[PATCH] cciss: Add cciss_allow_hpsa module parameter.

[PATCH] cciss: Add cciss_allow_hpsa module parameter.

[Stephen M. Cameron]

Add cciss_allow_hpsa module parameter.  This parameter causes
the cciss driver to ignore any Smart Array devices known to be
supported by the hpsa driver.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
---

 drivers/block/cciss.c |   74 +++++++++++++++++++++++--------------------------
 1 files changed, 34 insertions(+), 40 deletions(-)

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 52f53c1..6399e50 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -68,6 +68,12 @@ MODULE_SUPPORTED_DEVICE("HP SA5i SA5i+ SA532 SA5300 SA5312 SA641 SA642 SA6400"
 MODULE_VERSION("3.6.20");
 MODULE_LICENSE("GPL");
 
+static int cciss_allow_hpsa;
+module_param(cciss_allow_hpsa, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(cciss_allow_hpsa,
+	"Prevent cciss driver from accessing hardware known to be "
+	" supported by the hpsa driver");
+
 #include "cciss_cmd.h"
 #include "cciss.h"
 #include <linux/cciss_ioctl.h>
@@ -101,8 +107,6 @@ static const struct pci_device_id cciss_pci_device_id[] = {
 	{PCI_VENDOR_ID_HP,     PCI_DEVICE_ID_HP_CISSE,     0x103C, 0x3249},
 	{PCI_VENDOR_ID_HP,     PCI_DEVICE_ID_HP_CISSE,     0x103C, 0x324A},
 	{PCI_VENDOR_ID_HP,     PCI_DEVICE_ID_HP_CISSE,     0x103C, 0x324B},
-	{PCI_VENDOR_ID_HP,     PCI_ANY_ID,	PCI_ANY_ID, PCI_ANY_ID,
-		PCI_CLASS_STORAGE_RAID << 8, 0xffff << 8, 0},
 	{0,}
 };
 
@@ -123,8 +127,6 @@ static struct board_type products[] = {
 	{0x409D0E11, "Smart Array 6400 EM", &SA5_access},
 	{0x40910E11, "Smart Array 6i", &SA5_access},
 	{0x3225103C, "Smart Array P600", &SA5_access},
-	{0x3223103C, "Smart Array P800", &SA5_access},
-	{0x3234103C, "Smart Array P400", &SA5_access},
 	{0x3235103C, "Smart Array P400i", &SA5_access},
 	{0x3211103C, "Smart Array E200i", &SA5_access},
 	{0x3212103C, "Smart Array E200", &SA5_access},
@@ -132,6 +134,10 @@ static struct board_type products[] = {
 	{0x3214103C, "Smart Array E200i", &SA5_access},
 	{0x3215103C, "Smart Array E200i", &SA5_access},
 	{0x3237103C, "Smart Array E500", &SA5_access},
+/* controllers below this line are also supported by the hpsa driver. */
+#define HPSA_BOUNDARY 0x3223103C
+	{0x3223103C, "Smart Array P800", &SA5_access},
+	{0x3234103C, "Smart Array P400", &SA5_access},
 	{0x323D103C, "Smart Array P700m", &SA5_access},
 	{0x3241103C, "Smart Array P212", &SA5_access},
 	{0x3243103C, "Smart Array P410", &SA5_access},
@@ -140,7 +146,6 @@ static struct board_type products[] = {
 	{0x3249103C, "Smart Array P812", &SA5_access},
 	{0x324A103C, "Smart Array P712m", &SA5_access},
 	{0x324B103C, "Smart Array P711m", &SA5_access},
-	{0xFFFF103C, "Unknown Smart Array", &SA5_access},
 };
 
 /* How long to wait (in milliseconds) for board to go into simple mode */
@@ -3754,7 +3759,27 @@ static int __devinit cciss_pci_init(ctlr_info_t *c, struct pci_dev *pdev)
 	__u64 cfg_offset;
 	__u32 cfg_base_addr;
 	__u64 cfg_base_addr_index;
-	int i, err;
+	int i, prod_index, err;
+
+	subsystem_vendor_id = pdev->subsystem_vendor;
+	subsystem_device_id = pdev->subsystem_device;
+	board_id = (((__u32) (subsystem_device_id << 16) & 0xffff0000) |
+		    subsystem_vendor_id);
+
+	for (i = 0; i < ARRAY_SIZE(products); i++) {
+		/* Stand aside for hpsa driver on request */
+		if (cciss_allow_hpsa && products[i].board_id == HPSA_BOUNDARY)
+			return -ENODEV;
+		if (board_id == products[i].board_id)
+			break;
+	}
+	prod_index = i;
+	if (prod_index == ARRAY_SIZE(products)) {
+		dev_warn(&pdev->dev,
+			"unrecognized board ID: 0x%08lx, ignoring.\n",
+			(unsigned long) board_id);
+		return -ENODEV;
+	}
 
 	/* check to see if controller has been disabled */
 	/* BEFORE trying to enable it */
@@ -3778,11 +3803,6 @@ static int __devinit cciss_pci_init(ctlr_info_t *c, struct pci_dev *pdev)
 		return err;
 	}
 
