diff options
| -rw-r--r-- | src/gallium/drivers/cell/spu/spu_dcache.c | 50 |
1 files changed, 32 insertions, 18 deletions
diff --git a/src/gallium/drivers/cell/spu/spu_dcache.c b/src/gallium/drivers/cell/spu/spu_dcache.c index 3baeaea9981..a1701d80d18 100644 --- a/src/gallium/drivers/cell/spu/spu_dcache.c +++ b/src/gallium/drivers/cell/spu/spu_dcache.c @@ -49,43 +49,57 @@ /** * Fetch between arbitrary number of bytes from an unaligned address + * + * \param dst Destination data buffer + * \param ea Main memory effective address of source data + * \param size Number of bytes to read + * + * \warning + * As is hinted by the type of the \c dst pointer, this function writes + * multiples of 16-bytes. */ void spu_dcache_fetch_unaligned(qword *dst, unsigned ea, unsigned size) { const int shift = ea & 0x0f; - const unsigned aligned_start_ea = ea & ~0x0f; - const unsigned aligned_end_ea = ROUNDUP16(ea + size); - const unsigned num_entries = (aligned_end_ea - aligned_start_ea) / 16; + const unsigned read_size = ROUNDUP16(size + shift); + const unsigned last_read = ROUNDUP16(ea + size); + const qword *const last_write = dst + (ROUNDUP16(size) / 16); unsigned i; if (shift == 0) { /* Data is already aligned. Fetch directly into the destination buffer. */ - for (i = 0; i < num_entries; i++) { - dst[i] = cache_rd(data, ea + (i * 16)); + for (i = 0; i < size; i += 16) { + *(dst++) = cache_rd(data, ea + i); } } else { - qword tmp[2] ALIGN16_ATTRIB; - + qword hi; - tmp[0] = cache_rd(data, (ea & ~0x0f)); - for (i = 0; i < (num_entries & ~1); i++) { - const unsigned curr = i & 1; - const unsigned next = curr ^ 1; - tmp[next] = cache_rd(data, (ea & ~0x0f) + (next * 16)); - - dst[i] = si_or((qword) spu_slqwbyte(tmp[curr], shift), - (qword) spu_rlmaskqwbyte(tmp[next], shift - 16)); + /* Please exercise extreme caution when modifying this code. This code + * must not read past the end of the page containing the source data, + * and it must not write more than ((size + 15) / 16) qwords to the + * destination buffer. + */ + ea &= ~0x0f; + hi = cache_rd(data, ea); + for (i = 16; i < read_size; i += 16) { + qword lo = cache_rd(data, ea + i); + + *(dst++) = si_or((qword) spu_slqwbyte(hi, shift), + (qword) spu_rlmaskqwbyte(lo, shift - 16)); + hi = lo; } - if (i < num_entries) { - dst[i] = si_or((qword) spu_slqwbyte(tmp[(i & 1)], shift), - si_il(0)); + if (dst != last_write) { + *(dst++) = si_or((qword) spu_slqwbyte(hi, shift), si_il(0)); } } + + ASSERT((ea + i) == last_read); + ASSERT(dst == last_write); } |