4 files changed, 420 insertions, 4 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 7278295f94d2..9a5b6658c65e 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -950,6 +950,41 @@ and is between 256 and 4096 characters. It is defined in the file
                         when set.
                         Format: <int>
 
+        libata.force=   [LIBATA] Force configurations.  The format is comma
+                        separated list of "[ID:]VAL" where ID is
+                        PORT[:DEVICE].  PORT and DEVICE are decimal numbers
+                        matching port, link or device.  Basically, it matches
+                        the ATA ID string printed on console by libata.  If
+                        the whole ID part is omitted, the last PORT and DEVICE
+                        values are used.  If ID hasn't been specified yet, the
+                        configuration applies to all ports, links and devices.
+
+                        If only DEVICE is omitted, the parameter applies to
+                        the port and all links and devices behind it.  DEVICE
+                        number of 0 either selects the first device or the
+                        first fan-out link behind PMP device.  It does not
+                        select the host link.  DEVICE number of 15 selects the
+                        host link and device attached to it.
+
+                        The VAL specifies the configuration to force.  As long
+                        as there's no ambiguity shortcut notation is allowed.
+                        For example, both 1.5 and 1.5G would work for 1.5Gbps.
+                        The following configurations can be forced.
+
+                        * Cable type: 40c, 80c, short40c, unk, ign or sata.
+                          Any ID with matching PORT is used.
+
+                        * SATA link speed limit: 1.5Gbps or 3.0Gbps.
+
+                        * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
+                          udma[/][16,25,33,44,66,100,133] notation is also
+                          allowed.
+
+                        * [no]ncq: Turn on or off NCQ.
+
+                        If there are multiple matching configurations changing
+                        the same attribute, the last one is used.
+
         load_ramdisk=   [RAM] List of ramdisks to load from floppy
                         See Documentation/ramdisk.txt.
 
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index def3682f416a..60d1bb556973 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -87,6 +87,28 @@ static struct workqueue_struct *ata_wq;
 
 struct workqueue_struct *ata_aux_wq;
 
+struct ata_force_param {
+        const char      *name;
+        unsigned int    cbl;
+        int             spd_limit;
+        unsigned long   xfer_mask;
+        unsigned int    horkage_on;
+        unsigned int    horkage_off;
+};
+
+struct ata_force_ent {
+        int                     port;
+        int                     device;
+        struct ata_force_param  param;
+};
+
+static struct ata_force_ent *ata_force_tbl;
+static int ata_force_tbl_size;
+
+static char ata_force_param_buf[PAGE_SIZE] __initdata;
+module_param_string(force, ata_force_param_buf, sizeof(ata_force_param_buf), 0444);
+MODULE_PARM_DESC(force, "Force ATA configurations including cable type, link speed and transfer mode (see Documentation/kernel-parameters.txt for details)");
+
 int atapi_enabled = 1;
 module_param(atapi_enabled, int, 0444);
 MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on)");
@@ -130,6 +152,179 @@ MODULE_VERSION(DRV_VERSION);
 