-	subsystem_vendor_id = pdev->subsystem_vendor;
-	subsystem_device_id = pdev->subsystem_device;
-	board_id = (((__u32) (subsystem_device_id << 16) & 0xffff0000) |
-		    subsystem_vendor_id);
-
 #ifdef CCISS_DEBUG
 	printk("command = %x\n", command);
 	printk("irq = %x\n", pdev->irq);
@@ -3868,14 +3888,9 @@ static int __devinit cciss_pci_init(ctlr_info_t *c, struct pci_dev *pdev)
 	 * leave a little room for ioctl calls.
 	 */
 	c->max_commands = readl(&(c->cfgtable->CmdsOutMax));
-	for (i = 0; i < ARRAY_SIZE(products); i++) {
-		if (board_id == products[i].board_id) {
-			c->product_name = products[i].product_name;
-			c->access = *(products[i].access);
-			c->nr_cmds = c->max_commands - 4;
-			break;
-		}
-	}
+	c->product_name = products[prod_index].product_name;
+	c->access = *(products[prod_index].access);
+	c->nr_cmds = c->max_commands - 4;
 	if ((readb(&c->cfgtable->Signature[0]) != 'C') ||
 	    (readb(&c->cfgtable->Signature[1]) != 'I') ||
 	    (readb(&c->cfgtable->Signature[2]) != 'S') ||
@@ -3884,27 +3899,6 @@ static int __devinit cciss_pci_init(ctlr_info_t *c, struct pci_dev *pdev)
 		err = -ENODEV;
 		goto err_out_free_res;
 	}
-	/* We didn't find the controller in our list. We know the
-	 * signature is valid. If it's an HP device let's try to
-	 * bind to the device and fire it up. Otherwise we bail.
-	 */
-	if (i == ARRAY_SIZE(products)) {
-		if (subsystem_vendor_id == PCI_VENDOR_ID_HP) {
-			c->product_name = products[i-1].product_name;
-			c->access = *(products[i-1].access);
-			c->nr_cmds = c->max_commands - 4;
-			printk(KERN_WARNING "cciss: This is an unknown "
-				"Smart Array controller.\n"
-				"cciss: Please update to the latest driver "
-				"available from www.hp.com.\n");
-		} else {
-			printk(KERN_WARNING "cciss: Sorry, I don't know how"
-				" to access the Smart Array controller %08lx\n"
-					, (unsigned long)board_id);
-			err = -ENODEV;
-			goto err_out_free_res;
-		}
-	}
 #ifdef CONFIG_X86
 	{
 		/* Need to enable prefetch in the SCSI core for 6400 in x86 */

Re: [PATCH] cciss: Add cciss_allow_hpsa module parameter.

[Andrew Morton]

On Mon, 12 Oct 2009 10:36:25 -0500
"Stephen M. Cameron" <scameron@beardog.cce.hp.com> wrote:

> Add cciss_allow_hpsa module parameter.  This parameter causes
> the cciss driver to ignore any Smart Array devices known to be
> supported by the hpsa driver.

An alternative approach would be to ensure that hpsa is loaded first. 
Then when cciss tries to control a device it will fail to acquire that
devices's PCI regions and will bale out in an orderly manner.

I don't know how we can reliably arrange for hpsa to execute first, but
I'm sure someone does ;)

Unless CONFIG_CCISS=y, CONFIG_HPSA=m.  Then we're screwed.

Re: [PATCH] cciss: Add cciss_allow_hpsa module parameter.

[Jens Axboe]

On Mon, Oct 12 2009, Stephen M. Cameron wrote:
> Add cciss_allow_hpsa module parameter.  This parameter causes
> the cciss driver to ignore any Smart Array devices known to be
> supported by the hpsa driver.

Thanks, applied.

-- 
Jens Axboe

Re: [PATCH] cciss: Add cciss_allow_hpsa module parameter.

[scameron]

On Mon, Oct 12, 2009 at 03:06:15PM -0700, Andrew Morton wrote:
> On Mon, 12 Oct 2009 10:36:25 -0500
> "Stephen M. Cameron" <scameron@beardog.cce.hp.com> wrote:
> 
> > Add cciss_allow_hpsa module parameter.  This parameter causes
> > the cciss driver to ignore any Smart Array devices known to be
> > supported by the hpsa driver.
> 
> An alternative approach would be to ensure that hpsa is loaded first. 
> Then when cciss tries to control a device it will fail to acquire that
> devices's PCI regions and will bale out in an orderly manner.
> 
> I don't know how we can reliably arrange for hpsa to execute first, but
> I'm sure someone does ;)
> 
> Unless CONFIG_CCISS=y, CONFIG_HPSA=m.  Then we're screwed.

My thinking was that with the module parameter, the default behavior
of cciss would be (almost*) unchanged, which would mean that people putting a
new kernel on an existing system would not get surprised when say,
 /dev/cciss/c0d0, likely their boot device, suddenly showed up as
/dev/sda instead, and their system wouldn't boot, their (old) Array
Configuration Utility didn't know what to make of hpsa, etc.

If somebody wants to switch to hpsa then they can via the module parameter,
but I think it's not a good idea to force them to switch at this time with no
real notice other than sudden failure to boot due to broken grub entries, 
fstab entries, etc.

(*the change in the default behavior would be that cciss would no longer load
on controllers which it doesn't explicitly know about.)

-- steve