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authorHarry Zhang <harry.zhang@amd.com>2010-04-23 17:28:38 +0800
committerJeff Garzik <jgarzik@redhat.com>2010-05-14 17:35:51 -0400
commitc06231661e4fb5f2f50c73ff33702937a11764cf (patch)
treee82300639ad09429fb3a6881bb6985363dd9ddbe
parent008dbd61ebee3e647f63bbe8315192e1331cd75f (diff)
downloadop-kernel-dev-c06231661e4fb5f2f50c73ff33702937a11764cf.zip
op-kernel-dev-c06231661e4fb5f2f50c73ff33702937a11764cf.tar.gz
ahci: add "em_buffer" attribute for AHCI hosts
Add "em_buffer" attribute for SATA AHCI hosts to provide a way for userland to access AHCI EM (enclosure management) buffer directly if the host supports EM. AHCI driver should support SGPIO EM messages. However the SATA/AHCI specs did not define the SGPIO message format filled in EM buffer. Different HW vendors may have different definitions. The mainly purpose of this attribute is to solve this issue by allowing HW vendors to provide userland drivers and tools for their SGPIO initiators. Signed-off-by: Harry Zhang <harry.zhang@amd.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
-rw-r--r--drivers/ata/ahci.h10
-rw-r--r--drivers/ata/libahci.c104
2 files changed, 111 insertions, 3 deletions
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 5edce44..7113c57 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -224,9 +224,12 @@ enum {
EM_MAX_RETRY = 5,
/* em_ctl bits */
- EM_CTL_RST = (1 << 9), /* Reset */
- EM_CTL_TM = (1 << 8), /* Transmit Message */
- EM_CTL_ALHD = (1 << 26), /* Activity LED */
+ EM_CTL_RST = (1 << 9), /* Reset */
+ EM_CTL_TM = (1 << 8), /* Transmit Message */
+ EM_CTL_MR = (1 << 0), /* Message Recieved */
+ EM_CTL_ALHD = (1 << 26), /* Activity LED */
+ EM_CTL_XMT = (1 << 25), /* Transmit Only */
+ EM_CTL_SMB = (1 << 24), /* Single Message Buffer */
/* em message type */
EM_MSG_TYPE_LED = (1 << 0), /* LED */
@@ -288,6 +291,7 @@ struct ahci_host_priv {
u32 saved_cap2; /* saved initial cap2 */
u32 saved_port_map; /* saved initial port_map */
u32 em_loc; /* enclosure management location */
+ u32 em_buf_sz; /* EM buffer size in byte */
u32 em_msg_type; /* EM message type */
};
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 817bcd0..1984a6e 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -108,11 +108,18 @@ static ssize_t ahci_show_host_version(struct device *dev,
struct device_attribute *attr, char *buf);
static ssize_t ahci_show_port_cmd(struct device *dev,
struct device_attribute *attr, char *buf);
+static ssize_t ahci_read_em_buffer(struct device *dev,
+ struct device_attribute *attr, char *buf);
+static ssize_t ahci_store_em_buffer(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size);
static DEVICE_ATTR(ahci_host_caps, S_IRUGO, ahci_show_host_caps, NULL);
static DEVICE_ATTR(ahci_host_cap2, S_IRUGO, ahci_show_host_cap2, NULL);
static DEVICE_ATTR(ahci_host_version, S_IRUGO, ahci_show_host_version, NULL);
static DEVICE_ATTR(ahci_port_cmd, S_IRUGO, ahci_show_port_cmd, NULL);
+static DEVICE_ATTR(em_buffer, S_IWUSR | S_IRUGO,
+ ahci_read_em_buffer, ahci_store_em_buffer);
static struct device_attribute *ahci_shost_attrs[] = {
