[PATCH 7/7] [v3] drivers/misc: introduce Freescale hypervisor management driver
Timur Tabi
timur at freescale.com
Sat Jun 4 06:47:37 EST 2011
The Freescale hypervisor management driver provides several services to
drivers and applications related to the Freescale hypervisor:
1. An ioctl interface for querying and managing partitions
2. A file interface to reading incoming doorbells
3. An interrupt handler for shutting down the partition upon receiving the
shutdown doorbell from a manager partition
4. An interface for receiving callbacks when a managed partition shuts down.
Signed-off-by: Timur Tabi <timur at freescale.com>
---
drivers/misc/Kconfig | 7 +
drivers/misc/Makefile | 1 +
drivers/misc/fsl_hypervisor.c | 954 ++++++++++++++++++++++++++++++++++++++++
include/linux/Kbuild | 1 +
include/linux/fsl_hypervisor.h | 214 +++++++++
5 files changed, 1177 insertions(+), 0 deletions(-)
create mode 100644 drivers/misc/fsl_hypervisor.c
create mode 100644 include/linux/fsl_hypervisor.h
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index d80dcde..3e016b3 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -216,6 +216,13 @@ config ENCLOSURE_SERVICES
driver (SCSI/ATA) which supports enclosures
or a SCSI enclosure device (SES) to use these services.
+config FSL_HV_MANAGER
+ tristate "Freescale hypervisor management driver"
+ depends on FSL_SOC
+ help
+ This driver allows applications to communicate with the Freescale
+ Hypervisor.
+
config SGI_XP
tristate "Support communication between SGI SSIs"
depends on NET
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 848e846..d93bd76 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_SENSORS_BH1770) += bh1770glc.o
obj-$(CONFIG_SENSORS_APDS990X) += apds990x.o
obj-$(CONFIG_SGI_IOC4) += ioc4.o
obj-$(CONFIG_ENCLOSURE_SERVICES) += enclosure.o
+obj-$(CONFIG_FSL_HV_MANAGER) += fsl_hypervisor.o
obj-$(CONFIG_KGDB_TESTS) += kgdbts.o
obj-$(CONFIG_SGI_XP) += sgi-xp/
obj-$(CONFIG_SGI_GRU) += sgi-gru/
diff --git a/drivers/misc/fsl_hypervisor.c b/drivers/misc/fsl_hypervisor.c
new file mode 100644
index 0000000..64d38379
--- /dev/null
+++ b/drivers/misc/fsl_hypervisor.c
@@ -0,0 +1,954 @@
+/*
+ * Freescale Hypervisor Management Driver
+
+ * Copyright (C) 2008-2011 Freescale Semiconductor, Inc.
+ * Author: Timur Tabi <timur at freescale.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ *
+ * This driver contains functions to support the Freescale hypervisor.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/of.h>
+#include <linux/reboot.h>
+#include <linux/uaccess.h>
+#include <linux/notifier.h>
+
+#include <linux/io.h>
+#include <asm/fsl_hcalls.h>
+
+#include <linux/fsl_hypervisor.h>
+
+static BLOCKING_NOTIFIER_HEAD(failover_subscribers);
+
+/*
+ * Ioctl interface for FSL_HV_IOCTL_PARTITION_RESTART
+ *
+ * Restart a running partition
+ */
+static long ioctl_restart(struct fsl_hv_ioctl_restart __user *p)
+{
+ struct fsl_hv_ioctl_restart param;
+
+ /* Get the parameters from the user */
+ if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_restart)))
+ return -EFAULT;
+
+ param.ret = fh_partition_restart(param.partition);
+
+ if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32)))
+ return -EFAULT;
+
+ return 0;
+}
+
+/*
+ * Ioctl interface for FSL_HV_IOCTL_PARTITION_STATUS
+ *
+ * Query the status of a partition
+ */
+static long ioctl_status(struct fsl_hv_ioctl_status __user *p)
+{
+ struct fsl_hv_ioctl_status param;
+ u32 status;
+
+ /* Get the parameters from the user */
+ if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_status)))
+ return -EFAULT;
+
+ param.ret = fh_partition_get_status(param.partition, &status);
+ if (!param.ret)
+ param.status = status;
+
+ if (copy_to_user(p, ¶m, sizeof(struct fsl_hv_ioctl_status)))
+ return -EFAULT;
+
+ return 0;
+}
+
+/*
+ * Ioctl interface for FSL_HV_IOCTL_PARTITION_START
+ *
+ * Start a stopped partition.
