From: Janne Grunau j@jannau.net
These functions can be used with struct lmb pointers and will be used to manage IOVA space in the apple_dart iommu driver. This restores part of the pointer base struct lmb API from before commit ed17a33fed29 ("lmb: make LMB memory map persistent and global"). io_lmb_add() and io_lmb_free() can trivially reuse exisiting lmb functions. io_lmb_setup() is separate for unique error log messages. io_lmb_alloc() is a simplified copy of _lmb_alloc_base() since the later has unused features and internal use of the global LMB memory map.
Signed-off-by: Janne Grunau j@jannau.net --- include/lmb.h | 51 +++++++++++++++++++++++++++++++++++++ lib/lmb.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 131 insertions(+)
diff --git a/include/lmb.h b/include/lmb.h index 2201d6f2b67bb605dbff015fa2a6a008b780c57a..fa91bf17adea84d335ba43ee7749e2a12a1d44c0 100644 --- a/include/lmb.h +++ b/include/lmb.h @@ -156,6 +156,57 @@ static inline int lmb_read_check(phys_addr_t addr, phys_size_t len) return lmb_alloc_addr(addr, len) == addr ? 0 : -1; }
+/** + * io_lmb_setup() - Initialize LMB struct + * @lmb: IO LMB to initialize + * + * Returns: 0 on success, negative error code on failure + */ +int io_lmb_setup(struct lmb *io_lmb); + +/** + * io_lmb_teardown() - Tear LMB struct down + * @lmb: IO LMB to teardown + */ +void io_lmb_teardown(struct lmb *io_lmb); + +/** + * io_lmb_add() - Add an IOVA range for allocations + * @io_lmb: LMB to add the space to + * @base: Base Address of region to add + * @size: Size of the region to add + * + * Add the IOVA space [base, base + size] to be managed by io_lmb. + * + * Returns: 0 if the region addition was successful, -1 on failure + */ +long io_lmb_add(struct lmb *io_lmb, phys_addr_t base, phys_size_t size); + +/** + * io_lmb_alloc() - Allocate specified IO memory address with specified alignment + * @io_lmb: LMB to alloc from + * @size: Size of the region requested + * @align: Required address and size alignment + * + * Allocate a region of IO memory. The base parameter is used to specify the + * base address of the requested region. + * + * Return: base IO address on success, 0 on error + */ +phys_addr_t io_lmb_alloc(struct lmb *io_lmb, phys_size_t size, ulong align); + +/** + * io_lmb_free() - Free up a region of IOVA space + * @io_lmb: LMB to return the IO address space to + * @base: Base Address of region to be freed + * @size: Size of the region to be freed + * + * Free up a region of IOVA space. + * + * Return: 0 if successful, -1 on failure + */ +long io_lmb_free(struct lmb *io_lmb, phys_addr_t base, phys_size_t size); + #endif /* __KERNEL__ */
#endif /* _LINUX_LMB_H */ diff --git a/lib/lmb.c b/lib/lmb.c index 2ce91f7521cfe58577b092fdaea8004b17f0eeff..cfc1763e49a76c6d4d9c85cd2b0342c6e0a7c4cf 100644 --- a/lib/lmb.c +++ b/lib/lmb.c @@ -351,6 +351,86 @@ static phys_addr_t lmb_align_down(phys_addr_t addr, phys_size_t size) return addr & ~(size - 1); }
+/* + * IOVA LMB memory maps using lmb pointers instead of the global LMB memory map. + */ + +int io_lmb_setup(struct lmb *io_lmb) +{ + int ret; + + ret = alist_init(&io_lmb->free_mem, sizeof(struct lmb_region), + (uint)LMB_ALIST_INITIAL_SIZE); + if (!ret) { + log_debug("Unable to initialise the list for LMB free IOVA\n"); + return -ENOMEM; + } + + ret = alist_init(&io_lmb->used_mem, sizeof(struct lmb_region), + (uint)LMB_ALIST_INITIAL_SIZE); + if (!ret) { + log_debug("Unable to initialise the list for LMB used IOVA\n"); + return -ENOMEM; + } + + io_lmb->test = false; + + return 0; +} + +void io_lmb_teardown(struct lmb *io_lmb) +{ + alist_uninit(&io_lmb->free_mem); + alist_uninit(&io_lmb->used_mem); +} + +long io_lmb_add(struct lmb *io_lmb, phys_addr_t base, phys_size_t size) +{ + return lmb_add_region_flags(&io_lmb->free_mem, base, size, LMB_NONE); +} + +/* derived and simplified from _lmb_alloc_base() */ +phys_addr_t io_lmb_alloc(struct lmb *io_lmb, phys_size_t size, ulong align) +{ + long i, rgn; + phys_addr_t base = 0; + phys_addr_t res_base; + struct lmb_region *lmb_used = io_lmb->used_mem.data; + struct lmb_region *lmb_memory = io_lmb->free_mem.data; + + for (i = io_lmb->free_mem.count - 1; i >= 0; i--) { + phys_addr_t lmbbase = lmb_memory[i].base; + phys_size_t lmbsize = lmb_memory[i].size; + + if (lmbsize < size) + continue; + base = lmb_align_down(lmbbase + lmbsize - size, align); + + while (base && lmbbase <= base) { + rgn = lmb_overlaps_region(&io_lmb->used_mem, base, size); + if (rgn < 0) { + /* This area isn't reserved, take it */ + if (lmb_add_region_flags(&io_lmb->used_mem, base, + size, LMB_NONE) < 0) + return 0; + + return base; + } + + res_base = lmb_used[rgn].base; + if (res_base < size) + break; + base = lmb_align_down(res_base - size, align); + } + } + return 0; +} + +long io_lmb_free(struct lmb *io_lmb, phys_addr_t base, phys_size_t size) +{ + return _lmb_free(&io_lmb->used_mem, base, size); +} + /* * Low level LMB functions are used to manage IOVA memory maps for the Apple * dart iommu. They must not access the global LMB memory map.