From 5907eb8f5a32b0514bb63a6ed847ead1712bc454 Mon Sep 17 00:00:00 2001 From: Aaron Durbin Date: Wed, 28 Oct 2015 16:09:42 -0500 Subject: commonlib/region: add xlate_region_device There are cases where one region_device needs to be accessed using offset/sizes from one address space that need the offset translated into a different address space for operations to take place. The xlate_region_device provides an offset that is subtracted from the incoming transaction before deferring to the backing access region. Change-Id: I41d43924bb6fbc7b4d3681877543209e1085e15c Signed-off-by: Aaron Durbin Reviewed-on: http://review.coreboot.org/12227 Tested-by: build bot (Jenkins) Reviewed-by: Alexandru Gagniuc --- src/commonlib/include/commonlib/region.h | 23 ++++++++++++++ src/commonlib/region.c | 53 ++++++++++++++++++++++++++++++++ 2 files changed, 76 insertions(+) diff --git a/src/commonlib/include/commonlib/region.h b/src/commonlib/include/commonlib/region.h index d3e7ebdfff..fbc1790033 100644 --- a/src/commonlib/include/commonlib/region.h +++ b/src/commonlib/include/commonlib/region.h @@ -154,4 +154,27 @@ void mmap_helper_device_init(struct mmap_helper_region_device *mdev, void *mmap_helper_rdev_mmap(const struct region_device *, size_t, size_t); int mmap_helper_rdev_munmap(const struct region_device *, void *); +/* A translated region device provides the ability to publish a region device + * in one address space and use an access mechansim within another address + * space. The sub region is the window within the 1st address space and + * the request is modified prior to accessing the second address space + * provided by access_dev. */ +struct xlate_region_device { + const struct region_device *access_dev; + struct region sub_region; + struct region_device rdev; +}; + +extern const struct region_device_ops xlate_rdev_ops; + +#define XLATE_REGION_INIT(access_dev_, sub_offset_, sub_size_, parent_sz_) \ + { \ + .access_dev = access_dev_, \ + .sub_region = { \ + .offset = (sub_offset_), \ + .size = (sub_size_), \ + }, \ + .rdev = REGION_DEV_INIT(&xlate_rdev_ops, 0, (parent_sz_)),\ + } + #endif /* _REGION_H_ */ diff --git a/src/commonlib/region.c b/src/commonlib/region.c index 352f92e37f..49626005b9 100644 --- a/src/commonlib/region.c +++ b/src/commonlib/region.c @@ -194,3 +194,56 @@ int mmap_helper_rdev_munmap(const struct region_device *rd, void *mapping) return 0; } + +static void *xlate_mmap(const struct region_device *rd, size_t offset, + size_t size) +{ + const struct xlate_region_device *xldev; + struct region req = { + .offset = offset, + .size = size, + }; + + xldev = container_of(rd, typeof(*xldev), rdev); + + if (!is_subregion(&xldev->sub_region, &req)) + return NULL; + + offset -= region_offset(&xldev->sub_region); + + return rdev_mmap(xldev->access_dev, offset, size); +} + +static int xlate_munmap(const struct region_device *rd, void *mapping) +{ + const struct xlate_region_device *xldev; + + xldev = container_of(rd, typeof(*xldev), rdev); + + return rdev_munmap(xldev->access_dev, mapping); +} + +static ssize_t xlate_readat(const struct region_device *rd, void *b, + size_t offset, size_t size) +{ + struct region req = { + .offset = offset, + .size = size, + }; + const struct xlate_region_device *xldev; + + xldev = container_of(rd, typeof(*xldev), rdev); + + if (!is_subregion(&xldev->sub_region, &req)) + return -1; + + offset -= region_offset(&xldev->sub_region); + + return rdev_readat(xldev->access_dev, b, offset, size); +} + +const struct region_device_ops xlate_rdev_ops = { + .mmap = xlate_mmap, + .munmap = xlate_munmap, + .readat = xlate_readat, +}; -- cgit v1.2.3