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authorStephen Rothwell <sfr@canb.auug.org.au>2005-09-28 03:12:35 +1000
committerStephen Rothwell <sfr@canb.auug.org.au>2005-09-28 03:12:35 +1000
commitd223e721b743787fad71f6aef5e860176214c8f9 (patch)
treee2fec87364dc1cbaa983f31c8276eb709ee491bd /arch/powerpc/platforms
parentb6b8681843f9eaee12f8c30ffac399f7b2601ab3 (diff)
powerpc: Move viopath.c to powerpc/platforms/iseries
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Diffstat (limited to 'arch/powerpc/platforms')
-rw-r--r--arch/powerpc/platforms/iseries/Makefile1
-rw-r--r--arch/powerpc/platforms/iseries/viopath.c672
2 files changed, 673 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/iseries/Makefile b/arch/powerpc/platforms/iseries/Makefile
index 202f17419df..5a27b888103 100644
--- a/arch/powerpc/platforms/iseries/Makefile
+++ b/arch/powerpc/platforms/iseries/Makefile
@@ -3,3 +3,4 @@ obj-y += hvlog.o hvlpconfig.o lpardata.o setup.o mf.o lpevents.o \
obj-$(CONFIG_PCI) += pci.o irq.o vpdinfo.o
obj-$(CONFIG_IBMVIO) += vio.o
obj-$(CONFIG_SMP) += smp.o
+obj-$(CONFIG_VIOPATH) += viopath.o
diff --git a/arch/powerpc/platforms/iseries/viopath.c b/arch/powerpc/platforms/iseries/viopath.c
new file mode 100644
index 00000000000..c0c767bd37f
--- /dev/null
+++ b/arch/powerpc/platforms/iseries/viopath.c
@@ -0,0 +1,672 @@
+/* -*- linux-c -*-
+ *
+ * iSeries Virtual I/O Message Path code
+ *
+ * Authors: Dave Boutcher <boutcher@us.ibm.com>
+ * Ryan Arnold <ryanarn@us.ibm.com>
+ * Colin Devilbiss <devilbis@us.ibm.com>
+ *
+ * (C) Copyright 2000-2005 IBM Corporation
+ *
+ * This code is used by the iSeries virtual disk, cd,
+ * tape, and console to communicate with OS/400 in another
+ * partition.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) anyu later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/vmalloc.h>
+#include <linux/string.h>
+#include <linux/proc_fs.h>
+#include <linux/dma-mapping.h>
+#include <linux/wait.h>
+#include <linux/seq_file.h>
+#include <linux/smp_lock.h>
+#include <linux/interrupt.h>
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/iSeries/HvTypes.h>
+#include <asm/iSeries/ItExtVpdPanel.h>
+#include <asm/iSeries/HvLpEvent.h>
+#include <asm/iSeries/HvLpConfig.h>
+#include <asm/iSeries/mf.h>
+#include <asm/iSeries/vio.h>
+
+/* Status of the path to each other partition in the system.
+ * This is overkill, since we will only ever establish connections
+ * to our hosting partition and the primary partition on the system.
+ * But this allows for other support in the future.
+ */
+static struct viopathStatus {
+ int isOpen; /* Did we open the path? */
+ int isActive; /* Do we have a mon msg outstanding */
+ int users[VIO_MAX_SUBTYPES];
+ HvLpInstanceId mSourceInst;
+ HvLpInstanceId mTargetInst;
+ int numberAllocated;
+} viopathStatus[HVMAXARCHITECTEDLPS];
+
+static DEFINE_SPINLOCK(statuslock);
+
+/*
+ * For each kind of event we allocate a buffer that is
+ * guaranteed not to cross a page boundary
+ */
+static unsigned char event_buffer[VIO_MAX_SUBTYPES * 256] __page_aligned;
+static atomic_t event_buffer_available[VIO_MAX_SUBTYPES];
+static int event_buffer_initialised;
+
+static void handleMonitorEvent(struct HvLpEvent *event);
+
+/*
+ * We use this structure to handle asynchronous responses. The caller
+ * blocks on the semaphore and the handler posts the semaphore. However,
+ * if system_state is not SYSTEM_RUNNING, then wait_atomic is used ...
+ */
+struct alloc_parms {
+ struct semaphore sem;
+ int number;
+ atomic_t wait_atomic;
+ int used_wait_atomic;
+};
+
+/* Put a sequence number in each mon msg. The value is not
+ * important. Start at something other than 0 just for
+ * readability. wrapping this is ok.
