MFC 291225:

Add a new -B flag for use with list mode (-l) that lists details about
bridges.  Currently this includes information about what resources a
bridge decodes on the upstream side for use by downstream devices including
bus numbers, I/O port resources, and memory resources.  Windows and bus
ranges are enumerated for both PCI-PCI bridges and PCI-CardBus bridges.

To simplify the implementation, all enumeration is done by reading the
appropriate config space registers directly rather than querying the
bridge driver in the kernel via new ioctls.  This does result in a few
limitations.

First, an unimplemented window in a PCI-PCI bridge cannot be accurately
detected as accurate detection requires writing to the window base
register.  That is not safe for pciconf(8).  Instead, this assumes that
any window where both the base and limit read as all zeroes is
unimplemented.

Second, the PCI-PCI bridge driver in a tree has a few quirks for
PCI-PCI bridges that use subtractive decoding but do not indicate that
via the progif config register.  The list of quirks is duplicated in
pciconf's source.

2 files changed, 241 insertions, 13 deletions

diff --git a/usr.sbin/pciconf/pciconf.8 b/usr.sbin/pciconf/pciconf.8
index 8dbb2a6..705b594 100644
--- a/usr.sbin/pciconf/pciconf.8
+++ b/usr.sbin/pciconf/pciconf.8
@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd September 06, 2015
+.Dd November 23, 2015
 .Dt PCICONF 8
 .Os
 .Sh NAME
@@ -33,7 +33,7 @@
 .Nd diagnostic utility for the PCI bus
 .Sh SYNOPSIS
 .Nm
-.Fl l Oo Fl bcevV Oc Op Ar device
+.Fl l Oo Fl BbceVv Oc Op Ar device
 .Nm
 .Fl a Ar device
 .Nm
@@ -112,6 +112,42 @@ device, which contains several (similar or independent) functions on
 one chip.
 .Pp
 If the
+.Fl B
+option is supplied,
+.Nm
+will list additional information for
+.Tn PCI
+to
+.Tn PCI
+and
+.Tn PCI
+to
+.Tn CardBus
+bridges,
+specifically the resource ranges decoded by the bridge for use by devices
+behind the bridge.
+Each bridge lists a range of bus numbers handled by the bridge and its
+downstream devices.
+Memory and I/O port decoding windows are enumerated via a line in the
+following format:
+.Bd -literal
+    window[1c] = type I/O Port, range 16, addr 0x5000-0x8fff, enabled
+.Ed
+.Pp
+The first value after the
+.Dq Li window
+prefix in the square brackets is the offset of the decoding window in
+config space in hexadecimal.
+The type of a window is one of
+.Dq Memory ,
+.Dq Prefetchable Memory ,
+or
+.Dq I/O Port .
+The range indicates the binary log of the maximum address the window decodes.
+The address field indicates the start and end addresses of the decoded range.
+Finally, the last flag indicates if the window is enabled or disabled.
+.Pp
+If the
 .Fl b
 option is supplied,
 .Nm
@@ -132,7 +168,7 @@ The type of a BAR is one of
 .Dq Prefetchable Memory ,
 or
 .Dq I/O Port .
-The range indicates the maximum address the BAR decodes.
+The range indicates the binary log of the maximum address the BAR decodes.
 The base and size indicate the start and length of the BAR's address window,
 respectively.
 Finally, the last flag indicates if the BAR is enabled or disabled.
diff --git a/usr.sbin/pciconf/pciconf.c b/usr.sbin/pciconf/pciconf.c
index ad709db..bb013b0 100644
--- a/usr.sbin/pciconf/pciconf.c
+++ b/usr.sbin/pciconf/pciconf.c
@@ -39,6 +39,7 @@ static const char rcsid[] =
 #include <ctype.h>
 #include <err.h>
 #include <inttypes.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -69,9 +70,10 @@ struct pci_vendor_info
 TAILQ_HEAD(,pci_vendor_info)	pci_vendors;
 
