dmaengine: idxd: remove interrupt disable for dev_lock

The spinlock is not being used in hard interrupt context. There is no need
to disable irq when acquiring the lock. The interrupt thread handler also
is not in bottom half context, therefore we can also remove disabling of
the bh. Convert all dev_lock acquisition to plain spin_lock() calls.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162984026772.1939166.11504067782824765879.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
index 4d2ecdb130e702acd1805fb6bfdf3ccacfa12635..b9b2b4a4124eee75dd04720c082023cd8a875177 100644 (file)
--- a/drivers/dma/idxd/cdev.c
+++ b/drivers/dma/idxd/cdev.c
@@ -218,14 +218,13 @@ static __poll_t idxd_cdev_poll(struct file *filp,
        struct idxd_user_context *ctx = filp->private_data;
        struct idxd_wq *wq = ctx->wq;
        struct idxd_device *idxd = wq->idxd;
-       unsigned long flags;
        __poll_t out = 0;
 
        poll_wait(filp, &wq->err_queue, wait);
-       spin_lock_irqsave(&idxd->dev_lock, flags);
+       spin_lock(&idxd->dev_lock);
        if (idxd->sw_err.valid)
                out = EPOLLIN | EPOLLRDNORM;
-       spin_unlock_irqrestore(&idxd->dev_lock, flags);
+       spin_unlock(&idxd->dev_lock);
 
        return out;
 }

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 4f6516d7555fb6c7dbfc79e647380e028e90217d..83a5ff2ecf2a0fcab3a8d148f0b7bf046cbcac1f 100644 (file)
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -341,19 +341,18 @@ int idxd_wq_set_pasid(struct idxd_wq *wq, int pasid)
        int rc;
        union wqcfg wqcfg;
        unsigned int offset;
-       unsigned long flags;
 
        rc = idxd_wq_disable(wq, false);
        if (rc < 0)
                return rc;
 
        offset = WQCFG_OFFSET(idxd, wq->id, WQCFG_PASID_IDX);
-       spin_lock_irqsave(&idxd->dev_lock, flags);
+       spin_lock(&idxd->dev_lock);
        wqcfg.bits[WQCFG_PASID_IDX] = ioread32(idxd->reg_base + offset);
        wqcfg.pasid_en = 1;
        wqcfg.pasid = pasid;
        iowrite32(wqcfg.bits[WQCFG_PASID_IDX], idxd->reg_base + offset);
-       spin_unlock_irqrestore(&idxd->dev_lock, flags);
+       spin_unlock(&idxd->dev_lock);
 
        rc = idxd_wq_enable(wq);
        if (rc < 0)
@@ -368,19 +367,18 @@ int idxd_wq_disable_pasid(struct idxd_wq *wq)
        int rc;
        union wqcfg wqcfg;
        unsigned int offset;
-       unsigned long flags;
 
        rc = idxd_wq_disable(wq, false);
        if (rc < 0)
                return rc;
 
        offset = WQCFG_OFFSET(idxd, wq->id, WQCFG_PASID_IDX);
-       spin_lock_irqsave(&idxd->dev_lock, flags);
+       spin_lock(&idxd->dev_lock);
        wqcfg.bits[WQCFG_PASID_IDX] = ioread32(idxd->reg_base + offset);
        wqcfg.pasid_en = 0;
        wqcfg.pasid = 0;
        iowrite32(wqcfg.bits[WQCFG_PASID_IDX], idxd->reg_base + offset);
-       spin_unlock_irqrestore(&idxd->dev_lock, flags);
+       spin_unlock(&idxd->dev_lock);
 
        rc = idxd_wq_enable(wq);
        if (rc < 0)
@@ -558,7 +556,6 @@ int idxd_device_disable(struct idxd_device *idxd)
 {
        struct device *dev = &idxd->pdev->dev;
        u32 status;
-       unsigned long flags;
 
        if (!idxd_is_enabled(idxd)) {
                dev_dbg(dev, "Device is not enabled\n");
@@ -574,22 +571,20 @@ int idxd_device_disable(struct idxd_device *idxd)
                return -ENXIO;
        }
 
-       spin_lock_irqsave(&idxd->dev_lock, flags);
+       spin_lock(&idxd->dev_lock);
        idxd_device_clear_state(idxd);
        idxd->state = IDXD_DEV_DISABLED;
-       spin_unlock_irqrestore(&idxd->dev_lock, flags);
+       spin_unlock(&idxd->dev_lock);
        return 0;
 }
 
 void idxd_device_reset(struct idxd_device *idxd)
 {
-       unsigned long flags;
-
        idxd_cmd_exec(idxd, IDXD_CMD_RESET_DEVICE, 0, NULL);
-       spin_lock_irqsave(&idxd->dev_lock, flags);
+       spin_lock(&idxd->dev_lock);
        idxd_device_clear_state(idxd);
        idxd->state = IDXD_DEV_DISABLED;
-       spin_unlock_irqrestore(&idxd->dev_lock, flags);
+       spin_unlock(&idxd->dev_lock);
 }
 
 void idxd_device_drain_pasid(struct idxd_device *idxd, int pasid)
@@ -1164,7 +1159,6 @@ int __drv_enable_wq(struct idxd_wq *wq)
 {
        struct idxd_device *idxd = wq->idxd;
        struct device *dev = &idxd->pdev->dev;
-       unsigned long flags;
        int rc = -ENXIO;
 