+ */
+static u8 viomonseq = 22;
+
+/* Our hosting logical partition. We get this at startup
+ * time, and different modules access this variable directly.
+ */
+HvLpIndex viopath_hostLp = HvLpIndexInvalid;
+EXPORT_SYMBOL(viopath_hostLp);
+HvLpIndex viopath_ourLp = HvLpIndexInvalid;
+EXPORT_SYMBOL(viopath_ourLp);
+
+/* For each kind of incoming event we set a pointer to a
+ * routine to call.
+ */
+static vio_event_handler_t *vio_handler[VIO_MAX_SUBTYPES];
+
+#define VIOPATH_KERN_WARN KERN_WARNING "viopath: "
+#define VIOPATH_KERN_INFO KERN_INFO "viopath: "
+
+static int proc_viopath_show(struct seq_file *m, void *v)
+{
+ char *buf;
+ u16 vlanMap;
+ dma_addr_t handle;
+ HvLpEvent_Rc hvrc;
+ DECLARE_MUTEX_LOCKED(Semaphore);
+
+ buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!buf)
+ return 0;
+ memset(buf, 0, PAGE_SIZE);
+
+ handle = dma_map_single(iSeries_vio_dev, buf, PAGE_SIZE,
+ DMA_FROM_DEVICE);
+
+ hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
+ HvLpEvent_Type_VirtualIo,
+ viomajorsubtype_config | vioconfigget,
+ HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
+ viopath_sourceinst(viopath_hostLp),
+ viopath_targetinst(viopath_hostLp),
+ (u64)(unsigned long)&Semaphore, VIOVERSION << 16,
+ ((u64)handle) << 32, PAGE_SIZE, 0, 0);
+
+ if (hvrc != HvLpEvent_Rc_Good)
+ printk(VIOPATH_KERN_WARN "hv error on op %d\n", (int)hvrc);
+
+ down(&Semaphore);
+
+ vlanMap = HvLpConfig_getVirtualLanIndexMap();
+
+ buf[PAGE_SIZE-1] = '\0';
+ seq_printf(m, "%s", buf);
+ seq_printf(m, "AVAILABLE_VETH=%x\n", vlanMap);
+ seq_printf(m, "SRLNBR=%c%c%c%c%c%c%c\n",
+ e2a(xItExtVpdPanel.mfgID[2]),
+ e2a(xItExtVpdPanel.mfgID[3]),
+ e2a(xItExtVpdPanel.systemSerial[1]),
+ e2a(xItExtVpdPanel.systemSerial[2]),
+ e2a(xItExtVpdPanel.systemSerial[3]),
+ e2a(xItExtVpdPanel.systemSerial[4]),
+ e2a(xItExtVpdPanel.systemSerial[5]));
+
+ dma_unmap_single(iSeries_vio_dev, handle, PAGE_SIZE, DMA_FROM_DEVICE);
+ kfree(buf);
+
+ return 0;
+}
+
+static int proc_viopath_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, proc_viopath_show, NULL);
+}
+
+static struct file_operations proc_viopath_operations = {
+ .open = proc_viopath_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init vio_proc_init(void)
+{
+ struct proc_dir_entry *e;
+
+ e = create_proc_entry("iSeries/config", 0, NULL);
+ if (e)
+ e->proc_fops = &proc_viopath_operations;
+
+ return 0;
+}
+__initcall(vio_proc_init);
+
+/* See if a given LP is active. Allow for invalid lps to be passed in
+ * and just return invalid
+ */
+int viopath_isactive(HvLpIndex lp)
+{
+ if (lp == HvLpIndexInvalid)
+ return 0;
+ if (lp < HVMAXARCHITECTEDLPS)
+ return viopathStatus[lp].isActive;
+ else
+ return 0;
+}
+EXPORT_SYMBOL(viopath_isactive);
+
+/*
+ * We cache the source and target instance ids for each
+ * partition.
+ */
+HvLpInstanceId viopath_sourceinst(HvLpIndex lp)
+{
+ return viopathStatus[lp].mSourceInst;
+}
+EXPORT_SYMBOL(viopath_sourceinst);
+
+HvLpInstanceId viopath_targetinst(HvLpIndex lp)
+{
+ return viopathStatus[lp].mTargetInst;
+}
+EXPORT_SYMBOL(viopath_targetinst);
+
+/*
+ * Send a monitor message. This is a message with the acknowledge
+ * bit on that the other side will NOT explicitly acknowledge. When
+ * the other side goes down, the hypervisor will acknowledge any
+ * outstanding messages....so we will know when the other side dies.