+ */
+static long ioctl_start(struct fsl_hv_ioctl_start __user *p)
+{
+ struct fsl_hv_ioctl_start param;
+
+ /* Get the parameters from the user */
+ if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_start)))
+ return -EFAULT;
+
+ param.ret = fh_partition_start(param.partition, param.entry_point,
+ param.load);
+
+ if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32)))
+ return -EFAULT;
+
+ return 0;
+}
+
+/*
+ * Ioctl interface for FSL_HV_IOCTL_PARTITION_STOP
+ *
+ * Stop a running partition
+ */
+static long ioctl_stop(struct fsl_hv_ioctl_stop __user *p)
+{
+ struct fsl_hv_ioctl_stop param;
+
+ /* Get the parameters from the user */
+ if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_stop)))
+ return -EFAULT;
+
+ param.ret = fh_partition_stop(param.partition);
+
+ if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32)))
+ return -EFAULT;
+
+ return 0;
+}
+
+/*
+ * Ioctl interface for FSL_HV_IOCTL_MEMCPY
+ *
+ * The FH_MEMCPY hypercall takes an array of address/address/size structures
+ * to represent the data being copied. As a convenience to the user, this
+ * ioctl takes a user-create buffer and a pointer to a guest physically
+ * contiguous buffer in the remote partition, and creates the
+ * address/address/size array for the hypercall.
+ */
+static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
+{
+ struct fsl_hv_ioctl_memcpy param;
+
+ struct page **pages = NULL;
+ void *sg_list_unaligned = NULL;
+ struct fh_sg_list *sg_list = NULL;
+
+ unsigned int num_pages;
+ unsigned long lb_offset; /* Offset within a page of the local buffer */
+
+ unsigned int i;
+ long ret = 0;
+ int num_pinned; /* return value from get_user_pages() */
+ phys_addr_t remote_paddr; /* The next address in the remote buffer */
+ uint32_t count; /* The number of bytes left to copy */
+
+ /* Get the parameters from the user */
+ if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_memcpy)))
+ return -EFAULT;
+
+ /* One partition must be local, the other must be remote. In other
+ words, if source and target are both -1, or are both not -1, then
+ return an error. */
+ if ((param.source == -1) == (param.target == -1))
+ return -EINVAL;
+
+ /*
+ * The array of pages returned by get_user_pages() covers only
+ * page-aligned memory. Since the user buffer is probably not
+ * page-aligned, we need to handle the discrepancy.
+ *
+ * We calculate the offset within a page of the S/G list, and make
+ * adjustments accordingly. This will result in a page list that looks
+ * like this:
+ *
+ * ---- <-- first page starts before the buffer
+ * | |
+ * |////|-> ----
+ * |////| | |
+ * ---- | |
+ * | |
+ * ---- | |
+ * |////| | |
+ * |////| | |
+ * |////| | |
+ * ---- | |
+ * | |
+ * ---- | |
+ * |////| | |
+ * |////| | |
+ * |////| | |
+ * ---- | |
+ * | |
+ * ---- | |
+ * |////| | |
+ * |////|-> ----
+ * | | <-- last page ends after the buffer
+ * ----
+ *
+ * The distance between the start of the first page and the start of the
+ * buffer is lb_offset. The hashed (///) areas are the parts of the
+ * page list that contain the actual buffer.
+ *
+ * The advantage of this approach is that the number of pages is
+ * equal to the number of entries in the S/G list that we give to the
+ * hypervisor.
+ */
+ lb_offset = param.local_vaddr & (PAGE_SIZE - 1);
+ num_pages = (param.count + lb_offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+ /* Allocate the buffers we need */
+
+ /* pages is an array of struct page pointers that's initialized by
+ get_user_pages() */
+ pages = kzalloc(num_pages * sizeof(struct page *), GFP_KERNEL);
+ if (!pages) {
+ pr_debug("fsl-hv: could not allocate page list\n");
+ return -ENOMEM;
+ }
+
+ /* sg_list is the list of fh_sg_list objects that we pass to the
+ hypervisor */
+ sg_list_unaligned = kmalloc(num_pages * sizeof(struct fh_sg_list) +
+ sizeof(struct fh_sg_list) - 1, GFP_KERNEL);
+ if (!sg_list_unaligned) {
+ pr_debug("fsl-hv: could not allocate S/G list\n");
+ ret = -ENOMEM;
+ goto exit;
+ }
+ sg_list = PTR_ALIGN(sg_list_unaligned, sizeof(struct fh_sg_list));
+
+ /* Get the physical addresses of the source buffer */
+ down_read(¤t->mm->mmap_sem);
+ num_pinned = get_user_pages(current, current->mm,
+ param.local_vaddr - lb_offset, num_pages,
+ (param.source == -1) ? READ : WRITE,
+ 0, pages, NULL);
+ up_read(¤t->mm->mmap_sem);
+
+ if (num_pinned != num_pages) {
+ /* get_user_pages() failed */
+ pr_debug("fsl-hv: could not lock source buffer\n");
+ ret = (num_pinned < 0) ? num_pinned : -EFAULT;
+ goto exit;
+ }
+
+ /*
+ * Build the fh_sg_list[] array. The first page is special
+ * because it's misaligned.
