[PATCH 2/6] scsi: hpsa: Support HBA mode on HP Smart Array P410i controllers

[Ivan Mironov <mironov.ivan@gmail.com>]

This patch is based on code from the 316b221, most of which was removed by
the b9092b7.

Originally, HBA mode on these controllers was supported only on
Itanium-based HP Integrity servers running HP-UX. Tool for switching
between RAID and HBA modes existed only in form of EFI binary for
ia64 architecture: saupdate.efi[1]. However, I guessed how to overwrite the
corresponding flags field in controller's NVRAM, and was able to
reimplement RAID/HBA mode switching tool for Linux[2].

This change was successfully tested using blktests[3] and xfstests[4] on
my hardware, with embedded P410i controller (PCI ID: 103c:3245, board
ID: 0x3245103c) with firmware version 6.64.

This may work with some other controllers, but it is not tested
(because I do not have the hardware) and it may be very dangerous. That is
why this functionality is disabled by default and may be enabled only
manually using the new module parameter.

[1] https://support.hpe.com/hpsc/swd/public/detail?swItemId=MTX_0b76aec489764aea9802a6d27b
[2] https://github.com/im-0/hpsahba
[3] https://github.com/osandov/blktests
[4] https://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git

Signed-off-by: Ivan Mironov <mironov.ivan@gmail.com>
---
 drivers/scsi/hpsa.c | 98 +++++++++++++++++++++++++++++++++++++++++++--
 drivers/scsi/hpsa.h |  3 ++
 2 files changed, 97 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index fc06b790f16b..ee3d7c722a63 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -88,6 +88,11 @@ module_param(hpsa_simple_mode, int, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(hpsa_simple_mode,
 	"Use 'simple mode' rather than 'performant mode'");
 
+static bool hpsa_use_nvram_hba_flag;
+module_param(hpsa_use_nvram_hba_flag, bool, 0444);
+MODULE_PARM_DESC(hpsa_use_nvram_hba_flag,
+	"Use flag from NVRAM to enable HBA mode");
+
 /* define the PCI info for the cards we can control */
 static const struct pci_device_id hpsa_pci_device_id[] = {
 	{PCI_VENDOR_ID_HP,     PCI_DEVICE_ID_HP_CISSE,     0x103C, 0x3241},
@@ -3039,6 +3044,37 @@ static int hpsa_scsi_do_inquiry(struct ctlr_info *h, unsigned char *scsi3addr,
 	return rc;
 }
 
+static int hpsa_bmic_ctrl_mode_sense(struct ctlr_info *h,
+	struct bmic_controller_parameters *buf)
+{
+	int rc = IO_OK;
+	struct CommandList *c;
+	struct ErrorInfo *ei;
+
+	c = cmd_alloc(h);
+
+	if (fill_cmd(c, BMIC_SENSE_CONTROLLER_PARAMETERS, h, buf, sizeof(*buf),
+			0, RAID_CTLR_LUNID, TYPE_CMD)) {
+		rc = -1;
+		goto out;
+	}
+
+	rc = hpsa_scsi_do_simple_cmd_with_retry(h, c, PCI_DMA_FROMDEVICE,
+		NO_TIMEOUT);
+	if (rc)
+		goto out;
+
+	ei = c->err_info;
+	if (ei->CommandStatus != 0 && ei->CommandStatus != CMD_DATA_UNDERRUN) {
+		hpsa_scsi_interpret_error(h, c);
+		rc = -1;
+	}
+
+out:
+	cmd_free(h, c);
+	return rc;
+}
+
 static int hpsa_send_reset(struct ctlr_info *h, unsigned char *scsi3addr,
 	u8 reset_type, int reply_queue)
 {
@@ -4296,6 +4332,50 @@ static bool hpsa_skip_device(struct ctlr_info *h, u8 *lunaddrbytes,
 	return false;
 }
 
+static int hpsa_nvram_hba_flag_enabled(struct ctlr_info *h, bool *flag_enabled)
+{
+	int rc;
+	struct bmic_controller_parameters *ctlr_params;
+
+	ctlr_params = kzalloc(sizeof(*ctlr_params), GFP_KERNEL);
+	if (!ctlr_params) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	rc = hpsa_bmic_ctrl_mode_sense(h, ctlr_params);
+	if (rc)
+		goto out;
+
+	*flag_enabled = ctlr_params->nvram_flags & HPSA_NVRAM_FLAG_HBA;
+
+out:
+	kfree(ctlr_params);
+	return rc;
+}
+
+static int hpsa_update_nvram_hba_mode(struct ctlr_info *h)
+{
+	int rc;
+	bool flag_enabled;
+
+	if (!hpsa_use_nvram_hba_flag)
+		return 0;
+
+	rc = hpsa_nvram_hba_flag_enabled(h, &flag_enabled);
+	if (rc == -ENOMEM)
+		dev_warn(&h->pdev->dev, "Out of memory.\n");
+	if (rc)
+		return rc;
+
+	dev_info(&h->pdev->dev, "NVRAM HBA flag: %s\n",
+		flag_enabled ? "enabled" : "disabled");
+
+	h->nvram_hba_mode_enabled = flag_enabled;
+
+	return 0;
+}
+
 static void hpsa_update_scsi_devices(struct ctlr_info *h)
 {
 	/* the idea here is we could get notified
@@ -4352,6 +4432,11 @@ static void hpsa_update_scsi_devices(struct ctlr_info *h)
 			__func__);
 	}
 
+	if (hpsa_update_nvram_hba_mode(h)) {
+		h->drv_req_rescan = 1;
+		goto out;
+	}
+
 	/* We might see up to the maximum number of logical and physical disks
 	 * plus external target devices, and a device for the local RAID
 	 * controller.
@@ -4437,11 +4522,16 @@ static void hpsa_update_scsi_devices(struct ctlr_info *h)
 		 * Expose all devices except for physical devices that
 		 * are masked.
 		 */
-		if (MASKED_DEVICE(lunaddrbytes) && this_device->physical_device)
-			this_device->expose_device = 0;
-		else
+		if (MASKED_DEVICE(lunaddrbytes) &&
+				this_device->physical_device) {
+			if (is_disk_or_zbc(this_device) &&
+					h->nvram_hba_mode_enabled)
+				this_device->expose_device = 1;
+			else
+				this_device->expose_device = 0;
+		} else {
 			this_device->expose_device = 1;
-
+		}
 
 		/*
 		 * Get the SAS address for physical devices that are exposed.
diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index 59e023696fff..5b508f270520 100644
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -158,6 +158,8 @@ struct bmic_controller_parameters {
 };
 #pragma pack()
 
+#define HPSA_NVRAM_FLAG_HBA (1 << 3)
+
 struct ctlr_info {
 	unsigned int *reply_map;
 	int	ctlr;
@@ -182,6 +184,7 @@ struct ctlr_info {
 	unsigned int msix_vectors;
 	int intr_mode; /* either PERF_MODE_INT or SIMPLE_MODE_INT */
 	struct access_method access;
+	bool nvram_hba_mode_enabled;
 
 	/* queue and queue Info */
 	unsigned int Qdepth;
-- 
2.19.2