[PATCH 2/5] scsi: megaraid_sas - added bios_param in scsi_host_template

[PATCH 2/5] scsi: megaraid_sas - added bios_param in scsi_host_template

[Sumant Patro]

[-- Attachment #1: Type: text/plain, Size: 2056 bytes --]

Added bios_param in scsi_host_template to return disk geometry.

Signed-off-by: Sumant Patro <sumant.patro@lsi.com>
---

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

diff -uprN 2.6.new-p1/drivers/scsi/megaraid/megaraid_sas.c 2.6.new-p2/drivers/scsi/megaraid/megaraid_sas.c
--- 2.6.new-p1/drivers/scsi/megaraid/megaraid_sas.c	2007-02-06 06:54:07.000000000 -0800
+++ 2.6.new-p2/drivers/scsi/megaraid/megaraid_sas.c	2007-02-06 08:43:40.000000000 -0800
@@ -35,6 +35,7 @@
 #include <asm/uaccess.h>
 #include <linux/fs.h>
 #include <linux/compat.h>
+#include <linux/blkdev.h>
 #include <linux/mutex.h>
 
 #include <scsi/scsi.h>
@@ -1015,6 +1016,49 @@ static int megasas_reset_bus_host(struct
 }
 
 /**
+ * megasas_bios_param - Returns disk geometry for a disk
+ * @sdev: 		device handle
+ * @bdev:		block device
+ * @capacity:		drive capacity
+ * @geom:		geometry parameters
+ */
+static int
+megasas_bios_param(struct scsi_device *sdev, struct block_device *bdev,
+		 sector_t capacity, int geom[])
+{
+	int 		heads;
+	int 		sectors;
+	sector_t	cylinders;
+	ulong		dummy;
+	/* Default heads (64) & sectors (32) */
+	heads 		= 64;
+	sectors 	= 32;
+
+	dummy		= heads * sectors;
+	cylinders	=  capacity;
+
+	sector_div(cylinders, dummy);
+
+	/*
+	 * Handle extended translation size for logical drives > 1Gb
+	 */
+	
+	if ((ulong)capacity >= 0x200000) {
+		heads = 255;
+		sectors = 63;
+		dummy = heads*sectors;
+		cylinders = capacity;
+		sector_div(cylinders, dummy);
+	}
+	
+	geom[0] = heads;
+	geom[1] = sectors;
+	geom[2] = cylinders;
+
+	return 0;
+}
+
+/**
  * megasas_service_aen -	Processes an event notification
  * @instance:			Adapter soft state
  * @cmd:			AEN command completed by the ISR
@@ -1054,6 +1098,7 @@ static struct scsi_host_template megasas
 	.eh_device_reset_handler = megasas_reset_device,
 	.eh_bus_reset_handler = megasas_reset_bus_host,
 	.eh_host_reset_handler = megasas_reset_bus_host,
+	.bios_param = megasas_bios_param,
 	.use_clustering = ENABLE_CLUSTERING,
 };
 


[-- Attachment #2: p2-bios_param.patch --]
[-- Type: text/x-patch, Size: 1827 bytes --]

diff -uprN 2.6.new-p1/drivers/scsi/megaraid/megaraid_sas.c 2.6.new-p2/drivers/scsi/megaraid/megaraid_sas.c
--- 2.6.new-p1/drivers/scsi/megaraid/megaraid_sas.c	2007-02-06 06:54:07.000000000 -0800
+++ 2.6.new-p2/drivers/scsi/megaraid/megaraid_sas.c	2007-02-06 08:43:40.000000000 -0800
@@ -35,6 +35,7 @@
 #include <asm/uaccess.h>
 #include <linux/fs.h>
 #include <linux/compat.h>
+#include <linux/blkdev.h>
 #include <linux/mutex.h>
 
 #include <scsi/scsi.h>
@@ -1015,6 +1016,49 @@ static int megasas_reset_bus_host(struct
 }
 
 /**
+ * megasas_bios_param - Returns disk geometry for a disk
+ * @sdev: 		device handle
+ * @bdev:		block device
+ * @capacity:		drive capacity
+ * @geom:		geometry parameters
+ */
+static int
+megasas_bios_param(struct scsi_device *sdev, struct block_device *bdev,
+		 sector_t capacity, int geom[])
+{
+	int 		heads;
+	int 		sectors;
+	sector_t	cylinders;
+	ulong		dummy;
+	/* Default heads (64) & sectors (32) */
+	heads 		= 64;
+	sectors 	= 32;
+
+	dummy		= heads * sectors;
+	cylinders	=  capacity;
+
+	sector_div(cylinders, dummy);
+
+	/*
+	 * Handle extended translation size for logical drives > 1Gb
+	 */
+	
+	if ((ulong)capacity >= 0x200000) {
+		heads = 255;
+		sectors = 63;
+		dummy = heads*sectors;
+		cylinders = capacity;
+		sector_div(cylinders, dummy);
+	}
+	
+	geom[0] = heads;
+	geom[1] = sectors;
+	geom[2] = cylinders;
+
+	return 0;
+}
+
+/**
  * megasas_service_aen -	Processes an event notification
  * @instance:			Adapter soft state
  * @cmd:			AEN command completed by the ISR
@@ -1054,6 +1098,7 @@ static struct scsi_host_template megasas
 	.eh_device_reset_handler = megasas_reset_device,
 	.eh_bus_reset_handler = megasas_reset_bus_host,
 	.eh_host_reset_handler = megasas_reset_bus_host,
+	.bios_param = megasas_bios_param,
 	.use_clustering = ENABLE_CLUSTERING,
 };
 

Re: [PATCH 2/5] scsi: megaraid_sas - added bios_param in scsi_host_template

[Andrew Morton]

On Tue, 06 Feb 2007 13:57:23 -0800
Sumant Patro <sumantp@lsil.com> wrote:

> +static int
> +megasas_bios_param(struct scsi_device *sdev, struct block_device *bdev,
> +		 sector_t capacity, int geom[])
> +{
> +	int 		heads;
> +	int 		sectors;
> +	sector_t	cylinders;
> +	ulong		dummy;

Plain old `unsigned long' is preferred.

> +	/* Default heads (64) & sectors (32) */
> +	heads 		= 64;
> +	sectors 	= 32;
> +
> +	dummy		= heads * sectors;
> +	cylinders	=  capacity;
> +
> +	sector_div(cylinders, dummy);
> +
> +	/*
> +	 * Handle extended translation size for logical drives > 1Gb
> +	 */
> +	
> +	if ((ulong)capacity >= 0x200000) {

Here we're casting a sector_t down to a 32-bit number.  Are you sure that
`capacity' here can never exceed 0xffffffff?