diff mbox series

[V2] scsi: ufs-pci: Add LTR support for Intel controllers

Message ID 20200827072030.24655-1-adrian.hunter@intel.com
State New
Headers show
Series [V2] scsi: ufs-pci: Add LTR support for Intel controllers | expand

Commit Message

Adrian Hunter Aug. 27, 2020, 7:20 a.m. UTC
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@intel.com>
---


Changes in V2:

	Put debugfs code altogether


 drivers/scsi/ufs/ufshcd-pci.c | 127 +++++++++++++++++++++++++++++++++-
 1 file changed, 125 insertions(+), 2 deletions(-)

Comments

Adrian Hunter Sept. 2, 2020, 9:27 a.m. UTC | #1
On 2/09/20 5:12 am, Martin K. Petersen wrote:
> 
> Adrian,
> 
>> 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.
> 
> Does not apply to 5.10/scsi-queue. Please rebase. Thanks!
> 

Hi

Thanks for processing this.

The 5.10/scsi-queue branch seems to be missing the following fix.  If you cherry
pick that, then it applies.


                                                                                                                                                                                                                                                                                          
commit 8da76f71fef7d8a1a72af09d48899573feb60065                                                                                                                                                                                                                                                                                                                                     
Author: Adrian Hunter <adrian.hunter@intel.com>                                                                                                                                                                                                                                                                                                                                     
Date:   Mon Aug 10 17:10:24 2020 +0300                                                                                                                                                                                                                                                                                                                                              
                                                                                                                                                                                                                                                                                                                                                                                    
    scsi: ufs-pci: Add quirk for broken auto-hibernate for Intel EHL                                                                                                                                                                                                                                                                                                                
                                                                                                                                                                                                                                                                                                                                                                                    
    Intel EHL UFS host controller advertises auto-hibernate capability but it
    does not work correctly. Add a quirk for that.
    
    [mkp: checkpatch fix]
    
    Link: https://lore.kernel.org/r/20200810141024.28859-1-adrian.hunter@intel.com
    Fixes: 8c09d7527697 ("scsi: ufshdc-pci: Add Intel PCI IDs for EHL")
    Acked-by: Stanley Chu <stanley.chu@mediatek.com>
    Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
    Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Adrian Hunter Sept. 9, 2020, 2:06 p.m. UTC | #2
On 2/09/20 12:27 pm, Adrian Hunter wrote:
> On 2/09/20 5:12 am, Martin K. Petersen wrote:
>>
>> Adrian,
>>
>>> 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.
>>
>> Does not apply to 5.10/scsi-queue. Please rebase. Thanks!
>>
> 
> Hi
> 
> Thanks for processing this.
> 
> The 5.10/scsi-queue branch seems to be missing the following fix.  If you cherry
> pick that, then it applies.

Now there seem to be conflicts between 5.10/scsi-queue and v5.9-rc4.
I am not sure what I can do?


~/git/scsi-mkp$ git branch -v --list 5.10/scsi-queue
* 5.10/scsi-queue 2e9defc7e918 [ahead 427, behind 97] scsi: ufs: Fix a race condition between error handler and runtime PM ops
~/git/scsi-mkp$ git rebase --onto v5.9-rc4 v5.9-rc1
First, rewinding head to replay your work on top of it...
Applying: scsi: ufs: Add checks before setting clk-gating states
Applying: scsi: ufs: ufs-qcom: Fix race conditions caused by ufs_qcom_testbus_config()
Applying: scsi: ufs-qcom: Remove testbus dump in ufs_qcom_dump_dbg_regs
Applying: scsi: ufs: Add some debug information to ufshcd_print_host_state()
Applying: scsi: ufs: Fix concurrency of error handler and other error recovery paths
Applying: scsi: ufs: Recover HBA runtime PM error in error handler
Applying: scsi: ufs: Move dumps in IRQ handler to error handler
Applying: scsi: ufs: Fix a race condition between error handler and runtime PM ops
Applying: scsi: ufs: Properly release resources if a task is aborted successfully
Using index info to reconstruct a base tree...
M       drivers/scsi/ufs/ufshcd.c
Falling back to patching base and 3-way merge...
Auto-merging drivers/scsi/ufs/ufshcd.c
CONFLICT (content): Merge conflict in drivers/scsi/ufs/ufshcd.c
error: Failed to merge in the changes.
Patch failed at 0009 scsi: ufs: Properly release resources if a task is aborted successfully
Use 'git am --show-current-patch' to see the failed patch

Resolve all conflicts manually, mark them as resolved with
"git add/rm <conflicted_files>", then run "git rebase --continue".
You can instead skip this commit: run "git rebase --skip".
To abort and get back to the state before "git rebase", run "git rebase --abort".

