Solaris support for multiple PCI segments (domains)

1. Removed hardcoded maximum size of 256 PCI devices, which is
too small for large systems.  The number of devices is dynamically
resized as needed.

2. pci_device_solx_devfs_probe() no longer walks the device tree
from the very top ("/") but instead starts at the nexus which
owns the bus.  Performance optimization for systems with multiple
bus nodes (including systems with just one segment/domain).

3. Added support for multiple domains/segments.  Code tested
on kernels with and without multiple segment support so it should
be safe to integrate independent of the kernel version.

Signed-off-by: John Martin <John.M.Martin@Oracle.COM>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>

1 files changed, 88 insertions, 62 deletions

diff --git a/src/solx_devfs.c b/src/solx_devfs.c
index 24bb1b9..d47a846 100644
--- a/src/solx_devfs.c
+++ b/src/solx_devfs.c
@@ -1,6 +1,6 @@
 /*
  * (C) Copyright IBM Corporation 2006
- * Copyright (c) 2007, 2009, Oracle and/or its affiliates.
+ * Copyright (c) 2007, 2009, 2011, Oracle and/or its affiliates.
  * All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
@@ -43,7 +43,7 @@
 
 /* #define DEBUG */
 
-#define	MAX_DEVICES	256
+#define	INITIAL_NUM_DEVICES	256
 #define	CELL_NUMS_1275	(sizeof(pci_regspec_t) / sizeof(uint_t))
 
 typedef union {
@@ -62,10 +62,18 @@ typedef struct nexus {
     int fd;
     int first_bus;
     int last_bus;
+    int domain;
     char *path;			/* for errors/debugging; fd is all we need */
+    char *dev_path;
     struct nexus *next;
 } nexus_t;
 
+typedef struct probe_info {
+    volatile size_t num_allocated_elems;
+    volatile size_t num_devices;
+    struct pci_device_private * volatile devices;
+} probe_info_t;
+
 static nexus_t *nexus_list = NULL;
 static int xsvc_fd = -1;
 
@@ -118,10 +126,9 @@ static int pci_device_solx_devfs_write( struct pci_device * dev,
     const void * data, pciaddr_t offset, pciaddr_t size,
     pciaddr_t * bytes_written );
 
-static int probe_dev(nexus_t *nexus, pcitool_reg_t *prg_p,
-		     struct pci_system *pci_sys);
+static int probe_dev(nexus_t *nexus, pcitool_reg_t *prg_p, probe_info_t *pinfo);
 
-static int do_probe(nexus_t *nexus, struct pci_system *pci_sys);
+static int do_probe(nexus_t *nexus, probe_info_t *pinfo);
 
 static int probe_nexus_node(di_node_t di_node, di_minor_t minor, void *arg);
 
@@ -147,12 +154,13 @@ static const struct pci_system_methods solx_devfs_methods = {
 };
 
 static nexus_t *
-find_nexus_for_bus( int bus )
+find_nexus_for_bus( int domain, int bus )
 {
     nexus_t *nexus;
 
     for (nexus = nexus_list ; nexus != NULL ; nexus = nexus->next) {
-	if ((bus >= nexus->first_bus) && (bus <= nexus->last_bus)) {
+	if ((domain == nexus->domain) &&
+	    (bus >= nexus->first_bus) && (bus <= nexus->last_bus)) {
 	    return nexus;
 	}
     }
@@ -186,6 +194,7 @@ pci_system_solx_devfs_destroy( void )
 	next = nexus->next;
 	close(nexus->fd);
 	free(nexus->path);
+	free(nexus->dev_path);
 	free(nexus);
     }
     nexus_list = NULL;
@@ -205,49 +214,42 @@ pci_system_solx_devfs_create( void )
 {
     int err = 0;
     di_node_t di_node;
-
+    probe_info_t pinfo;
+    struct pci_device_private *devices;
 
     if (nexus_list != NULL) {
 	return 0;
     }
 
-    /*
-     * Only allow MAX_DEVICES exists
-     * I will fix it later to get
-     * the total devices first
-     */
-    if ((pci_sys = calloc(1, sizeof (struct pci_system))) != NULL) {
-	pci_sys->methods = &solx_devfs_methods;
-
-	if ((pci_sys->devices =
-	     calloc(MAX_DEVICES, sizeof (struct pci_device_private)))
-	    != NULL) {
-
-	    if ((di_node = di_init("/", DINFOCPYALL)) == DI_NODE_NIL) {
-		err = errno;
-		(void) fprintf(stderr, "di_init() failed: %s\n",
-			       strerror(errno));
-	    } else {
-		(void) di_walk_minor(di_node, DDI_NT_REGACC, 0, pci_sys,
-				     probe_nexus_node);
-		di_fini(di_node);
-	    }
-	}
-	else {
-	    err = errno;
-	}
-    } else {
+    if ((di_node = di_init("/", DINFOCPYALL)) == DI_NODE_NIL) {
 	err = errno;
+	(void) fprintf(stderr, "di_init() failed: %s\n",
+		       strerror(errno));
+	return (err);
     }
 
