1 files changed, 211 insertions, 91 deletions

diff --git a/drivers/sh/maple/maple.c b/drivers/sh/maple/maple.c
index 617efb1640b1..d1812d32f47d 100644
--- a/drivers/sh/maple/maple.c
+++ b/drivers/sh/maple/maple.c
@@ -2,6 +2,7 @@
  * Core maple bus functionality
  *
  *  Copyright (C) 2007, 2008 Adrian McMenamin
+ *  Copyright (C) 2001 - 2008 Paul Mundt
  *
  * Based on 2.4 code by:
  *
@@ -24,15 +25,14 @@
 #include <linux/slab.h>
 #include <linux/maple.h>
 #include <linux/dma-mapping.h>
+#include <linux/delay.h>
 #include <asm/cacheflush.h>
 #include <asm/dma.h>
 #include <asm/io.h>
-#include <asm/mach/dma.h>
-#include <asm/mach/sysasic.h>
-#include <asm/mach/maple.h>
-#include <linux/delay.h>
+#include <mach/dma.h>
+#include <mach/sysasic.h>
 
-MODULE_AUTHOR("Yaegshi Takeshi, Paul Mundt, M.R. Brown, Adrian McMenamin");
+MODULE_AUTHOR("Yaegashi Takeshi, Paul Mundt, M. R. Brown, Adrian McMenamin");
 MODULE_DESCRIPTION("Maple bus driver for Dreamcast");
 MODULE_LICENSE("GPL v2");
 MODULE_SUPPORTED_DEVICE("{{SEGA, Dreamcast/Maple}}");
@@ -46,14 +46,15 @@ static DECLARE_WORK(maple_vblank_process, maple_vblank_handler);
 static LIST_HEAD(maple_waitq);
 static LIST_HEAD(maple_sentq);
 
-static DEFINE_MUTEX(maple_list_lock);
+/* mutex to protect queue of waiting packets */
+static DEFINE_MUTEX(maple_wlist_lock);
 
 static struct maple_driver maple_dummy_driver;
 static struct device maple_bus;
 static int subdevice_map[MAPLE_PORTS];
 static unsigned long *maple_sendbuf, *maple_sendptr, *maple_lastptr;
 static unsigned long maple_pnp_time;
-static int started, scanning, liststatus, fullscan;
+static int started, scanning, fullscan;
 static struct kmem_cache *maple_queue_cache;
 
 struct maple_device_specify {
@@ -65,19 +66,36 @@ static bool checked[4];
 static struct maple_device *baseunits[4];
 
 /**
- *  maple_driver_register - register a device driver
- *  automatically makes the driver bus a maple bus
- *  @drv: the driver to be registered
+ * maple_driver_register - register a maple driver
+ * @drv: maple driver to be registered.
+ *
+ * Registers the passed in @drv, while updating the bus type.
+ * Devices with matching function IDs will be automatically probed.
  */
-int maple_driver_register(struct device_driver *drv)
+int maple_driver_register(struct maple_driver *drv)
 {
         if (!drv)
                 return -EINVAL;
-        drv->bus = &maple_bus_type;
-        return driver_register(drv);
+
+        drv->drv.bus = &maple_bus_type;
+
+        return driver_register(&drv->drv);
 }
 EXPORT_SYMBOL_GPL(maple_driver_register);
 
+/**
+ * maple_driver_unregister - unregister a maple driver.
+ * @drv: maple driver to unregister.
+ *
+ * Cleans up after maple_driver_register(). To be invoked in the exit
+ * path of any module drivers.
+ */
+void maple_driver_unregister(struct maple_driver *drv)
+{
+        driver_unregister(&drv->drv);
+}
+EXPORT_SYMBOL_GPL(maple_driver_unregister);
+
 /* set hardware registers to enable next round of dma */
 static void maplebus_dma_reset(void)
 {
@@ -131,33 +149,123 @@ static void maple_release_device(struct device *dev)
 
