[PATCH 08/13] mpt3sas: Add app owned flag support for diag buffer

[Sreekanth Reddy <sreekanth.reddy@broadcom.com>]

Added a new status flag named MPT3_DIAG_BUFFER_IS_APP_OWNED and it will
set whenever application registers the diag buffer & it will be cleared
when application unregisters the buffer.

When this flag is enabled and if application issues diag buffer register
command without releasing the buffer then register command will be failed
with -EINVAL status by saying that this buffer is already registered by
the application.

When user issues a trace buffer register command through sysfs parameter
and if trace buffer is in released stated but not yet unregistered by the
application which was owning it then driver will unregister the buffer
by itself and freshly registers the 1MB sized trace buffer with the
HBA firmware.

Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
---
 drivers/scsi/mpt3sas/mpt3sas_base.h |  1 +
 drivers/scsi/mpt3sas/mpt3sas_ctl.c  | 43 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.h b/drivers/scsi/mpt3sas/mpt3sas_base.h
index eaeb71f..91f6636 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.h
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.h
@@ -304,6 +304,7 @@ struct mpt3sas_nvme_cmd {
 #define MPT3_DIAG_BUFFER_IS_RELEASED	(0x02)
 #define MPT3_DIAG_BUFFER_IS_DIAG_RESET	(0x04)
 #define MPT3_DIAG_BUFFER_IS_DRIVER_ALLOCATED (0x08)
+#define MPT3_DIAG_BUFFER_IS_APP_OWNED (0x10)
 
 /*
  * HP HBA branding
diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
index b5492f1..62e878d 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
@@ -1565,6 +1565,16 @@ _ctl_diag_register_2(struct MPT3SAS_ADAPTER *ioc,
 		return -EINVAL;
 	}
 
+	if ((ioc->diag_buffer_status[buffer_type] &
+	    MPT3_DIAG_BUFFER_IS_APP_OWNED) &&
+	    !(ioc->diag_buffer_status[buffer_type] &
+	    MPT3_DIAG_BUFFER_IS_RELEASED)) {
+		ioc_err(ioc,
+		    "%s: buffer_type(0x%02x) is already registered by application with UID(0x%08x)\n",
+		    __func__, buffer_type, ioc->unique_id[buffer_type]);
+		return -EINVAL;
+	}
+
 	if (ioc->diag_buffer_status[buffer_type] &
 	    MPT3_DIAG_BUFFER_IS_REGISTERED) {
 		/*
@@ -1884,6 +1894,12 @@ _ctl_diag_register(struct MPT3SAS_ADAPTER *ioc, void __user *arg)
 	}
 
 	rc = _ctl_diag_register_2(ioc, &karg);
+
+	if (!rc && (ioc->diag_buffer_status[karg.buffer_type] &
+	    MPT3_DIAG_BUFFER_IS_REGISTERED))
+		ioc->diag_buffer_status[karg.buffer_type] |=
+		    MPT3_DIAG_BUFFER_IS_APP_OWNED;
+
 	return rc;
 }
 
@@ -1956,6 +1972,8 @@ _ctl_diag_unregister(struct MPT3SAS_ADAPTER *ioc, void __user *arg)
 	    MPT3_DIAG_BUFFER_IS_DRIVER_ALLOCATED) {
 		ioc->unique_id[buffer_type] = MPT3DIAGBUFFUNIQUEID;
 		ioc->diag_buffer_status[buffer_type] &=
+		    ~MPT3_DIAG_BUFFER_IS_APP_OWNED;
+		ioc->diag_buffer_status[buffer_type] &=
 		    ~MPT3_DIAG_BUFFER_IS_REGISTERED;
 	} else {
 		request_data_sz = ioc->diag_buffer_sz[buffer_type];
@@ -2040,6 +2058,10 @@ _ctl_diag_query(struct MPT3SAS_ADAPTER *ioc, void __user *arg)
 	    MPT3_DIAG_BUFFER_IS_DRIVER_ALLOCATED))
 		karg.application_flags |= MPT3_APP_FLAGS_DYNAMIC_BUFFER_ALLOC;
 
+	if ((ioc->diag_buffer_status[buffer_type] &
+	    MPT3_DIAG_BUFFER_IS_APP_OWNED))
+		karg.application_flags |= MPT3_APP_FLAGS_APP_OWNED;
+
 	for (i = 0; i < MPT3_PRODUCT_SPECIFIC_DWORDS; i++)
 		karg.product_specific[i] =
 		    ioc->product_specific[buffer_type][i];
@@ -3331,8 +3353,27 @@ host_trace_buffer_enable_store(struct device *cdev,
 			/* post the same buffer allocated previously */
 			diag_register.requested_buffer_size =
 			    ioc->diag_buffer_sz[MPI2_DIAG_BUF_TYPE_TRACE];
-		} else
+		} else {
+			/*
+			 * Free the diag buffer memory which was previously
+			 * allocated by an application.
+			 */
+			if ((ioc->diag_buffer_sz[MPI2_DIAG_BUF_TYPE_TRACE] != 0)
+			    &&
+			    (ioc->diag_buffer_status[MPI2_DIAG_BUF_TYPE_TRACE] &
+			    MPT3_DIAG_BUFFER_IS_APP_OWNED)) {
+				pci_free_consistent(ioc->pdev,
+				    ioc->diag_buffer_sz[
+				    MPI2_DIAG_BUF_TYPE_TRACE],
+				    ioc->diag_buffer[MPI2_DIAG_BUF_TYPE_TRACE],
+				    ioc->diag_buffer_dma[
+				    MPI2_DIAG_BUF_TYPE_TRACE]);
+				ioc->diag_buffer[MPI2_DIAG_BUF_TYPE_TRACE] =
+				    NULL;
+			}
+
 			diag_register.requested_buffer_size = (1024 * 1024);
+		}
 
 		diag_register.unique_id =
 		    (ioc->hba_mpi_version_belonged == MPI2_VERSION) ?
-- 
1.8.3.1