ide: preserve Host Protected Area by default (v2)

From the perspective of most users of recent systems, disabling Host
Protected Area (HPA) can break vendor RAID formats, GPT partitions and
risks corrupting firmware or overwriting vendor system recovery tools.

Unfortunately the original (kernels < 2.6.30) behavior (unconditionally
disabling HPA and using full disk capacity) was introduced at the time
when the main use of HPA was to make the drive look small enough for the
BIOS to allow the system to boot with large capacity drives.

Thus to allow the maximum compatibility with the existing setups (using
HPA and partitioned with HPA disabled) we automically disable HPA if
any partitions overlapping HPA are detected.  Additionally HPA can also
be disabled using the "nohpa" module parameter (i.e. "ide_core.nohpa=0.0"
to disable HPA on /dev/hda).

v2:
Fix ->resume HPA support.

While at it:
- remove stale "idebus=" entry from Documentation/kernel-parameters.txt

Cc: Robert Hancock <hancockrwd@gmail.com>
Cc: Frans Pop <elendil@planet.nl>
Cc: "Andries E. Brouwer" <Andries.Brouwer@cwi.nl>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
[patch description was based on input from Alan Cox and Frans Pop]
Emphatically-Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

diff --git a/Documentation/ide/ide.txt b/Documentation/ide/ide.txt
index 0c78f4b1d9d9f1df5298e9147c058a32aee90353..e77bebfa7b0d9b7cd459050970581034281538ee 100644 (file)
--- a/Documentation/ide/ide.txt
+++ b/Documentation/ide/ide.txt
@@ -216,6 +216,8 @@ Other kernel parameters for ide_core are:
 
 * "noflush=[interface_number.device_number]" to disable flush requests
 
+* "nohpa=[interface_number.device_number]" to disable Host Protected Area
+
 * "noprobe=[interface_number.device_number]" to skip probing
 
 * "nowerr=[interface_number.device_number]" to ignore the WRERR_STAT bit

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a19f021f081a8239e1ba40861dc0b6af2651df5d..e58c91ca802c33bb3942ef6725877489789c9029 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -835,11 +835,8 @@ and is between 256 and 4096 characters. It is defined in the file
 
        ide-core.nodma= [HW] (E)IDE subsystem
                        Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc
-                       .vlb_clock .pci_clock .noflush .noprobe .nowerr .cdrom
-                       .chs .ignore_cable are additional options
-                       See Documentation/ide/ide.txt.
-
-       idebus=         [HW] (E)IDE subsystem - VLB/PCI bus speed
+                       .vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr
+                       .cdrom .chs .ignore_cable are additional options
                        See Documentation/ide/ide.txt.
 
        ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem

diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 61a6d3546221ad8ca888fefe75279fd3314dbfbe..3d92c9d54d4744fe96282621ca951deac77e6167 100644 (file)
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -350,6 +350,9 @@ static void idedisk_check_hpa(ide_drive_t *drive)
                         capacity, sectors_to_MB(capacity),
                         set_max, sectors_to_MB(set_max));
 
+       if ((drive->dev_flags & IDE_DFLAG_NOHPA) == 0)
+               return;
+
        set_max = ide_disk_hpa_set_capacity(drive, set_max, lba48);
        if (set_max)
                printk(KERN_INFO "%s: Host Protected Area disabled.\n",
@@ -430,8 +433,11 @@ static u64 ide_disk_set_capacity(ide_drive_t *drive, u64 capacity)
                goto out;
 
        set = ide_disk_hpa_set_capacity(drive, set, lba48);
-       if (set)
+       if (set) {
+               /* needed for ->resume to disable HPA */
+               drive->dev_flags |= IDE_DFLAG_NOHPA;
                return set;
+       }
 out:
        return drive->capacity64;
 }

diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index 92c9b90931e73393f0d47b311b3fb1839483a1df..16d056939f9f313119c5a0c51da62456d85669aa 100644 (file)
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -211,6 +211,11 @@ static unsigned int ide_noflush;
 module_param_call(noflush, ide_set_dev_param_mask, NULL, &ide_noflush, 0);
 MODULE_PARM_DESC(noflush, "disable flush requests for a device");
 
+static unsigned int ide_nohpa;
+
+module_param_call(nohpa, ide_set_dev_param_mask, NULL, &ide_nohpa, 0);
+MODULE_PARM_DESC(nohpa, "disable Host Protected Area for a device");
+
 static unsigned int ide_noprobe;
 
 module_param_call(noprobe, ide_set_dev_param_mask, NULL, &ide_noprobe, 0);
@@ -281,6 +286,11 @@ static void ide_dev_apply_params(ide_drive_t *drive, u8 unit)
                                 drive->name);
                drive->dev_flags |= IDE_DFLAG_NOFLUSH;
        }
+       if (ide_nohpa & (1 << i)) {
+               printk(KERN_INFO "ide: disabling Host Protected Area for %s\n",
+                                drive->name);
+               drive->dev_flags |= IDE_DFLAG_NOHPA;
+       }
        if (ide_noprobe & (1 << i)) {
                printk(KERN_INFO "ide: skipping probe for %s\n", drive->name);
                drive->dev_flags |= IDE_DFLAG_NOPROBE;

diff --git a/include/linux/ide.h b/include/linux/ide.h
index e96ace12872a2438e1b3a6267abec3ada756faff..45dce3b4c88cb2347fab26a521e158895515b62d 100644 (file)
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -475,6 +475,8 @@ enum {
        IDE_DFLAG_NICE1                 = (1 << 5),
        /* device is physically present */
        IDE_DFLAG_PRESENT               = (1 << 6),
+       /* disable Host Protected Area */
+       IDE_DFLAG_NOHPA                 = (1 << 7),
        /* id read from device (synthetic if not set) */
        IDE_DFLAG_ID_READ               = (1 << 8),
        IDE_DFLAG_NOPROBE               = (1 << 9),