 /**
  * maple_add_packet - add a single instruction to the queue
- * @mq: instruction to add to waiting queue
+ * @mdev: maple device
+ * @function: function on device being queried
+ * @command: maple command to add
+ * @length: length of command string (in 32 bit words)
+ * @data: remainder of command string
  */
-void maple_add_packet(struct mapleq *mq)
+int maple_add_packet(struct maple_device *mdev, u32 function, u32 command,
+        size_t length, void *data)
 {
-        mutex_lock(&maple_list_lock);
-        list_add(&mq->list, &maple_waitq);
-        mutex_unlock(&maple_list_lock);
+        int locking, ret = 0;
+        void *sendbuf = NULL;
+
+        mutex_lock(&maple_wlist_lock);
+        /* bounce if device already locked */
+        locking = mutex_is_locked(&mdev->mq->mutex);
+        if (locking) {
+                ret = -EBUSY;
+                goto out;
+        }
+
+        mutex_lock(&mdev->mq->mutex);
+
+        if (length) {
+                sendbuf = kmalloc(length * 4, GFP_KERNEL);
+                if (!sendbuf) {
+                        mutex_unlock(&mdev->mq->mutex);
+                        ret = -ENOMEM;
+                        goto out;
+                }
+                ((__be32 *)sendbuf)[0] = cpu_to_be32(function);
+        }
+
+        mdev->mq->command = command;
+        mdev->mq->length = length;
+        if (length > 1)
+                memcpy(sendbuf + 4, data, (length - 1) * 4);
+        mdev->mq->sendbuf = sendbuf;
+
+        list_add(&mdev->mq->list, &maple_waitq);
+out:
+        mutex_unlock(&maple_wlist_lock);
+        return ret;
 }
 EXPORT_SYMBOL_GPL(maple_add_packet);
 
+/**
+ * maple_add_packet_sleeps - add a single instruction to the queue
+ * @mdev: maple device
+ * @function: function on device being queried
+ * @command: maple command to add
+ * @length: length of command string (in 32 bit words)
+ * @data: remainder of command string
+ *
+ * Same as maple_add_packet(), but waits for the lock to become free.
+ */
+int maple_add_packet_sleeps(struct maple_device *mdev, u32 function,
+        u32 command, size_t length, void *data)
+{
+        int locking, ret = 0;
+        void *sendbuf = NULL;
+
+        locking = mutex_lock_interruptible(&mdev->mq->mutex);
+        if (locking) {
+                ret = -EIO;
+                goto out;
+        }
+
+        if (length) {
+                sendbuf = kmalloc(length * 4, GFP_KERNEL);
+                if (!sendbuf) {
+                        mutex_unlock(&mdev->mq->mutex);
+                        ret = -ENOMEM;
+                        goto out;
+                }
+                ((__be32 *)sendbuf)[0] = cpu_to_be32(function);
+        }
+
+        mdev->mq->command = command;
+        mdev->mq->length = length;
+        if (length > 1)
+                memcpy(sendbuf + 4, data, (length - 1) * 4);
+        mdev->mq->sendbuf = sendbuf;
+
+        mutex_lock(&maple_wlist_lock);
+        list_add(&mdev->mq->list, &maple_waitq);
+        mutex_unlock(&maple_wlist_lock);
+out:
+        return ret;
+}
+EXPORT_SYMBOL_GPL(maple_add_packet_sleeps);
+
 static struct mapleq *maple_allocq(struct maple_device *mdev)
 {
         struct mapleq *mq;
 
         mq = kmalloc(sizeof(*mq), GFP_KERNEL);
         if (!mq)
-                return NULL;
+                goto failed_nomem;
 
         mq->dev = mdev;
         mq->recvbufdcsp = kmem_cache_zalloc(maple_queue_cache, GFP_KERNEL);
         mq->recvbuf = (void *) P2SEGADDR(mq->recvbufdcsp);
-        if (!mq->recvbuf) {
-                kfree(mq);
-                return NULL;
-        }
+        if (!mq->recvbuf)
+                goto failed_p2;
+        /*
+         * most devices do not need the mutex - but
+         * anything that injects block reads or writes
+         * will rely on it
+         */
+        mutex_init(&mq->mutex);
 
         return mq;
+
+failed_p2:
+        kfree(mq);
+failed_nomem:
+        return NULL;
 }
 
 static struct maple_device *maple_alloc_dev(int port, int unit)
@@ -178,7 +286,6 @@ static struct maple_device *maple_alloc_dev(int port, int unit)
         }
         mdev->dev.bus = &maple_bus_type;
         mdev->dev.parent = &maple_bus;
-        mdev->function = 0;
         return mdev;
 }
 