+ */
+static void sendMonMsg(HvLpIndex remoteLp)
+{
+ HvLpEvent_Rc hvrc;
+
+ viopathStatus[remoteLp].mSourceInst =
+ HvCallEvent_getSourceLpInstanceId(remoteLp,
+ HvLpEvent_Type_VirtualIo);
+ viopathStatus[remoteLp].mTargetInst =
+ HvCallEvent_getTargetLpInstanceId(remoteLp,
+ HvLpEvent_Type_VirtualIo);
+
+ /*
+ * Deliberately ignore the return code here. if we call this
+ * more than once, we don't care.
+ */
+ vio_setHandler(viomajorsubtype_monitor, handleMonitorEvent);
+
+ hvrc = HvCallEvent_signalLpEventFast(remoteLp, HvLpEvent_Type_VirtualIo,
+ viomajorsubtype_monitor, HvLpEvent_AckInd_DoAck,
+ HvLpEvent_AckType_DeferredAck,
+ viopathStatus[remoteLp].mSourceInst,
+ viopathStatus[remoteLp].mTargetInst,
+ viomonseq++, 0, 0, 0, 0, 0);
+
+ if (hvrc == HvLpEvent_Rc_Good)
+ viopathStatus[remoteLp].isActive = 1;
+ else {
+ printk(VIOPATH_KERN_WARN "could not connect to partition %d\n",
+ remoteLp);
+ viopathStatus[remoteLp].isActive = 0;
+ }
+}
+
+static void handleMonitorEvent(struct HvLpEvent *event)
+{
+ HvLpIndex remoteLp;
+ int i;
+
+ /*
+ * This handler is _also_ called as part of the loop
+ * at the end of this routine, so it must be able to
+ * ignore NULL events...
+ */
+ if (!event)
+ return;
+
+ /*
+ * First see if this is just a normal monitor message from the
+ * other partition
+ */
+ if (event->xFlags.xFunction == HvLpEvent_Function_Int) {
+ remoteLp = event->xSourceLp;
+ if (!viopathStatus[remoteLp].isActive)
+ sendMonMsg(remoteLp);
+ return;
+ }
+
+ /*
+ * This path is for an acknowledgement; the other partition
+ * died
+ */
+ remoteLp = event->xTargetLp;
+ if ((event->xSourceInstanceId != viopathStatus[remoteLp].mSourceInst) ||
+ (event->xTargetInstanceId != viopathStatus[remoteLp].mTargetInst)) {
+ printk(VIOPATH_KERN_WARN "ignoring ack....mismatched instances\n");
+ return;
+ }
+
+ printk(VIOPATH_KERN_WARN "partition %d ended\n", remoteLp);
+
+ viopathStatus[remoteLp].isActive = 0;
+
+ /*
+ * For each active handler, pass them a NULL
+ * message to indicate that the other partition
+ * died
+ */
+ for (i = 0; i < VIO_MAX_SUBTYPES; i++) {
+ if (vio_handler[i] != NULL)
+ (*vio_handler[i])(NULL);
+ }
+}
+
+int vio_setHandler(int subtype, vio_event_handler_t *beh)
+{
+ subtype = subtype >> VIOMAJOR_SUBTYPE_SHIFT;
+ if ((subtype < 0) || (subtype >= VIO_MAX_SUBTYPES))
+ return -EINVAL;
+ if (vio_handler[subtype] != NULL)
+ return -EBUSY;
+ vio_handler[subtype] = beh;
+ return 0;
+}
+EXPORT_SYMBOL(vio_setHandler);
+
+int vio_clearHandler(int subtype)
+{
+ subtype = subtype >> VIOMAJOR_SUBTYPE_SHIFT;
+ if ((subtype < 0) || (subtype >= VIO_MAX_SUBTYPES))
+ return -EINVAL;
+ if (vio_handler[subtype] == NULL)
+ return -EAGAIN;
+ vio_handler[subtype] = NULL;
+ return 0;
+}
+EXPORT_SYMBOL(vio_clearHandler);
+
+static void handleConfig(struct HvLpEvent *event)
+{
+ if (!event)
+ return;
+ if (event->xFlags.xFunction == HvLpEvent_Function_Int) {
+ printk(VIOPATH_KERN_WARN
+ "unexpected config request from partition %d",
+ event->xSourceLp);
+
+ if ((event->xFlags.xFunction == HvLpEvent_Function_Int) &&
+ (event->xFlags.xAckInd == HvLpEvent_AckInd_DoAck)) {
+ event->xRc = HvLpEvent_Rc_InvalidSubtype;
+ HvCallEvent_ackLpEvent(event);
+ }
+ return;
+ }
+
