Enclosure Management via LED

This patch implements Enclosure Management via the LED protocol as specified
in AHCI specification.

Signed-off-by: Kristen Carlson Accardi <[EMAIL PROTECTED]>
---
This revision makes the change to the comment requested by Mark Lord,
fixes some bugs in the bit shifting for writing the new led state,
and implements a show function so that led status can be read as
well as written.

 drivers/ata/ahci.c        |  184 +++++++++++++++++++++++++++++++++++++++++++++-
 drivers/ata/libata-scsi.c |    5 -
 include/linux/libata.h    |    2 
 3 files changed, 187 insertions(+), 4 deletions(-)

Index: 2.6-git/drivers/ata/ahci.c
===================================================================
--- 2.6-git.orig/drivers/ata/ahci.c     2007-11-30 12:04:12.000000000 -0800
+++ 2.6-git/drivers/ata/ahci.c  2007-11-30 18:02:19.000000000 -0800
@@ -44,6 +44,7 @@
 #include <linux/dmi.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
 #include <linux/libata.h>
 
 #define DRV_NAME       "ahci"
@@ -92,6 +93,8 @@ enum {
        HOST_IRQ_STAT           = 0x08, /* interrupt status */
        HOST_PORTS_IMPL         = 0x0c, /* bitmap of implemented ports */
        HOST_VERSION            = 0x10, /* AHCI spec. version compliancy */
+       HOST_EM_LOC             = 0x1c, /* Enclosure Management location */
+       HOST_EM_CTL             = 0x20, /* Enclosure Management Control */
 
        /* HOST_CTL bits */
        HOST_RESET              = (1 << 0),  /* reset controller; self-clear */
@@ -99,6 +102,7 @@ enum {
        HOST_AHCI_EN            = (1 << 31), /* AHCI enabled */
 
        /* HOST_CAP bits */
+       HOST_CAP_EMS            = (1 << 6),  /* Enclosure Management support */
        HOST_CAP_SSC            = (1 << 14), /* Slumber capable */
        HOST_CAP_PMP            = (1 << 17), /* Port Multiplier support */
        HOST_CAP_CLO            = (1 << 24), /* Command List Override support */
@@ -193,6 +197,10 @@ enum {
                                          ATA_FLAG_ACPI_SATA | ATA_FLAG_AN |
                                          ATA_FLAG_IPM,
        AHCI_LFLAG_COMMON               = ATA_LFLAG_SKIP_D2H_BSY,
+
+       /* em_ctl bits */
+       EM_CTL_RST                      = (1 << 9), /* Reset */
+       EM_CTL_TM                       = (1 << 8), /* Transmit Message */
 };
 
 struct ahci_cmd_hdr {
@@ -216,6 +224,7 @@ struct ahci_host_priv {
        u32                     port_map;       /* port map to use */
        u32                     saved_cap;      /* saved initial cap */
        u32                     saved_port_map; /* saved initial port_map */
+       u32                     em_loc; /* enclosure management location */
 };
 
 struct ahci_port_priv {
@@ -231,6 +240,7 @@ struct ahci_port_priv {
        unsigned int            ncq_saw_dmas:1;
        unsigned int            ncq_saw_sdb:1;
        u32                     intr_mask;      /* interrupts to enable */
+       u16                     led_state;      /* saved current led state */
 };
 
 static int ahci_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
@@ -572,6 +582,11 @@ static struct pci_driver ahci_pci_driver
 #endif
 };
 
+static int ahci_em_messages = 1;
+module_param(ahci_em_messages, int, 0444);
+/* add other LED protocol types when they become supported */
+MODULE_PARM_DESC(ahci_em_messages,
+       "Set AHCI Enclosure Management Message type (0 = disabled, 1 = LED");
 
 static inline int ahci_nr_ports(u32 cap)
 {
@@ -1079,6 +1094,148 @@ static int ahci_reset_controller(struct 
        return 0;
 }
 