@@ -216,7 +323,6 @@ static void maple_build_block(struct mapleq *mq)
         *maple_sendptr++ = PHYSADDR(mq->recvbuf);
         *maple_sendptr++ =
             mq->command | (to << 8) | (from << 16) | (len << 24);
-
         while (len-- > 0)
                 *maple_sendptr++ = *lsendbuf++;
 }
@@ -224,22 +330,27 @@ static void maple_build_block(struct mapleq *mq)
 /* build up command queue */
 static void maple_send(void)
 {
-        int i;
-        int maple_packets;
+        int i, maple_packets = 0;
         struct mapleq *mq, *nmq;
 
         if (!list_empty(&maple_sentq))
                 return;
-        if (list_empty(&maple_waitq) || !maple_dma_done())
+        mutex_lock(&maple_wlist_lock);
+        if (list_empty(&maple_waitq) || !maple_dma_done()) {
+                mutex_unlock(&maple_wlist_lock);
                 return;
-        maple_packets = 0;
-        maple_sendptr = maple_lastptr = maple_sendbuf;
+        }
+        mutex_unlock(&maple_wlist_lock);
+        maple_lastptr = maple_sendbuf;
+        maple_sendptr = maple_sendbuf;
+        mutex_lock(&maple_wlist_lock);
         list_for_each_entry_safe(mq, nmq, &maple_waitq, list) {
                 maple_build_block(mq);
                 list_move(&mq->list, &maple_sentq);
                 if (maple_packets++ > MAPLE_MAXPACKETS)
                         break;
         }
+        mutex_unlock(&maple_wlist_lock);
         if (maple_packets > 0) {
                 for (i = 0; i < (1 << MAPLE_DMA_PAGES); i++)
                         dma_cache_sync(0, maple_sendbuf + i * PAGE_SIZE,
@@ -247,7 +358,8 @@ static void maple_send(void)
         }
 }
 
-static int attach_matching_maple_driver(struct device_driver *driver,
+/* check if there is a driver registered likely to match this device */
+static int check_matching_maple_driver(struct device_driver *driver,
                                         void *devptr)
 {
         struct maple_driver *maple_drv;
@@ -255,12 +367,8 @@ static int attach_matching_maple_driver(struct device_driver *driver,
 
         mdev = devptr;
         maple_drv = to_maple_driver(driver);
-        if (mdev->devinfo.function & be32_to_cpu(maple_drv->function)) {
-                if (maple_drv->connect(mdev) == 0) {
-                        mdev->driver = maple_drv;
-                        return 1;
-                }
-        }
+        if (mdev->devinfo.function & cpu_to_be32(maple_drv->function))
+                return 1;
         return 0;
 }
 
@@ -268,11 +376,6 @@ static void maple_detach_driver(struct maple_device *mdev)
 {
         if (!mdev)
                 return;
-        if (mdev->driver) {
-                if (mdev->driver->disconnect)
-                        mdev->driver->disconnect(mdev);
-        }
-        mdev->driver = NULL;
         device_unregister(&mdev->dev);
         mdev = NULL;
 }
@@ -328,8 +431,8 @@ static void maple_attach_driver(struct maple_device *mdev)
                         mdev->port, mdev->unit, function);
 
                 matched =
-                    bus_for_each_drv(&maple_bus_type, NULL, mdev,
-                                     attach_matching_maple_driver);
+                        bus_for_each_drv(&maple_bus_type, NULL, mdev,
+                                check_matching_maple_driver);
 
                 if (matched == 0) {
                         /* Driver does not exist yet */
@@ -373,45 +476,48 @@ static int detach_maple_device(struct device *device, void *portptr)
 
