libata: add a host flag to ignore detected ATA devices

Where devices are visible via more than one host we sometimes wish to
indicate that cirtain devices should be ignored on a specific host.  Add a
host flag indicating that this host wishes to ignore ATA specific devices.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 23763a1..d31ee55 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1973,6 +1973,12 @@ retry:
        if (class == ATA_DEV_ATA) {
                if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
                        goto err_out;
+               if (ap->host->flags & ATA_HOST_IGNORE_ATA &&
+                                                       ata_id_is_ata(id)) {
+                       ata_dev_dbg(dev,
+                               "host indicates ignore ATA devices, ignored\n");
+                       return -ENOENT;
+               }
        } else {
                if (ata_id_is_ata(id))
                        goto err_out;

diff --git a/include/linux/libata.h b/include/linux/libata.h
index e926df7..6e887c7 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -247,6 +247,7 @@ enum {
        ATA_HOST_SIMPLEX        = (1 << 0),     /* Host is simplex, one DMA channel per host only */
        ATA_HOST_STARTED        = (1 << 1),     /* Host started */
        ATA_HOST_PARALLEL_SCAN  = (1 << 2),     /* Ports on this host can be scanned in parallel */
+       ATA_HOST_IGNORE_ATA     = (1 << 3),     /* Ignore ATA devices on this host. */
 
        /* bits 24:31 of host->flags are reserved for LLD specific flags */