+/****** LED Enclosure Management routines ********/
+static int ahci_reset_em(struct ata_host *host)
+{
+       void __iomem *mmio = host->iomap[AHCI_PCI_BAR];
+       u32 em_ctl;
+
+       em_ctl = readl(mmio + HOST_EM_CTL);
+       if ((em_ctl & EM_CTL_TM) || (em_ctl & EM_CTL_RST))
+               return -EINVAL;
+
+       writel(em_ctl | EM_CTL_RST, mmio + HOST_EM_CTL);
+       return 0;
+}
+
+static int ahci_transmit_led_message(struct ata_port *ap, int led_num,
+                       int state)
+{
+       struct ahci_host_priv *hpriv = ap->host->private_data;
+       void __iomem *mmio = ap->host->iomap[AHCI_PCI_BAR];
+       struct ahci_port_priv *pp = ap->private_data;
+       u32 em_ctl;
+       u32 message[] = {0, 0};
+       unsigned int flags;
+
+       spin_lock_irqsave(ap->lock, flags);
+
+       /*
+        * if we are still busy transmitting a previous message,
+        * do not allow
+        */
+       em_ctl = readl(mmio + HOST_EM_CTL);
+       if (em_ctl & EM_CTL_TM) {
+               spin_unlock_irqrestore(ap->lock, flags);
+               return -EINVAL;
+       }
+
+       /*
+        * create message header - this is all zero except for
+        * the message size, which is 4 bytes.
+        */
+       message[0] |= (4 << 8);
+
+       pp->led_state &= ~(7 << (3*led_num));
+
+       /*
+        * create the actual message
+        * This does not support Port Multiplier at this time
+        * due to lack of hardware for testing
+        * so the PM field is always zero.
+        */
+       message[1] = (ap->port_no | (pp->led_state << 16));
+
+       /* LED bit locations are determined by the led_num */
+       message[1] |= (state << (16 + (3*led_num)));
+
+       /* write message to EM_LOC */
+       writel(message[0], mmio + hpriv->em_loc);
+       writel(message[1], mmio + hpriv->em_loc+4);
+
+       /* save off new led state */
+       pp->led_state = ((message[1] >> 16) & 0x01ff);
+
+       /*
+        * tell hardware to transmit the message
+        */
+       writel(em_ctl | EM_CTL_TM, mmio + HOST_EM_CTL);
+
+       spin_unlock_irqrestore(ap->lock, flags);
+       return 0;
+}
+
+static int ahci_led_show(struct device *dev, char *buf, int num)
+{
+       struct scsi_device *sdev = to_scsi_device(dev);
+       struct ata_port *ap = ata_shost_to_port(sdev->host);
+       struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
+       struct ahci_port_priv *pp = ap->private_data;
+
+       if (!atadev || !ata_dev_enabled(atadev))
+               return -EINVAL;
+
+       return sprintf(buf, "%d\n",
+               ((pp->led_state & (7 << (3*num))) >> 3*num));
+}
+
+static int ahci_led_store(struct device *dev, const char *buf, int num)
+{
+       struct scsi_device *sdev = to_scsi_device(dev);
+       struct ata_port *ap = ata_shost_to_port(sdev->host);
+       struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
+       int state;
+
+       if (!atadev || !ata_dev_enabled(atadev))
+               return -EINVAL;
+
+       state = simple_strtoul(buf, NULL, 0);
+       if (state != 0 && state != 1)
+               return -EINVAL;
+
+       return ahci_transmit_led_message(ap, num, state);
+}
+
+static ssize_t ahci_led_locate_show(struct device *dev,
+       struct device_attribute *attr, char *buf)
+{
+       return ahci_led_show(dev, buf, 1);
+}
+
+static ssize_t ahci_led_locate_store(struct device *dev,
+       struct device_attribute *attr, const char *buf, size_t count)
+{
+       int rc = ahci_led_store(dev, buf, 1);
+       if (!rc)
+               return count;
+       return rc;
+}
+static DEVICE_ATTR(locate, S_IWUSR | S_IRUGO, ahci_led_locate_show,
+                       ahci_led_locate_store);
+
+static ssize_t ahci_led_fault_show(struct device *dev,
+       struct device_attribute *attr, char *buf)
+{
+       return ahci_led_show(dev, buf, 2);
+}
+
+static ssize_t ahci_led_fault_store(struct device *dev,
+       struct device_attribute *attr, const char *buf, size_t count)
+{
+       int rc = ahci_led_store(dev, buf, 2);
+       if (!rc)
+               return count;
+       return rc;
+}
+static DEVICE_ATTR(fault, S_IWUSR | S_IRUGO, ahci_led_fault_show,
+                       ahci_led_fault_store);
+
+static struct device_attribute *ahci_em_led_attrs[] = {
+       &dev_attr_locate,
+       &dev_attr_fault,
+       NULL
+};
+
 static void ahci_port_init(struct pci_dev *pdev, struct ata_port *ap,
                           int port_no, void __iomem *mmio,
                           void __iomem *port_mmio)
@@ -2175,7 +2332,8 @@ static void ahci_print_info(struct ata_h
        dev_printk(KERN_INFO, &pdev->dev,
                "flags: "
                "%s%s%s%s%s%s%s"
-               "%s%s%s%s%s%s%s\n"
+               "%s%s%s%s%s%s%s"
+               "%s\n"
                ,
 