 static int setup_maple_commands(struct device *device, void *ignored)
 {
+        int add;
         struct maple_device *maple_dev = to_maple_dev(device);
 
         if ((maple_dev->interval > 0)
             && time_after(jiffies, maple_dev->when)) {
-                maple_dev->when = jiffies + maple_dev->interval;
-                maple_dev->mq->command = MAPLE_COMMAND_GETCOND;
-                maple_dev->mq->sendbuf = &maple_dev->function;
-                maple_dev->mq->length = 1;
-                maple_add_packet(maple_dev->mq);
-                liststatus++;
+                /* bounce if we cannot lock */
+                add = maple_add_packet(maple_dev,
+                        be32_to_cpu(maple_dev->devinfo.function),
+                        MAPLE_COMMAND_GETCOND, 1, NULL);
+                if (!add)
+                        maple_dev->when = jiffies + maple_dev->interval;
         } else {
-                if (time_after(jiffies, maple_pnp_time)) {
-                        maple_dev->mq->command = MAPLE_COMMAND_DEVINFO;
-                        maple_dev->mq->length = 0;
-                        maple_add_packet(maple_dev->mq);
-                        liststatus++;
-                }
+                if (time_after(jiffies, maple_pnp_time))
+                        /* This will also bounce */
+                        maple_add_packet(maple_dev, 0,
+                                MAPLE_COMMAND_DEVINFO, 0, NULL);
         }
-
         return 0;
 }
 
 /* VBLANK bottom half - implemented via workqueue */
 static void maple_vblank_handler(struct work_struct *work)
 {
-        if (!maple_dma_done())
-                return;
-        if (!list_empty(&maple_sentq))
+        if (!list_empty(&maple_sentq) || !maple_dma_done())
                 return;
+
         ctrl_outl(0, MAPLE_ENABLE);
-        liststatus = 0;
+
         bus_for_each_dev(&maple_bus_type, NULL, NULL,
                          setup_maple_commands);
+
         if (time_after(jiffies, maple_pnp_time))
                 maple_pnp_time = jiffies + MAPLE_PNP_INTERVAL;
-        if (liststatus && list_empty(&maple_sentq)) {
-                INIT_LIST_HEAD(&maple_sentq);
+
+        mutex_lock(&maple_wlist_lock);
+        if (!list_empty(&maple_waitq) && list_empty(&maple_sentq)) {
+                mutex_unlock(&maple_wlist_lock);
                 maple_send();
+        } else {
+                mutex_unlock(&maple_wlist_lock);
         }
+
         maplebus_dma_reset();
 }
 
@@ -422,8 +528,8 @@ static void maple_map_subunits(struct maple_device *mdev, int submask)
         struct maple_device *mdev_add;
         struct maple_device_specify ds;
 
+        ds.port = mdev->port;
         for (k = 0; k < 5; k++) {
-                ds.port = mdev->port;
                 ds.unit = k + 1;
                 retval =
                     bus_for_each_dev(&maple_bus_type, NULL, &ds,
@@ -437,9 +543,9 @@ static void maple_map_subunits(struct maple_device *mdev, int submask)
                         mdev_add = maple_alloc_dev(mdev->port, k + 1);
                         if (!mdev_add)
                                 return;
-                        mdev_add->mq->command = MAPLE_COMMAND_DEVINFO;
-                        mdev_add->mq->length = 0;
-                        maple_add_packet(mdev_add->mq);
+                        maple_add_packet(mdev_add, 0, MAPLE_COMMAND_DEVINFO,
+                                0, NULL);
+                        /* mark that we are checking sub devices */
                         scanning = 1;
                 }
                 submask = submask >> 1;
@@ -505,6 +611,28 @@ static void maple_response_devinfo(struct maple_device *mdev,
         }
 }
 
