OS-6771 ppt device nodes sometimes disappear after module unloading

Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Patrick Mooney <patrick.mooney@joyent.com>
Approved by: Jerry Jelinek <jerry.jelinek@joyent.com>

2 files changed, 43 insertions, 60 deletions

diff --git a/usr/src/cmd/devfsadm/i386/misc_link_i386.c b/usr/src/cmd/devfsadm/i386/misc_link_i386.c
index fbb344cdf6..6b21eabe3b 100644
--- a/usr/src/cmd/devfsadm/i386/misc_link_i386.c
+++ b/usr/src/cmd/devfsadm/i386/misc_link_i386.c
@@ -46,6 +46,7 @@ static int kdmouse(di_minor_t minor, di_node_t node);
 static int ipmi(di_minor_t minor, di_node_t node);
 static int mc_node(di_minor_t minor, di_node_t node);
 static int vmmctl(di_minor_t minor, di_node_t node);
+static int ppt(di_minor_t minor, di_node_t node);
 
 static devfsadm_create_t misc_cbt[] = {
 	{ "vt00", "ddi_display", NULL,
@@ -92,7 +93,7 @@ static devfsadm_create_t misc_cbt[] = {
 	    TYPE_EXACT | DRV_EXACT, ILEVEL_0, vmmctl,
 	},
 	{ "pseudo", "ddi_pseudo", "ppt",
-	    TYPE_EXACT | DRV_EXACT, ILEVEL_0, ln_minor_name,
+	    TYPE_EXACT | DRV_EXACT, ILEVEL_0, ppt,
 	}
 };
 
@@ -375,3 +376,15 @@ vmmctl(di_minor_t minor, di_node_t node)
 		(void) devfsadm_mklink("vmmctl", node, minor, 0);
 	return (DEVFSADM_CONTINUE);
 }
+
+static int
+ppt(di_minor_t minor, di_node_t node)
+{
+	char linkpath[PATH_MAX];
+
+	(void) snprintf(linkpath, sizeof (linkpath), "ppt%d",
+	    di_instance(node));
+
+	(void) devfsadm_mklink(linkpath, node, minor, 0);
+	return (DEVFSADM_CONTINUE);
+}
diff --git a/usr/src/uts/i86pc/io/vmm/io/ppt.c b/usr/src/uts/i86pc/io/vmm/io/ppt.c
index 5cc8156137..777d4129e0 100644
--- a/usr/src/uts/i86pc/io/vmm/io/ppt.c
+++ b/usr/src/uts/i86pc/io/vmm/io/ppt.c
@@ -57,7 +57,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/pci_cap.h>
 #include <sys/ppt_dev.h>
 #include <sys/mkdev.h>
-#include <sys/id_space.h>
 
 #include "vmm_lapic.h"
 #include "vmm_ktr.h"
@@ -101,7 +100,6 @@ struct pptdev {
 	dev_info_t		*pptd_dip;
 	list_node_t		pptd_node;
 	ddi_acc_handle_t	pptd_cfg;
-	dev_t			pptd_dev;
 	struct pptbar		pptd_bars[PCI_BASE_NUM];
 	struct vm		*vm;
 	struct pptseg mmio[MAX_MMIOSEGS];
@@ -123,10 +121,12 @@ struct pptdev {
 };
 
 
+static major_t		ppt_major;
 static void		*ppt_state;
 static kmutex_t		pptdev_mtx;
 static list_t		pptdev_list;
-static id_space_t	*pptdev_minors = NULL;
+
+#define	PPT_MINOR_NAME	"ppt"
 
 static ddi_device_acc_attr_t ppt_attr = {
 	DDI_DEVICE_ATTR_V0,
@@ -385,42 +385,22 @@ ppt_bar_crawl(struct pptdev *ppt)
 	return (err);
 }
 
-static struct pptdev *
-ppt_find_dev(dev_t dev)
-{
-	struct pptdev *ppt;
-
-	ASSERT(MUTEX_HELD(&pptdev_mtx));
-
-	for (ppt = list_head(&pptdev_list); ppt != NULL;
-	    ppt = list_next(&pptdev_list, ppt)) {
-		if (ppt->pptd_dev == dev) {
-			return (ppt);
-		}
-	}
-
-	return (NULL);
-}
-
 static int
 ppt_ddi_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
 {
 	struct pptdev *ppt = NULL;
 	char name[PPT_MAXNAMELEN];
-	minor_t minor;
+	int inst;
 
 	if (cmd != DDI_ATTACH)
 		return (DDI_FAILURE);
 
-	minor = id_alloc_nosleep(pptdev_minors);
-	if (minor == -1) {
-		return (DDI_FAILURE);
-	}
+	inst = ddi_get_instance(dip);
 
-	if (ddi_soft_state_zalloc(ppt_state, minor) != DDI_SUCCESS) {
+	if (ddi_soft_state_zalloc(ppt_state, inst) != DDI_SUCCESS) {
 		goto fail;
 	}
-	VERIFY(ppt = ddi_get_soft_state(ppt_state, minor));
+	VERIFY(ppt = ddi_get_soft_state(ppt_state, inst));
 	ppt->pptd_dip = dip;
 	ddi_set_driver_private(dip, ppt);
 
@@ -431,16 +411,11 @@ ppt_ddi_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
 		goto fail;
 	}
 