 
 /**
+ *      ata_force_cbl - force cable type according to libata.force
+ *      @link: ATA link of interest
+ *
+ *      Force cable type according to libata.force and whine about it.
+ *      The last entry which has matching port number is used, so it
+ *      can be specified as part of device force parameters.  For
+ *      example, both "a:40c,1.00:udma4" and "1.00:40c,udma4" have the
+ *      same effect.
+ *
+ *      LOCKING:
+ *      EH context.
+ */
+void ata_force_cbl(struct ata_port *ap)
+{
+        int i;
+
+        for (i = ata_force_tbl_size - 1; i >= 0; i--) {
+                const struct ata_force_ent *fe = &ata_force_tbl[i];
+
+                if (fe->port != -1 && fe->port != ap->print_id)
+                        continue;
+
+                if (fe->param.cbl == ATA_CBL_NONE)
+                        continue;
+
+                ap->cbl = fe->param.cbl;
+                ata_port_printk(ap, KERN_NOTICE,
+                                "FORCE: cable set to %s\n", fe->param.name);
+                return;
+        }
+}
+
+/**
+ *      ata_force_spd_limit - force SATA spd limit according to libata.force
+ *      @link: ATA link of interest
+ *
+ *      Force SATA spd limit according to libata.force and whine about
+ *      it.  When only the port part is specified (e.g. 1:), the limit
+ *      applies to all links connected to both the host link and all
+ *      fan-out ports connected via PMP.  If the device part is
+ *      specified as 0 (e.g. 1.00:), it specifies the first fan-out
+ *      link not the host link.  Device number 15 always points to the
+ *      host link whether PMP is attached or not.
+ *
+ *      LOCKING:
+ *      EH context.
+ */
+static void ata_force_spd_limit(struct ata_link *link)
+{
+        int linkno, i;
+
+        if (ata_is_host_link(link))
+                linkno = 15;
+        else
+                linkno = link->pmp;
+
+        for (i = ata_force_tbl_size - 1; i >= 0; i--) {
+                const struct ata_force_ent *fe = &ata_force_tbl[i];
+
+                if (fe->port != -1 && fe->port != link->ap->print_id)
+                        continue;
+
+                if (fe->device != -1 && fe->device != linkno)
+                        continue;
+
+                if (!fe->param.spd_limit)
+                        continue;
+
+                link->hw_sata_spd_limit = (1 << fe->param.spd_limit) - 1;
+                ata_link_printk(link, KERN_NOTICE,
+                        "FORCE: PHY spd limit set to %s\n", fe->param.name);
+                return;
+        }
+}
+
+/**
+ *      ata_force_xfermask - force xfermask according to libata.force
+ *      @dev: ATA device of interest
+ *
+ *      Force xfer_mask according to libata.force and whine about it.
+ *      For consistency with link selection, device number 15 selects
+ *      the first device connected to the host link.
+ *
+ *      LOCKING:
+ *      EH context.
+ */
+static void ata_force_xfermask(struct ata_device *dev)
+{
+        int devno = dev->link->pmp + dev->devno;
+        int alt_devno = devno;
+        int i;
+
+        /* allow n.15 for the first device attached to host port */
+        if (ata_is_host_link(dev->link) && devno == 0)
+                alt_devno = 15;
+
+        for (i = ata_force_tbl_size - 1; i >= 0; i--) {
+                const struct ata_force_ent *fe = &ata_force_tbl[i];
+                unsigned long pio_mask, mwdma_mask, udma_mask;
+
+                if (fe->port != -1 && fe->port != dev->link->ap->print_id)
+                        continue;
+
+                if (fe->device != -1 && fe->device != devno &&
+                    fe->device != alt_devno)
+                        continue;
+
+                if (!fe->param.xfer_mask)
+                        continue;
+
+                ata_unpack_xfermask(fe->param.xfer_mask,
+                                    &pio_mask, &mwdma_mask, &udma_mask);
+                if (udma_mask)
+                        dev->udma_mask = udma_mask;
+                else if (mwdma_mask) {
+                        dev->udma_mask = 0;
+                        dev->mwdma_mask = mwdma_mask;
+                } else {
+                        dev->udma_mask = 0;
+                        dev->mwdma_mask = 0;
+                        dev->pio_mask = pio_mask;
+                }
+
+                ata_dev_printk(dev, KERN_NOTICE,
+                        "FORCE: xfer_mask set to %s\n", fe->param.name);
+                return;
+        }
+}
+
+/**
+ *      ata_force_horkage - force horkage according to libata.force
+ *      @dev: ATA device of interest
+ *
+ *      Force horkage according to libata.force and whine about it.
+ *      For consistency with link selection, device number 15 selects
+ *      the first device connected to the host link.
+ *
+ *      LOCKING:
+ *      EH context.
+ */
+static void ata_force_horkage(struct ata_device *dev)
+{
+        int devno = dev->link->pmp + dev->devno;
+        int alt_devno = devno;
+        int i;
+
+        /* allow n.15 for the first device attached to host port */
+        if (ata_is_host_link(dev->link) && devno == 0)
+                alt_devno = 15;
+
+        for (i = 0; i < ata_force_tbl_size; i++) {
+                const struct ata_force_ent *fe = &ata_force_tbl[i];
+
+                if (fe->port != -1 && fe->port != dev->link->ap->print_id)
+                        continue;
+
+                if (fe->device != -1 && fe->device != devno &&
+                    fe->device != alt_devno)
+                        continue;
+
+                if (!(~dev->horkage & fe->param.horkage_on) &&
+                    !(dev->horkage & fe->param.horkage_off))
+                        continue;
+
+                dev->horkage |= fe->param.horkage_on;
+                dev->horkage &= ~fe->param.horkage_off;
+
+                ata_dev_printk(dev, KERN_NOTICE,
+                        "FORCE: horkage modified (%s)\n", fe->param.name);
+        }
+}
+
+/**
  *      ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
  *      @tf: Taskfile to convert
  *      @pmp: Port multiplier port
@@ -2067,6 +2262,7 @@ int ata_dev_configure(struct ata_device *dev)
 
         /* set horkage */
         dev->horkage |= ata_dev_blacklisted(dev);
+        ata_force_horkage(dev);
 
