Add locking to ppc and ppbus and mark the whole lot MPSAFE:

- To avoid having a bunch of locks that end up always getting acquired as
  a group, give each ppc(4) device a mutex which it shares with all the
  child devices including ppbus(4), lpt(4), plip(4), etc.  This mutex
  is then used for all the locking.
- Rework the interrupt handling stuff yet again.  Now ppbus drivers setup
  their interrupt handler during attach and tear it down during detach
  like most other drivers.  ppbus(4) only invokes the interrupt handler
  of the device that currently owns the bus (if any) when an interrupt
  occurs, however.  Also, interrupt handlers in general now accept their
  softc pointers as their argument rather than the device_t.  Another
  feature of the ppbus interrupt handlers is that they are called with
  the parent ppc device's lock already held.  This minimizes the number
  of lock operations during an interrupt.
- Mark plip(4), lpt(4), pcfclock(4), ppi(4), vpo(4) MPSAFE.
- lpbb(4) uses the ppc lock instead of Giant.
- Other plip(4) changes:
  - Add a mutex to protect the global tables in plip(4) and free them on
    module unload.
  - Add a detach routine.
  - Split out the init/stop code from the ioctl routine into separate
    functions.
- Other lpt(4) changes:
  - Use device_printf().
  - Use a dedicated callout for the lptout timer.
  - Allocate the I/O buffers at attach and detach rather than during
    open and close as this simplifies the locking at the cost of
    1024+32 bytes when the driver is attached.
- Other ppi(4) changes:
  - Use an sx lock to serialize open and close.
  - Remove unused HADBUS flag.
  - Add a detach routine.
  - Use a malloc'd buffer for each read and write to avoid races with
    concurrent read/write.
- Other pps(4) changes:
  - Use a callout rather than a callout handle with timeout().
  - Conform to the new ppbus requirements (regular mutex, non-filter
    interrupt handler).  pps(4) is probably going to have to become a
    standalone driver that doesn't use ppbus(4) to satisfy it's
    requirements for low latency as a result.
  - Use an sx lock to serialize open and close.
- Other vpo(4) changes:
  - Use the parent ppc device's lock to create the CAM sim instead of
    Giant.
- Other ppc(4) changes:
  - Fix ppc_isa's detach method to detach instead of calling attach.

Tested by:	  no one :-(

1 files changed, 58 insertions, 64 deletions

diff --git a/sys/dev/ppc/ppc.c b/sys/dev/ppc/ppc.c
index b318932..2ad788e 100644
--- a/sys/dev/ppc/ppc.c
+++ b/sys/dev/ppc/ppc.c
@@ -34,9 +34,11 @@ __FBSDID("$FreeBSD$");
 #include <sys/systm.h>
 #include <sys/bus.h>
 #include <sys/kernel.h>
+#include <sys/lock.h>
 #include <sys/interrupt.h>
 #include <sys/module.h>
 #include <sys/malloc.h>
+#include <sys/mutex.h>
 #include <sys/proc.h>
 
 #include <machine/bus.h>
@@ -119,6 +121,7 @@ ppc_ecp_sync(device_t dev)
 	int i, r;
 	struct ppc_data *ppc = DEVTOSOFTC(dev);
 
+	PPC_ASSERT_LOCKED(ppc);
 	if (!(ppc->ppc_avm & PPB_ECP) && !(ppc->ppc_dtm & PPB_ECP))
 		return;
 
@@ -474,7 +477,7 @@ ppc_pc873xx_detect(struct ppc_data *ppc, int chipset_mode)	/* XXX mode never for
 
 	    /* First try to change the port address to that requested... */
 
-	    switch(ppc->ppc_base) {
+	    switch (ppc->ppc_base) {
 		case 0x378:
 		val &= 0xfc;
 		break;
@@ -1320,6 +1323,7 @@ ppc_exec_microseq(device_t dev, struct ppb_microseq **p_msq)
 