+ */
+ if (param.source == -1) {
+ sg_list[0].source = page_to_phys(pages[0]) + lb_offset;
+ sg_list[0].target = param.remote_paddr;
+ } else {
+ sg_list[0].source = param.remote_paddr;
+ sg_list[0].target = page_to_phys(pages[0]) + lb_offset;
+ }
+ sg_list[0].size = min_t(uint64_t, param.count, PAGE_SIZE - lb_offset);
+
+ remote_paddr = param.remote_paddr + sg_list[0].size;
+ count = param.count - sg_list[0].size;
+
+ for (i = 1; i < num_pages; i++) {
+ if (param.source == -1) {
+ /* local to remote */
+ sg_list[i].source = page_to_phys(pages[i]);
+ sg_list[i].target = remote_paddr;
+ } else {
+ /* remote to local */
+ sg_list[i].source = remote_paddr;
+ sg_list[i].target = page_to_phys(pages[i]);
+ }
+ sg_list[i].size = min_t(uint64_t, count, PAGE_SIZE);
+
+ remote_paddr += sg_list[i].size;
+ count -= sg_list[i].size;
+ }
+
+ param.ret = fh_partition_memcpy(param.source, param.target,
+ virt_to_phys(sg_list), num_pages);
+
+exit:
+ if (pages) {
+ for (i = 0; i < num_pages; i++)
+ if (pages[i])
+ put_page(pages[i]);
+ }
+
+ kfree(sg_list_unaligned);
+ kfree(pages);
+
+ if (!ret)
+ if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32)))
+ return -EFAULT;
+
+ return ret;
+}
+
+/*
+ * Ioctl interface for FSL_HV_IOCTL_DOORBELL
+ *
+ * Ring a doorbell
+ */
+static long ioctl_doorbell(struct fsl_hv_ioctl_doorbell __user *p)
+{
+ struct fsl_hv_ioctl_doorbell param;
+
+ /* Get the parameters from the user */
+ if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_doorbell)))
+ return -EFAULT;
+
+ param.ret = ev_doorbell_send(param.doorbell);
+
+ if (copy_to_user(&p->ret, ¶m.ret, sizeof(__u32)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static long ioctl_dtprop(struct fsl_hv_ioctl_prop __user *p, int set)
+{
+ struct fsl_hv_ioctl_prop param;
+ char __user *upath, *upropname;
+ void __user *upropval;
+ char *path = NULL, *propname = NULL;
+ void *propval = NULL;
+ int ret = 0;
+
+ /* Get the parameters from the user */
+ if (copy_from_user(¶m, p, sizeof(struct fsl_hv_ioctl_prop)))
+ return -EFAULT;
+
+ upath = (char __user *)(uintptr_t)param.path;
+ upropname = (char __user *)(uintptr_t)param.propname;
+ upropval = (void __user *)(uintptr_t)param.propval;
+
+ path = strndup_user(upath, FH_DTPROP_MAX_PATHLEN);
+ if (IS_ERR(path)) {
+ ret = PTR_ERR(path);
+ goto out;
+ }
+
+ propname = strndup_user(upropname, FH_DTPROP_MAX_PATHLEN);
+ if (IS_ERR(propname)) {
+ ret = PTR_ERR(propname);
+ goto out;
+ }
+
+ if (param.proplen > FH_DTPROP_MAX_PROPLEN) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ propval = kmalloc(param.proplen, GFP_KERNEL);
+ if (!propval) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (set) {
+ if (copy_from_user(propval, upropval, param.proplen)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ param.ret = fh_partition_set_dtprop(param.handle,
+ virt_to_phys(path),
+ virt_to_phys(propname),
+ virt_to_phys(propval),
+ param.proplen);
+ } else {
+ param.ret = fh_partition_get_dtprop(param.handle,
+ virt_to_phys(path),
+ virt_to_phys(propname),
+ virt_to_phys(propval),
+ ¶m.proplen);
+
+ if (param.ret == 0) {
+ if (copy_to_user(upropval, propval, param.proplen) ||
+ put_user(param.proplen, &p->proplen)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ }
+ }
+
+ if (put_user(param.ret, &p->ret))
+ ret = -EFAULT;
+
+out:
+ kfree(path);
+ kfree(propval);
+ kfree(propname);
+
+ return ret;
+}
+
+/*
+ * Ioctl main entry point
+ */
+static long fsl_hv_ioctl(struct file *file, unsigned int cmd,
+ unsigned long argaddr)
+{
+ void __user *arg = (void __user *)argaddr;
+ long ret;
+ size_t size;
+
+ /* Make sure the application is called the right driver. */
+ if (_IOC_TYPE(cmd) != 0) {
+ pr_debug("fsl-hv: ioctl type %u should be 0\n", _IOC_TYPE(cmd));
+ return -EINVAL;
+ }
+
+ /* Make sure the application set the direction flag correctly. */
+ if (_IOC_DIR(cmd) != (_IOC_READ | _IOC_WRITE)) {
+ pr_debug("fsl-hv: ioctl direction should be _IOWR\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Make sure the application is passing the right structure to us.
+ * For backwards compatibility with older applications, we only check
+ * if the size is too small, rather than unequal.
