Allow for resizing of LMB regions if the region attributes match. The current code returns a failure status on detecting an overlapping address. This worked up until now since the LMB calls were not persistent and global -- the LMB memory map was specific and private to a given caller of the LMB API's.
With the change in the LMB code to make the LMB reservations persistent, there needs to be a check on whether the memory region can be resized, and then do it if so. To distinguish between memory that cannot be resized, add a new flag, LMB_NOOVERWRITE. Reserving a region of memory with this attribute would indicate that the region cannot be resized.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org --- Changes since V1: * Do the check for the region flags in lmb_resize_regions() and lmb_merge_overlap_regions() to decide on merging the overlapping regions.
include/lmb.h | 1 + lib/lmb.c | 116 ++++++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 103 insertions(+), 14 deletions(-)
diff --git a/include/lmb.h b/include/lmb.h index 069c6af2a3..99fcf5781f 100644 --- a/include/lmb.h +++ b/include/lmb.h @@ -20,6 +20,7 @@ enum lmb_flags { LMB_NONE = 0x0, LMB_NOMAP = 0x4, + LMB_NOOVERWRITE = 0x8, };
/** diff --git a/lib/lmb.c b/lib/lmb.c index 0d01e58a46..80945e3cae 100644 --- a/lib/lmb.c +++ b/lib/lmb.c @@ -230,12 +230,88 @@ void lmb_init_and_reserve_range(phys_addr_t base, phys_size_t size, lmb_reserve_common(fdt_blob); }
+static bool lmb_region_flags_match(struct lmb_region *rgn, unsigned long r1, + enum lmb_flags flags) +{ + return rgn->region[r1].flags == flags; +} + +static long lmb_merge_overlap_regions(struct lmb_region *rgn, unsigned long i, + phys_addr_t base, phys_size_t size, + enum lmb_flags flags) +{ + phys_size_t rgnsize; + unsigned long rgn_cnt, idx; + phys_addr_t rgnbase, rgnend; + phys_addr_t mergebase, mergeend; + + rgn_cnt = 0; + idx = i; + /* + * First thing to do is to identify how many regions does + * the requested region overlap. + * If the flags match, combine all these overlapping + * regions into a single region, and remove the merged + * regions. + */ + while (idx < rgn->cnt - 1) { + rgnbase = rgn->region[idx].base; + rgnsize = rgn->region[idx].size; + + if (lmb_addrs_overlap(base, size, rgnbase, + rgnsize)) { + if (!lmb_region_flags_match(rgn, idx, flags)) + return -1; + rgn_cnt++; + idx++; + } + } + + /* The merged region's base and size */ + rgnbase = rgn->region[i].base; + mergebase = min(base, rgnbase); + rgnend = rgn->region[idx].base + rgn->region[idx].size; + mergeend = max(rgnend, (base + size)); + + rgn->region[i].base = mergebase; + rgn->region[i].size = mergeend - mergebase; + + /* Now remove the merged regions */ + while (--rgn_cnt) + lmb_remove_region(rgn, i + 1); + + return 0; +} + +static long lmb_resize_regions(struct lmb_region *rgn, unsigned long i, + phys_addr_t base, phys_size_t size, + enum lmb_flags flags) +{ + long ret = 0; + phys_addr_t rgnend; + + if (i == rgn->cnt - 1 || + base + size < rgn->region[i + 1].base) { + if (!lmb_region_flags_match(rgn, i, flags)) + return -1; + + rgnend = rgn->region[i].base + rgn->region[i].size; + rgn->region[i].base = min(base, rgn->region[i].base); + rgnend = max(base + size, rgnend); + rgn->region[i].size = rgnend - rgn->region[i].base; + } else { + ret = lmb_merge_overlap_regions(rgn, i, base, size, flags); + } + + return ret; +} + /* This routine called with relocation disabled. */ static long lmb_add_region_flags(struct lmb_region *rgn, phys_addr_t base, phys_size_t size, enum lmb_flags flags) { unsigned long coalesced = 0; - long adjacent, i; + long ret, i;
if (rgn->cnt == 0) { rgn->region[0].base = base; @@ -260,23 +336,28 @@ static long lmb_add_region_flags(struct lmb_region *rgn, phys_addr_t base, return -1; /* regions with new flags */ }
- adjacent = lmb_addrs_adjacent(base, size, rgnbase, rgnsize); - if (adjacent > 0) { + ret = lmb_addrs_adjacent(base, size, rgnbase, rgnsize); + if (ret > 0) { if (flags != rgnflags) break; rgn->region[i].base -= size; rgn->region[i].size += size; coalesced++; break; - } else if (adjacent < 0) { + } else if (ret < 0) { if (flags != rgnflags) break; rgn->region[i].size += size; coalesced++; break; } else if (lmb_addrs_overlap(base, size, rgnbase, rgnsize)) { - /* regions overlap */ - return -1; + ret = lmb_resize_regions(rgn, i, base, size, + flags); + if (ret < 0) + return -1; + + coalesced++; + break; } }
@@ -418,7 +499,7 @@ static phys_addr_t lmb_align_down(phys_addr_t addr, phys_size_t size) }
static phys_addr_t __lmb_alloc_base(phys_size_t size, ulong align, - phys_addr_t max_addr) + phys_addr_t max_addr, enum lmb_flags flags) { long i, rgn; phys_addr_t base = 0; @@ -468,7 +549,7 @@ phys_addr_t lmb_alloc_base(phys_size_t size, ulong align, phys_addr_t max_addr) { phys_addr_t alloc;
- alloc = __lmb_alloc_base(size, align, max_addr); + alloc = __lmb_alloc_base(size, align, max_addr, LMB_NONE);
if (alloc == 0) printf("ERROR: Failed to allocate 0x%lx bytes below 0x%lx.\n", @@ -477,11 +558,8 @@ phys_addr_t lmb_alloc_base(phys_size_t size, ulong align, phys_addr_t max_addr) return alloc; }
-/* - * Try to allocate a specific address range: must be in defined memory but not - * reserved - */ -phys_addr_t lmb_alloc_addr(phys_addr_t base, phys_size_t size) +static phys_addr_t __lmb_alloc_addr(phys_addr_t base, phys_size_t size, + enum lmb_flags flags) { long rgn;
@@ -496,13 +574,23 @@ phys_addr_t lmb_alloc_addr(phys_addr_t base, phys_size_t size) lmb->memory.region[rgn].size, base + size - 1, 1)) { /* ok, reserve the memory */ - if (lmb_reserve(base, size) >= 0) + if (lmb_reserve_flags(base, size, flags) >= 0) return base; } } + return 0; }
+/* + * Try to allocate a specific address range: must be in defined memory but not + * reserved + */ +phys_addr_t lmb_alloc_addr(phys_addr_t base, phys_size_t size) +{ + return __lmb_alloc_addr(base, size, LMB_NONE); +} + /* Return number of bytes from a given address that are free */ phys_size_t lmb_get_free_size(phys_addr_t addr) {