ -#define PCIE_GEN1_BW_MBPS 250 -#define PCIE_GEN2_BW_MBPS 500 -#define PCIE_GEN3_BW_MBPS 985 -#define PCIE_GEN4_BW_MBPS 1969 +#define QCOM_PCIE_LINK_SPEED_TO_BW(speed) \ + Mbps_to_icc(PCIE_SPEED2MBS_ENC(pcie_link_speed[speed])) #define to_pcie_ep(x) dev_get_drvdata((x)->dev) @@ -266,7 +265,7 @@ static void qcom_pcie_dw_stop_link(struct dw_pcie *pci) static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep) { struct dw_pcie *pci = &pcie_ep->pci; - u32 offset, status, bw; + u32 offset, status; int speed, width; int ret; @@ -279,25 +278,7 @@ static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep) speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status); width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status); - switch (speed) { - case 1: - bw = MBps_to_icc(PCIE_GEN1_BW_MBPS); - break; - case 2: - bw = MBps_to_icc(PCIE_GEN2_BW_MBPS); - break; - case 3: - bw = MBps_to_icc(PCIE_GEN3_BW_MBPS); - break; - default: - dev_warn(pci->dev, "using default GEN4 bandwidth\n"); - fallthrough; - case 4: - bw = MBps_to_icc(PCIE_GEN4_BW_MBPS); - break; - } - - ret = icc_set_bw(pcie_ep->icc_mem, 0, width * bw); + ret = icc_set_bw(pcie_ep->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); @@ -335,7 +316,7 @@ static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep) * Set an initial peak bandwidth corresponding to single-lane Gen 1 * for the pcie-mem path. */ - ret = icc_set_bw(pcie_ep->icc_mem, 0, MBps_to_icc(PCIE_GEN1_BW_MBPS)); + ret = icc_set_bw(pcie_ep->icc_mem, 0, QCOM_PCIE_LINK_SPEED_TO_BW(1)); if (ret) { dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n", ret);
Instead of hardcoding the link speed in MBps, let's make use of the existing PCIE_SPEED2MBS_ENC() macro that does the encoding of the link speed for us. Also, let's Wrap it with QCOM_PCIE_LINK_SPEED_TO_BW() macro to do the conversion to ICC speed. This eliminates the need for a switch case in qcom_pcie_icc_update() and also works for future Gen speeds without any code modifications. Suggested-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> --- Changes in v3: - New patch drivers/pci/controller/dwc/pcie-qcom-ep.c | 31 +++++------------------ 1 file changed, 6 insertions(+), 25 deletions(-)