-    if (err != 0) {
-	if (pci_sys != NULL) {
-	    free(pci_sys->devices);
-	    free(pci_sys);
-	    pci_sys = NULL;
-	}
+    if ((devices = calloc(INITIAL_NUM_DEVICES,
+			sizeof (struct pci_device_private))) == NULL) {
+	err = errno;
+	di_fini(di_node);
+	return (err);
     }
 
+    pinfo.num_allocated_elems = INITIAL_NUM_DEVICES;
+    pinfo.num_devices = 0;
+    pinfo.devices = devices;
+    (void) di_walk_minor(di_node, DDI_NT_REGACC, 0, &pinfo, probe_nexus_node);
+    di_fini(di_node);
+
+    if ((pci_sys = calloc(1, sizeof (struct pci_system))) == NULL) {
+	err = errno;
+	free(devices);
+	return (err);
+    }
+    pci_sys->methods = &solx_devfs_methods;
+    pci_sys->devices = pinfo.devices;
+    pci_sys->num_devices = pinfo.num_devices;
+
     return (err);
 }
 
@@ -289,7 +291,7 @@ get_config_header(int fd, uint8_t bus_no, uint8_t dev_no, uint8_t func_no,
  * Probe device's functions.  Modifies many fields in the prg_p.
  */
 static int
-probe_dev(nexus_t *nexus, pcitool_reg_t *prg_p, struct pci_system *pci_sys)
+probe_dev(nexus_t *nexus, pcitool_reg_t *prg_p, probe_info_t *pinfo)
 {
     pci_conf_hdr_t	config_hdr;
     boolean_t		multi_function_device;
@@ -412,12 +414,9 @@ probe_dev(nexus_t *nexus, pcitool_reg_t *prg_p, struct pci_system *pci_sys)
 	     * function number.
 	     */
 
-	    pci_base = &pci_sys->devices[pci_sys->num_devices].base;
+	    pci_base = &pinfo->devices[pinfo->num_devices].base;
 
-	    /*
-	     * Domain is peer bus??
-	     */
-	    pci_base->domain = 0;
+	    pci_base->domain = nexus->domain;
 	    pci_base->bus = prg_p->bus_no;
 	    pci_base->dev = prg_p->dev_no;
 	    pci_base->func = func;
@@ -437,7 +436,7 @@ probe_dev(nexus_t *nexus, pcitool_reg_t *prg_p, struct pci_system *pci_sys)
 	    pci_base->subvendor_id 	= GET_CONFIG_VAL_16(PCI_CONF_SUBVENID);
 	    pci_base->subdevice_id 	= GET_CONFIG_VAL_16(PCI_CONF_SUBSYSID);
 
-	    pci_sys->devices[pci_sys->num_devices].header_type
+	    pinfo->devices[pinfo->num_devices].header_type
 					= GET_CONFIG_VAL_8(PCI_CONF_HEADER);
 
 #ifdef DEBUG
@@ -446,15 +445,26 @@ probe_dev(nexus_t *nexus, pcitool_reg_t *prg_p, struct pci_system *pci_sys)
 		    nexus->path, prg_p->bus_no, prg_p->dev_no, func);
 #endif
 
-	    if (pci_sys->num_devices < (MAX_DEVICES - 1)) {
-		pci_sys->num_devices++;
-	    } else {
-		(void) fprintf(stderr,
-			       "Maximum number of PCI devices found,"
-			       " discarding additional devices\n");
+	    pinfo->num_devices++;
+	    if (pinfo->num_devices == pinfo->num_allocated_elems) {
+		struct pci_device_private *new_devs;
+		size_t new_num_elems = pinfo->num_allocated_elems * 2;
+
+		new_devs = realloc(pinfo->devices,
+			new_num_elems * sizeof (struct pci_device_private));
+		if (new_devs == NULL) {
+		    (void) fprintf(stderr,
+			           "Maximum number of PCI devices found,"
+			           " discarding additional devices\n");
+		    return (rval);
+		}
+		(void) memset(&new_devs[pinfo->num_devices], 0,
+			pinfo->num_allocated_elems *
+			sizeof (struct pci_device_private));
+		pinfo->num_allocated_elems = new_num_elems;
+		pinfo->devices = new_devs;
 	    }
 
-
 	    /*
 	     * Accommodate devices which state their
 	     * multi-functionality only in their function 0 config
@@ -476,8 +486,8 @@ probe_dev(nexus_t *nexus, pcitool_reg_t *prg_p, struct pci_system *pci_sys)
 static int
 probe_nexus_node(di_node_t di_node, di_minor_t minor, void *arg)
 {
-    struct pci_system *pci_sys = (struct pci_system *) arg;
-    char *nexus_name;
+    probe_info_t *pinfo = (probe_info_t *)arg;
+    char *nexus_name, *nexus_dev_path;
     nexus_t *nexus;
     int fd;
     char nexus_path[MAXPATHLEN];
@@ -488,6 +498,7 @@ probe_nexus_node(di_node_t di_node, di_minor_t minor, void *arg)
     int numval;
     int pci_node = 0;
     int first_bus = 0, last_bus = PCI_REG_BUS_G(PCI_REG_BUS_M);
+    int domain = 0;
 