+ up((struct semaphore *)event->xCorrelationToken);
+}
+
+/*
+ * Initialization of the hosting partition
+ */
+void vio_set_hostlp(void)
+{
+ /*
+ * If this has already been set then we DON'T want to either change
+ * it or re-register the proc file system
+ */
+ if (viopath_hostLp != HvLpIndexInvalid)
+ return;
+
+ /*
+ * Figure out our hosting partition. This isn't allowed to change
+ * while we're active
+ */
+ viopath_ourLp = HvLpConfig_getLpIndex();
+ viopath_hostLp = HvLpConfig_getHostingLpIndex(viopath_ourLp);
+
+ if (viopath_hostLp != HvLpIndexInvalid)
+ vio_setHandler(viomajorsubtype_config, handleConfig);
+}
+EXPORT_SYMBOL(vio_set_hostlp);
+
+static void vio_handleEvent(struct HvLpEvent *event, struct pt_regs *regs)
+{
+ HvLpIndex remoteLp;
+ int subtype = (event->xSubtype & VIOMAJOR_SUBTYPE_MASK)
+ >> VIOMAJOR_SUBTYPE_SHIFT;
+
+ if (event->xFlags.xFunction == HvLpEvent_Function_Int) {
+ remoteLp = event->xSourceLp;
+ /*
+ * The isActive is checked because if the hosting partition
+ * went down and came back up it would not be active but it
+ * would have different source and target instances, in which
+ * case we'd want to reset them. This case really protects
+ * against an unauthorized active partition sending interrupts
+ * or acks to this linux partition.
+ */
+ if (viopathStatus[remoteLp].isActive
+ && (event->xSourceInstanceId !=
+ viopathStatus[remoteLp].mTargetInst)) {
+ printk(VIOPATH_KERN_WARN
+ "message from invalid partition. "
+ "int msg rcvd, source inst (%d) doesnt match (%d)\n",
+ viopathStatus[remoteLp].mTargetInst,
+ event->xSourceInstanceId);
+ return;
+ }
+
+ if (viopathStatus[remoteLp].isActive
+ && (event->xTargetInstanceId !=
+ viopathStatus[remoteLp].mSourceInst)) {
+ printk(VIOPATH_KERN_WARN
+ "message from invalid partition. "
+ "int msg rcvd, target inst (%d) doesnt match (%d)\n",
+ viopathStatus[remoteLp].mSourceInst,
+ event->xTargetInstanceId);
+ return;
+ }
+ } else {
+ remoteLp = event->xTargetLp;
+ if (event->xSourceInstanceId !=
+ viopathStatus[remoteLp].mSourceInst) {
+ printk(VIOPATH_KERN_WARN
+ "message from invalid partition. "
+ "ack msg rcvd, source inst (%d) doesnt match (%d)\n",
+ viopathStatus[remoteLp].mSourceInst,
+ event->xSourceInstanceId);
+ return;
+ }
+
+ if (event->xTargetInstanceId !=
+ viopathStatus[remoteLp].mTargetInst) {
+ printk(VIOPATH_KERN_WARN
+ "message from invalid partition. "
+ "viopath: ack msg rcvd, target inst (%d) doesnt match (%d)\n",
+ viopathStatus[remoteLp].mTargetInst,
+ event->xTargetInstanceId);
+ return;
+ }
+ }
+
+ if (vio_handler[subtype] == NULL) {
+ printk(VIOPATH_KERN_WARN
+ "unexpected virtual io event subtype %d from partition %d\n",
+ event->xSubtype, remoteLp);
+ /* No handler. Ack if necessary */
+ if ((event->xFlags.xFunction == HvLpEvent_Function_Int) &&
+ (event->xFlags.xAckInd == HvLpEvent_AckInd_DoAck)) {
+ event->xRc = HvLpEvent_Rc_InvalidSubtype;
+ HvCallEvent_ackLpEvent(event);
+ }
+ return;
+ }
+
+ /* This innocuous little line is where all the real work happens */
+ (*vio_handler[subtype])(event);
+}
+
+static void viopath_donealloc(void *parm, int number)
+{
+ struct alloc_parms *parmsp = parm;
+
+ parmsp->number = number;
+ if (parmsp->used_wait_atomic)
+ atomic_set(&parmsp->wait_atomic, 0);
+ else
