ahci: NCQ support

common/include/minix/blockdriver.h

@@ -3,6 +3,7 @@
 
 #include <minix/driver.h>
 
+typedef int device_id_t;
 typedef int thread_id_t;
 
 /* Types supported for the 'type' field of struct blockdriver. */
@@ -26,7 +27,7 @@ struct blockdriver {
   _PROTOTYPE( void (*bdr_intr), (unsigned int irqs) );
   _PROTOTYPE( void (*bdr_alarm), (clock_t stamp) );
   _PROTOTYPE( int (*bdr_other), (message *m_ptr) );
-  _PROTOTYPE( int (*bdr_thread), (dev_t minor, thread_id_t *threadp) );
+  _PROTOTYPE( int (*bdr_device), (dev_t minor, device_id_t *id) );
 };
 
 /* Functions defined by libblockdriver. These can be used for both

common/include/minix/blockdriver_mt.h

@@ -4,13 +4,11 @@
 #define BLOCKDRIVER_MT_API 1	/* do not expose the singlethreaded API */
 #include <minix/blockdriver.h>
 
-/* The maximum number of worker threads. */
-#define BLOCKDRIVER_MT_MAX_WORKERS	32
-
 _PROTOTYPE( void blockdriver_mt_task, (struct blockdriver *driver_tab) );
 _PROTOTYPE( void blockdriver_mt_sleep, (void) );
 _PROTOTYPE( void blockdriver_mt_wakeup, (thread_id_t id) );
-_PROTOTYPE( void blockdriver_mt_stop, (void) );
 _PROTOTYPE( void blockdriver_mt_terminate, (void) );
+_PROTOTYPE( void blockdriver_mt_set_workers, (device_id_t id, int workers) );
+_PROTOTYPE( thread_id_t blockdriver_mt_get_tid, (void) );
 
 #endif /* _MINIX_BLOCKDRIVER_MT_H */

drivers/ahci/ahci.h

@@ -4,13 +4,13 @@
 #include <minix/drivers.h>
 
 #define NR_PORTS 32		/* maximum number of ports */
-#define NR_CMDS 1		/* maximum number of queued commands */
+#define NR_CMDS 32		/* maximum number of queued commands */
 
 /* Time values that can be set with options. */
 #define SPINUP_TIMEOUT		5000	/* initial spin-up time (ms) */
 #define SIG_TIMEOUT		250	/* time between signature checks (ms) */
 #define NR_SIG_CHECKS		60	/* maximum number of times to check */
-#define COMMAND_TIMEOUT		5000	/* time to wait for non-I/O cmd (ms) */
+#define COMMAND_TIMEOUT		10000	/* time to wait for non-I/O cmd (ms) */
 #define TRANSFER_TIMEOUT	30000	/* time to wait for I/O cmd (ms) */
 #define FLUSH_TIMEOUT		60000	/* time to wait for flush cmd (ms) */
 
@@ -30,6 +30,8 @@
 #define ATA_H2D_CMD			2	/* Command */
 #define 	ATA_CMD_READ_DMA_EXT	0x25	/* READ DMA EXT */
 #define 	ATA_CMD_WRITE_DMA_EXT	0x35	/* WRITE DMA EXT */
+#define 	ATA_CMD_READ_FPDMA_QUEUED	0x60	/* READ FPDMA QUEUED */
+#define 	ATA_CMD_WRITE_FPDMA_QUEUED	0x61	/* WRITE FPDMA QUEUED */
 #define 	ATA_CMD_WRITE_DMA_FUA_EXT	0x3D	/* WRITE DMA FUA EXT */
 #define 	ATA_CMD_PACKET		0xA0	/* PACKET */
 #define 	ATA_CMD_IDENTIFY_PACKET	0xA1	/* IDENTIFY PACKET DEVICE */
@@ -44,14 +46,20 @@
 #define ATA_H2D_LBA_HIGH		6	/* LBA High */
 #define ATA_H2D_DEV			7	/* Device */
 #define 	ATA_DEV_LBA		0x40	/* use LBA addressing */
+#define 	ATA_DEV_FUA		0x80	/* Force Unit Access (FPDMA) */
 #define ATA_H2D_LBA_LOW_EXP		8	/* LBA Low (exp) */
 #define ATA_H2D_LBA_MID_EXP		9	/* LBA Mid (exp) */
 #define ATA_H2D_LBA_HIGH_EXP		10	/* LBA High (exp) */
 #define ATA_H2D_FEAT_EXP		11	/* Features (exp) */
 #define ATA_H2D_SEC			12	/* Sector Count */
+#define 	ATA_SEC_TAG_SHIFT	3	/* NCQ command tag */
 #define ATA_H2D_SEC_EXP			13	/* Sector Count (exp) */
 #define ATA_H2D_CTL			15	/* Control */
 