         /* let ACPI work its magic */
         rc = ata_acpi_on_devcfg(dev);
@@ -3150,6 +3346,7 @@ int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
                         mode_mask = ATA_DMA_MASK_CFA;
 
                 ata_dev_xfermask(dev);
+                ata_force_xfermask(dev);
 
                 pio_mask = ata_pack_xfermask(dev->pio_mask, 0, 0);
                 dma_mask = ata_pack_xfermask(0, dev->mwdma_mask, dev->udma_mask);
@@ -6497,7 +6694,8 @@ void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
  */
 int sata_link_init_spd(struct ata_link *link)
 {
-        u32 scontrol, spd;
+        u32 scontrol;
+        u8 spd;
         int rc;
 
         rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
@@ -6508,6 +6706,8 @@ int sata_link_init_spd(struct ata_link *link)
         if (spd)
                 link->hw_sata_spd_limit &= (1 << spd) - 1;
 
+        ata_force_spd_limit(link);
+
         link->sata_spd_limit = link->hw_sata_spd_limit;
 
         return 0;
@@ -7218,10 +7418,187 @@ int ata_pci_device_resume(struct pci_dev *pdev)
 
 #endif /* CONFIG_PCI */
 
+static int __init ata_parse_force_one(char **cur,
+                                      struct ata_force_ent *force_ent,
+                                      const char **reason)
+{
+        /* FIXME: Currently, there's no way to tag init const data and
+         * using __initdata causes build failure on some versions of
+         * gcc.  Once __initdataconst is implemented, add const to the
+         * following structure.
+         */
+        static struct ata_force_param force_tbl[] __initdata = {
+                { "40c",        .cbl            = ATA_CBL_PATA40 },
+                { "80c",        .cbl            = ATA_CBL_PATA80 },
+                { "short40c",   .cbl            = ATA_CBL_PATA40_SHORT },
+                { "unk",        .cbl            = ATA_CBL_PATA_UNK },
+                { "ign",        .cbl            = ATA_CBL_PATA_IGN },
+                { "sata",       .cbl            = ATA_CBL_SATA },
+                { "1.5Gbps",    .spd_limit      = 1 },
+                { "3.0Gbps",    .spd_limit      = 2 },
+                { "noncq",      .horkage_on     = ATA_HORKAGE_NONCQ },
+                { "ncq",        .horkage_off    = ATA_HORKAGE_NONCQ },
+                { "pio0",       .xfer_mask      = 1 << (ATA_SHIFT_PIO + 0) },
+                { "pio1",       .xfer_mask      = 1 << (ATA_SHIFT_PIO + 1) },
+                { "pio2",       .xfer_mask      = 1 << (ATA_SHIFT_PIO + 2) },
+                { "pio3",       .xfer_mask      = 1 << (ATA_SHIFT_PIO + 3) },
+                { "pio4",       .xfer_mask      = 1 << (ATA_SHIFT_PIO + 4) },
+                { "pio5",       .xfer_mask      = 1 << (ATA_SHIFT_PIO + 5) },
+                { "pio6",       .xfer_mask      = 1 << (ATA_SHIFT_PIO + 6) },
+                { "mwdma0",     .xfer_mask      = 1 << (ATA_SHIFT_MWDMA + 0) },
+                { "mwdma1",     .xfer_mask      = 1 << (ATA_SHIFT_MWDMA + 1) },
+                { "mwdma2",     .xfer_mask      = 1 << (ATA_SHIFT_MWDMA + 2) },
+                { "mwdma3",     .xfer_mask      = 1 << (ATA_SHIFT_MWDMA + 3) },
+                { "mwdma4",     .xfer_mask      = 1 << (ATA_SHIFT_MWDMA + 4) },
+                { "udma0",      .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 0) },
+                { "udma16",     .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 0) },
+                { "udma/16",    .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 0) },
+                { "udma1",      .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 1) },
+                { "udma25",     .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 1) },
+                { "udma/25",    .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 1) },
+                { "udma2",      .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 2) },
+                { "udma33",     .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 2) },
+                { "udma/33",    .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 2) },
+                { "udma3",      .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 3) },
+                { "udma44",     .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 3) },
+                { "udma/44",    .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 3) },
+                { "udma4",      .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 4) },
+                { "udma66",     .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 4) },
+                { "udma/66",    .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 4) },
+                { "udma5",      .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 5) },
+                { "udma100",    .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 5) },
+                { "udma/100",   .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 5) },
+                { "udma6",      .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 6) },
+                { "udma133",    .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 6) },
+                { "udma/133",   .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 6) },
+                { "udma7",      .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 7) },
+        };
+        char *start = *cur, *p = *cur;
+        char *id, *val, *endp;
+        const struct ata_force_param *match_fp = NULL;
+        int nr_matches = 0, i;
+
+        /* find where this param ends and update *cur */
+        while (*p != '\0' && *p != ',')
+                p++;
+
+        if (*p == '\0')
+                *cur = p;
+        else
+                *cur = p + 1;
+
+        *p = '\0';
+
+        /* parse */
+        p = strchr(start, ':');
+        if (!p) {
+                val = strstrip(start);
+                goto parse_val;
+        }
+        *p = '\0';
+
+        id = strstrip(start);
+        val = strstrip(p + 1);
+
+        /* parse id */
+        p = strchr(id, '.');
+        if (p) {
+                *p++ = '\0';
+                force_ent->device = simple_strtoul(p, &endp, 10);
+                if (p == endp || *endp != '\0') {
+                        *reason = "invalid device";
+                        return -EINVAL;
+                }
+        }
+
+        force_ent->port = simple_strtoul(id, &endp, 10);
+        if (p == endp || *endp != '\0') {
+                *reason = "invalid port/link";
+                return -EINVAL;
+        }
+
+ parse_val:
+        /* parse val, allow shortcuts so that both 1.5 and 1.5Gbps work */
+        for (i = 0; i < ARRAY_SIZE(force_tbl); i++) {
+                const struct ata_force_param *fp = &force_tbl[i];
+
+                if (strncasecmp(val, fp->name, strlen(val)))
+                        continue;
+
+                nr_matches++;
+                match_fp = fp;
+
+                if (strcasecmp(val, fp->name) == 0) {
+                        nr_matches = 1;
+                        break;
+                }
+        }
+
+        if (!nr_matches) {
+                *reason = "unknown value";
+                return -EINVAL;
+        }
+        if (nr_matches > 1) {
+                *reason = "ambigious value";
+                return -EINVAL;
+        }
+
+        force_ent->param = *match_fp;
+
+        return 0;
+}
+
+static void __init ata_parse_force_param(void)
+{
+        int idx = 0, size = 1;
+        int last_port = -1, last_device = -1;
+        char *p, *cur, *next;
+
+        /* calculate maximum number of params and allocate force_tbl */
+        for (p = ata_force_param_buf; *p; p++)
+                if (*p == ',')
+                        size++;
+
+        ata_force_tbl = kzalloc(sizeof(ata_force_tbl[0]) * size, GFP_KERNEL);
+        if (!ata_force_tbl) {
+                printk(KERN_WARNING "ata: failed to extend force table, "
+                       "libata.force ignored\n");
+                return;
+        }
+
+        /* parse and populate the table */
+        for (cur = ata_force_param_buf; *cur != '\0'; cur = next) {
+                const char *reason = "";
+                struct ata_force_ent te = { .port = -1, .device = -1 };
+
+                next = cur;
+                if (ata_parse_force_one(&next, &te, &reason)) {
+                        printk(KERN_WARNING "ata: failed to parse force "
+                               "parameter \"%s\" (%s)\n",
+                               cur, reason);
+                        continue;
+                }
+
+                if (te.port == -1) {
+                        te.port = last_port;
+                        te.device = last_device;
+                }
+
+                ata_force_tbl[idx++] = te;
+
+                last_port = te.port;
+                last_device = te.device;
+        }
+
+        ata_force_tbl_size = idx;
+}
 