 #define INCR_PC (mi ++)		/* increment program counter */
 
+	PPC_ASSERT_LOCKED(ppc);
 	mi = *p_msq;
 	for (;;) {
 		switch (mi->opcode) {
@@ -1388,8 +1392,11 @@ ppc_exec_microseq(device_t dev, struct ppb_microseq **p_msq)
 			break;
 
 		case MS_OP_ADELAY:
-			if (mi->arg[0].i)
+			if (mi->arg[0].i) {
+				PPC_UNLOCK(ppc);
 				pause("ppbdelay", mi->arg[0].i * (hz/1000));
+				PPC_LOCK(ppc);
+			}
 			INCR_PC;
 			break;
 
@@ -1521,8 +1528,10 @@ ppcintr(void *arg)
 	 * XXX: If DMA is in progress should we just complete that w/o
 	 * doing this?
 	 */
-	if (ppc->ppc_child_handlers > 0) {
-		intr_event_execute_handlers(curproc, ppc->ppc_intr_event);
+	PPC_LOCK(ppc);
+	if (ppc->ppc_intr_hook != NULL &&
+	    ppc->ppc_intr_hook(ppc->ppc_intr_arg) == 0) {
+		PPC_UNLOCK(ppc);
 		return;
 	}
 
@@ -1536,6 +1545,7 @@ ppcintr(void *arg)
 
 	/* don't use ecp mode with IRQENABLE set */
 	if (ctr & IRQENABLE) {
+		PPC_UNLOCK(ppc);
 		return;
 	}
 
@@ -1550,6 +1560,7 @@ ppcintr(void *arg)
 			ppc->ppc_irqstat &= ~PPC_IRQ_nFAULT;
 		} else {
 			/* shall be handled by underlying layers XXX */
+			PPC_UNLOCK(ppc);
 			return;
 		}
 	}
@@ -1585,6 +1596,7 @@ ppcintr(void *arg)
 		/* classic interrupt I/O */
 		ppc->ppc_irqstat &= ~PPC_IRQ_FIFO;
 	}
+	PPC_UNLOCK(ppc);
 
 	return;
 }
@@ -1606,6 +1618,7 @@ ppc_reset_epp(device_t dev)
 {
 	struct ppc_data *ppc = DEVTOSOFTC(dev);
 
+	PPC_ASSERT_LOCKED(ppc);
 	ppc_reset_epp_timeout(ppc);
 
 	return;
@@ -1616,6 +1629,7 @@ ppc_setmode(device_t dev, int mode)
 {
 	struct ppc_data *ppc = DEVTOSOFTC(dev);
 
+	PPC_ASSERT_LOCKED(ppc);
 	switch (ppc->ppc_type) {
 	case PPC_TYPE_SMCLIKE:
 		return (ppc_smclike_setmode(ppc, mode));
@@ -1796,9 +1810,10 @@ int
 ppc_attach(device_t dev)
 {
 	struct ppc_data *ppc = DEVTOSOFTC(dev);
-	device_t ppbus;
 	int error;
 
+	mtx_init(&ppc->ppc_lock, device_get_nameunit(dev), "ppc", MTX_DEF);
+
 	device_printf(dev, "%s chipset (%s) in %s mode%s\n",
 		      ppc_models[ppc->ppc_model], ppc_avms[ppc->ppc_avm],
 		      ppc_modes[ppc->ppc_mode], (PPB_IS_EPP(ppc->ppc_mode)) ?
@@ -1809,36 +1824,25 @@ ppc_attach(device_t dev)
 			      ppc->ppc_fifo, ppc->ppc_wthr, ppc->ppc_rthr);
 
 	if (ppc->res_irq) {
-		/*
-		 * Create an interrupt event to manage the handlers of
-		 * child devices.
-		 */
-		error = intr_event_create(&ppc->ppc_intr_event, ppc, 0, -1,
-		    NULL, NULL, NULL, NULL, "%s:", device_get_nameunit(dev));
-		if (error) {
-			device_printf(dev,
-			    "failed to create interrupt event: %d\n", error);
-			return (error);
-		}
-
 		/* default to the tty mask for registration */	/* XXX */
-		error = bus_setup_intr(dev, ppc->res_irq, INTR_TYPE_TTY,
-		    NULL, ppcintr, ppc, &ppc->intr_cookie);
+		error = bus_setup_intr(dev, ppc->res_irq, INTR_TYPE_TTY |
+		    INTR_MPSAFE, NULL, ppcintr, ppc, &ppc->intr_cookie);
 		if (error) {
 			device_printf(dev,
 			    "failed to register interrupt handler: %d\n",
 			    error);
+			mtx_destroy(&ppc->ppc_lock);
 			return (error);
 		}
 	}
 
