<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Thu, May 3, 2018 at 6:12 PM, Kenneth Graunke <<a href="mailto:kenneth@whitecape.org" target="_blank">kenneth@whitecape.org</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">From: Jason Ekstrand <<a href="mailto:jason.ekstrand@intel.com">jason.ekstrand@intel.com</a>> This is simple linear-walk first-fit allocator roughly based on the allocator in the radeon winsys code. This allocator has two primary functional differences: 1) It cleanly returns 0 on allocation failure 2) It allocates addresses top-down instead of bottom-up. The second one is needed for Intel because high addresses (with bit 47 set) need to be canonicalized in order to work properly. If we allocate bottom-up, then high addresses will be very rare (if they ever happen). We'd rather always have high addresses so that the canonicalization code gets better testing. --- src/util/Makefile.sources | 4 +- src/util/meson.build | 2 + src/util/vma.c | 232 ++++++++++++++++++++++++++++++++++++++ src/util/vma.h | 53 +++++++++ 4 files changed, 290 insertions(+), 1 deletion(-) create mode 100644 src/util/vma.c create mode 100644 src/util/vma.h This is the exact same patch as Scott recently sent: <a href="https://patchwork.freedesktop.org/patch/219951/" rel="noreferrer" target="_blank">https://patchwork.freedesktop.org/patch/219951/</a> It may make more sense to review it on that existing thread. I mostly resent it here to note that it's required for this series. </blockquote><div> </div><div>You could review it. :-P </div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources index 104ecae8ed3..534520ce763 100644 --- a/src/util/Makefile.sources +++ b/src/util/Makefile.sources @@ -56,7 +56,9 @@ MESA_UTIL_FILES := \ u_string.h \ u_thread.h \ u_vector.c \ - u_vector.h + u_vector.h \ + vma.c \ + vma.h MESA_UTIL_GENERATED_FILES = \ format_srgb.c diff --git a/src/util/meson.build b/src/util/meson.build index eece1cefef6..14660e0fa0c 100644 --- a/src/util/meson.build +++ b/src/util/meson.build @@ -81,6 +81,8 @@ files_mesa_util = files( 'u_thread.h', 'u_vector.c', 'u_vector.h', + 'vma.c', + 'vma.h', ) install_data('drirc', install_dir : get_option('sysconfdir')) diff --git a/src/util/vma.c b/src/util/vma.c new file mode 100644 index 00000000000..3d61f6969ed --- /dev/null +++ b/src/util/vma.c @@ -0,0 +1,232 @@ +/* + * Copyright © 2018 Intel Corporation + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#include <stdlib.h> + +#include "util/u_math.h" +#include "util/vma.h" + +struct util_vma_hole { + struct list_head link; + uint64_t offset; + uint64_t size; +}; + +#define util_vma_foreach_hole(_hole, _heap) \ + list_for_each_entry(struct util_vma_hole, _hole, &(_heap)->holes, link) + +#define util_vma_foreach_hole_safe(_hole, _heap) \ + list_for_each_entry_safe(struct util_vma_hole, _hole, &(_heap)->holes, link) + +void +util_vma_heap_init(struct util_vma_heap *heap, + uint64_t start, uint64_t size) +{ + list_inithead(&heap->holes); + util_vma_heap_free(heap, start, size); +} + +void +util_vma_heap_finish(struct util_vma_heap *heap) +{ + util_vma_foreach_hole_safe(hole, heap) + free(hole); +} + +static void +util_vma_heap_validate(struct util_vma_heap *heap) +{ + uint64_t prev_offset = 0; + util_vma_foreach_hole(hole, heap) { + assert(hole->offset > 0); + assert(hole->size > 0); + + if (&hole->link == heap->holes.next) { + /* This must be the top-most hole. Assert that, if it overflows, it + * overflows to 0, i.e. 2^64. + */ + assert(hole->size + hole->offset == 0 || + hole->size + hole->offset > hole->offset); + } else { + /* This is not the top-most hole so it must not overflow and, in + * fact, must be strictly lower than the top-most hole. If + * hole->size + hole->offset == prev_offset, then we failed to join + * holes during a util_vma_heap_free. + */ + assert(hole->size + hole->offset > hole->offset && + hole->size + hole->offset < prev_offset); + } + prev_offset = hole->offset; + } +} + +uint64_t +util_vma_heap_alloc(struct util_vma_heap *heap, + uint64_t size, uint64_t alignment) +{ + /* The caller is expected to reject zero-size allocations */ + assert(size > 0); + + assert(alignment > 0); + assert(util_is_power_of_two_nonzero(alignment)); + + util_vma_heap_validate(heap); + + util_vma_foreach_hole_safe(hole, heap) { + if (size > hole->size) + continue; + + /* Compute the offset as the highest address where a chunk of the given + * size can be without going over the top of the hole. + * + * This calculation is known to not overflow because we know that + * hole->size + hole->offset can only overflow to 0 and size > 0. + */ + uint64_t