                cap & (1 << 31) ? "64bit " : "",
@@ -2192,7 +2350,8 @@ static void ahci_print_info(struct ata_h
                cap & (1 << 17) ? "pmp " : "",
                cap & (1 << 15) ? "pio " : "",
                cap & (1 << 14) ? "slum " : "",
-               cap & (1 << 13) ? "part " : ""
+               cap & (1 << 13) ? "part " : "",
+               cap & (1 << 6) ? "ems ": ""
                );
 }
 
@@ -2328,6 +2487,27 @@ static int ahci_init_one(struct pci_dev 
        ahci_init_controller(host);
        ahci_print_info(host);
 
+       if (ahci_em_messages && (hpriv->cap & HOST_CAP_EMS)) {
+               u8 messages;
+               void __iomem *mmio = host->iomap[AHCI_PCI_BAR];
+               u32 em_loc = readl(mmio + HOST_EM_LOC);
+               u32 em_ctl = readl(mmio + HOST_EM_CTL);
+
+               messages = (em_ctl & 0x000f0000) >> 16;
+
+               /* we only support LED message type right now */
+               if ((messages & 0x01) && (ahci_em_messages == 1)) {
+                       /* store em_loc */
+                       hpriv->em_loc = ((em_loc >> 16) * 4);
+
+                       /* reset the LEDs */
+                       ahci_reset_em(host);
+
+                       /* modify sht to add led sysfs files */
+                       ahci_sht.sdev_attrs = ahci_em_led_attrs;
+               }
+       }
+
        pci_set_master(pdev);
        return ata_host_activate(host, pdev->irq, ahci_interrupt, IRQF_SHARED,
                                 &ahci_sht);
Index: 2.6-git/drivers/ata/libata-scsi.c
===================================================================
--- 2.6-git.orig/drivers/ata/libata-scsi.c      2007-11-30 12:04:21.000000000 
-0800
+++ 2.6-git/drivers/ata/libata-scsi.c   2007-11-30 15:31:12.000000000 -0800
@@ -55,7 +55,7 @@ typedef unsigned int (*ata_xlat_func_t)(
 
 static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
                                        const struct scsi_device *scsidev);
-static struct ata_device *ata_scsi_find_dev(struct ata_port *ap,
+struct ata_device *ata_scsi_find_dev(struct ata_port *ap,
                                            const struct scsi_device *scsidev);
 static int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
                              unsigned int id, unsigned int lun);
@@ -2622,7 +2622,7 @@ static int ata_scsi_dev_enabled(struct a
  *     RETURNS:
  *     Associated ATA device, or %NULL if not found.
  */
-static struct ata_device *
+struct ata_device *
 ata_scsi_find_dev(struct ata_port *ap, const struct scsi_device *scsidev)
 {
        struct ata_device *dev = __ata_scsi_find_dev(ap, scsidev);
@@ -2632,6 +2632,7 @@ ata_scsi_find_dev(struct ata_port *ap, c
 
        return dev;
 }
+EXPORT_SYMBOL_GPL(ata_scsi_find_dev);
 
 /*
  *     ata_scsi_map_proto - Map pass-thru protocol value to taskfile value.
Index: 2.6-git/include/linux/libata.h
===================================================================
--- 2.6-git.orig/include/linux/libata.h 2007-11-30 12:04:21.000000000 -0800
+++ 2.6-git/include/linux/libata.h      2007-11-30 15:31:12.000000000 -0800
@@ -900,6 +900,8 @@ extern int ata_scsi_slave_config(struct 
 extern void ata_scsi_slave_destroy(struct scsi_device *sdev);
 extern int ata_scsi_change_queue_depth(struct scsi_device *sdev,
                                       int queue_depth);
+struct ata_device *ata_scsi_find_dev(struct ata_port *ap,
+                                     const struct scsi_device *scsidev);
 extern struct ata_device *ata_dev_pair(struct ata_device *adev);
 extern int ata_do_set_mode(struct ata_link *link, struct ata_device 
**r_failed_dev);
 extern u8 ata_irq_on(struct ata_port *ap);
-
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