[PATCH 2/12] scsi: megaraid_sas - Add poll mechanism to megaraidsas driver (part I)

[Yang, Bo]

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@xxxxxxx>

---
drivers/scsi/megaraid/megaraid_sas.c |   45 ++++++++++++++++++++++++++++++++++-
 drivers/scsi/megaraid/megaraid_sas.h |    1
 2 files changed, 45 insertions(+), 1 deletion(-)

diff -rupN linux-2.6.28_orig/drivers/scsi/megaraid/megaraid_sas.c linux-2.6.28_new/drivers/scsi/megaraid/megaraid_sas.c
--- linux-2.6.28_orig/drivers/scsi/megaraid/megaraid_sas.c      2009-06-10 14:31:17.000000000 -0400
+++ linux-2.6.28_new/drivers/scsi/megaraid/megaraid_sas.c       2009-09-13 09:45:56.000000000 -0400
@@ -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_
 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 *s
 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_inst
 {
        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_inst
        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,

        *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,

        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,

        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 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, s
 }

 /**
+ * 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_ins
         */
        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 mega
        .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 -rupN linux-2.6.28_orig/drivers/scsi/megaraid/megaraid_sas.h linux-2.6.28_new/drivers/scsi/megaraid/megaraid_sas.h
--- linux-2.6.28_orig/drivers/scsi/megaraid/megaraid_sas.h      2009-06-10 14:31:17.000000000 -0400
+++ linux-2.6.28_new/drivers/scsi/megaraid/megaraid_sas.h       2009-09-13 09:27:23.000000000 -0400
@@ -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;
--
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