+ */
+
+ switch (_IOC_NR(cmd)) {
+ case FSL_HV_IOCTL_PARTITION_RESTART:
+ size = sizeof(struct fsl_hv_ioctl_restart);
+ if (_IOC_SIZE(cmd) < size)
+ goto size_error;
+ ret = ioctl_restart(arg);
+ break;
+ case FSL_HV_IOCTL_PARTITION_GET_STATUS:
+ size = sizeof(struct fsl_hv_ioctl_status);
+ if (_IOC_SIZE(cmd) < size)
+ goto size_error;
+ ret = ioctl_status(arg);
+ break;
+ case FSL_HV_IOCTL_PARTITION_START:
+ size = sizeof(struct fsl_hv_ioctl_start);
+ if (_IOC_SIZE(cmd) < size)
+ goto size_error;
+ ret = ioctl_start(arg);
+ break;
+ case FSL_HV_IOCTL_PARTITION_STOP:
+ size = sizeof(struct fsl_hv_ioctl_stop);
+ if (_IOC_SIZE(cmd) < size)
+ goto size_error;
+ ret = ioctl_stop(arg);
+ break;
+ case FSL_HV_IOCTL_MEMCPY:
+ size = sizeof(struct fsl_hv_ioctl_memcpy);
+ if (_IOC_SIZE(cmd) < size)
+ goto size_error;
+ ret = ioctl_memcpy(arg);
+ break;
+ case FSL_HV_IOCTL_DOORBELL:
+ size = sizeof(struct fsl_hv_ioctl_doorbell);
+ if (_IOC_SIZE(cmd) < size)
+ goto size_error;
+ ret = ioctl_doorbell(arg);
+ break;
+ case FSL_HV_IOCTL_GETPROP:
+ size = sizeof(struct fsl_hv_ioctl_prop);
+ if (_IOC_SIZE(cmd) < size)
+ goto size_error;
+ ret = ioctl_dtprop(arg, 0);
+ break;
+ case FSL_HV_IOCTL_SETPROP:
+ size = sizeof(struct fsl_hv_ioctl_prop);
+ if (_IOC_SIZE(cmd) < size)
+ goto size_error;
+ ret = ioctl_dtprop(arg, 1);
+ break;
+ default:
+ pr_debug("fsl-hv: unknown ioctl %u\n", _IOC_NR(cmd));
+ return -ENOTTY;
+ }
+
+ return ret;
+
+size_error:
+ pr_debug("fsl-hv: ioctl %u parameter size %u should be %zu\n",
+ _IOC_NR(cmd), _IOC_SIZE(cmd), size);
+ return -EINVAL;
+}
+
+/* Linked list of processes that have us open */
+static struct list_head db_list;
+
+/* spinlock for db_list */
+static DEFINE_SPINLOCK(db_list_lock);
+
+/* The size of the doorbell event queue. This must be a power of two. */
+#define QSIZE 16
+
+/* Returns the next head/tail pointer, wrapping around the queue if necessary */
+#define nextp(x) (((x) + 1) & (QSIZE - 1))
+
+/* Per-open data structure */
+struct doorbell_queue {
+ struct list_head list;
+ spinlock_t lock;
+ wait_queue_head_t wait;
+ unsigned int head;
+ unsigned int tail;
+ uint32_t q[QSIZE];
+};
+
+/* Linked list of ISRs that we registered */
+struct list_head isr_list;
+
+/* Per-ISR data structure */
+struct doorbell_isr {
+ struct list_head list;
+ unsigned int irq;
+ uint32_t doorbell; /* The doorbell handle */
+ uint32_t partition; /* The partition handle, if used */
+};
+
+/*
+ * Add a doorbell to all of the doorbell queues
+ */
+static void fsl_hv_queue_doorbell(uint32_t doorbell)
+{
+ struct doorbell_queue *dbq;
+ unsigned long flags;
+
+ /* Prevent another core from modifying db_list */
+ spin_lock_irqsave(&db_list_lock, flags);
+
+ list_for_each_entry(dbq, &db_list, list) {
+ if (dbq->head != nextp(dbq->tail)) {
+ dbq->q[dbq->tail] = doorbell;
+ /* This memory barrier eliminates the need to grab
+ * the spinlock for dbq. */
+ smp_wmb();
+ dbq->tail = nextp(dbq->tail);
+ wake_up_interruptible(&dbq->wait);
+ }
+ }
+
+ spin_unlock_irqrestore(&db_list_lock, flags);
+}
+
+/*
+ * Interrupt handler for all doorbells
+ *
+ * We use the same interrupt handler for all doorbells. Whenever a doorbell
+ * is rung, and we receive an interrupt, we just put the handle for that
+ * doorbell (passed to us as *data) into all of the queues.
+ */
+static irqreturn_t fsl_hv_isr(int irq, void *data)
+{
+ fsl_hv_queue_doorbell((uintptr_t) data);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * State change thread function
+ *
+ * The state change notification arrives in an interrupt, but we can't call
+ * blocking_notifier_call_chain() in an interrupt handler. We could call
+ * atomic_notifier_call_chain(), but that would require the clients' call-back
+ * function to run in interrupt context. Since we don't want to impose that
+ * restriction on the clients, we use a threaded IRQ to process the
+ * notification in kernel context.