+#define ATA_IS_FPDMA_CMD(c)			\
+	((c) == ATA_CMD_READ_FPDMA_QUEUED ||	\
+	 (c) == ATA_CMD_WRITE_FPDMA_QUEUED)
+
 /* ATA constants. */
 #define ATA_SECTOR_SIZE		512		/* default sector size */
 #define ATA_MAX_SECTORS		0x10000		/* max sectors per transfer */
@@ -73,6 +81,10 @@
 #define ATA_ID_DMADIR		62		/* DMADIR */
 #define ATA_ID_DMADIR_DMADIR	0x8000		/* DMADIR required */
 #define ATA_ID_DMADIR_DMA	0x0400		/* DMA supported (DMADIR) */
+#define ATA_ID_QDEPTH		75		/* NCQ queue depth */
+#define ATA_ID_QDEPTH_MASK	0x000F		/* NCQ queue depth mask */
+#define ATA_ID_SATA_CAP		76		/* SATA capabilities */
+#define ATA_ID_SATA_CAP_NCQ	0x0100		/* NCQ support */
 #define ATA_ID_SUP0		82		/* Features supported (1/3) */
 #define ATA_ID_SUP0_WCACHE	0x0020		/* Write cache supported */
 #define ATA_ID_SUP1		83		/* Features supported (2/3) */
@@ -160,6 +172,7 @@
 #define 	AHCI_PORT_IS_IFS	(1L << 27)	/* Interface Fatal */
 #define 	AHCI_PORT_IS_PRCS	(1L << 22)	/* PhyRdy Change */
 #define 	AHCI_PORT_IS_PCS	(1L <<  6)	/* Port Conn Change */
+#define 	AHCI_PORT_IS_SDBS	(1L <<  3)	/* Set Device Bits FIS */
 #define 	AHCI_PORT_IS_PSS	(1L <<  1)	/* PIO Setup FIS */
 #define 	AHCI_PORT_IS_DHRS	(1L <<  0)	/* D2H Register FIS */
 #define AHCI_PORT_IS_RESTART \
@@ -167,7 +180,7 @@
 	 AHCI_PORT_IS_IFS)
 #define AHCI_PORT_IS_MASK \
 	(AHCI_PORT_IS_RESTART | AHCI_PORT_IS_PRCS | AHCI_PORT_IS_PCS | \
-	 AHCI_PORT_IS_DHRS | AHCI_PORT_IS_PSS)
+	 AHCI_PORT_IS_DHRS | AHCI_PORT_IS_PSS | AHCI_PORT_IS_SDBS)
 #define AHCI_PORT_IE	5		/* Interrupt Enable */
 #define 	AHCI_PORT_IE_MASK	AHCI_PORT_IS_MASK
 #define 	AHCI_PORT_IE_PRCE	AHCI_PORT_IS_PRCS
@@ -196,6 +209,7 @@
 #define 	AHCI_PORT_SCTL_DET_NONE	0x00000000L	/* No Action Req'd */
 #define AHCI_PORT_SERR	12		/* Serial ATA Error */
 #define 	AHCI_PORT_SERR_DIAG_N	(1L << 16)	/* PhyRdy Change */
+#define AHCI_PORT_SACT	13		/* Serial ATA Active */
 #define AHCI_PORT_CI	14		/* Command Issue */
 
 /* Number of Physical Region Descriptors (PRDs). Must be at least NR_IOREQS+2,
@@ -262,6 +276,12 @@ enum {
 	STATE_GOOD_DEV		/* a usable device has been detected */
 };
 
+/* Command results. */
+enum {
+	RESULT_FAILURE,
+	RESULT_SUCCESS
+};
+
 /* Port flags. */
 #define FLAG_ATAPI		0x00000001	/* is this an ATAPI device? */
 #define FLAG_HAS_MEDIUM		0x00000002	/* is a medium present? */
@@ -274,6 +294,8 @@ enum {
 #define FLAG_HAS_FLUSH		0x00000100	/* is FLUSH CACHE supported? */
 #define FLAG_SUSPENDED		0x00000200	/* is the thread suspended? */
 #define FLAG_HAS_FUA		0x00000400	/* is WRITE DMA FUA EX sup.? */
+#define FLAG_HAS_NCQ		0x00000800	/* is NCQ supported? */
+#define FLAG_NCQ_MODE		0x00001000	/* issuing NCQ commands? */
 
 /* Mapping between devices and ports. */
 #define NO_PORT		-1	/* this device maps to no port */

lib/libblockdriver/Makefile

@@ -3,7 +3,7 @@
 
 LIB=	blockdriver
 
-SRCS=	driver.c drvlib.c driver_st.c driver_mt.c mq.c event.c trace.c
+SRCS=	driver.c drvlib.c driver_st.c driver_mt.c mq.c trace.c
 