        lockdep_assert_held(&wq->wq_lock);
@@ -1216,10 +1210,10 @@ int __drv_enable_wq(struct idxd_wq *wq)
        }
 
        rc = 0;
-       spin_lock_irqsave(&idxd->dev_lock, flags);
+       spin_lock(&idxd->dev_lock);
        if (test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
                rc = idxd_device_config(idxd);
-       spin_unlock_irqrestore(&idxd->dev_lock, flags);
+       spin_unlock(&idxd->dev_lock);
        if (rc < 0) {
                dev_dbg(dev, "Writing wq %d config failed: %d\n", wq->id, rc);
                goto err;
@@ -1288,7 +1282,6 @@ void drv_disable_wq(struct idxd_wq *wq)
 int idxd_device_drv_probe(struct idxd_dev *idxd_dev)
 {
        struct idxd_device *idxd = idxd_dev_to_idxd(idxd_dev);
-       unsigned long flags;
        int rc = 0;
 
        /*
@@ -1302,10 +1295,10 @@ int idxd_device_drv_probe(struct idxd_dev *idxd_dev)
        }
 
        /* Device configuration */
-       spin_lock_irqsave(&idxd->dev_lock, flags);
+       spin_lock(&idxd->dev_lock);
        if (test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
                rc = idxd_device_config(idxd);
-       spin_unlock_irqrestore(&idxd->dev_lock, flags);
+       spin_unlock(&idxd->dev_lock);
        if (rc < 0)
                return -ENXIO;
 

diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c
index d221c2e374603a896d20d25d147f3e35760abc63..ca88fa7a328e741b8c8ec4a447173a01009b7b51 100644 (file)
--- a/drivers/dma/idxd/irq.c
+++ b/drivers/dma/idxd/irq.c
@@ -64,7 +64,7 @@ static int process_misc_interrupts(struct idxd_device *idxd, u32 cause)
        bool err = false;
 
        if (cause & IDXD_INTC_ERR) {
-               spin_lock_bh(&idxd->dev_lock);
+               spin_lock(&idxd->dev_lock);
                for (i = 0; i < 4; i++)
                        idxd->sw_err.bits[i] = ioread64(idxd->reg_base +
                                        IDXD_SWERR_OFFSET + i * sizeof(u64));
@@ -89,7 +89,7 @@ static int process_misc_interrupts(struct idxd_device *idxd, u32 cause)
                        }
                }
 
-               spin_unlock_bh(&idxd->dev_lock);
+               spin_unlock(&idxd->dev_lock);
                val |= IDXD_INTC_ERR;
 
                for (i = 0; i < 4; i++)
@@ -133,7 +133,7 @@ static int process_misc_interrupts(struct idxd_device *idxd, u32 cause)
                        INIT_WORK(&idxd->work, idxd_device_reinit);
                        queue_work(idxd->wq, &idxd->work);
                } else {
-                       spin_lock_bh(&idxd->dev_lock);
+                       spin_lock(&idxd->dev_lock);
                        idxd_wqs_quiesce(idxd);
                        idxd_wqs_unmap_portal(idxd);
                        idxd_device_clear_state(idxd);
@@ -141,7 +141,7 @@ static int process_misc_interrupts(struct idxd_device *idxd, u32 cause)
                                "idxd halted, need %s.\n",
                                gensts.reset_type == IDXD_DEVICE_RESET_FLR ?
                                "FLR" : "system reset");
-                       spin_unlock_bh(&idxd->dev_lock);
+                       spin_unlock(&idxd->dev_lock);
                        return -ENXIO;
                }
        }

diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index a88886d0f27bca0e336c129e0cb0888ec54e084c..a9025be940db2a964ef6c3da6472d0611383d0f7 100644 (file)
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -1099,16 +1099,15 @@ static ssize_t clients_show(struct device *dev,
                            struct device_attribute *attr, char *buf)
 {
        struct idxd_device *idxd = confdev_to_idxd(dev);
-       unsigned long flags;
        int count = 0, i;
 
-       spin_lock_irqsave(&idxd->dev_lock, flags);
+       spin_lock(&idxd->dev_lock);
        for (i = 0; i < idxd->max_wqs; i++) {
                struct idxd_wq *wq = idxd->wqs[i];
 
                count += wq->client_count;
        }
-       spin_unlock_irqrestore(&idxd->dev_lock, flags);
+       spin_unlock(&idxd->dev_lock);
 
        return sysfs_emit(buf, "%d\n", count);
 }
@@ -1146,12 +1145,11 @@ static ssize_t errors_show(struct device *dev,
 {
        struct idxd_device *idxd = confdev_to_idxd(dev);
        int i, out = 0;
-       unsigned long flags;
 
-       spin_lock_irqsave(&idxd->dev_lock, flags);
+       spin_lock(&idxd->dev_lock);
        for (i = 0; i < 4; i++)
                out += sysfs_emit_at(buf, out, "%#018llx ", idxd->sw_err.bits[i]);
-       spin_unlock_irqrestore(&idxd->dev_lock, flags);
+       spin_unlock(&idxd->dev_lock);
        out--;
        out += sysfs_emit_at(buf, out, "\n");
        return out;