- Add a new ioctl to /dev/pci to fetch details on an individual BAR of a

  device.  The details include the current value of the BAR (including all
  the flag bits and the current base address), its length, and whether or not
  it is enabled.  Since this operation is not invasive, non-root users are
  allowed to use it (unlike manual config register access which requires
  root).  The intention is that userland apps (such as Xorg) will use this
  interface rather than dangerously frobbing the BARs from userland to
  obtain this information.
- Add a new sub-mode to the 'list' mode of pciconf.  The -b flag when used
  with -l will now list all the active BARs for each device.

MFC after:	1 month

2 files changed, 73 insertions, 4 deletions

diff --git a/sys/dev/pci/pci_user.c b/sys/dev/pci/pci_user.c
index b7ae55a..ed75353 100644
--- a/sys/dev/pci/pci_user.c
+++ b/sys/dev/pci/pci_user.c
@@ -307,7 +307,10 @@ pci_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *t
 	struct pci_conf_io *cio;
 	struct pci_devinfo *dinfo;
 	struct pci_io *io;
+	struct pci_bar_io *bio;
 	struct pci_match_conf *pattern_buf;
+	struct resource_list_entry *rle;
+	uint32_t value;
 	size_t confsz, iolen, pbufsz;
 	int error, ionum, i, num_patterns;
 #ifdef PRE7_COMPAT
@@ -319,11 +322,11 @@ pci_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *t
 	io_old = NULL;
 	pattern_buf_old = NULL;
 
-	if (!(flag & FWRITE) &&
-	    (cmd != PCIOCGETCONF && cmd != PCIOCGETCONF_OLD))
+	if (!(flag & FWRITE) && cmd != PCIOCGETBAR &&
+	    cmd != PCIOCGETCONF && cmd != PCIOCGETCONF_OLD)
 		return EPERM;
 #else
-	if (!(flag & FWRITE) && cmd != PCIOCGETCONF)
+	if (!(flag & FWRITE) && cmd != PCIOCGETBAR && cmd != PCIOCGETCONF)
 		return EPERM;
 #endif
 
@@ -669,6 +672,70 @@ getconfexit:
 		}
 		break;
 
+	case PCIOCGETBAR:
+		bio = (struct pci_bar_io *)data;
+
+		/*
+		 * Assume that the user-level bus number is
+		 * in fact the physical PCI bus number.
+		 */
+		pcidev = pci_find_dbsf(bio->pbi_sel.pc_domain,
+		    bio->pbi_sel.pc_bus, bio->pbi_sel.pc_dev,
+		    bio->pbi_sel.pc_func);
+		if (pcidev == NULL) {
+			error = ENODEV;
+			break;
+		}
+		dinfo = device_get_ivars(pcidev);
+		
+		/*
+		 * Look for a resource list entry matching the requested BAR.
+		 *
+		 * XXX: This will not find BARs that are not initialized, but
+		 * maybe that is ok?
+		 */
+		rle = resource_list_find(&dinfo->resources, SYS_RES_MEMORY,
+		    bio->pbi_reg);
+		if (rle == NULL)
+			rle = resource_list_find(&dinfo->resources,
+			    SYS_RES_IOPORT, bio->pbi_reg);
+		if (rle == NULL || rle->res == NULL) {
+			error = EINVAL;
+			break;
+		}
+
+		/*
+		 * Ok, we have a resource for this BAR.  Read the lower
+		 * 32 bits to get any flags.
+		 */
+		value = pci_read_config(pcidev, bio->pbi_reg, 4);
+		if (PCI_BAR_MEM(value)) {
+			if (rle->type != SYS_RES_MEMORY) {
+				error = EINVAL;
+				break;
+			}
+			value &= ~PCIM_BAR_MEM_BASE;
+		} else {
+			if (rle->type != SYS_RES_IOPORT) {
+				error = EINVAL;
+				break;
+			}
+			value &= ~PCIM_BAR_IO_BASE;
+		}
+		bio->pbi_base = rman_get_start(rle->res) | value;
+		bio->pbi_length = rman_get_size(rle->res);
+
+		/*
+		 * Check the command register to determine if this BAR
+		 * is enabled.
+		 */
+		value = pci_read_config(pcidev, PCIR_COMMAND, 2);
+		if (rle->type == SYS_RES_MEMORY)
+			bio->pbi_enabled = (value & PCIM_CMD_MEMEN) != 0;
+		else
+			bio->pbi_enabled = (value & PCIM_CMD_PORTEN) != 0;
+		error = 0;
+		break;
 	default:
 		error = ENOTTY;
 		break;
diff --git a/sys/dev/pci/pcireg.h b/sys/dev/pci/pcireg.h
index e9ba5e7..0b69ca4 100644
--- a/sys/dev/pci/pcireg.h
+++ b/sys/dev/pci/pcireg.h
@@ -117,7 +117,7 @@
 
 #define	PCIR_BARS	0x10
 #define	PCIR_BAR(x)		(PCIR_BARS + (x) * 4)
-#define	PCI_MAX_BAR_0		5	/* Number of standard bars */
+#define	PCIR_MAX_BAR_0		5
 #define	PCI_RID2BAR(rid)	(((rid) - PCIR_BARS) / 4)
 #define	PCI_BAR_IO(x)		(((x) & PCIM_BAR_SPACE) == PCIM_BAR_IO_SPACE)
 #define	PCI_BAR_MEM(x)		(((x) & PCIM_BAR_SPACE) == PCIM_BAR_MEM_SPACE)
@@ -158,6 +158,7 @@
 
 /* config registers for header type 1 (PCI-to-PCI bridge) devices */
 
+#define	PCIR_MAX_BAR_1	1
 #define	PCIR_SECSTAT_1	0x1e
 
 #define	PCIR_PRIBUS_1	0x18
@@ -188,6 +189,7 @@
 
 /* config registers for header type 2 (CardBus) devices */
 
+#define	PCIR_MAX_BAR_2	0
 #define	PCIR_CAP_PTR_2	0x14
 #define	PCIR_SECSTAT_2	0x16