 .if ${USE_STATECTL} != "no"
 CPPFLAGS+= -DUSE_STATECTL

lib/libblockdriver/const.h

@@ -0,0 +1,14 @@
+#ifndef _BLOCKDRIVER_CONST_H
+#define _BLOCKDRIVER_CONST_H
+
+/* Maximum number of devices supported. */
+#define MAX_DEVICES	32
+
+/* The maximum number of worker threads per device. */
+#define MAX_WORKERS	32
+
+#define MAX_THREADS	(MAX_DEVICES * MAX_WORKERS)	/* max nr of threads */
+#define MAIN_THREAD	(MAX_THREADS)			/* main thread ID */
+#define SINGLE_THREAD	(0)				/* single-thread ID */
+
+#endif /* _BLOCKDRIVER_CONST_H */

lib/libblockdriver/driver.h

@@ -1,9 +1,6 @@
 #ifndef _BLOCKDRIVER_DRIVER_H
 #define _BLOCKDRIVER_DRIVER_H
 
-#define SINGLE_THREAD	(0)				/* single-thread ID */
-#define MAIN_THREAD	(BLOCKDRIVER_MT_MAX_WORKERS)	/* main thread ID */
-
 _PROTOTYPE( void blockdriver_handle_notify, (struct blockdriver *bdp,
 	message *m_ptr) );
 _PROTOTYPE( int blockdriver_handle_request, (struct blockdriver *bdp,

lib/libblockdriver/driver_mt.c

@@ -8,84 +8,132 @@
  *   blockdriver_mt_terminate:	break out of the main message loop
  *   blockdriver_mt_sleep:	put the current thread to sleep
  *   blockdriver_mt_wakeup:	wake up a sleeping thread
- *   blockdriver_mt_stop:	put up the current thread for termination
+ *   blockdriver_mt_set_workers:set the number of worker threads
  */
 
 #include <minix/blockdriver_mt.h>
 #include <minix/mthread.h>
 #include <assert.h>
 
+#include "const.h"
 #include "driver.h"
 #include "mq.h"
-#include "event.h"
+
+/* A thread ID is composed of a device ID and a per-device worker thread ID.
+ * All thread IDs must be in the range 0..(MAX_THREADS-1) inclusive.
+ */
+#define MAKE_TID(did, wid)	((did) * MAX_WORKERS + (wid))
+#define TID_DEVICE(tid)		((tid) / MAX_WORKERS)
+#define TID_WORKER(tid)		((tid) % MAX_WORKERS)
+
+typedef int worker_id_t;
 
 typedef enum {
   STATE_DEAD,
   STATE_RUNNING,
-  STATE_STOPPING,
+  STATE_BUSY,
   STATE_EXITED
 } worker_state;
 
-/* Structure to handle running worker threads. */
+/* Structure with information about a worker thread. */
 typedef struct {
-  thread_id_t id;
+  device_id_t device_id;
+  worker_id_t worker_id;
   worker_state state;
   mthread_thread_t mthread;
-  event_t queue_event;
+  mthread_event_t sleep_event;
-  event_t sleep_event;
 } worker_t;
 
+/* Structure with information about a device. */
+typedef struct {
+  device_id_t id;
+  unsigned int workers;
+  worker_t worker[MAX_WORKERS];
+  mthread_event_t queue_event;
+  mthread_rwlock_t barrier;
+} device_t;
+
 PRIVATE struct blockdriver *bdtab;
 PRIVATE int running = FALSE;
 
 PRIVATE mthread_key_t worker_key;
 
-PRIVATE worker_t worker[BLOCKDRIVER_MT_MAX_WORKERS];
+PRIVATE device_t device[MAX_DEVICES];
 
-PRIVATE worker_t *exited[BLOCKDRIVER_MT_MAX_WORKERS];
+PRIVATE worker_t *exited[MAX_THREADS];
 PRIVATE int num_exited = 0;
 
 /*===========================================================================*
  *				enqueue					     *
  *===========================================================================*/
-PRIVATE void enqueue(worker_t *wp, const message *m_src, int ipc_status)
+PRIVATE void enqueue(device_t *dp, const message *m_src, int ipc_status)
 {
-/* Enqueue a message into a worker thread's queue, and signal the thread.
+/* Enqueue a message into the device's queue, and signal the event.
  * Must be called from the master thread.
  */
 
-  assert(wp->state == STATE_RUNNING || wp->state == STATE_STOPPING);
+  if (!mq_enqueue(dp->id, m_src, ipc_status))
-
-  if (!mq_enqueue(wp->id, m_src, ipc_status))
 	panic("blockdriver_mt: enqueue failed (message queue full)");
 