+ up(&parmsp->sem);
+}
+
+static int allocateEvents(HvLpIndex remoteLp, int numEvents)
+{
+ struct alloc_parms parms;
+
+ if (system_state != SYSTEM_RUNNING) {
+ parms.used_wait_atomic = 1;
+ atomic_set(&parms.wait_atomic, 1);
+ } else {
+ parms.used_wait_atomic = 0;
+ init_MUTEX_LOCKED(&parms.sem);
+ }
+ mf_allocate_lp_events(remoteLp, HvLpEvent_Type_VirtualIo, 250, /* It would be nice to put a real number here! */
+ numEvents, &viopath_donealloc, &parms);
+ if (system_state != SYSTEM_RUNNING) {
+ while (atomic_read(&parms.wait_atomic))
+ mb();
+ } else
+ down(&parms.sem);
+ return parms.number;
+}
+
+int viopath_open(HvLpIndex remoteLp, int subtype, int numReq)
+{
+ int i;
+ unsigned long flags;
+ int tempNumAllocated;
+
+ if ((remoteLp >= HVMAXARCHITECTEDLPS) || (remoteLp == HvLpIndexInvalid))
+ return -EINVAL;
+
+ subtype = subtype >> VIOMAJOR_SUBTYPE_SHIFT;
+ if ((subtype < 0) || (subtype >= VIO_MAX_SUBTYPES))
+ return -EINVAL;
+
+ spin_lock_irqsave(&statuslock, flags);
+
+ if (!event_buffer_initialised) {
+ for (i = 0; i < VIO_MAX_SUBTYPES; i++)
+ atomic_set(&event_buffer_available[i], 1);
+ event_buffer_initialised = 1;
+ }
+
+ viopathStatus[remoteLp].users[subtype]++;
+
+ if (!viopathStatus[remoteLp].isOpen) {
+ viopathStatus[remoteLp].isOpen = 1;
+ HvCallEvent_openLpEventPath(remoteLp, HvLpEvent_Type_VirtualIo);
+
+ /*
+ * Don't hold the spinlock during an operation that
+ * can sleep.
+ */
+ spin_unlock_irqrestore(&statuslock, flags);
+ tempNumAllocated = allocateEvents(remoteLp, 1);
+ spin_lock_irqsave(&statuslock, flags);
+
+ viopathStatus[remoteLp].numberAllocated += tempNumAllocated;
+
+ if (viopathStatus[remoteLp].numberAllocated == 0) {
+ HvCallEvent_closeLpEventPath(remoteLp,
+ HvLpEvent_Type_VirtualIo);
+
+ spin_unlock_irqrestore(&statuslock, flags);
+ return -ENOMEM;
+ }
+
+ viopathStatus[remoteLp].mSourceInst =
+ HvCallEvent_getSourceLpInstanceId(remoteLp,
+ HvLpEvent_Type_VirtualIo);
+ viopathStatus[remoteLp].mTargetInst =
+ HvCallEvent_getTargetLpInstanceId(remoteLp,
+ HvLpEvent_Type_VirtualIo);
+ HvLpEvent_registerHandler(HvLpEvent_Type_VirtualIo,
+ &vio_handleEvent);
+ sendMonMsg(remoteLp);
+ printk(VIOPATH_KERN_INFO "opening connection to partition %d, "
+ "setting sinst %d, tinst %d\n",
+ remoteLp, viopathStatus[remoteLp].mSourceInst,
+ viopathStatus[remoteLp].mTargetInst);
+ }
+
+ spin_unlock_irqrestore(&statuslock, flags);
+ tempNumAllocated = allocateEvents(remoteLp, numReq);
+ spin_lock_irqsave(&statuslock, flags);
+ viopathStatus[remoteLp].numberAllocated += tempNumAllocated;
+ spin_unlock_irqrestore(&statuslock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL(viopath_open);
+
+int viopath_close(HvLpIndex remoteLp, int subtype, int numReq)
+{
+ unsigned long flags;
+ int i;
+ int numOpen;
+ struct alloc_parms parms;
+
+ if ((remoteLp >= HVMAXARCHITECTEDLPS) || (remoteLp == HvLpIndexInvalid))
+ return -EINVAL;
+
+ subtype = subtype >> VIOMAJOR_SUBTYPE_SHIFT;
+ if ((subtype < 0) || (subtype >= VIO_MAX_SUBTYPES))
+ return -EINVAL;
+
+ spin_lock_irqsave(&statuslock, flags);
+ /*
+ * If the viopath_close somehow gets called before a
+ * viopath_open it could decrement to -1 which is a non
+ * recoverable state so we'll prevent this from
+ * happening.
