fix ide, pit interfaces

7 files changed, 53 insertions, 56 deletions

diff --git a/8253pit.c b/8253pit.c
index 0b82e29..d94d59c 100644
--- a/8253pit.c
+++ b/8253pit.c
@@ -42,5 +42,5 @@ pit8253_timerinit(void)
   outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
   outb(IO_TIMER1, TIMER_DIV(100) % 256);
   outb(IO_TIMER1, TIMER_DIV(100) / 256);
-  irq_setmask_8259A(irq_mask_8259A & ~(1<<IRQ_TIMER));
+  irq_enable(IRQ_TIMER);
 }
diff --git a/bio.c b/bio.c
index f157305..43286da 100644
--- a/bio.c
+++ b/bio.c
@@ -102,37 +102,28 @@ bget(uint dev, uint sector)
 struct buf*
 bread(uint dev, uint sector)
 {
-  void *c;
   struct buf *b;
-  extern struct spinlock ide_lock;
 
   b = bget(dev, sector);
   if(b->flags & B_VALID)
     return b;
 
-  acquire(&ide_lock);
-  c = ide_start_rw(dev & 0xff, sector, b->data, 1, 1);
-  sleep(c, &ide_lock);
-  ide_finish(c);
+  ide_rw(dev & 0xff, sector, b->data, 1, 1);
   b->flags |= B_VALID;
-  release(&ide_lock);
 
   return b;
 }
 
 // Write buf's contents to disk.
+// Must be locked.
 void
 bwrite(struct buf *b, uint sector)
 {
-  void *c;
-  extern struct spinlock ide_lock;
+  if((b->flags & B_BUSY) == 0)
+    panic("bwrite");
 
-  acquire(&ide_lock);
-  c = ide_start_rw(b->dev & 0xff, sector, b->data, 1, 0);
-  sleep(c, &ide_lock);
-  ide_finish(c);
+  ide_rw(b->dev & 0xff, sector, b->data, 1, 0);
   b->flags |= B_VALID;
-  release(&ide_lock);
 }
 
 // Release the buffer buf.
diff --git a/console.c b/console.c
index b2c363e..218a627 100644
--- a/console.c
+++ b/console.c
@@ -409,7 +409,7 @@ console_init()
   devsw[CONSOLE].write = console_write;
   devsw[CONSOLE].read = console_read;
 
-  irq_setmask_8259A(irq_mask_8259A & ~(1 << IRQ_KBD));
+  irq_enable(IRQ_KBD);
   ioapic_enable(IRQ_KBD, 0);
 
   use_console_lock = 1;
diff --git a/defs.h b/defs.h
index 9babf92..0225e5d 100644
--- a/defs.h
+++ b/defs.h
@@ -49,9 +49,8 @@ int argptr(int, char**, int);
 int argstr(int, char**);
 
 // picirq.c
-extern ushort irq_mask_8259A;
 void pic_init(void);
-void irq_setmask_8259A(ushort);
+void irq_enable(int);
 
 // 8253pit.c
 void pit8253_timerinit(void);
@@ -109,8 +108,7 @@ void fileincref(struct file*);
 // ide.c
 void ide_init(void);
 void ide_intr(void);
-void* ide_start_rw(int, uint, void*, uint, int);
-int ide_finish(void*);
+void ide_rw(int, uint, void*, uint, int);
 
 // bio.c
 void binit(void);
diff --git a/ide.c b/ide.c
index 3afd19b..ffe1b08 100644
--- a/ide.c
+++ b/ide.c
@@ -31,15 +31,16 @@ struct ide_request {
   uint read;
 };
 
-struct ide_request request[NREQUEST];
-int head, tail;
-struct spinlock ide_lock;
+static struct ide_request request[NREQUEST];
+static int head, tail;
+static struct spinlock ide_lock;
 
-int disk_1_present;
-int disk_channel;
+static int disk_1_present;
+static int disk_queue;
 
-int ide_probe_disk1(void);
+static int ide_probe_disk1(void);
 
+// Wait for IDE disk to become ready.
 static int
 ide_wait_ready(int check_error)
 {
@@ -57,12 +58,13 @@ void
 ide_init(void)
 {
   initlock(&ide_lock, "ide");
-  irq_setmask_8259A(irq_mask_8259A & ~(1 << IRQ_IDE));
-  ioapic_enable (IRQ_IDE, ncpu - 1);
+  irq_enable(IRQ_IDE);
+  ioapic_enable(IRQ_IDE, ncpu - 1);
   ide_wait_ready(0);
   disk_1_present = ide_probe_disk1();
 }
 