-  event_fire(&wp->queue_event);
+  mthread_event_fire(&dp->queue_event);
 }
 
 /*===========================================================================*
  *				try_dequeue				     *
  *===========================================================================*/
-PRIVATE int try_dequeue(worker_t *wp, message *m_dst, int *ipc_status)
+PRIVATE int try_dequeue(device_t *dp, message *m_dst, int *ipc_status)
 {
-/* See if a message can be dequeued from the current worker thread's queue. If
+/* See if a message can be dequeued from the current worker thread's device
- * so, dequeue the message and return TRUE. If not, return FALSE. Must be
+ * queue. If so, dequeue the message and return TRUE. If not, return FALSE.
- * called from a worker thread. Does not block.
+ * Must be called from a worker thread. Does not block.
  */
 
-  return mq_dequeue(wp->id, m_dst, ipc_status);
+  return mq_dequeue(dp->id, m_dst, ipc_status);
 }
 
 /*===========================================================================*
  *				dequeue					     *
  *===========================================================================*/
-PRIVATE void dequeue(worker_t *wp, message *m_dst, int *ipc_status)
+PRIVATE int dequeue(device_t *dp, worker_t *wp, message *m_dst,
+  int *ipc_status)
 {
-/* Dequeue a message from the current worker thread's queue. Block the current
+/* Dequeue a message from the current worker thread's device queue. Block the
- * thread if necessary. Must be called from a worker thread. Always successful.
+ * current thread if necessary. Must be called from a worker thread. Either
+ * succeeds with a message (TRUE) or indicates that the thread should be
+ * terminated (FALSE).
  */
 
-  while (!try_dequeue(wp, m_dst, ipc_status))
+  do {
-	event_wait(&wp->queue_event);
+	mthread_event_wait(&dp->queue_event);
+
+	/* If we were woken up as a result of terminate or set_workers, break
+	 * out of the loop and terminate the thread.
+	 */
+	if (!running || wp->worker_id >= dp->workers)
+		return FALSE;
+  } while (!try_dequeue(dp, m_dst, ipc_status));
+
+  return TRUE;
+}
+
+/*===========================================================================*
+ *				is_transfer_req				     *
+ *===========================================================================*/
+PRIVATE int is_transfer_req(int type)
+{
+/* Return whether the given block device request is a transfer request.
+ */
+
+  switch (type) {
+  case BDEV_READ:
+  case BDEV_WRITE:
+  case BDEV_GATHER:
+  case BDEV_SCATTER:
+	return TRUE;
+
+  default:
+	return FALSE;
+  }
 }
 
 /*===========================================================================*
@@ -99,36 +147,50 @@ PRIVATE void *worker_thread(void *param)
  * for this condition and exit if so.
  */
   worker_t *wp;
+  device_t *dp;
+  thread_id_t tid;
   message m;
   int ipc_status, r;
 
   wp = (worker_t *) param;
   assert(wp != NULL);
+  dp = &device[wp->device_id];
+  tid = MAKE_TID(wp->device_id, wp->worker_id);
 
   if (mthread_setspecific(worker_key, wp))
 	panic("blockdriver_mt: could not save local thread pointer");
 
-  while (running) {
+  while (running && wp->worker_id < dp->workers) {
+
 	/* See if a new message is available right away. */
-	if (!try_dequeue(wp, &m, &ipc_status)) {
+	if (!try_dequeue(dp, &m, &ipc_status)) {
-		/* If not, and this thread should be stopped, stop now. */
-		if (wp->state == STATE_STOPPING)
-			break;
 
-		/* Otherwise, block waiting for a new message. */
+		/* If not, block waiting for a new message or a thread
-		dequeue(wp, &m, &ipc_status);
+		 * termination event.
-
+		 */
-		if (!running)
+		if (!dequeue(dp, wp, &m, &ipc_status))
 			break;
 	}
 
 	/* Even if the thread was stopped before, a new message resumes it. */
-	wp->state = STATE_RUNNING;
+	wp->state = STATE_BUSY;
 
-	/* Handle the request, and send a reply. */
+	/* If the request is a transfer request, we acquire the read barrier
-	r = blockdriver_handle_request(bdtab, &m, wp->id);
+	 * lock. Otherwise, we acquire the write lock.
+	 */
+	if (is_transfer_req(m.m_type))
+		mthread_rwlock_rdlock(&dp->barrier);
+	else
+		mthread_rwlock_wrlock(&dp->barrier);
+
+	/* Handle the request and send a reply. */
+	r = blockdriver_handle_request(bdtab, &m, tid);
 
 	blockdriver_reply(&m, ipc_status, r);
+
+	/* Switch the thread back to running state, and unlock the barrier. */
+	wp->state = STATE_RUNNING;
+	mthread_rwlock_unlock(&dp->barrier);
   }
 
   /* Clean up and terminate this thread. */
@@ -145,23 +207,24 @@ PRIVATE void *worker_thread(void *param)
 /*===========================================================================*
  *				master_create_worker			     *
  *===========================================================================*/
-PRIVATE void master_create_worker(worker_t *wp, thread_id_t id)
+PRIVATE void master_create_worker(worker_t *wp, worker_id_t worker_id,
+  device_id_t device_id)
 {
 /* Start a new worker thread.
  */
   int r;
 
