MFC 261790:

Add support for managing PCI bus numbers.  As with BARs and PCI-PCI bridge
I/O windows, the default is to preserve the firmware-assigned resources.
PCI bus numbers are only managed if NEW_PCIB is enabled and the architecture
defines a PCI_RES_BUS resource type.
- Add a helper API to create top-level PCI bus resource managers for each
  PCI domain/segment.  Host-PCI bridge drivers use this API to allocate
  bus numbers from their associated domain.
- Change the PCI bus and CardBus drivers to allocate a bus resource for
  their bus number from the parent PCI bridge device.
- Change the PCI-PCI and PCI-CardBus bridge drivers to allocate the
  full range of bus numbers from secbus to subbus from their parent bridge.
  The drivers also always program their primary bus register.  The bridge
  drivers also support growing their bus range by extending the bus resource
  and updating subbus to match the larger range.
- Add support for managing PCI bus resources to the Host-PCI bridge drivers
  used for amd64 and i386 (acpi_pcib, mptable_pcib, legacy_pcib, and qpi_pcib).
- Define a PCI_RES_BUS resource type for amd64 and i386.

PR:		197076

1 files changed, 99 insertions, 0 deletions

diff --git a/sys/dev/pci/pci_subr.c b/sys/dev/pci/pci_subr.c
index 2d16896..82852b7 100644
--- a/sys/dev/pci/pci_subr.c
+++ b/sys/dev/pci/pci_subr.c
@@ -35,6 +35,7 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/bus.h>
+#include <sys/malloc.h>
 #include <sys/rman.h>
 #include <sys/systm.h>
 
@@ -282,4 +283,102 @@ pcib_host_res_adjust(struct pcib_host_resources *hr, device_t dev, int type,
 	}
 	return (ERANGE);
 }
+
+#ifdef PCI_RES_BUS
+struct pci_domain {
+	int	pd_domain;
+	struct rman pd_bus_rman;
+	TAILQ_ENTRY(pci_domain) pd_link;
+};
+
+static TAILQ_HEAD(, pci_domain) domains = TAILQ_HEAD_INITIALIZER(domains);
+
+/*
+ * Each PCI domain maintains its own resource manager for PCI bus
+ * numbers in that domain.  Domain objects are created on first use.
+ * Host to PCI bridge drivers and PCI-PCI bridge drivers should
+ * allocate their bus ranges from their domain.
+ */
+static struct pci_domain *
+pci_find_domain(int domain)
+{
+	struct pci_domain *d;
+	char buf[64];
+	int error;
+
+	TAILQ_FOREACH(d, &domains, pd_link) {
+		if (d->pd_domain == domain)
+			return (d);
+	}
+
+	snprintf(buf, sizeof(buf), "PCI domain %d bus numbers", domain);
+	d = malloc(sizeof(*d) + strlen(buf) + 1, M_DEVBUF, M_WAITOK | M_ZERO);
+	d->pd_domain = domain;
+	d->pd_bus_rman.rm_start = 0;
+	d->pd_bus_rman.rm_end = PCI_BUSMAX;
+	d->pd_bus_rman.rm_type = RMAN_ARRAY;
+	strcpy((char *)(d + 1), buf);
+	d->pd_bus_rman.rm_descr = (char *)(d + 1);
+	error = rman_init(&d->pd_bus_rman);
+	if (error == 0)
+		error = rman_manage_region(&d->pd_bus_rman, 0, PCI_BUSMAX);
+	if (error)
+		panic("Failed to initialize PCI domain %d rman", domain);
+	TAILQ_INSERT_TAIL(&domains, d, pd_link);
+	return (d);
+}
+
+struct resource *
+pci_domain_alloc_bus(int domain, device_t dev, int *rid, u_long start,
+    u_long end, u_long count, u_int flags)
+{
+	struct pci_domain *d;
+	struct resource *res;
+
+	if (domain < 0 || domain > PCI_DOMAINMAX)
+		return (NULL);
+	d = pci_find_domain(domain);
+	res = rman_reserve_resource(&d->pd_bus_rman, start, end, count, flags,
+	    dev);
+	if (res == NULL)
+		return (NULL);
+
+	rman_set_rid(res, *rid);
+	return (res);
+}
+
+int
+pci_domain_adjust_bus(int domain, device_t dev, struct resource *r,
+    u_long start, u_long end)
+{
+#ifdef INVARIANTS
+	struct pci_domain *d;
+#endif
+
+	if (domain < 0 || domain > PCI_DOMAINMAX)
+		return (EINVAL);
+#ifdef INVARIANTS
+	d = pci_find_domain(domain);
+	KASSERT(rman_is_region_manager(r, &d->pd_bus_rman), ("bad resource"));
+#endif
+	return (rman_adjust_resource(r, start, end));
+}
+
+int
+pci_domain_release_bus(int domain, device_t dev, int rid, struct resource *r)
+{
+#ifdef INVARIANTS
+	struct pci_domain *d;
+#endif
+
+	if (domain < 0 || domain > PCI_DOMAINMAX)
+		return (EINVAL);
+#ifdef INVARIANTS
+	d = pci_find_domain(domain);
+	KASSERT(rman_is_region_manager(r, &d->pd_bus_rman), ("bad resource"));
+#endif
+	return (rman_release_resource(r));
+}
+#endif /* PCI_RES_BUS */
+
 #endif /* NEW_PCIB */