+ */
+static irqreturn_t fsl_hv_state_change_thread(int irq, void *data)
+{
+ struct doorbell_isr *dbisr = data;
+
+ blocking_notifier_call_chain(&failover_subscribers, dbisr->partition,
+ NULL);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * Interrupt handler for state-change doorbells
+ */
+static irqreturn_t fsl_hv_state_change_isr(int irq, void *data)
+{
+ unsigned int status;
+ struct doorbell_isr *dbisr = data;
+ int ret;
+
+ /* It's still a doorbell, so add it to all the queues */
+ fsl_hv_queue_doorbell(dbisr->doorbell);
+
+ /* Determine the new state, and if it's stopped, notify the clients. */
+ ret = fh_partition_get_status(dbisr->partition, &status);
+ if (!ret && (status == FH_PARTITION_STOPPED))
+ return IRQ_WAKE_THREAD;
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * fsl_hv_poll - returns a bitmask indicating whether a read will block
+ *
+ * @return unsigned int
+ */
+static unsigned int fsl_hv_poll(struct file *filp, struct poll_table_struct *p)
+{
+ struct doorbell_queue *dbq = filp->private_data;
+ unsigned long flags;
+ unsigned int mask;
+
+ spin_lock_irqsave(&dbq->lock, flags);
+
+ poll_wait(filp, &dbq->wait, p);
+ mask = (dbq->head == dbq->tail) ? 0 : (POLLIN | POLLRDNORM);
+
+ spin_unlock_irqrestore(&dbq->lock, flags);
+
+ return mask;
+}
+
+/**
+ * fsl_hv_read - return the handles for any incoming doorbells
+ *
+ * If there are doorbell handles in the queue for this open instance, then
+ * return them to the caller as an array of 32-bit integers. Otherwise,
+ * block until there is at least one handle to return.
+ */
+static ssize_t fsl_hv_read(struct file *filp, char __user *buf, size_t len,
+ loff_t *off)
+{
+ struct doorbell_queue *dbq = filp->private_data;
+ uint32_t __user *p = (uint32_t __user *) buf; /* for put_user() */
+ unsigned long flags;
+ ssize_t count = 0;
+
+ /* Make sure we stop when the user buffer is full. */
+ while (len >= sizeof(uint32_t)) {
+ uint32_t dbell; /* Local copy of doorbell queue data */
+
+ spin_lock_irqsave(&dbq->lock, flags);
+
+ /* If the queue is empty, then either we're done or we need
+ * to block. If the application specified O_NONBLOCK, then
+ * we return the appropriate error code.
+ */
+ if (dbq->head == dbq->tail) {
+ spin_unlock_irqrestore(&dbq->lock, flags);
+ if (count)
+ break;
+ if (filp->f_flags & O_NONBLOCK)
+ return -EAGAIN;
+ if (wait_event_interruptible(dbq->wait,
+ dbq->head != dbq->tail))
+ return -ERESTARTSYS;
+ continue;
+ }
+
+ /* Even though we have an smp_wmb() in the ISR, the core
+ * might speculatively execute the "dbell = ..." below while
+ * it's evaluating the if-statement above. In that case, the
+ * value put into dbell could be stale if the core accepts the
+ * speculation. To prevent that, we need a read memory barrier
+ * here as well.
+ */
+ smp_rmb();
+
+ /* Copy the data to a temporary local buffer, because
+ * we can't call copy_to_user() from inside a spinlock
+ */
+ dbell = dbq->q[dbq->head];
+ dbq->head = nextp(dbq->head);
+
+ spin_unlock_irqrestore(&dbq->lock, flags);
+
+ if (put_user(dbell, p))
+ return -EFAULT;
+ p++;
+ count += sizeof(uint32_t);
+ len -= sizeof(uint32_t);
+ }
+
+ return count;
+}
+
+/**
+ * fsl_hv_open - open the driver
+ *
+ * Open the driver and prepare for reading doorbells.
+ *
+ * Every time an application opens the driver, we create a doorbell queue
+ * for that file handle. This queue is used for any incoming doorbells.
