[SCSI] mpt2sas: Added NUNA IO support in driver which uses multi-reply queue support of the HBA

Support added for controllers capable of multi reply queues.

The following are the modifications to the driver to support NUMA.

1) Create the new structure adapter_reply_queue to contain the reply queue
   info for every msix vector.  This object will contain a
   reply_post_host_index, reply_post_free for each instance, msix_index, among
   other parameters.  We will track all the reply queues on a link list called
   ioc->reply_queue_list. Each reply queue is aligned with each IRQ, and is
   passed to the interrupt via the bus_id parameter.

(2) The driver will figure out the msix_vector_count from the PCIe MSIX
    capabilities register instead of the IOC Facts->MaxMSIxVectors. This is
    because the firmware is not filling in this field until the driver has
    already registered MSIX support.

(3) If the ioc_facts reports that the controller is MSIX compatible in the
    capabilities, then the driver will request for multiple irqs.  This count
    is calculated based on the minimum between the online cpus available and
    the ioc->msix_vector_count.  This count is reported to firmware in the
    ioc_init request.

(4) New routines were added _base_free_irq and _base_request_irq, so
    registering and freeing msix vectors were done thru simple function API.

(5) The new routine _base_assign_reply_queues was added to align the msix
    indexes across cpus. This will initialize the array called
    ioc->cpu_msix_table.  This array is looked up on every MPI request so the
    MSIxIndex is set appropriately.

(6) A new shost sysfs attribute was added to report the reply_queue_count.

(7) User needs to set the affinity cpu mask, so the interrupts occur on the
    same cpu that sent the original request.

Signed-off-by: Nagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/scsi/mpt2sas/mpt2sas_ctl.c b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
index 38ed0260959d..bf70f95f19ce 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_ctl.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
@@ -2705,6 +2705,33 @@ _ctl_ioc_reset_count_show(struct device *cdev, struct device_attribute *attr,
 static DEVICE_ATTR(ioc_reset_count, S_IRUGO,
     _ctl_ioc_reset_count_show, NULL);
 
+/**
+ * _ctl_ioc_reply_queue_count_show - number of reply queues
+ * @cdev - pointer to embedded class device
+ * @buf - the buffer returned
+ *
+ * This is number of reply queues
+ *
+ * A sysfs 'read-only' shost attribute.
+ */
+static ssize_t
+_ctl_ioc_reply_queue_count_show(struct device *cdev,
+         struct device_attribute *attr, char *buf)
+{
+        u8 reply_queue_count;
+        struct Scsi_Host *shost = class_to_shost(cdev);
+        struct MPT2SAS_ADAPTER *ioc = shost_priv(shost);
+
+        if ((ioc->facts.IOCCapabilities &
+            MPI2_IOCFACTS_CAPABILITY_MSI_X_INDEX) && ioc->msix_enable)
+                reply_queue_count = ioc->reply_queue_count;
+        else
+                reply_queue_count = 1;
+        return snprintf(buf, PAGE_SIZE, "%d\n", reply_queue_count);
+}
+static DEVICE_ATTR(reply_queue_count, S_IRUGO,
+         _ctl_ioc_reply_queue_count_show, NULL);
+
 struct DIAG_BUFFER_START {
         __le32 Size;
         __le32 DiagVersion;
@@ -2915,6 +2942,7 @@ struct device_attribute *mpt2sas_host_attrs[] = {
         &dev_attr_host_trace_buffer_size,
         &dev_attr_host_trace_buffer,
         &dev_attr_host_trace_buffer_enable,
+        &dev_attr_reply_queue_count,
         NULL,
 };