 #ifdef DEBUG
     nexus_name = di_devfs_minor_path(minor);
@@ -522,6 +533,12 @@ probe_nexus_node(di_node_t di_node, di_minor_t minor, void *arg)
 		last_bus = ints[1];
 	    }
 	}
+	else if (strcmp(prop_name, "pciseg") == 0) {
+	    numval = di_prop_ints(prop, &ints);
+	    if (numval == 1) {
+		domain = ints[0];
+	    }
+	}
     }
 
 #ifdef __x86  /* sparc pci nodes don't have the device_type set */
@@ -538,6 +555,7 @@ probe_nexus_node(di_node_t di_node, di_minor_t minor, void *arg)
     }
     nexus->first_bus = first_bus;
     nexus->last_bus = last_bus;
+    nexus->domain = domain;
 
     nexus_name = di_devfs_minor_path(minor);
     if (nexus_name == NULL) {
@@ -558,11 +576,15 @@ probe_nexus_node(di_node_t di_node, di_minor_t minor, void *arg)
     if ((fd = open(nexus_path, O_RDWR)) >= 0) {
 	nexus->fd = fd;
 	nexus->path = strdup(nexus_path);
-	if ((do_probe(nexus, pci_sys) != 0) && (errno != ENXIO)) {
+	nexus_dev_path = di_devfs_path(di_node);
+	nexus->dev_path = strdup(nexus_dev_path);
+	di_devfs_path_free(nexus_dev_path);
+	if ((do_probe(nexus, pinfo) != 0) && (errno != ENXIO)) {
 	    (void) fprintf(stderr, "Error probing node %s: %s\n",
 			   nexus_path, strerror(errno));
 	    (void) close(fd);
 	    free(nexus->path);
+	    free(nexus->dev_path);
 	    free(nexus);
 	} else {
 	    nexus->next = nexus_list;
@@ -586,7 +608,7 @@ probe_nexus_node(di_node_t di_node, di_minor_t minor, void *arg)
  * input_args contains commandline options as specified by the user.
  */
 static int
-do_probe(nexus_t *nexus, struct pci_system *pci_sys)
+do_probe(nexus_t *nexus, probe_info_t *pinfo)
 {
     pcitool_reg_t prg;
     uint32_t bus;
@@ -620,7 +642,7 @@ do_probe(nexus_t *nexus, struct pci_system *pci_sys)
 
 	for (dev = first_dev; ((dev <= last_dev) && (rval == 0)); dev++) {
 	    prg.dev_no = dev;
-	    rval = probe_dev(nexus, &prg, pci_sys);
+	    rval = probe_dev(nexus, &prg, pinfo);
 	}
 
 	/*
@@ -712,6 +734,10 @@ pci_device_solx_devfs_probe( struct pci_device * dev )
     if ( bytes >= 64 ) {
 	struct pci_device_private *priv =
 	    (struct pci_device_private *) dev;
+    nexus_t *nexus;
+
+    if ( (nexus = find_nexus_for_bus(dev->domain, dev->bus)) == NULL )
+	return ENODEV;
 
 	dev->vendor_id = (uint16_t)config[0] + ((uint16_t)config[1] << 8);
 	dev->device_id = (uint16_t)config[2] + ((uint16_t)config[3] << 8);
@@ -733,7 +759,7 @@ pci_device_solx_devfs_probe( struct pci_device * dev )
 	 * starting to find if it is MEM/MEM64/IO
 	 * using libdevinfo
 	 */
-	if ((rnode = di_init("/", DINFOCPYALL)) == DI_NODE_NIL) {
+	if ((rnode = di_init(nexus->dev_path, DINFOCPYALL)) == DI_NODE_NIL) {
 	    err = errno;
 	    (void) fprintf(stderr, "di_init failed: %s\n", strerror(errno));
 	} else {
@@ -880,7 +906,7 @@ pci_device_solx_devfs_read( struct pci_device * dev, void * data,
     pcitool_reg_t cfg_prg;
     int err = 0;
     int i = 0;
-    nexus_t *nexus = find_nexus_for_bus(dev->bus);
+    nexus_t *nexus = find_nexus_for_bus(dev->domain, dev->bus);
 
     *bytes_read = 0;
 
@@ -932,7 +958,7 @@ pci_device_solx_devfs_write( struct pci_device * dev, const void * data,
     pcitool_reg_t cfg_prg;
     int err = 0;
     int cmd;
-    nexus_t *nexus = find_nexus_for_bus(dev->bus);
+    nexus_t *nexus = find_nexus_for_bus(dev->domain, dev->bus);
 
     if ( bytes_written != NULL ) {
 	*bytes_written = 0;