+ */
+static int fsl_hv_open(struct inode *inode, struct file *filp)
+{
+ struct doorbell_queue *dbq;
+ unsigned long flags;
+ int ret = 0;
+
+ dbq = kzalloc(sizeof(struct doorbell_queue), GFP_KERNEL);
+ if (!dbq) {
+ pr_err("fsl-hv: out of memory\n");
+ return -ENOMEM;
+ }
+
+ spin_lock_init(&dbq->lock);
+ init_waitqueue_head(&dbq->wait);
+
+ spin_lock_irqsave(&db_list_lock, flags);
+ list_add(&dbq->list, &db_list);
+ spin_unlock_irqrestore(&db_list_lock, flags);
+
+ filp->private_data = dbq;
+
+ return ret;
+}
+
+/**
+ * fsl_hv_close - close the driver
+ */
+static int fsl_hv_close(struct inode *inode, struct file *filp)
+{
+ struct doorbell_queue *dbq = filp->private_data;
+ unsigned long flags;
+
+ int ret = 0;
+
+ spin_lock_irqsave(&db_list_lock, flags);
+ list_del(&dbq->list);
+ spin_unlock_irqrestore(&db_list_lock, flags);
+
+ kfree(dbq);
+
+ return ret;
+}
+
+static const struct file_operations fsl_hv_fops = {
+ .owner = THIS_MODULE,
+ .open = fsl_hv_open,
+ .release = fsl_hv_close,
+ .poll = fsl_hv_poll,
+ .read = fsl_hv_read,
+ .unlocked_ioctl = fsl_hv_ioctl,
+};
+
+static struct miscdevice fsl_hv_misc_dev = {
+ MISC_DYNAMIC_MINOR,
+ "fsl-hv",
+ &fsl_hv_fops
+};
+
+static irqreturn_t fsl_hv_shutdown_isr(int irq, void *data)
+{
+ orderly_poweroff(false);
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * get_parent_handle -- returns the handle of the parent of the given node
+ *
+ * The handle is the value of the 'reg' property
+ */
+static int get_parent_handle(struct device_node *np)
+{
+ struct device_node *parent;
+ const uint32_t *prop;
+ int len;
+
+ parent = of_get_parent(np);
+ if (!parent)
+ /* It's not really possible for this to fail */
+ return -ENODEV;
+
+ prop = of_get_property(parent, "reg", &len);
+ of_node_put(parent);
+
+ if (!prop || (len != sizeof(uint32_t)))
+ /* This can happen only if the node is malformed */
+ return -ENODEV;
+
+ return *prop;
+}
+
+/**
+ * fsl_hv_failover_register -- register a callback for failover events
+ *
+ * This function is called by device drivers to register their callback
+ * functions for fail-over events.
+ */
+int fsl_hv_failover_register(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&failover_subscribers, nb);
+}
+EXPORT_SYMBOL(fsl_hv_failover_register);
+
+/**
+ * fsl_hv_failover_unregister -- unregister a callback for failover events
+ */
+int fsl_hv_failover_unregister(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&failover_subscribers, nb);
+}
+EXPORT_SYMBOL(fsl_hv_failover_unregister);
+
+/**
+ * has_fsl_hypervisor - return TRUE if we're running under FSL hypervisor
+ *
+ * This function checks to see if we're running under the Freescale
+ * hypervisor, and returns zero if we're not, or non-zero if we are.
+ *
+ * First, it checks if MSR[GS]==1, which means we're running under some
+ * hypervisor. Then it checks if there is a hypervisor node in the device
+ * tree. Currently, that means there needs to be a node in the root called
+ * "hypervisor" and which has a property named "fsl,hv-version".
+ */
+static int has_fsl_hypervisor(void)
+{
+ struct device_node *node;
+ int ret;
+
+ if (!(mfmsr() & MSR_GS))
+ return 0;
+
+ node = of_find_node_by_path("/hypervisor");
+ if (!node)
+ return 0;
+
+ ret = of_find_property(node, "fsl,hv-version", NULL) != NULL;
+
+ of_node_put(node);
+
+ return ret;
+}
+
+/**
+ * fsl_hypervisor_init: Freescale hypervisor management driver init
+ *
+ * This function is called when this module is loaded.
+ *
+ * Register ourselves as a miscellaneous driver. This will register the
+ * fops structure and create the right sysfs entries for udev.
+ */
+static int __init fsl_hypervisor_init(void)
+{
+ struct device_node *np;
+ struct doorbell_isr *dbisr, *n;
+ int ret;
+
+ pr_info("Freescale hypervisor management driver\n");
+
+ if (!has_fsl_hypervisor()) {
+ pr_info("fsl-hv: no hypervisor found\n");
+ return -ENODEV;
+ }
+
+ ret = misc_register(&fsl_hv_misc_dev);
+ if (ret) {
+ pr_err("fsl-hv: cannot register device\n");
+ return ret;
+ }
+
+ INIT_LIST_HEAD(&db_list);
+ INIT_LIST_HEAD(&isr_list);
+
+ for_each_compatible_node(np, NULL, "epapr,hv-receive-doorbell") {
+ unsigned int irq;
+ const uint32_t *handle;
+
+ handle = of_get_property(np, "interrupts", NULL);
+ irq = irq_of_parse_and_map(np, 0);
+ if (!handle || (irq == NO_IRQ)) {
+ pr_err("fsl-hv: no 'interrupts' property in %s node\n",
+ np->full_name);
+ continue;
+ }
+
+ dbisr = kzalloc(sizeof(*dbisr), GFP_KERNEL);
+ if (!dbisr)
+ goto out_of_memory;
+
+ dbisr->irq = irq;
+ dbisr->doorbell = *handle;
+
+ if (of_device_is_compatible(np, "fsl,hv-shutdown-doorbell")) {
+ /* The shutdown doorbell gets its own ISR */
+ ret = request_irq(irq, fsl_hv_shutdown_isr, 0,
+ np->name, NULL);
+ } else if (of_device_is_compatible(np,
+ "fsl,hv-state-change-doorbell")) {
+ /* The state change doorbell triggers a notification if
+ * the state of the managed partition changes to
+ * "stopped". We need a separate interrupt handler for
+ * that, and we also need to know the handle of the
+ * target partition, not just the handle of the
+ * doorbell.