-	if (snprintf(name, sizeof (name), "ppt%u", minor)
-	    >= PPT_MAXNAMELEN - 1) {
-		goto fail;
-	}
-	if (ddi_create_minor_node(dip, name, S_IFCHR, minor,
+	if (ddi_create_minor_node(dip, PPT_MINOR_NAME, S_IFCHR, inst,
 	    DDI_PSEUDO, 0) != DDI_SUCCESS) {
 		goto fail;
 	}
 
-	ppt->pptd_dev = makedevice(ddi_driver_major(dip), minor);
 	mutex_enter(&pptdev_mtx);
 	list_insert_tail(&pptdev_list, ppt);
 	mutex_exit(&pptdev_mtx);
@@ -454,9 +429,8 @@ fail:
 			pci_config_teardown(&ppt->pptd_cfg);
 		}
 		ppt_bar_wipe(ppt);
-		ddi_soft_state_free(ppt_state, minor);
+		ddi_soft_state_free(ppt_state, inst);
 	}
-	id_free(pptdev_minors, minor);
 	return (DDI_FAILURE);
 }
 
@@ -464,15 +438,15 @@ static int
 ppt_ddi_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
 {
 	struct pptdev *ppt;
-	minor_t minor;
+	int inst;
 
 	if (cmd != DDI_DETACH)
 		return (DDI_FAILURE);
 
 	ppt = ddi_get_driver_private(dip);
-	minor = getminor(ppt->pptd_dev);
+	inst = ddi_get_instance(dip);
 
-	ASSERT3P(ddi_get_soft_state(ppt_state, minor), ==, ppt);
+	ASSERT3P(ddi_get_soft_state(ppt_state, inst), ==, ppt);
 
 	mutex_enter(&pptdev_mtx);
 	if (ppt->vm != NULL) {
@@ -482,12 +456,11 @@ ppt_ddi_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
 	list_remove(&pptdev_list, ppt);
 	mutex_exit(&pptdev_mtx);
 
-	ddi_remove_minor_node(dip, NULL);
+	ddi_remove_minor_node(dip, PPT_MINOR_NAME);
 	ppt_bar_wipe(ppt);
 	pci_config_teardown(&ppt->pptd_cfg);
 	ddi_set_driver_private(dip, NULL);
-	ddi_soft_state_free(ppt_state, minor);
-	id_free(pptdev_minors, minor);
+	ddi_soft_state_free(ppt_state, inst);
 
 	return (DDI_SUCCESS);
 }
@@ -496,22 +469,20 @@ static int
 ppt_ddi_info(dev_info_t *dip, ddi_info_cmd_t cmd, void *arg, void **result)
 {
 	int error = DDI_FAILURE;
+	int inst = getminor((dev_t)arg);
 
 	switch (cmd) {
 	case DDI_INFO_DEVT2DEVINFO: {
-		struct pptdev *ppt;
+		struct pptdev *ppt = ddi_get_soft_state(ppt_state, inst);
 
-		mutex_enter(&pptdev_mtx);
-		ppt = ppt_find_dev((dev_t)arg);
 		if (ppt != NULL) {
 			*result = (void *)ppt->pptd_dip;
 			error = DDI_SUCCESS;
 		}
-		mutex_exit(&pptdev_mtx);
 		break;
 	}
 	case DDI_INFO_DEVT2INSTANCE: {
-		*result = (void *)(uintptr_t)getminor((dev_t)arg);
+		*result = (void *)(uintptr_t)inst;
 		error = DDI_SUCCESS;
 		break;
 	}
@@ -572,7 +543,6 @@ _init(void)
 	mutex_init(&pptdev_mtx, NULL, MUTEX_DRIVER, NULL);
 	list_create(&pptdev_list, sizeof (struct pptdev),
 	    offsetof(struct pptdev, pptd_node));
-	pptdev_minors = id_space_create("ppt_minors", 0, MAXMIN32);
 
 	error = ddi_soft_state_init(&ppt_state, sizeof (struct pptdev), 0);
 	if (error) {
@@ -581,11 +551,10 @@ _init(void)
 
 	error = mod_install(&modlinkage);
 
+	ppt_major = ddi_name_to_major("ppt");
 fail:
 	if (error) {
 		ddi_soft_state_fini(&ppt_state);
-		id_space_destroy(pptdev_minors);
-		pptdev_minors = NULL;
 	}
 	return (error);
 }
@@ -598,9 +567,6 @@ _fini(void)
 	error = mod_remove(&modlinkage);
 	if (error)
 		return (error);
-
-	id_space_destroy(pptdev_minors);
-	pptdev_minors = NULL;
 	ddi_soft_state_fini(&ppt_state);
 
 	return (0);
@@ -770,14 +736,18 @@ ppt_findf(int fd)
 	}
 
 	va.va_mask = AT_RDEV;
-	if (VOP_GETATTR(fp->f_vnode, &va, NO_FOLLOW, fp->f_cred, NULL) == 0) {
-		ppt = ppt_find_dev(va.va_rdev);
-	}
+	if (VOP_GETATTR(fp->f_vnode, &va, NO_FOLLOW, fp->f_cred, NULL) != 0 ||
+	    getmajor(va.va_rdev) != ppt_major)
+		goto fail;
 
-	if (ppt == NULL) {
-		releasef(fd);
-	}
-	return (ppt);
+	ppt = ddi_get_soft_state(ppt_state, getminor(va.va_rdev));
+
+	if (ppt != NULL)
+		return (ppt);
+
+fail:
+	releasef(fd);
+	return (NULL);
 }
 
 static void