 static int __init ata_init(void)
 {
         ata_probe_timeout *= HZ;
+
+        ata_parse_force_param();
+
         ata_wq = create_workqueue("ata");
         if (!ata_wq)
                 return -ENOMEM;
@@ -7238,6 +7615,7 @@ static int __init ata_init(void)
 
 static void __exit ata_exit(void)
 {
+        kfree(ata_force_tbl);
         destroy_workqueue(ata_wq);
         destroy_workqueue(ata_aux_wq);
 }
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 4e31071acc02..698ce2cea52c 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2393,9 +2393,11 @@ static int ata_eh_revalidate_and_attach(struct ata_link *link,
         }
 
         /* PDIAG- should have been released, ask cable type if post-reset */
-        if (ata_is_host_link(link) && ap->ops->cable_detect &&
-            (ehc->i.flags & ATA_EHI_DID_RESET))
-                ap->cbl = ap->ops->cable_detect(ap);
+        if ((ehc->i.flags & ATA_EHI_DID_RESET) && ata_is_host_link(link)) {
+                if (ap->ops->cable_detect)
+                        ap->cbl = ap->ops->cable_detect(ap);
+                ata_force_cbl(ap);
+        }
 
         /* Configure new devices forward such that user doesn't see
          * device detection messages backwards.
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 409ffb9af163..6036dedfe377 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -61,6 +61,7 @@ extern int atapi_passthru16;
 extern int libata_fua;
 extern int libata_noacpi;
 extern int libata_allow_tpm;
+extern void ata_force_cbl(struct ata_port *ap);
 extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev);
 extern int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
                            u64 block, u32 n_block, unsigned int tf_flags,