-  wp->id = id;
+  wp->device_id = device_id;
+  wp->worker_id = worker_id;
   wp->state = STATE_RUNNING;
 
   /* Initialize synchronization primitives. */
-  event_init(&wp->queue_event);
+  mthread_event_init(&wp->sleep_event);
-  event_init(&wp->sleep_event);
 
   r = mthread_create(&wp->mthread, NULL /*attr*/, worker_thread, (void *) wp);
 
   if (r != 0)
-	panic("blockdriver_mt: could not start thread %d (%d)", id, r);
+	panic("blockdriver_mt: could not start thread %d (%d)", worker_id, r);
 }
 
 /*===========================================================================*
@@ -171,20 +234,16 @@ PRIVATE void master_destroy_worker(worker_t *wp)
 {
 /* Clean up resources used by an exited worker thread.
  */
-  message m;
-  int ipc_status;
 
   assert(wp != NULL);
   assert(wp->state == STATE_EXITED);
-  assert(!mq_dequeue(wp->id, &m, &ipc_status));
 
   /* Join the thread. */
   if (mthread_join(wp->mthread, NULL))
-	panic("blockdriver_mt: could not join thread %d", wp->id);
+	panic("blockdriver_mt: could not join thread %d", wp->worker_id);
 
   /* Destroy resources. */
-  event_destroy(&wp->sleep_event);
+  mthread_event_destroy(&wp->sleep_event);
-  event_destroy(&wp->queue_event);
 
   wp->state = STATE_DEAD;
 }
@@ -209,13 +268,14 @@ PRIVATE void master_handle_exits(void)
  *===========================================================================*/
 PRIVATE void master_handle_request(message *m_ptr, int ipc_status)
 {
-/* For real request messages, query the thread ID, start a thread if one with
+/* For real request messages, query the device ID, start a thread if none is
- * that ID is not already running, and enqueue the message in the thread's
+ * free and the maximum number of threads for that device has not yet been
- * message queue.
+ * reached, and enqueue the message in the devices's message queue.
  */
-  thread_id_t thread_id;
+  device_id_t id;
   worker_t *wp;
-  int r;
+  device_t *dp;
+  int r, wid;
 
   /* If this is not a block driver request, we cannot get the minor device
    * associated with it, and thus we can not tell which thread should process
@@ -230,27 +290,38 @@ PRIVATE void master_handle_request(message *m_ptr, int ipc_status)
 	return;
   }
 
-  /* Query the thread ID. Upon failure, send the error code to the caller. */
+  /* Query the device ID. Upon failure, send the error code to the caller. */
-  r = (*bdtab->bdr_thread)(m_ptr->DEVICE, &thread_id);
+  r = (*bdtab->bdr_device)(m_ptr->BDEV_MINOR, &id);
-
   if (r != OK) {
 	blockdriver_reply(m_ptr, ipc_status, r);
 
 	return;
   }
 
-  /* Start the thread if it is not already running. */
+  /* Look up the device control block. */
-  assert(thread_id >= 0 && thread_id < BLOCKDRIVER_MT_MAX_WORKERS);
+  assert(id >= 0 && id < MAX_DEVICES);
+  dp = &device[id];
 
-  wp = &worker[thread_id];
+  /* Find the first non-busy worker thread. */
+  for (wid = 0; wid < dp->workers; wid++)
+	if (dp->worker[wid].state != STATE_BUSY)
+		break;
 
-  assert(wp->state != STATE_EXITED);
+  /* If the worker thread is dead, start a thread now, unless we have already
+   * reached the maximum number of threads.
+   */
+  if (wid < dp->workers) {
+	wp = &dp->worker[wid];
 
-  if (wp->state == STATE_DEAD)
+	assert(wp->state != STATE_EXITED);
-	master_create_worker(wp, thread_id);
 
-  /* Enqueue the message for the thread, and possibly wake it up. */
+	/* If the non-busy thread has not yet been created, create one now. */
-  enqueue(wp, m_ptr, ipc_status);
+	if (wp->state == STATE_DEAD)
+		master_create_worker(wp, wid, dp->id);
+  }
+
+  /* Enqueue the message at the device queue. */
+  enqueue(dp, m_ptr, ipc_status);
 }
 
 /*===========================================================================*
@@ -260,17 +331,25 @@ PRIVATE void master_init(struct blockdriver *bdp)
 {
 /* Initialize the state of the master thread.
  */
-  int i;
+  int i, j;
 
   assert(bdp != NULL);
-  assert(bdp->bdr_thread != NULL);
+  assert(bdp->bdr_device != NULL);
 
   mthread_init();
 
   bdtab = bdp;
 
