path: root/sys/sys/bus.h
diff options
authorJohn Baldwin <jhb@FreeBSD.org>2016-05-20 17:57:47 +0000
committerJohn Baldwin <jhb@FreeBSD.org>2016-05-20 17:57:47 +0000
commitcc981af2045c3c0379c237576737f8f128da1ba5 (patch)
tree3aa16fa17a986984dd375052ea627ea43a7d21dd /sys/sys/bus.h
parentc99d7183654cfcc5a3ff71bcad5ff9758feb023e (diff)
Add new bus methods for mapping resources.
Add a pair of bus methods that can be used to "map" resources for direct CPU access using bus_space(9). bus_map_resource() creates a mapping and bus_unmap_resource() releases a previously created mapping. Mappings are described by 'struct resource_map' object. Pointers to these objects can be passed as the first argument to the bus_space wrapper API used for bus resources. Drivers that wish to map all of a resource using default settings (for example, using uncacheable memory attributes) do not need to change. However, drivers that wish to use non-default settings can now do so without jumping through hoops. First, an RF_UNMAPPED flag is added to request that a resource is not implicitly mapped with the default settings when it is activated. This permits other activation steps (such as enabling I/O or memory decoding in a device's PCI command register) to be taken without creating a mapping. Right now the AGP drivers don't set RF_ACTIVE to avoid using up a large amount of KVA to map the AGP aperture on 32-bit platforms. Once RF_UNMAPPED is supported on all platforms that support AGP this can be changed to using RF_UNMAPPED with RF_ACTIVE instead. Second, bus_map_resource accepts an optional structure that defines additional settings for a given mapping. For example, a driver can now request to map only a subset of a resource instead of the entire range. The AGP driver could also use this to only map the first page of the aperture (IIRC, it calls pmap_mapdev() directly to map the first page currently). I will also eventually change the PCI-PCI bridge driver to request mappings of the subset of the I/O window resource on its parent side to create mappings for child devices rather than passing child resources directly up to nexus to be mapped. This also permits bridges that do address translation to request suitable mappings from a resource on the "upper" side of the bus when mapping resources on the "lower" side of the bus. Another attribute that can be specified is an alternate memory attribute for memory-mapped resources. This can be used to request a Write-Combining mapping of a PCI BAR in an MI fashion. (Currently the drivers that do this call pmap_change_attr() directly for x86 only.) Note that this commit only adds the MI framework. Each platform needs to add support for handling RF_UNMAPPED and thew new bus_map/unmap_resource methods. Generally speaking, any drivers that are calling rman_set_bustag() and rman_set_bushandle() need to be updated. Discussed on: arch Reviewed by: cem Differential Revision: https://reviews.freebsd.org/D5237
Notes: svn path=/head/; revision=300317
Diffstat (limited to 'sys/sys/bus.h')
1 files changed, 37 insertions, 0 deletions
diff --git a/sys/sys/bus.h b/sys/sys/bus.h
index 9b989af66031..4e7d37563ec2 100644
--- a/sys/sys/bus.h
+++ b/sys/sys/bus.h
@@ -294,6 +294,31 @@ struct driver {
+ * @brief A resource mapping.
+ */
+struct resource_map {
+ bus_space_tag_t r_bustag;
+ bus_space_handle_t r_bushandle;
+ bus_size_t r_size;
+ void *r_vaddr;
+ * @brief Optional properties of a resource mapping request.
+ */
+struct resource_map_request {
+ size_t size;
+ rman_res_t offset;
+ rman_res_t length;
+ vm_memattr_t memattr;
+void resource_init_map_request_impl(struct resource_map_request *_args,
+ size_t _sz);
+#define resource_init_map_request(rmr) \
+ resource_init_map_request_impl((rmr), sizeof(*(rmr)))
* Definitions for drivers which need to keep simple lists of resources
* for their child devices.
@@ -407,6 +432,10 @@ bus_space_tag_t
int bus_generic_get_domain(device_t dev, device_t child, int *domain);
struct resource_list *
bus_generic_get_resource_list (device_t, device_t);
+int bus_generic_map_resource(device_t dev, device_t child, int type,
+ struct resource *r,
+ struct resource_map_request *args,
+ struct resource_map *map);
void bus_generic_new_pass(device_t dev);
int bus_print_child_header(device_t dev, device_t child);
int bus_print_child_domain(device_t dev, device_t child);
@@ -440,6 +469,9 @@ int bus_generic_suspend(device_t dev);
int bus_generic_suspend_child(device_t dev, device_t child);
int bus_generic_teardown_intr(device_t dev, device_t child,
struct resource *irq, void *cookie);
+int bus_generic_unmap_resource(device_t dev, device_t child, int type,
+ struct resource *r,
+ struct resource_map *map);
int bus_generic_write_ivar(device_t dev, device_t child, int which,
uintptr_t value);
int bus_null_rescan(device_t dev);
@@ -469,6 +501,11 @@ int bus_activate_resource(device_t dev, int type, int rid,
struct resource *r);
int bus_deactivate_resource(device_t dev, int type, int rid,
struct resource *r);
+int bus_map_resource(device_t dev, int type, struct resource *r,
+ struct resource_map_request *args,
+ struct resource_map *map);
+int bus_unmap_resource(device_t dev, int type, struct resource *r,
+ struct resource_map *map);
int bus_get_cpus(device_t dev, enum cpu_sets op, size_t setsize,
struct _cpuset *cpuset);
bus_dma_tag_t bus_get_dma_tag(device_t dev);