 static struct pcisel getsel(const char *str);
+static void list_bridge(int fd, struct pci_conf *p);
 static void list_bars(int fd, struct pci_conf *p);
-static void list_devs(const char *name, int verbose, int bars, int caps,
-    int errors, int vpd);
+static void list_devs(const char *name, int verbose, int bars, int bridge,
+    int caps, int errors, int vpd);
 static void list_verbose(struct pci_conf *p);
 static void list_vpd(int fd, struct pci_conf *p);
 static const char *guess_class(struct pci_conf *p);
@@ -87,7 +89,7 @@ static void
 usage(void)
 {
 	fprintf(stderr, "%s\n%s\n%s\n%s\n",
-		"usage: pciconf -l [-bcevV] [device]",
+		"usage: pciconf -l [-BbcevV] [device]",
 		"       pciconf -a device",
 		"       pciconf -r [-b | -h] device addr[:addr2]",
 		"       pciconf -w [-b | -h] device addr value");
@@ -99,18 +101,22 @@ main(int argc, char **argv)
 {
 	int c;
 	int listmode, readmode, writemode, attachedmode;
-	int bars, caps, errors, verbose, vpd;
+	int bars, bridge, caps, errors, verbose, vpd;
 	int byte, isshort;
 
 	listmode = readmode = writemode = attachedmode = 0;
-	bars = caps = errors = verbose = vpd = byte = isshort = 0;
+	bars = bridge = caps = errors = verbose = vpd = byte = isshort = 0;
 
-	while ((c = getopt(argc, argv, "abcehlrwvV")) != -1) {
+	while ((c = getopt(argc, argv, "aBbcehlrwVv")) != -1) {
 		switch(c) {
 		case 'a':
 			attachedmode = 1;
 			break;
 
+		case 'B':
+			bridge = 1;
+			break;
+
 		case 'b':
 			bars = 1;
 			byte = 1;
@@ -161,7 +167,7 @@ main(int argc, char **argv)
 
 	if (listmode) {
 		list_devs(optind + 1 == argc ? argv[optind] : NULL, verbose,
-		    bars, caps, errors, vpd);
+		    bars, bridge, caps, errors, vpd);
 	} else if (attachedmode) {
 		chkattached(argv[optind]);
 	} else if (readmode) {
@@ -178,8 +184,8 @@ main(int argc, char **argv)
 }
 
 static void
-list_devs(const char *name, int verbose, int bars, int caps, int errors,
-    int vpd)
+list_devs(const char *name, int verbose, int bars, int bridge, int caps,
+    int errors, int vpd)
 {
 	int fd;
 	struct pci_conf_io pc;
@@ -190,7 +196,8 @@ list_devs(const char *name, int verbose, int bars, int caps, int errors,
 	if (verbose)
 		load_vendors();
 
-	fd = open(_PATH_DEVPCI, (caps || errors) ? O_RDWR : O_RDONLY, 0);
+	fd = open(_PATH_DEVPCI, (bridge || caps || errors) ? O_RDWR : O_RDONLY,
+	    0);
 	if (fd < 0)
 		err(1, "%s", _PATH_DEVPCI);
 
@@ -248,6 +255,8 @@ list_devs(const char *name, int verbose, int bars, int caps, int errors,
 				list_verbose(p);
 			if (bars)
 				list_bars(fd, p);
+			if (bridge)
+				list_bridge(fd, p);
 			if (caps)
 				list_caps(fd, p);
 			if (errors)
@@ -261,6 +270,189 @@ list_devs(const char *name, int verbose, int bars, int caps, int errors,
 }
 
