ide: add "hdx=nodma" kernel parameter

* Add "hdx=nodma" option allowing user to disallow DMA for a given device.

* Obsolete "ide=nodma" option.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

4 files changed, 9 insertions, 5 deletions

diff --git a/Documentation/ide.txt b/Documentation/ide.txt
index c1640e306c53..1d50f23a5cab 100644
--- a/Documentation/ide.txt
+++ b/Documentation/ide.txt
@@ -242,6 +242,8 @@ Summary of ide driver parameters for kernel command line
                           and quite likely to cause trouble with
                           older/odd IDE drives.
 
+ "hdx=nodma"            : disallow DMA
+
  "hdx=swapdata"         : when the drive is a disk, byte swap all data
 
  "hdx=bswap"            : same as above..........
@@ -286,8 +288,6 @@ Summary of ide driver parameters for kernel command line
 
  "ide=reverse"          : formerly called to pci sub-system, but now local.
 
- "ide=nodma"            : disable DMA globally for the IDE subsystem.
-
 The following are valid ONLY on ide0, which usually corresponds
 to the first ATA interface found on the particular host, and the defaults for
 the base,ctl ports must not be altered.
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index 45fa1ef29d2c..bc57ce6bf0b3 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -759,7 +759,7 @@ static int ide_tune_dma(ide_drive_t *drive)
 {
         u8 speed;
 
-        if (noautodma || (drive->id->capability & 1) == 0)
+        if (noautodma || drive->nodma || (drive->id->capability & 1) == 0)
                 return 0;
 
         /* consult the list of known "bad" drives */
diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index 27c4fe250701..5b090662683e 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -1272,7 +1272,7 @@ static int __init ide_setup(char *s)
         if (!strcmp(s, "ide=nodma")) {
                 printk(" : Prevented DMA\n");
                 noautodma = 1;
-                return 1;
+                goto obsolete_option;
         }
 
 #ifdef CONFIG_IDEPCI_PCIBUS_ORDER
@@ -1306,7 +1306,7 @@ static int __init ide_setup(char *s)
          */
         if (s[0] == 'h' && s[1] == 'd' && s[2] >= 'a' && s[2] <= max_drive) {
                 const char *hd_words[] = {
-                        "none", "noprobe", "nowerr", "cdrom", "minus5",
+                        "none", "noprobe", "nowerr", "cdrom", "nodma",
                         "autotune", "noautotune", "minus8", "swapdata", "bswap",
                         "noflush", "remap", "remap63", "scsi", NULL };
                 unit = s[2] - 'a';
@@ -1334,6 +1334,9 @@ static int __init ide_setup(char *s)
                                 drive->ready_stat = 0;
                                 hwif->noprobe = 0;
                                 goto done;
+                        case -5: /* nodma */
+                                drive->nodma = 1;
+                                goto done;
                         case -6: /* "autotune" */
                                 drive->autotune = IDE_TUNE_AUTO;
                                 goto obsolete_option;
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 79652c5c0ea5..e39ee2fa2607 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -599,6 +599,7 @@ typedef struct ide_drive_s {
         unsigned nice0          : 1;    /* give obvious excess bandwidth */
         unsigned nice2          : 1;    /* give a share in our own bandwidth */
         unsigned doorlocking    : 1;    /* for removable only: door lock/unlock works */
+        unsigned nodma          : 1;    /* disallow DMA */
         unsigned autotune       : 2;    /* 0=default, 1=autotune, 2=noautotune */
         unsigned remap_0_to_1   : 1;    /* 0=noremap, 1=remap 0->1 (for EZDrive) */
         unsigned blocked        : 1;    /* 1=powermanagment told us not to do anything, so sleep nicely */