+ */
+ if (viopathStatus[remoteLp].users[subtype] > 0)
+ viopathStatus[remoteLp].users[subtype]--;
+
+ spin_unlock_irqrestore(&statuslock, flags);
+
+ parms.used_wait_atomic = 0;
+ init_MUTEX_LOCKED(&parms.sem);
+ mf_deallocate_lp_events(remoteLp, HvLpEvent_Type_VirtualIo,
+ numReq, &viopath_donealloc, &parms);
+ down(&parms.sem);
+
+ spin_lock_irqsave(&statuslock, flags);
+ for (i = 0, numOpen = 0; i < VIO_MAX_SUBTYPES; i++)
+ numOpen += viopathStatus[remoteLp].users[i];
+
+ if ((viopathStatus[remoteLp].isOpen) && (numOpen == 0)) {
+ printk(VIOPATH_KERN_INFO "closing connection to partition %d",
+ remoteLp);
+
+ HvCallEvent_closeLpEventPath(remoteLp,
+ HvLpEvent_Type_VirtualIo);
+ viopathStatus[remoteLp].isOpen = 0;
+ viopathStatus[remoteLp].isActive = 0;
+
+ for (i = 0; i < VIO_MAX_SUBTYPES; i++)
+ atomic_set(&event_buffer_available[i], 0);
+ event_buffer_initialised = 0;
+ }
+ spin_unlock_irqrestore(&statuslock, flags);
+ return 0;
+}
+EXPORT_SYMBOL(viopath_close);
+
+void *vio_get_event_buffer(int subtype)
+{
+ subtype = subtype >> VIOMAJOR_SUBTYPE_SHIFT;
+ if ((subtype < 0) || (subtype >= VIO_MAX_SUBTYPES))
+ return NULL;
+
+ if (atomic_dec_if_positive(&event_buffer_available[subtype]) == 0)
+ return &event_buffer[subtype * 256];
+ else
+ return NULL;
+}
+EXPORT_SYMBOL(vio_get_event_buffer);
+
+void vio_free_event_buffer(int subtype, void *buffer)
+{
+ subtype = subtype >> VIOMAJOR_SUBTYPE_SHIFT;
+ if ((subtype < 0) || (subtype >= VIO_MAX_SUBTYPES)) {
+ printk(VIOPATH_KERN_WARN
+ "unexpected subtype %d freeing event buffer\n", subtype);
+ return;
+ }
+
+ if (atomic_read(&event_buffer_available[subtype]) != 0) {
+ printk(VIOPATH_KERN_WARN
+ "freeing unallocated event buffer, subtype %d\n",
+ subtype);
+ return;
+ }
+
+ if (buffer != &event_buffer[subtype * 256]) {
+ printk(VIOPATH_KERN_WARN
+ "freeing invalid event buffer, subtype %d\n", subtype);
+ }
+
+ atomic_set(&event_buffer_available[subtype], 1);
+}
+EXPORT_SYMBOL(vio_free_event_buffer);
+
+static const struct vio_error_entry vio_no_error =
+ { 0, 0, "Non-VIO Error" };
+static const struct vio_error_entry vio_unknown_error =
+ { 0, EIO, "Unknown Error" };
+
+static const struct vio_error_entry vio_default_errors[] = {
+ {0x0001, EIO, "No Connection"},
+ {0x0002, EIO, "No Receiver"},
+ {0x0003, EIO, "No Buffer Available"},
+ {0x0004, EBADRQC, "Invalid Message Type"},
+ {0x0000, 0, NULL},
+};
+
+const struct vio_error_entry *vio_lookup_rc(
+ const struct vio_error_entry *local_table, u16 rc)
+{
+ const struct vio_error_entry *cur;
+
+ if (!rc)
+ return &vio_no_error;
+ if (local_table)
+ for (cur = local_table; cur->rc; ++cur)
+ if (cur->rc == rc)
+ return cur;
+ for (cur = vio_default_errors; cur->rc; ++cur)
+ if (cur->rc == rc)
+ return cur;
+ return &vio_unknown_error;
+}
+EXPORT_SYMBOL(vio_lookup_rc);