 static void
+print_bus_range(int fd, struct pci_conf *p, int secreg, int subreg)
+{
+	uint8_t secbus, subbus;
+
+	secbus = read_config(fd, &p->pc_sel, secreg, 1);
+	subbus = read_config(fd, &p->pc_sel, subreg, 1);
+	printf("    bus range  = %u-%u\n", secbus, subbus);
+}
+
+static void
+print_window(int reg, const char *type, int range, uint64_t base,
+    uint64_t limit)
+{
+
+	printf("    window[%02x] = type %s, range %2d, addr %#jx-%#jx, %s\n",
+	    reg, type, range, (uintmax_t)base, (uintmax_t)limit,
+	    base < limit ? "enabled" : "disabled");
+}
+
+static void
+print_special_decode(bool isa, bool vga, bool subtractive)
+{
+	bool comma;
+
+	if (isa || vga || subtractive) {
+		comma = false;
+		printf("    decode     = ");
+		if (isa) {
+			printf("ISA");
+			comma = true;
+		}
+		if (vga) {
+			printf("%sVGA", comma ? ", " : "");
+			comma = true;
+		}
+		if (subtractive)
+			printf("%ssubtractive", comma ? ", " : "");
+		printf("\n");
+	}
+}
+
+static void
+print_bridge_windows(int fd, struct pci_conf *p)
+{
+	uint64_t base, limit;
+	uint32_t val;
+	uint16_t bctl;
+	bool subtractive;
+	int range;
+
+	/*
+	 * XXX: This assumes that a window with a base and limit of 0
+	 * is not implemented.  In theory a window might be programmed
+	 * at the smallest size with a base of 0, but those do not seem
+	 * common in practice.
+	 */
+	val = read_config(fd, &p->pc_sel, PCIR_IOBASEL_1, 1);
+	if (val != 0 || read_config(fd, &p->pc_sel, PCIR_IOLIMITL_1, 1) != 0) {
+		if ((val & PCIM_BRIO_MASK) == PCIM_BRIO_32) {
+			base = PCI_PPBIOBASE(
+			    read_config(fd, &p->pc_sel, PCIR_IOBASEH_1, 2),
+			    val);
+			limit = PCI_PPBIOLIMIT(
+			    read_config(fd, &p->pc_sel, PCIR_IOLIMITH_1, 2),
+			    read_config(fd, &p->pc_sel, PCIR_IOLIMITL_1, 1));
+			range = 32;
+		} else {
+			base = PCI_PPBIOBASE(0, val);
+			limit = PCI_PPBIOLIMIT(0,
+			    read_config(fd, &p->pc_sel, PCIR_IOLIMITL_1, 1));
+			range = 16;
+		}
+		print_window(PCIR_IOBASEL_1, "I/O Port", range, base, limit);
+	}
+
+	base = PCI_PPBMEMBASE(0,
+	    read_config(fd, &p->pc_sel, PCIR_MEMBASE_1, 2));
+	limit = PCI_PPBMEMLIMIT(0,
+	    read_config(fd, &p->pc_sel, PCIR_MEMLIMIT_1, 2));
+	print_window(PCIR_MEMBASE_1, "Memory", 32, base, limit);
+
+	val = read_config(fd, &p->pc_sel, PCIR_PMBASEL_1, 2);
+	if (val != 0 || read_config(fd, &p->pc_sel, PCIR_PMLIMITL_1, 2) != 0) {
+		if ((val & PCIM_BRPM_MASK) == PCIM_BRPM_64) {
+			base = PCI_PPBMEMBASE(
+			    read_config(fd, &p->pc_sel, PCIR_PMBASEH_1, 4),
+			    val);
+			limit = PCI_PPBMEMLIMIT(
+			    read_config(fd, &p->pc_sel, PCIR_PMLIMITH_1, 4),
+			    read_config(fd, &p->pc_sel, PCIR_PMLIMITL_1, 2));
+			range = 64;
+		} else {
+			base = PCI_PPBMEMBASE(0, val);
+			limit = PCI_PPBMEMLIMIT(0,