&dev_attr_link_power_management_policy,
@@ -122,6 +129,7 @@ static struct device_attribute *ahci_shost_attrs[] = {
&dev_attr_ahci_host_cap2,
&dev_attr_ahci_host_version,
&dev_attr_ahci_port_cmd,
+ &dev_attr_em_buffer,
NULL
};
@@ -252,6 +260,101 @@ static ssize_t ahci_show_port_cmd(struct device *dev,
return sprintf(buf, "%x\n", readl(port_mmio + PORT_CMD));
}
+static ssize_t ahci_read_em_buffer(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct Scsi_Host *shost = class_to_shost(dev);
+ struct ata_port *ap = ata_shost_to_port(shost);
+ struct ahci_host_priv *hpriv = ap->host->private_data;
+ void __iomem *mmio = hpriv->mmio;
+ void __iomem *em_mmio = mmio + hpriv->em_loc;
+ u32 em_ctl, msg;
+ unsigned long flags;
+ size_t count;
+ int i;
+
+ spin_lock_irqsave(ap->lock, flags);
+
+ em_ctl = readl(mmio + HOST_EM_CTL);
+ if (!(ap->flags & ATA_FLAG_EM) || em_ctl & EM_CTL_XMT ||
+ !(hpriv->em_msg_type & EM_MSG_TYPE_SGPIO)) {
+ spin_unlock_irqrestore(ap->lock, flags);
+ return -EINVAL;
+ }
+
+ if (!(em_ctl & EM_CTL_MR)) {
+ spin_unlock_irqrestore(ap->lock, flags);
+ return -EAGAIN;
+ }
+
+ if (!(em_ctl & EM_CTL_SMB))
+ em_mmio += hpriv->em_buf_sz;
+
+ count = hpriv->em_buf_sz;
+
+ /* the count should not be larger than PAGE_SIZE */
+ if (count > PAGE_SIZE) {
+ if (printk_ratelimit())
+ ata_port_printk(ap, KERN_WARNING,
+ "EM read buffer size too large: "
+ "buffer size %u, page size %lu\n",
+ hpriv->em_buf_sz, PAGE_SIZE);
+ count = PAGE_SIZE;
+ }
+
+ for (i = 0; i < count; i += 4) {
+ msg = readl(em_mmio + i);
+ buf[i] = msg & 0xff;
+ buf[i + 1] = (msg >> 8) & 0xff;
+ buf[i + 2] = (msg >> 16) & 0xff;
+ buf[i + 3] = (msg >> 24) & 0xff;
+ }
+
+ spin_unlock_irqrestore(ap->lock, flags);
+
+ return i;
+}
+
+static ssize_t ahci_store_em_buffer(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct Scsi_Host *shost = class_to_shost(dev);
+ struct ata_port *ap = ata_shost_to_port(shost);
+ struct ahci_host_priv *hpriv = ap->host->private_data;
+ void __iomem *mmio = hpriv->mmio;
+ void __iomem *em_mmio = mmio + hpriv->em_loc;
+ u32 em_ctl, msg;
+ unsigned long flags;
+ int i;
+
+ /* check size validity */
+ if (!(ap->flags & ATA_FLAG_EM) ||
+ !(hpriv->em_msg_type & EM_MSG_TYPE_SGPIO) ||
+ size % 4 || size > hpriv->em_buf_sz)
+ return -EINVAL;
+
+ spin_lock_irqsave(ap->lock, flags);
+
+ em_ctl = readl(mmio + HOST_EM_CTL);
+ if (em_ctl & EM_CTL_TM) {
+ spin_unlock_irqrestore(ap->lock, flags);
+ return -EBUSY;
+ }
+
+ for (i = 0; i < size; i += 4) {
+ msg = buf[i] | buf[i + 1] << 8 |
+ buf[i + 2] << 16 | buf[i + 3] << 24;
+ writel(msg, em_mmio + i);
+ }
+
+ writel(em_ctl | EM_CTL_TM, mmio + HOST_EM_CTL);
+
+ spin_unlock_irqrestore(ap->lock, flags);
+
+ return size;
+}
+
/**
* ahci_save_initial_config - Save and fixup initial config values
* @dev: target AHCI device
@@ -2099,6 +2202,7 @@ void ahci_set_em_messages(struct ahci_host_priv *hpriv,
if (messages) {
/* store em_loc */
hpriv->em_loc = ((em_loc >> 16) * 4);
+ hpriv->em_buf_sz = ((em_loc & 0xff) * 4);
hpriv->em_msg_type = messages;
pi->flags |= ATA_FLAG_EM;
if (!(em_ctl & EM_CTL_ALHD))
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