-  for (i = 0; i < BLOCKDRIVER_MT_MAX_WORKERS; i++)
+  /* Initialize device-specific data structures. */
-	worker[i].state = STATE_DEAD;
+  for (i = 0; i < MAX_DEVICES; i++) {
+	device[i].id = i;
+	device[i].workers = 1;
+	mthread_event_init(&device[i].queue_event);
+	mthread_rwlock_init(&device[i].barrier);
+
+	for (j = 0; j < MAX_WORKERS; j++)
+		device[i].worker[j].state = STATE_DEAD;
+  }
 
   /* Initialize a per-thread key, where each worker thread stores its own
    * reference to the worker structure.
@@ -279,6 +358,23 @@ PRIVATE void master_init(struct blockdriver *bdp)
 	panic("blockdriver_mt: error initializing worker key");
 }
 
+/*===========================================================================*
+ *				blockdriver_mt_get_tid			     *
+ *===========================================================================*/
+PUBLIC thread_id_t blockdriver_mt_get_tid(void)
+{
+/* Return back the ID of this thread.
+ */
+  worker_t *wp;
+
+  wp = (worker_t *) mthread_getspecific(worker_key);
+
+  if (wp == NULL)
+	panic("blockdriver_mt: master thread cannot query thread ID\n");
+
+  return MAKE_TID(wp->device_id, wp->worker_id);
+}
+
 /*===========================================================================*
  *				blockdriver_mt_receive			     *
  *===========================================================================*/
@@ -301,7 +397,7 @@ PUBLIC void blockdriver_mt_task(struct blockdriver *driver_tab)
 {
 /* The multithreaded driver task.
  */
-  int ipc_status;
+  int ipc_status, i;
   message mess;
 
   /* Initialize first if necessary. */
@@ -329,6 +425,10 @@ PUBLIC void blockdriver_mt_task(struct blockdriver *driver_tab)
 	if (num_exited > 0)
 		master_handle_exits();
   }
+
+  /* Free up resources. */
+  for (i = 0; i < MAX_DEVICES; i++)
+	mthread_event_destroy(&device[i].queue_event);
 }
 
 /*===========================================================================*
@@ -356,7 +456,7 @@ PUBLIC void blockdriver_mt_sleep(void)
   if (wp == NULL)
 	panic("blockdriver_mt: master thread cannot sleep");
 
-  event_wait(&wp->sleep_event);
+  mthread_event_wait(&wp->sleep_event);
 }
 
 /*===========================================================================*
@@ -367,32 +467,41 @@ PUBLIC void blockdriver_mt_wakeup(thread_id_t id)
 /* Wake up a sleeping worker thread from the master thread.
  */
   worker_t *wp;
+  device_id_t device_id;
+  worker_id_t worker_id;
 
-  assert(id >= 0 && id < BLOCKDRIVER_MT_MAX_WORKERS);
+  device_id = TID_DEVICE(id);
+  worker_id = TID_WORKER(id);
 
-  wp = &worker[id];
+  assert(device_id >= 0 && device_id < MAX_DEVICES);
+  assert(worker_id >= 0 && worker_id < MAX_WORKERS);
 
-  assert(wp->state == STATE_RUNNING || wp->state == STATE_STOPPING);
+  wp = &device[device_id].worker[worker_id];
 
-  event_fire(&wp->sleep_event);
+  assert(wp->state == STATE_RUNNING || wp->state == STATE_BUSY);
+
+  mthread_event_fire(&wp->sleep_event);
 }
 
 /*===========================================================================*
- *				blockdriver_mt_stop			     *
+ *				blockdriver_mt_set_workers		     *
  *===========================================================================*/
-PUBLIC void blockdriver_mt_stop(void)
+PUBLIC void blockdriver_mt_set_workers(device_id_t id, int workers)
 {
-/* Put up the current worker thread for termination. Once the current dispatch
+/* Set the number of worker threads for the given device.
- * call has finished, and there are no more messages in the thread's message
- * queue, the thread will be terminated. Any messages in the queue will undo
- * the effect of this call.
  */
-  worker_t *wp;
+  device_t *dp;
 
-  wp = (worker_t *) mthread_getspecific(worker_key);
+  assert(id >= 0 && id < MAX_DEVICES);
 
-  assert(wp != NULL);
+  if (workers > MAX_WORKERS)
-  assert(wp->state == STATE_RUNNING || wp->state == STATE_STOPPING);
+	workers = MAX_WORKERS;
 
