>
> Intel host controllers support the setting of latency tolerance.
> Accordingly, implement the PM QoS ->set_latency_tolerance() callback. The
> raw register values are also exposed via debugfs.
>
> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Reviewed-by: Avri Altman <avri.altman@xxxxxxx>
Some nits below.
Thanks,
Avri
> ---
> drivers/scsi/ufs/ufshcd-pci.c | 122 +++++++++++++++++++++++++++++++++-
> 1 file changed, 120 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd-pci.c b/drivers/scsi/ufs/ufshcd-pci.c
> index 5a95a7bfbab0..e10f05013ae6 100644
> --- a/drivers/scsi/ufs/ufshcd-pci.c
> +++ b/drivers/scsi/ufs/ufshcd-pci.c
> @@ -13,6 +13,14 @@
> #include "ufshcd.h"
> #include <linux/pci.h>
> #include <linux/pm_runtime.h>
> +#include <linux/pm_qos.h>
> +#include <linux/debugfs.h>
> +
> +struct intel_host {
> + u32 active_ltr;
> + u32 idle_ltr;
> + struct dentry *debugfs_root;
> +};
>
> static int ufs_intel_disable_lcc(struct ufs_hba *hba)
> {
> @@ -44,20 +52,129 @@ static int ufs_intel_link_startup_notify(struct ufs_hba
> *hba,
> return err;
> }
>
> +#define INTEL_ACTIVELTR 0x804
> +#define INTEL_IDLELTR 0x808
> +
> +#define INTEL_LTR_REQ BIT(15)
> +#define INTEL_LTR_SCALE_MASK GENMASK(11, 10)
> +#define INTEL_LTR_SCALE_1US (2 << 10)
> +#define INTEL_LTR_SCALE_32US (3 << 10)
> +#define INTEL_LTR_VALUE_MASK GENMASK(9, 0)
> +
> +static void intel_cache_ltr(struct ufs_hba *hba)
> +{
> + struct intel_host *host = ufshcd_get_variant(hba);
> +
> + host->active_ltr = readl(hba->mmio_base + INTEL_ACTIVELTR);
> + host->idle_ltr = readl(hba->mmio_base + INTEL_IDLELTR);
You might want to use the standard ufshcd_readl
> +}
> +
> +static void intel_ltr_set(struct device *dev, s32 val)
> +{
> + struct ufs_hba *hba = dev_get_drvdata(dev);
> + struct intel_host *host = ufshcd_get_variant(hba);
> + u32 ltr;
> +
> + pm_runtime_get_sync(dev);
> +
> + /*
> + * Program latency tolerance (LTR) accordingly what has been asked
> + * by the PM QoS layer or disable it in case we were passed
> + * negative value or PM_QOS_LATENCY_ANY.
> + */
> + ltr = readl(hba->mmio_base + INTEL_ACTIVELTR);
> +
> + if (val == PM_QOS_LATENCY_ANY || val < 0) {
> + ltr &= ~INTEL_LTR_REQ;
> + } else {
> + ltr |= INTEL_LTR_REQ;
> + ltr &= ~INTEL_LTR_SCALE_MASK;
> + ltr &= ~INTEL_LTR_VALUE_MASK;
> +
> + if (val > INTEL_LTR_VALUE_MASK) {
> + val >>= 5;
> + if (val > INTEL_LTR_VALUE_MASK)
> + val = INTEL_LTR_VALUE_MASK;
> + ltr |= INTEL_LTR_SCALE_32US | val;
> + } else {
> + ltr |= INTEL_LTR_SCALE_1US | val;
> + }
> + }
> +
> + if (ltr == host->active_ltr)
> + goto out;
> +
> + writel(ltr, hba->mmio_base + INTEL_ACTIVELTR);
> + writel(ltr, hba->mmio_base + INTEL_IDLELTR);
> +
> + /* Cache the values into intel_host structure */
> + intel_cache_ltr(hba);
> +out:
> + pm_runtime_put(dev);
> +}
> +
> +static void ufs_intel_ltr_expose(struct ufs_hba *hba)
> +{
> + struct intel_host *host = ufshcd_get_variant(hba);
> + struct dentry *dir = host->debugfs_root;
> + struct device *dev = hba->dev;
> +
> + dev->power.set_latency_tolerance = intel_ltr_set;
> + dev_pm_qos_expose_latency_tolerance(dev);
> +
> + intel_cache_ltr(hba);
> +
> + debugfs_create_x32("active_ltr", 0444, dir, &host->active_ltr);
> + debugfs_create_x32("idle_ltr", 0444, dir, &host->idle_ltr);
You might as well allow those values to be traced, e.g. use dev_pm_qos_update_user_latency_tolerance
> +}
> +
> +static void ufs_intel_ltr_hide(struct ufs_hba *hba)
> +{
> + struct device *dev = hba->dev;
> +
> + dev_pm_qos_hide_latency_tolerance(dev);
> + dev->power.set_latency_tolerance = NULL;
> +}
> +
> +static int ufs_intel_common_init(struct ufs_hba *hba)
> +{
> + struct device *dev = hba->dev;
> + struct intel_host *host;
> +
> + host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
> + if (!host)
> + return -ENOMEM;
> + ufshcd_set_variant(hba, host);
> + host->debugfs_root = debugfs_create_dir(dev_name(dev), NULL);
Maybe pack the debugfs code together, i.e. move this just above debugfs_create_x32 ....
> + ufs_intel_ltr_expose(hba);
> + return 0;
> +}
> +
> +static void ufs_intel_common_exit(struct ufs_hba *hba)
> +{
> + struct intel_host *host = ufshcd_get_variant(hba);
> +
> + debugfs_remove_recursive(host->debugfs_root);
> + ufs_intel_ltr_hide(hba);
> +}
> +
> static int ufs_intel_ehl_init(struct ufs_hba *hba)
> {
> hba->quirks |= UFSHCD_QUIRK_BROKEN_AUTO_HIBERN8;
> - return 0;
> + return ufs_intel_common_init(hba);
> }
>
> static struct ufs_hba_variant_ops ufs_intel_cnl_hba_vops = {
> .name = "intel-pci",
> + .init = ufs_intel_common_init,
> + .exit = ufs_intel_common_exit,
> .link_startup_notify = ufs_intel_link_startup_notify,
> };
>
> static struct ufs_hba_variant_ops ufs_intel_ehl_hba_vops = {
> .name = "intel-pci",
> .init = ufs_intel_ehl_init,
> + .exit = ufs_intel_common_exit,
> .link_startup_notify = ufs_intel_link_startup_notify,
> };
>
> @@ -162,6 +279,8 @@ ufshcd_pci_probe(struct pci_dev *pdev, const struct
> pci_device_id *id)
> return err;
> }
>
> + pci_set_drvdata(pdev, hba);
> +
> hba->vops = (struct ufs_hba_variant_ops *)id->driver_data;
>
> err = ufshcd_init(hba, mmio_base, pdev->irq);
> @@ -171,7 +290,6 @@ ufshcd_pci_probe(struct pci_dev *pdev, const struct
> pci_device_id *id)
> return err;
> }
>
> - pci_set_drvdata(pdev, hba);
> pm_runtime_put_noidle(&pdev->dev);
> pm_runtime_allow(&pdev->dev);
>
> --
> 2.17.1