~/git/scsi-mkp$ git diff
diff --cc drivers/scsi/ufs/ufshcd.c
index d9386f85c255,efb40b1b95b4..000000000000
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@@ -6640,12 -6636,8 +6640,14 @@@ static int ufshcd_abort(struct scsi_cmn
                goto out;
        }
  
++<<<<<<< HEAD
 +cleanup:
 +      scsi_dma_unmap(cmd);
 +
++=======
++>>>>>>> scsi: ufs: Properly release resources if a task is aborted successfully
        spin_lock_irqsave(host->host_lock, flags);
-       ufshcd_outstanding_req_clear(hba, tag);
-       hba->lrb[tag].cmd = NULL;
+       __ufshcd_transfer_req_compl(hba, (1UL << tag));
        spin_unlock_irqrestore(host->host_lock, flags);
  
  out:

~/git/scsi-mkp$ git am --show-current-patch | head -25
commit 8bb2dde069d860e7ea379862a7d0e8ee01cec5e9
Author: Can Guo <cang@codeaurora.org>
Date:   Sun Aug 9 05:15:55 2020 -0700

    scsi: ufs: Properly release resources if a task is aborted successfully
    
    In current UFS task abort hook, namely ufshcd_abort(), if one task is
    aborted successfully, clk_gating.active_reqs held by this task is not
    decreased, which makes clk_gating.active_reqs stay above zero forever, thus
    clock gating would never happen. Instead of releasing resources of one task
    "manually", use the existing func __ufshcd_transfer_req_compl().  This
    change also eliminates a possible race of scsi_dma_unmap() from the real
    completion in IRQ handler path.
    
    Link: https://lore.kernel.org/r/1596975355-39813-10-git-send-email-cang@codeaurora.org
    Fixes: 1ab27c9cf8b6 ("ufs: Add support for clock gating")
    CC: Stanley Chu <stanley.chu@mediatek.com>
    Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
    Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
    Signed-off-by: Can Guo <cang@codeaurora.org>
    Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Martin K. Petersen Sept. 15, 2020, 8:19 p.m. UTC | #3
Adrian,

> 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.

Applied to 5.10/scsi-staging. Thanks!
Martin K. Petersen Sept. 22, 2020, 3:56 a.m. UTC | #4
On Thu, 27 Aug 2020 10:20:30 +0300, Adrian Hunter wrote:

> 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.


Applied to 5.10/scsi-queue, thanks!

[1/1] scsi: ufs-pci: Add LTR support for Intel controllers
      https://git.kernel.org/mkp/scsi/c/247f99445938

-- 
Martin K. Petersen	Oracle Linux Engineering
diff mbox series

Patch

diff --git a/drivers/scsi/ufs/ufshcd-pci.c b/drivers/scsi/ufs/ufshcd-pci.c
index 5a95a7bfbab0..df3a564c3e33 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 +52,134 @@  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);
+}
+
+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 intel_ltr_expose(struct device *dev)
+{
+	dev->power.set_latency_tolerance = intel_ltr_set;
+	dev_pm_qos_expose_latency_tolerance(dev);
+}
+
+static void intel_ltr_hide(struct device *dev)
+{
+	dev_pm_qos_hide_latency_tolerance(dev);
+	dev->power.set_latency_tolerance = NULL;
+}
+
+static void intel_add_debugfs(struct ufs_hba *hba)
+{
+	struct dentry *dir = debugfs_create_dir(dev_name(hba->dev), NULL);
+	struct intel_host *host = ufshcd_get_variant(hba);
+
+	intel_cache_ltr(hba);
+
+	host->debugfs_root = dir;
+	debugfs_create_x32("active_ltr", 0444, dir, &host->active_ltr);
+	debugfs_create_x32("idle_ltr", 0444, dir, &host->idle_ltr);
+}
+
+static void intel_remove_debugfs(struct ufs_hba *hba)
+{
+	struct intel_host *host = ufshcd_get_variant(hba);
+
+	debugfs_remove_recursive(host->debugfs_root);
+}
+
+static int ufs_intel_common_init(struct ufs_hba *hba)
+{
+	struct intel_host *host;
+
+	host = devm_kzalloc(hba->dev, sizeof(*host), GFP_KERNEL);
+	if (!host)
+		return -ENOMEM;
+	ufshcd_set_variant(hba, host);
+	intel_ltr_expose(hba->dev);
+	intel_add_debugfs(hba);
+	return 0;
+}
+
+static void ufs_intel_common_exit(struct ufs_hba *hba)
+{
+	intel_remove_debugfs(hba);
+	intel_ltr_hide(hba->dev);
+}
+
 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 +284,8 @@  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 +295,6 @@  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);