-  wp->state = STATE_STOPPING;
+  dp = &device[id];
+
+  /* If we are cleaning up, wake up all threads waiting on a queue event. */
+  if (workers == 1 && dp->workers > workers)
+	mthread_event_fire_all(&dp->queue_event);
+
+  dp->workers = workers;
 }

lib/libblockdriver/driver_st.c

@@ -14,6 +14,7 @@
 #include <minix/drivers.h>
 #include <minix/blockdriver.h>
 
+#include "const.h"
 #include "driver.h"
 #include "mq.h"
 

lib/libblockdriver/event.c

@@ -1,71 +0,0 @@
-/* This file contains a simple thread event implementation.
- */
-
-#include <minix/mthread.h>
-#include <minix/sysutil.h>
-
-#include "event.h"
-
-/*===========================================================================*
- *				event_init				     *
- *===========================================================================*/
-PUBLIC void event_init(event_t *event)
-{
-/* Initialize an event object.
- */
-  int r;
-
-  if ((r = mthread_mutex_init(&event->mutex, NULL)) != 0)
-	panic("libblockdriver: error initializing mutex (%d)", r);
-  if ((r = mthread_cond_init(&event->cond, NULL)) != 0)
-	panic("libblockdriver: error initializing condvar (%d)", r);
-}
-
-/*===========================================================================*
- *				event_destroy				     *
- *===========================================================================*/
-PUBLIC void event_destroy(event_t *event)
-{
-/* Destroy an event object.
- */
-  int r;
-
-  if ((r = mthread_cond_destroy(&event->cond)) != 0)
-	panic("libblockdriver: error destroying condvar (%d)", r);
-  if ((r = mthread_mutex_destroy(&event->mutex)) != 0)
-	panic("libblockdriver: error destroying mutex (%d)", r);
-}
-
-/*===========================================================================*
- *				event_wait				     *
- *===========================================================================*/
-PUBLIC void event_wait(event_t *event)
-{
-/* Wait for an event, blocking the current thread in the process.
- */
-  int r;
-
-  if ((r = mthread_mutex_lock(&event->mutex)) != 0)
-	panic("libblockdriver: error locking mutex (%d)", r);
-  if ((r = mthread_cond_wait(&event->cond, &event->mutex)) != 0)
-	panic("libblockdriver: error waiting for condvar (%d)", r);
-  if ((r = mthread_mutex_unlock(&event->mutex)) != 0)
-	panic("libblockdriver: error unlocking mutex (%d)", r);
-}
-
-/*===========================================================================*
- *				event_fire				     *
- *===========================================================================*/
-PUBLIC void event_fire(event_t *event)
-{
-/* Fire an event, waking up any thread blocked on it without scheduling it.
- */
-  int r;
-
-  if ((r = mthread_mutex_lock(&event->mutex)) != 0)
-	panic("libblockdriver: error locking mutex (%d)", r);
-  if ((r = mthread_cond_signal(&event->cond)) != 0)
-	panic("libblockdriver: error signaling condvar (%d)", r);
-  if ((r = mthread_mutex_unlock(&event->mutex)) != 0)
-	panic("libblockdriver: error unlocking mutex (%d)", r);
-}

lib/libblockdriver/event.h

@@ -1,14 +0,0 @@
-#ifndef _BLOCKDRIVER_EVENT_H
-#define _BLOCKDRIVER_EVENT_H
-
-typedef struct {
-  mthread_mutex_t mutex;
-  mthread_cond_t cond;
-} event_t;
-
-_PROTOTYPE( void event_init, (event_t *event) );
-_PROTOTYPE( void event_destroy, (event_t *event) );
-_PROTOTYPE( void event_wait, (event_t *event) );
-_PROTOTYPE( void event_fire, (event_t *event) );
-
-#endif /* _BLOCKDRIVER_EVENT_H */

lib/libblockdriver/mq.c

@@ -10,6 +10,7 @@
 #include <sys/queue.h>
 #include <assert.h>
 
+#include "const.h"
 #include "mq.h"
 
 #define MQ_SIZE		128
@@ -21,8 +22,7 @@ struct mq_cell {
 };
 
 PRIVATE struct mq_cell pool[MQ_SIZE];
-
+PRIVATE STAILQ_HEAD(queue, mq_cell) queue[MAX_DEVICES];
-PRIVATE STAILQ_HEAD(queue, mq_cell) queue[BLOCKDRIVER_MT_MAX_WORKERS];
 PRIVATE STAILQ_HEAD(free_list, mq_cell) free_list;
 
 /*===========================================================================*
@@ -36,7 +36,7 @@ PUBLIC void mq_init(void)
 
   STAILQ_INIT(&free_list);
 
-  for (i = 0; i < BLOCKDRIVER_MT_MAX_WORKERS; i++)
+  for (i = 0; i < MAX_DEVICES; i++)
 	STAILQ_INIT(&queue[i]);
 
   for (i = 0; i < MQ_SIZE; i++)
@@ -46,15 +46,15 @@ PUBLIC void mq_init(void)
 /*===========================================================================*
  *				mq_enqueue				     *
  *===========================================================================*/
-PUBLIC int mq_enqueue(thread_id_t thread_id, const message *mess,
+PUBLIC int mq_enqueue(device_id_t device_id, const message *mess,
   int ipc_status)
 {
-/* Add a message, including its IPC status, to the message queue of a thread.
+/* Add a message, including its IPC status, to the message queue of a device.
  * Return TRUE iff the message was added successfully.
  */
   struct mq_cell *cell;
 
