From afe56de947822bb981bd30242f4e3c2c469f9ecc Mon Sep 17 00:00:00 2001 From: Damjan Marion Date: Thu, 17 May 2018 12:44:00 +0200 Subject: Add buffer pointer-to-index and index-to-pointer array functions Change-Id: Ib3fcc3ceb7f315389bcdecbb7d9632540a5dd6ba Signed-off-by: Damjan Marion --- src/vlib/buffer_funcs.h | 143 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 143 insertions(+) (limited to 'src/vlib') diff --git a/src/vlib/buffer_funcs.h b/src/vlib/buffer_funcs.h index ba87d9566c7..6072b2ea44b 100644 --- a/src/vlib/buffer_funcs.h +++ b/src/vlib/buffer_funcs.h @@ -63,6 +63,73 @@ vlib_get_buffer (vlib_main_t * vm, u32 buffer_index) return uword_to_pointer (bm->buffer_mem_start + offset, void *); } +/** \brief Translate array of buffer indices into buffer pointers with offset + + @param vm - (vlib_main_t *) vlib main data structure pointer + @param bi - (u32 *) array of buffer indices + @param b - (void **) array to store buffer pointers + @param count - (uword) number of elements + @param offset - (i32) offset applied to each pointer +*/ +static_always_inline void +vlib_get_buffers_with_offset (vlib_main_t * vm, u32 * bi, void **b, int count, + i32 offset) +{ +#ifdef CLIB_HAVE_VEC256 + u64x4 off = u64x4_splat (buffer_main.buffer_mem_start + offset); + /* if count is not const, compiler will not unroll while loop + se we maintain two-in-parallel variant */ + while (count >= 8) + { + u64x4 b0 = u32x4_extend_to_u64x4 (u32x4_load_unaligned (bi)); + u64x4 b1 = u32x4_extend_to_u64x4 (u32x4_load_unaligned (bi + 4)); + /* shift and add to get vlib_buffer_t pointer */ + u64x4_store_unaligned ((b0 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b); + u64x4_store_unaligned ((b1 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b + 4); + b += 8; + bi += 8; + count -= 8; + } +#endif + while (count >= 4) + { +#ifdef CLIB_HAVE_VEC256 + u64x4 b0 = u32x4_extend_to_u64x4 (u32x4_load_unaligned (bi)); + /* shift and add to get vlib_buffer_t pointer */ + u64x4_store_unaligned ((b0 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b); +#else + b[0] = ((u8 *) vlib_get_buffer (vm, bi[0])) + offset; + b[1] = ((u8 *) vlib_get_buffer (vm, bi[1])) + offset; + b[2] = ((u8 *) vlib_get_buffer (vm, bi[2])) + offset; + b[3] = ((u8 *) vlib_get_buffer (vm, bi[3])) + offset; +#endif + b += 4; + bi += 4; + count -= 4; + } + while (count) + { + b[0] = ((u8 *) vlib_get_buffer (vm, bi[0])) + offset; + b += 1; + bi += 1; + count -= 1; + } +} + +/** \brief Translate array of buffer indices into buffer pointers + + @param vm - (vlib_main_t *) vlib main data structure pointer + @param bi - (u32 *) array of buffer indices + @param b - (vlib_buffer_t **) array to store buffer pointers + @param count - (uword) number of elements +*/ + +static_always_inline void +vlib_get_buffers (vlib_main_t * vm, u32 * bi, vlib_buffer_t ** b, int count) +{ + vlib_get_buffers_with_offset (vm, bi, (void **) b, count, 0); +} + /** \brief Translate buffer pointer into buffer index @param vm - (vlib_main_t *) vlib main data structure pointer @@ -81,6 +148,82 @@ vlib_get_buffer_index (vlib_main_t * vm, void *p) return offset >> CLIB_LOG2_CACHE_LINE_BYTES; } +/** \brief Translate array of buffer pointers into buffer indices with offset + + @param vm - (vlib_main_t *) vlib main data structure pointer + @param b - (void **) array of buffer pointers + @param bi - (u32 *) array to store buffer indices + @param count - (uword) number of elements + @param offset - (i32) offset applied to each pointer +*/ +static_always_inline void +vlib_get_buffer_indices_with_offset (vlib_main_t * vm, void **b, u32 * bi, + uword count, i32 offset) +{ +#ifdef CLIB_HAVE_VEC256 + u32x8 mask = { 0, 2, 4, 6, 1, 3, 5, 7 }; + u64x4 off4 = u64x4_splat (buffer_main.buffer_mem_start - offset); + + while (count >= 8) + { + /* load 4 pointers into 256-bit register */ + u64x4 v0 = u64x4_load_unaligned (b); + u64x4 v1 = u64x4_load_unaligned (b + 4); + u32x8 v2, v3; + + v0 -= off4; + v1 -= off4; + + v0 >>= CLIB_LOG2_CACHE_LINE_BYTES; + v1 >>= CLIB_LOG2_CACHE_LINE_BYTES; + + /* permute 256-bit register so lower u32s of each buffer index are + * placed into lower 128-bits */ + v2 = u32x8_permute ((u32x8) v0, mask); + v3 = u32x8_permute ((u32x8) v1, mask); + + /* extract lower 128-bits and save them to the array of buffer indices */ + u32x4_store_unaligned (u32x8_extract_lo (v2), bi); + u32x4_store_unaligned (u32x8_extract_lo (v3), bi + 4); + bi += 8; + b += 8; + count -= 8; + } +#endif + while (count >= 4) + { + /* equivalent non-nector implementation */ + bi[0] = vlib_get_buffer_index (vm, ((u8 *) b[0]) + offset); + bi[1] = vlib_get_buffer_index (vm, ((u8 *) b[1]) + offset); + bi[2] = vlib_get_buffer_index (vm, ((u8 *) b[2]) + offset); + bi[3] = vlib_get_buffer_index (vm, ((u8 *) b[3]) + offset); + bi += 4; + b += 4; + count -= 4; + } + while (count) + { + bi[0] = vlib_get_buffer_index (vm, b[0] + offset); + bi += 1; + b += 1; + count -= 1; + } +} + +/** \brief Translate array of buffer pointers into buffer indices + + @param vm - (vlib_main_t *) vlib main data structure pointer + @param b - (vlib_buffer_t **) array of buffer pointers + @param bi - (u32 *) array to store buffer indices + @param count - (uword) number of elements +*/ +static_always_inline void +vlib_get_buffer_indices (vlib_main_t * vm, vlib_buffer_t ** b, u32 * bi, + uword count) +{ + vlib_get_buffer_indices_with_offset (vm, (void **) b, bi, count, 0); +} + /** \brief Get next buffer in buffer linklist, or zero for end of list. @param vm - (vlib_main_t *) vlib main data structure pointer -- cgit 1.2.3-korg