 	/* add ppbus as a child of this isa to parallel bridge */
-	ppbus = device_add_child(dev, "ppbus", -1);
+	ppc->ppbus = device_add_child(dev, "ppbus", -1);
 
 	/*
 	 * Probe the ppbus and attach devices found.
 	 */
-	device_probe_and_attach(ppbus);
+	device_probe_and_attach(ppc->ppbus);
 
 	return (0);
 }
@@ -1876,6 +1880,8 @@ ppc_detach(device_t dev)
 				     ppc->res_drq);
 	}
 
+	mtx_destroy(&ppc->ppc_lock);
+
 	return (0);
 }
 
@@ -1884,6 +1890,7 @@ ppc_io(device_t ppcdev, int iop, u_char *addr, int cnt, u_char byte)
 {
 	struct ppc_data *ppc = DEVTOSOFTC(ppcdev);
 
+	PPC_ASSERT_LOCKED(ppc);
 	switch (iop) {
 	case PPB_OUTSB_EPP:
 	    bus_write_multi_1(ppc->res_ioport, PPC_EPP_DATA, addr, cnt);
@@ -1953,8 +1960,38 @@ ppc_read_ivar(device_t bus, device_t dev, int index, uintptr_t *val)
 
 	switch (index) {
 	case PPC_IVAR_EPP_PROTO:
+		PPC_ASSERT_LOCKED(ppc);
 		*val = (u_long)ppc->ppc_epp;
 		break;
+	case PPC_IVAR_LOCK:
+		*val = (uintptr_t)&ppc->ppc_lock;
+		break;
+	default:
+		return (ENOENT);
+	}
+
+	return (0);
+}
+
+int
+ppc_write_ivar(device_t bus, device_t dev, int index, uintptr_t val)
+{
+	struct ppc_data *ppc = (struct ppc_data *)device_get_softc(bus);
+
+	switch (index) {
+	case PPC_IVAR_INTR_HANDLER:
+		PPC_ASSERT_LOCKED(ppc);
+		if (dev != ppc->ppbus)
+			return (EINVAL);
+		if (val == 0) {
+			ppc->ppc_intr_hook = NULL;
+			break;
+		}
+		if (ppc->ppc_intr_hook != NULL)
+			return (EBUSY);
+		ppc->ppc_intr_hook = (void *)val;
+		ppc->ppc_intr_arg = device_get_softc(dev);
+		break;
 	default:
 		return (ENOENT);
 	}
@@ -2001,47 +2038,4 @@ ppc_release_resource(device_t bus, device_t child, int type, int rid,
 	return (EINVAL);
 }
 
-/*
- * If a child wants to add a handler for our IRQ, add it to our interrupt
- * event.  Otherwise, fail the request.
- */
-int
-ppc_setup_intr(device_t bus, device_t child, struct resource *r, int flags,
-    driver_filter_t *filt, void (*ihand)(void *), void *arg, void **cookiep)
-{
-	struct ppc_data *ppc = DEVTOSOFTC(bus);
-	int error;
-
-	if (r != ppc->res_irq)
-		return (EINVAL);
-
-	/* We don't allow filters. */
-	if (filt != NULL)
-		return (EINVAL);
-
-	error = intr_event_add_handler(ppc->ppc_intr_event,
-	    device_get_nameunit(child), NULL, ihand, arg, intr_priority(flags),
-	    flags, cookiep);
-	if (error == 0)
-		ppc->ppc_child_handlers++;
-	return (error);
-}
-
-int
-ppc_teardown_intr(device_t bus, device_t child, struct resource *r, void *cookie)
-{
-	struct ppc_data *ppc = DEVTOSOFTC(bus);
-	int error;
-
-	if (r != ppc->res_irq)
-		return (EINVAL);
-
-	KASSERT(intr_handler_source(cookie) == ppc,
-	    ("ppc_teardown_intr: source mismatch"));
-	error = intr_event_remove_handler(cookie);
-	if (error == 0)
-		ppc->ppc_child_handlers--;
-	return (error);
-}
-
 MODULE_DEPEND(ppc, ppbus, 1, 1, 1);