+			    read_config(fd, &p->pc_sel, PCIR_PMLIMITL_1, 2));
+			range = 32;
+		}
+		print_window(PCIR_PMBASEL_1, "Prefetchable Memory", range, base,
+		    limit);
+	}
+
+	/*
+	 * XXX: This list of bridges that are subtractive but do not set
+	 * progif to indicate it is copied from pci_pci.c.
+	 */
+	subtractive = p->pc_progif == PCIP_BRIDGE_PCI_SUBTRACTIVE;
+	switch (p->pc_device << 16 | p->pc_vendor) {
+	case 0xa002177d:		/* Cavium ThunderX */
+	case 0x124b8086:		/* Intel 82380FB Mobile */
+	case 0x060513d7:		/* Toshiba ???? */
+		subtractive = true;
+	}
+	if (p->pc_vendor == 0x8086 && (p->pc_device & 0xff00) == 0x2400)
+		subtractive = true;
+		
+	bctl = read_config(fd, &p->pc_sel, PCIR_BRIDGECTL_1, 2);
+	print_special_decode(bctl & PCIB_BCR_ISA_ENABLE,
+	    bctl & PCIB_BCR_VGA_ENABLE, subtractive);
+}
+
+static void
+print_cardbus_mem_window(int fd, struct pci_conf *p, int basereg, int limitreg,
+    bool prefetch)
+{
+
+	print_window(basereg, prefetch ? "Prefetchable Memory" : "Memory", 32,
+	    PCI_CBBMEMBASE(read_config(fd, &p->pc_sel, basereg, 4)),
+	    PCI_CBBMEMLIMIT(read_config(fd, &p->pc_sel, limitreg, 4)));
+}
+
+static void
+print_cardbus_io_window(int fd, struct pci_conf *p, int basereg, int limitreg)
+{
+	uint32_t base, limit;
+	uint32_t val;
+	int range;
+
+	val = read_config(fd, &p->pc_sel, basereg, 2);
+	if ((val & PCIM_CBBIO_MASK) == PCIM_CBBIO_32) {
+		base = PCI_CBBIOBASE(read_config(fd, &p->pc_sel, basereg, 4));
+		limit = PCI_CBBIOBASE(read_config(fd, &p->pc_sel, limitreg, 4));
+		range = 32;
+	} else {
+		base = PCI_CBBIOBASE(val);
+		limit = PCI_CBBIOBASE(read_config(fd, &p->pc_sel, limitreg, 2));
+		range = 16;
+	}
+	print_window(basereg, "I/O Port", range, base, limit);
+}
+
+static void
+print_cardbus_windows(int fd, struct pci_conf *p)
+{
+	uint16_t bctl;
+
+	bctl = read_config(fd, &p->pc_sel, PCIR_BRIDGECTL_2, 2);
+	print_cardbus_mem_window(fd, p, PCIR_MEMBASE0_2, PCIR_MEMLIMIT0_2,
+	    bctl & CBB_BCR_PREFETCH_0_ENABLE);
+	print_cardbus_mem_window(fd, p, PCIR_MEMBASE1_2, PCIR_MEMLIMIT1_2,
+	    bctl & CBB_BCR_PREFETCH_1_ENABLE);
+	print_cardbus_io_window(fd, p, PCIR_IOBASE0_2, PCIR_IOLIMIT0_2);
+	print_cardbus_io_window(fd, p, PCIR_IOBASE1_2, PCIR_IOLIMIT1_2);
+	print_special_decode(bctl & CBB_BCR_ISA_ENABLE,
+	    bctl & CBB_BCR_VGA_ENABLE, false);
+}
+
+static void
+list_bridge(int fd, struct pci_conf *p)
+{
+
+	switch (p->pc_hdr & PCIM_HDRTYPE) {
+	case PCIM_HDRTYPE_BRIDGE:
+		print_bus_range(fd, p, PCIR_SECBUS_1, PCIR_SUBBUS_1);
+		print_bridge_windows(fd, p);
+		break;
+	case PCIM_HDRTYPE_CARDBUS:
+		print_bus_range(fd, p, PCIR_SECBUS_2, PCIR_SUBBUS_2);
+		print_cardbus_windows(fd, p);
+		break;
+	}
+}
+
+static void
 list_bars(int fd, struct pci_conf *p)
 {
 	struct pci_bar_io bar;