+static void maple_port_rescan(void)
+{
+        int i;
+        struct maple_device *mdev;
+
+        fullscan = 1;
+        for (i = 0; i < MAPLE_PORTS; i++) {
+                if (checked[i] == false) {
+                        fullscan = 0;
+                        mdev = baseunits[i];
+                        /*
+                         *  test lock in case scan has failed
+                         *  but device is still locked
+                         */
+                        if (mutex_is_locked(&mdev->mq->mutex))
+                                mutex_unlock(&mdev->mq->mutex);
+                        maple_add_packet(mdev, 0, MAPLE_COMMAND_DEVINFO,
+                                0, NULL);
+                }
+        }
+}
+
 /* maple dma end bottom half - implemented via workqueue */
 static void maple_dma_handler(struct work_struct *work)
 {
@@ -512,7 +640,6 @@ static void maple_dma_handler(struct work_struct *work)
         struct maple_device *dev;
         char *recvbuf;
         enum maple_code code;
-        int i;
 
         if (!maple_dma_done())
                 return;
@@ -522,6 +649,10 @@ static void maple_dma_handler(struct work_struct *work)
                         recvbuf = mq->recvbuf;
                         code = recvbuf[0];
                         dev = mq->dev;
+                        kfree(mq->sendbuf);
+                        mutex_unlock(&mq->mutex);
+                        list_del_init(&mq->list);
+
                         switch (code) {
                         case MAPLE_RESPONSE_NONE:
                                 maple_response_none(dev, mq);
@@ -558,26 +689,16 @@ static void maple_dma_handler(struct work_struct *work)
                                 break;
                         }
                 }
-                INIT_LIST_HEAD(&maple_sentq);
+                /* if scanning is 1 then we have subdevices to check */
                 if (scanning == 1) {
                         maple_send();
                         scanning = 2;
                 } else
                         scanning = 0;
-
-                if (!fullscan) {
-                        fullscan = 1;
-                        for (i = 0; i < MAPLE_PORTS; i++) {
-                                if (checked[i] == false) {
-                                        fullscan = 0;
-                                        dev = baseunits[i];
-                                        dev->mq->command =
-                                                MAPLE_COMMAND_DEVINFO;
-                                        dev->mq->length = 0;
-                                        maple_add_packet(dev->mq);
-                                }
-                        }
-                }
+                /*check if we have actually tested all ports yet */
+                if (!fullscan)
+                        maple_port_rescan();
+                /* mark that we have been through the first scan */
                 if (started == 0)
                         started = 1;
         }
@@ -622,16 +743,14 @@ static int maple_get_dma_buffer(void)
 static int match_maple_bus_driver(struct device *devptr,
                                   struct device_driver *drvptr)
 {
-        struct maple_driver *maple_drv;
-        struct maple_device *maple_dev;
+        struct maple_driver *maple_drv = to_maple_driver(drvptr);
+        struct maple_device *maple_dev = to_maple_dev(devptr);
 
-        maple_drv = container_of(drvptr, struct maple_driver, drv);
-        maple_dev = container_of(devptr, struct maple_device, dev);
         /* Trap empty port case */
         if (maple_dev->devinfo.function == 0xFFFFFFFF)
                 return 0;
         else if (maple_dev->devinfo.function &
-                 be32_to_cpu(maple_drv->function))
+                 cpu_to_be32(maple_drv->function))
                 return 1;
         return 0;
 }
@@ -713,6 +832,9 @@ static int __init maple_bus_init(void)
         if (!maple_queue_cache)
                 goto cleanup_bothirqs;
 
+        INIT_LIST_HEAD(&maple_waitq);
+        INIT_LIST_HEAD(&maple_sentq);
+
         /* setup maple ports */
         for (i = 0; i < MAPLE_PORTS; i++) {
                 checked[i] = false;
@@ -723,9 +845,7 @@ static int __init maple_bus_init(void)
                                 maple_free_dev(mdev[i]);
                         goto cleanup_cache;
                 }
-                mdev[i]->mq->command = MAPLE_COMMAND_DEVINFO;
-                mdev[i]->mq->length = 0;
-                maple_add_packet(mdev[i]->mq);
+                maple_add_packet(mdev[i], 0, MAPLE_COMMAND_DEVINFO, 0, NULL);
                 subdevice_map[i] = 0;
         }