+// Interrupt handler - wake up the request that just finished.
 void
 ide_intr(void)
 {
@@ -71,7 +73,8 @@ ide_intr(void)
   release(&ide_lock);
 }
 
-int
+// Probe to see if disk 1 exists (we assume disk 0 exists).
+static int
 ide_probe_disk1(void)
 {
   int r, x;
@@ -92,7 +95,8 @@ ide_probe_disk1(void)
   return x < 1000;
 }
 
-void
+// Start the next request in the queue.
+static void
 ide_start_request (void)
 {
   struct ide_request *r;
@@ -115,16 +119,20 @@ ide_start_request (void)
   }
 }
 
-void*
-ide_start_rw(int diskno, uint secno, void *addr, uint nsecs, int read)
+// Run an entire disk operation.
+void
+ide_rw(int diskno, uint secno, void *addr, uint nsecs, int read)
 {
   struct ide_request *r;
 
   if(diskno && !disk_1_present)
     panic("ide disk 1 not present");
 
+  acquire(&ide_lock);
+  
+  // Add request to queue.
   while((head + 1) % NREQUEST == tail)
-    sleep(&disk_channel, &ide_lock);
+    sleep(&disk_queue, &ide_lock);
 
   r = &request[head];
   r->secno = secno;
@@ -132,35 +140,29 @@ ide_start_rw(int diskno, uint secno, void *addr, uint nsecs, int read)
   r->nsecs = nsecs;
   r->diskno = diskno;
   r->read = read;
-
   head = (head + 1) % NREQUEST;
 
+  // Start request if necessary.
   ide_start_request();
-
-  return r;
-}
-
-int
-ide_finish(void *c)
-{
-  int r;
-  struct ide_request *req = (struct ide_request*) c;
-
-  if(req->read) {
-    if((r = ide_wait_ready(1)) >= 0)
-      insl(0x1F0, req->addr, 512/4);
-  }
-
-  if((head + 1) % NREQUEST == tail) {
-    wakeup(&disk_channel);
+  
+  // Wait for request to finish.
+  sleep(r, &ide_lock);
+  
+  // Finish request.
+  if(read){
+    if(ide_wait_ready(1) >= 0)
+      insl(0x1F0, addr, 512/4);
   }
 
+  // Remove request from queue.
+  if((head + 1) % NREQUEST == tail)
+    wakeup(&disk_queue);
   tail = (tail + 1) % NREQUEST;
-  ide_start_request();
 
-  return 0;
+  release(&ide_lock);
 }
 
+// Synchronous disk write.
 int
 ide_write(int diskno, uint secno, const void *src, uint nsecs)
 {
diff --git a/picirq.c b/picirq.c
index eaac053..b7d0116 100644
--- a/picirq.c
+++ b/picirq.c
@@ -11,9 +11,9 @@
 
 // Current IRQ mask.
 // Initial IRQ mask has interrupt 2 enabled (for slave 8259A).
-ushort irq_mask_8259A = 0xFFFF & ~(1<<IRQ_SLAVE);
+static ushort irq_mask_8259A = 0xFFFF & ~(1<<IRQ_SLAVE);
 
-void
+static void
 irq_setmask_8259A(ushort mask)
 {
   irq_mask_8259A = mask;
@@ -22,6 +22,12 @@ irq_setmask_8259A(ushort mask)
   outb(IO_PIC2+1, (char)(mask >> 8));
 }
 
+void
+irq_enable(int irq)
+{
+  irq_setmask_8259A(irq_mask_8259A & ~(1<<irq));
+}
+
 // Initialize the 8259A interrupt controllers.
 void
 pic_init(void)
diff --git a/sysfile.c b/sysfile.c
index b45032e..45731f9 100644
--- a/sysfile.c
+++ b/sysfile.c
@@ -220,7 +220,7 @@ sys_mkdir(void)
     return -1;
   }
 
-  dp->nlink += 1;
+  dp->nlink++;
   iupdate(dp);
 
   memset(de.name, '\0', DIRSIZ);