-  assert(thread_id >= 0 && thread_id < BLOCKDRIVER_MT_MAX_WORKERS);
+  assert(device_id >= 0 && device_id < MAX_DEVICES);
 
   if (STAILQ_EMPTY(&free_list))
 	return FALSE;
@@ -65,7 +65,7 @@ PUBLIC int mq_enqueue(thread_id_t thread_id, const message *mess,
   cell->mess = *mess;
   cell->ipc_status = ipc_status;
 
-  STAILQ_INSERT_TAIL(&queue[thread_id], cell, next);
+  STAILQ_INSERT_TAIL(&queue[device_id], cell, next);
 
   return TRUE;
 }
@@ -73,20 +73,20 @@ PUBLIC int mq_enqueue(thread_id_t thread_id, const message *mess,
 /*===========================================================================*
  *				mq_dequeue				     *
  *===========================================================================*/
-PUBLIC int mq_dequeue(thread_id_t thread_id, message *mess, int *ipc_status)
+PUBLIC int mq_dequeue(device_id_t device_id, message *mess, int *ipc_status)
 {
 /* Return and remove a message, including its IPC status, from the message
  * queue of a thread. Return TRUE iff a message was available.
  */
   struct mq_cell *cell;
 
-  assert(thread_id >= 0 && thread_id < BLOCKDRIVER_MT_MAX_WORKERS);
+  assert(device_id >= 0 && device_id < MAX_DEVICES);
 
-  if (STAILQ_EMPTY(&queue[thread_id]))
+  if (STAILQ_EMPTY(&queue[device_id]))
 	return FALSE;
 
-  cell = STAILQ_FIRST(&queue[thread_id]);
+  cell = STAILQ_FIRST(&queue[device_id]);
-  STAILQ_REMOVE_HEAD(&queue[thread_id], next);
+  STAILQ_REMOVE_HEAD(&queue[device_id], next);
 
   *mess = cell->mess;
   *ipc_status = cell->ipc_status;

lib/libblockdriver/mq.h

@@ -2,9 +2,9 @@
 #define _BLOCKDRIVER_MQ_H
 
 _PROTOTYPE( void mq_init, (void) );
-_PROTOTYPE( int mq_enqueue, (thread_id_t thread_id, const message *mess,
+_PROTOTYPE( int mq_enqueue, (device_id_t device_id, const message *mess,
 	int ipc_status) );
-_PROTOTYPE( int mq_dequeue, (thread_id_t thread_id, message *mess,
+_PROTOTYPE( int mq_dequeue, (device_id_t device_id, message *mess,
 	int *ipc_status) );
 
 #endif /* _BLOCKDRIVER_MQ_H */

lib/libblockdriver/trace.c

@@ -7,6 +7,7 @@
 #include <minix/minlib.h>
 #include <assert.h>
 
+#include "const.h"
 #include "trace.h"
 
 #define NO_TRACEDEV		((dev_t) -1)
@@ -24,7 +25,7 @@ PRIVATE u64_t trace_tsc;
  * plus one for the main thread). Each pointer is set to NULL whenever no
  * operation is currently being traced for that thread, for whatever reason.
  */
-PRIVATE btrace_entry *trace_ptr[BLOCKDRIVER_MT_MAX_WORKERS + 1] = { NULL };
+PRIVATE btrace_entry *trace_ptr[MAX_THREADS + 1] = { NULL };
 
 /*===========================================================================*
  *				trace_gettime				     *
@@ -175,7 +176,7 @@ PUBLIC void trace_start(thread_id_t id, message *m_ptr)
 
   if (!trace_enabled || trace_dev != m_ptr->BDEV_MINOR) return;
 
-  assert(id >= 0 && id < BLOCKDRIVER_MT_MAX_WORKERS + 1);
+  assert(id >= 0 && id < MAX_THREADS + 1);
 
   if (trace_pos == trace_size)
 	return;
@@ -254,7 +255,7 @@ PUBLIC void trace_setsize(thread_id_t id, size_t size)
 
   if (!trace_enabled) return;
 
-  assert(id >= 0 && id < BLOCKDRIVER_MT_MAX_WORKERS + 1);
+  assert(id >= 0 && id < MAX_THREADS + 1);
 
   if ((entry = trace_ptr[id]) == NULL) return;
 
@@ -272,7 +273,7 @@ PUBLIC void trace_finish(thread_id_t id, int result)
 
   if (!trace_enabled) return;
 
-  assert(id >= 0 && id < BLOCKDRIVER_MT_MAX_WORKERS + 1);
+  assert(id >= 0 && id < MAX_THREADS + 1);
 
   if ((entry = trace_ptr[id]) == NULL) return;