+ */
+ dbisr->partition = ret = get_parent_handle(np);
+ if (ret < 0) {
+ pr_err("fsl-hv: node %s has missing or "
+ "malformed parent\n", np->full_name);
+ kfree(dbisr);
+ continue;
+ }
+ ret = request_threaded_irq(irq, fsl_hv_state_change_isr,
+ fsl_hv_state_change_thread,
+ 0, np->name, dbisr);
+ } else
+ ret = request_irq(irq, fsl_hv_isr, 0, np->name, dbisr);
+
+ if (ret < 0) {
+ pr_err("fsl-hv: could not request irq %u for node %s\n",
+ irq, np->full_name);
+ kfree(dbisr);
+ continue;
+ }
+
+ list_add(&dbisr->list, &isr_list);
+
+ pr_info("fsl-hv: registered handler for doorbell %u\n",
+ *handle);
+ }
+
+ return 0;
+
+out_of_memory:
+ list_for_each_entry_safe(dbisr, n, &isr_list, list) {
+ free_irq(dbisr->irq, dbisr);
+ list_del(&dbisr->list);
+ kfree(dbisr);
+ }
+
+ misc_deregister(&fsl_hv_misc_dev);
+
+ return -ENOMEM;
+}
+
+/**
+ * fsl_hypervisor_exit: Freescale hypervisor management driver termination
+ *
+ * This function is called when this driver is unloaded.
+ */
+static void __exit fsl_hypervisor_exit(void)
+{
+ struct doorbell_isr *dbisr, *n;
+
+ list_for_each_entry_safe(dbisr, n, &isr_list, list) {
+ free_irq(dbisr->irq, dbisr);
+ list_del(&dbisr->list);
+ kfree(dbisr);
+ }
+
+ misc_deregister(&fsl_hv_misc_dev);
+}
+
+module_init(fsl_hypervisor_init);
+module_exit(fsl_hypervisor_exit);
+
+MODULE_AUTHOR("Timur Tabi <timur at freescale.com>");
+MODULE_DESCRIPTION("Freescale hypervisor management driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/Kbuild b/include/linux/Kbuild
index 75cf611..68c341a 100644
--- a/include/linux/Kbuild
+++ b/include/linux/Kbuild
@@ -134,6 +134,7 @@ header-y += firewire-cdev.h
header-y += firewire-constants.h
header-y += flat.h
header-y += fs.h
+header-y += fsl_hypervisor.h
header-y += fuse.h
header-y += futex.h
header-y += gameport.h
diff --git a/include/linux/fsl_hypervisor.h b/include/linux/fsl_hypervisor.h
new file mode 100644
index 0000000..4d1e11a
--- /dev/null
+++ b/include/linux/fsl_hypervisor.h
@@ -0,0 +1,214 @@
+/*
+ * Freescale hypervisor ioctl interface
+ *
+ * Copyright (C) 2008-2011 Freescale Semiconductor, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of Freescale Semiconductor nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") as published by the Free Software
+ * Foundation, either version 2 of that License or (at your option) any
+ * later version.
+ *
+ * This software is provided by Freescale Semiconductor "as is" and any
+ * express or implied warranties, including, but not limited to, the implied
+ * warranties of merchantability and fitness for a particular purpose are
+ * disclaimed. In no event shall Freescale Semiconductor be liable for any
+ * direct, indirect, incidental, special, exemplary, or consequential damages
+ * (including, but not limited to, procurement of substitute goods or services;
+ * loss of use, data, or profits; or business interruption) however caused and
+ * on any theory of liability, whether in contract, strict liability, or tort
+ * (including negligence or otherwise) arising in any way out of the use of this
+ * software, even if advised of the possibility of such damage.
+ *
+ * This file is used by the Freescale hypervisor management driver. It can
+ * also be included by applications that need to communicate with the driver
+ * via the ioctl interface.