offset = (hole->size - size) + hole->offset; + + /* Align the offset. We align down and not up because we are allocating + * from the top of the hole and not the bottom. + */ + offset &= ~(alignment - 1); + + if (offset < hole->offset) + continue; + + if (offset == hole->offset && size == hole->size) { + /* Just get rid of the hole. */ + list_del(&hole->link); + free(hole); + util_vma_heap_validate(heap); + return offset; + } + + assert(offset - hole->offset <= hole->size - size); + uint64_t waste = (hole->size - size) - (offset - hole->offset); + if (waste == 0) { + /* We allocated at the top. Shrink the hole down. */ + hole->size -= size; + util_vma_heap_validate(heap); + return offset; + } + + if (offset == hole->offset) { + /* We allocated at the bottom. Shrink the hole up. */ + hole->offset += size; + hole->size -= size; + util_vma_heap_validate(heap); + return offset; + } + + /* We allocated in the middle. We need to split the old hole into two + * holes, one high and one low. + */ + struct util_vma_hole *high_hole = calloc(1, sizeof(*hole)); + high_hole->offset = offset + size; + high_hole->size = waste; + + /* Adjust the hole to be the amount of space left at he bottom of the + * original hole. + */ + hole->size = offset - hole->offset; + + /* Place the new hole before the old hole so that the list is in order + * from high to low. + */ + list_addtail(&high_hole->link, &hole->link); + + util_vma_heap_validate(heap); + + return offset; + } + + /* Failed to allocate */ + return 0; +} + +void +util_vma_heap_free(struct util_vma_heap *heap, + uint64_t offset, uint64_t size) +{ + /* An offset of 0 is reserved for allocation failure. It is not a valid + * address and cannot be freed. + */ + assert(offset > 0); + + /* Freeing something with a size of 0 is also not valid. */ + assert(size > 0); + + /* It's possible for offset + size to wrap around if we touch the top of + * the 64-bit address space, but we cannot go any higher than 2^64. + */ + assert(offset + size == 0 || offset + size > offset); + + util_vma_heap_validate(heap); + + /* Find immediately higher and lower holes if they exist. */ + struct util_vma_hole *high_hole = NULL, *low_hole = NULL; + util_vma_foreach_hole(hole, heap) { + if (hole->offset <= offset) { + low_hole = hole; + break; + } + high_hole = hole; + } + + if (high_hole) + assert(offset + size <= high_hole->offset); + bool high_adjacent = high_hole && offset + size == high_hole->offset; + + if (low_hole) { + assert(low_hole->offset + low_hole->size > low_hole->offset); + assert(low_hole->offset + low_hole->size <= offset); + } + bool low_adjacent = low_hole && low_hole->offset + low_hole->size == offset; + + if (low_adjacent && high_adjacent) { + /* Merge the two holes */ + low_hole->size += size + high_hole->size; + list_del(&high_hole->link); + free(high_hole); + } else if (low_adjacent) { + /* Merge into the low hole */ + low_hole->size += size; + } else if (high_adjacent) { + /* Merge into the high hole */ + high_hole->offset = offset; + high_hole->size += size; + } else { + /* Neither hole is adjacent; make a new one */ + struct util_vma_hole *hole = calloc(1, sizeof(*hole)); + + hole->offset = offset; + hole->size = size; + + /* Add it after the high hole so we maintain high-to-low ordering */ + if (high_hole) + list_add(&hole->link, &high_hole->link); + else + list_add(&hole->link, &heap->holes); + } + + util_vma_heap_validate(heap); +} diff --git a/src/util/vma.h b/src/util/vma.h new file mode 100644 index 00000000000..ed69914e4cb --- /dev/null +++ b/src/util/vma.h @@ -0,0 +1,53 @@ +/* + * Copyright © 2018 Intel Corporation + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#ifndef _UTIL_VMA_H +#define _UTIL_VMA_H + +#include <stdint.h> + +#include "list.h" + +#ifdef __cplusplus +extern "C" { +#endif + +struct util_vma_heap { + struct list_head holes; +}; + +void util_vma_heap_init(struct util_vma_heap *heap, + uint64_t start, uint64_t size); +void util_vma_heap_finish(struct util_vma_heap *heap); + +uint64_t util_vma_heap_alloc(struct util_vma_heap *heap, + uint64_t size, uint64_t alignment); + +void util_vma_heap_free(struct util_vma_heap *heap, + uint64_t offset, uint64_t size); + +#ifdef __cplusplus +} /* extern C */ +#endif + +#endif /* _UTIL_DEBUG_H */ -- 2.17.0 _______________________________________________ mesa-dev mailing list <a href="mailto:mesa-dev@lists.freedesktop.org">mesa-dev@lists.freedesktop.org</a> <a href="https://lists.freedesktop.org/mailman/listinfo/mesa-dev" rel="noreferrer" target="_blank">https://lists.freedesktop.org/mailman/listinfo/mesa-dev</a> </blockquote></div> </div></div>