[SCSI] megaraid_sas: Add poll mechanism to megaraid sas driver

Add Poll_wait mechanism to SAS-2 MegaRAID SAS Linux driver. Driver
will wakeup poll after the driver get event from MegaRAID SAS FW.

Signed-off-by Bo Yang<bo.yang@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

2 files changed, 45 insertions, 1 deletions

diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index 6fd1e1796029..0d44fecf367d 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -40,6 +40,7 @@
 #include <linux/compat.h>
 #include <linux/blkdev.h>
 #include <linux/mutex.h>
+#include <linux/poll.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -89,8 +90,14 @@ static struct megasas_mgmt_info megasas_mgmt_info;
 static struct fasync_struct *megasas_async_queue;
 static DEFINE_MUTEX(megasas_async_queue_mutex);
 
+static int megasas_poll_wait_aen;
+static DECLARE_WAIT_QUEUE_HEAD(megasas_poll_wait);
+
 static u32 megasas_dbg_lvl;
 
+/* define lock for aen poll */
+spinlock_t poll_aen_lock;
+
 static void
 megasas_complete_cmd(struct megasas_instance *instance, struct megasas_cmd *cmd,
                      u8 alt_status);
@@ -1292,11 +1299,17 @@ megasas_bios_param(struct scsi_device *sdev, struct block_device *bdev,
 static void
 megasas_service_aen(struct megasas_instance *instance, struct megasas_cmd *cmd)
 {
+        unsigned long flags;
         /*
          * Don't signal app if it is just an aborted previously registered aen
          */
-        if (!cmd->abort_aen)
+        if ((!cmd->abort_aen) && (instance->unload == 0)) {
+                spin_lock_irqsave(&poll_aen_lock, flags);
+                megasas_poll_wait_aen = 1;
+                spin_unlock_irqrestore(&poll_aen_lock, flags);
+                wake_up(&megasas_poll_wait);
                 kill_fasync(&megasas_async_queue, SIGIO, POLL_IN);
+        }
         else
                 cmd->abort_aen = 0;
 
@@ -1381,6 +1394,7 @@ megasas_complete_cmd(struct megasas_instance *instance, struct megasas_cmd *cmd,
 {
         int exception = 0;
         struct megasas_header *hdr = &cmd->frame->hdr;
+        unsigned long flags;
 
         if (cmd->scmd)
                 cmd->scmd->SCp.ptr = NULL;
@@ -1470,6 +1484,12 @@ megasas_complete_cmd(struct megasas_instance *instance, struct megasas_cmd *cmd,
         case MFI_CMD_SMP:
         case MFI_CMD_STP:
         case MFI_CMD_DCMD:
+                if (cmd->frame->dcmd.opcode == MR_DCMD_CTRL_EVENT_GET_INFO ||
+                        cmd->frame->dcmd.opcode == MR_DCMD_CTRL_EVENT_GET) {
+                        spin_lock_irqsave(&poll_aen_lock, flags);
+                        megasas_poll_wait_aen = 0;
+                        spin_unlock_irqrestore(&poll_aen_lock, flags);
+                }
 
                 /*
                  * See if got an event notification
@@ -2583,6 +2603,7 @@ megasas_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 
         *instance->producer = 0;
         *instance->consumer = 0;
+        megasas_poll_wait_aen = 0;
 
         instance->evt_detail = pci_alloc_consistent(pdev,
                                                     sizeof(struct
@@ -2607,6 +2628,7 @@ megasas_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 
         spin_lock_init(&instance->cmd_pool_lock);
         spin_lock_init(&instance->completion_lock);
+        spin_lock_init(&poll_aen_lock);
 
         mutex_init(&instance->aen_mutex);
         sema_init(&instance->ioctl_sem, MEGASAS_INT_CMDS);
@@ -2621,6 +2643,7 @@ megasas_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 
         megasas_dbg_lvl = 0;
         instance->flag = 0;
+        instance->unload = 0;
         instance->last_time = 0;
 
         /*
@@ -2924,6 +2947,7 @@ static void __devexit megasas_detach_one(struct pci_dev *pdev)
         struct megasas_instance *instance;
 
         instance = pci_get_drvdata(pdev);
+        instance->unload = 1;
         host = instance->host;
 
         if (poll_mode_io)
@@ -3027,6 +3051,23 @@ static int megasas_mgmt_fasync(int fd, struct file *filep, int mode)
 }
 
 /**
+ * megasas_mgmt_poll -  char node "poll" entry point
+ * */
+static unsigned int megasas_mgmt_poll(struct file *file, poll_table *wait)
+{
+        unsigned int mask;
+        unsigned long flags;
+        poll_wait(file, &megasas_poll_wait, wait);
+        spin_lock_irqsave(&poll_aen_lock, flags);
+        if (megasas_poll_wait_aen)
+                mask =   (POLLIN | POLLRDNORM);
+        else
+                mask = 0;
+        spin_unlock_irqrestore(&poll_aen_lock, flags);
+        return mask;
+}
+
+/**
  * megasas_mgmt_fw_ioctl -      Issues management ioctls to FW
  * @instance:                   Adapter soft state
  * @argp:                       User's ioctl packet
@@ -3067,6 +3108,7 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance,
          */
         memcpy(cmd->frame, ioc->frame.raw, 2 * MEGAMFI_FRAME_SIZE);
         cmd->frame->hdr.context = cmd->index;
+        cmd->frame->hdr.pad_0 = 0;
 
         /*
          * The management interface between applications and the fw uses
@@ -3348,6 +3390,7 @@ static const struct file_operations megasas_mgmt_fops = {
         .open = megasas_mgmt_open,
         .fasync = megasas_mgmt_fasync,
         .unlocked_ioctl = megasas_mgmt_ioctl,
+        .poll = megasas_mgmt_poll,
 #ifdef CONFIG_COMPAT
         .compat_ioctl = megasas_mgmt_compat_ioctl,
 #endif
diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
index 0d033248fdf1..900359fd3fb9 100644
--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -1120,6 +1120,7 @@ struct megasas_instance {
         struct tasklet_struct isr_tasklet;
 
         u8 flag;
+        u8 unload;
         unsigned long last_time;
 
         struct timer_list io_completion_timer;