+ */
+
+#ifndef FSL_HYPERVISOR_H
+#define FSL_HYPERVISOR_H
+
+#include <linux/types.h>
+
+/**
+ * struct fsl_hv_ioctl_restart: restart a partition
+ * @ret: return error code from the hypervisor
+ * @partition: the ID of the partition to restart, or -1 for the
+ * calling partition
+ *
+ * Used by FSL_HV_IOCTL_PARTITION_RESTART
+ */
+struct fsl_hv_ioctl_restart {
+ __u32 ret;
+ __u32 partition;
+};
+
+/**
+ * struct fsl_hv_ioctl_status: get a partition's status
+ * @ret: return error code from the hypervisor
+ * @partition: the ID of the partition to query, or -1 for the
+ * calling partition
+ * @status: The returned status of the partition
+ *
+ * Used by FSL_HV_IOCTL_PARTITION_GET_STATUS
+ *
+ * Values of 'status':
+ * 0 = Stopped
+ * 1 = Running
+ * 2 = Starting
+ * 3 = Stopping
+ */
+struct fsl_hv_ioctl_status {
+ __u32 ret;
+ __u32 partition;
+ __u32 status;
+};
+
+/**
+ * struct fsl_hv_ioctl_start: start a partition
+ * @ret: return error code from the hypervisor
+ * @partition: the ID of the partition to control
+ * @entry_point: The offset within the guest IMA to start execution
+ * @load: If non-zero, reload the partition's images before starting
+ *
+ * Used by FSL_HV_IOCTL_PARTITION_START
+ */
+struct fsl_hv_ioctl_start {
+ __u32 ret;
+ __u32 partition;
+ __u32 entry_point;
+ __u32 load;
+};
+
+/**
+ * struct fsl_hv_ioctl_stop: stop a partition
+ * @ret: return error code from the hypervisor
+ * @partition: the ID of the partition to stop, or -1 for the calling
+ * partition
+ *
+ * Used by FSL_HV_IOCTL_PARTITION_STOP
+ */
+struct fsl_hv_ioctl_stop {
+ __u32 ret;
+ __u32 partition;
+};
+
+/**
+ * struct fsl_hv_ioctl_memcpy: copy memory between partitions
+ * @ret: return error code from the hypervisor
+ * @source: the partition ID of the source partition, or -1 for this
+ * partition
+ * @target: the partition ID of the target partition, or -1 for this
+ * partition
+ * @local_addr: user-space virtual address of a buffer in the local
+ * partition
+ * @remote_addr: guest physical address of a buffer in the
+ * remote partition
+ * @count: the number of bytes to copy. Both the local and remote
+ * buffers must be at least 'count' bytes long
+ *
+ * Used by FSL_HV_IOCTL_MEMCPY
+ *
+ * The 'local' partition is the partition that calls this ioctl. The
+ * 'remote' partition is a different partition. The data is copied from
+ * the 'source' paritition' to the 'target' partition.
+ *
+ * The buffer in the remote partition must be guest physically
+ * contiguous.
+ *
+ * This ioctl does not support copying memory between two remote
+ * partitions or within the same partition, so either 'source' or
+ * 'target' (but not both) must be -1. In other words, either
+ *
+ * source == local and target == remote
+ * or
+ * source == remote and target == local
+ */
+struct fsl_hv_ioctl_memcpy {
+ __u32 ret;
+ __u32 source;
+ __u32 target;
+ __u64 local_vaddr;
+ __u64 remote_paddr;
+ __u64 count;
+};
+
+/**
+ * struct fsl_hv_ioctl_doorbell: ring a doorbell
+ * @ret: return error code from the hypervisor
+ * @doorbell: the handle of the doorbell to ring doorbell
+ *
+ * Used by FSL_HV_IOCTL_DOORBELL
+ */
+struct fsl_hv_ioctl_doorbell {
+ __u32 ret;
+ __u32 doorbell;
+};
+
+/**
+ * struct fsl_hv_ioctl_prop: get/set a device tree property
+ * @ret: return error code from the hypervisor
+ * @handle: handle of partition whose tree to access
+ * @path: virtual address of path name of node to access
+ * @propname: virtual address of name of property to access
+ * @propval: virtual address of property data buffer
+ * @proplen: Size of property data buffer
+ *
+ * Used by FSL_HV_IOCTL_DOORBELL
+ */
+struct fsl_hv_ioctl_prop {
+ __u32 ret;
+ __u32 handle;
+ __u64 path;
+ __u64 propname;
+ __u64 propval;
+ __u32 proplen;
+};
+
+/*
+ * ioctl commands.
+ */
+enum {
+ FSL_HV_IOCTL_PARTITION_RESTART = 1, /* Boot another partition */
+ FSL_HV_IOCTL_PARTITION_GET_STATUS = 2, /* Boot another partition */
+ FSL_HV_IOCTL_PARTITION_START = 3, /* Boot another partition */
+ FSL_HV_IOCTL_PARTITION_STOP = 4, /* Stop this or another partition */
+ FSL_HV_IOCTL_MEMCPY = 5, /* Copy data from one partition to another */
+ FSL_HV_IOCTL_DOORBELL = 6, /* Ring a doorbell */
+
+ /* Get a property from another guest's device tree */
+ FSL_HV_IOCTL_GETPROP = 7,
+
+ /* Set a property in another guest's device tree */
+ FSL_HV_IOCTL_SETPROP = 8,
+};
+
+#ifdef __KERNEL__
+
+/**
+ * fsl_hv_event_register -- register a callback for failover events
+ *
+ * This function is called by device drivers to register their callback
+ * functions for fail-over events.
+ */
+int fsl_hv_failover_register(struct notifier_block *nb);
+
+/**
+ * fsl_hv_event_unregister -- unregister a callback for failover events
+ */
+int fsl_hv_failover_unregister(struct notifier_block *nb);
+
+#endif
+
+#endif
--
1.7.3.4
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