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authorGabe Black <gblack@eecs.umich.edu>2012-01-16 04:27:10 -0800
committerGabe Black <gblack@eecs.umich.edu>2012-01-16 04:27:10 -0800
commitda2a4acc26ba264c3c4a12495776fd6a1c4fb133 (patch)
treef142100388b9d1403492c97b0d323728ce18ef8a /src/mem/packet.cc
parent241cc0c8402f1b9f2ec20d1cc152d96930959b2a (diff)
parenta7394ad6807bd5e85f680184bf308673ca00534a (diff)
downloadgem5-da2a4acc26ba264c3c4a12495776fd6a1c4fb133.tar.xz
Merge yet again with the main repository.
Diffstat (limited to 'src/mem/packet.cc')
-rw-r--r--src/mem/packet.cc112
1 files changed, 104 insertions, 8 deletions
diff --git a/src/mem/packet.cc b/src/mem/packet.cc
index 5ec977ed4..64f4fcd14 100644
--- a/src/mem/packet.cc
+++ b/src/mem/packet.cc
@@ -1,4 +1,16 @@
/*
+ * Copyright (c) 2011 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder. You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
* Copyright (c) 2006 The Regents of The University of Michigan
* Copyright (c) 2010 Advanced Micro Devices, Inc.
* All rights reserved.
@@ -192,14 +204,98 @@ Packet::checkFunctional(Printable *obj, Addr addr, int size, uint8_t *data)
memcpy(getPtr<uint8_t>(), data + offset, getSize());
return true;
} else {
- // In this case the timing packet only partially satisfies
- // the request, so we would need more information to make
- // this work. Like bytes valid in the packet or
- // something, so the request could continue and get this
- // bit of possibly newer data along with the older data
- // not written to yet.
- panic("Memory value only partially satisfies the functional "
- "request. Now what?");
+ // Offsets and sizes to copy in case of partial overlap
+ int func_offset;
+ int val_offset;
+ int overlap_size;
+
+ // calculate offsets and copy sizes for the two byte arrays
+ if (val_start < func_start && val_end <= func_end) {
+ val_offset = func_start - val_start;
+ func_offset = 0;
+ overlap_size = val_end - func_start;
+ } else if (val_start >= func_start && val_end > func_end) {
+ val_offset = 0;
+ func_offset = val_start - func_start;
+ overlap_size = func_end - val_start;
+ } else if (val_start >= func_start && val_end <= func_end) {
+ val_offset = 0;
+ func_offset = val_start - func_start;
+ overlap_size = size;
+ } else {
+ panic("BUG: Missed a case for a partial functional request");
+ }
+
+ // Figure out how much of the partial overlap should be copied
+ // into the packet and not overwrite previously found bytes.
+ if (bytesValidStart == 0 && bytesValidEnd == 0) {
+ // No bytes have been copied yet, just set indices
+ // to found range
+ bytesValidStart = func_offset;
+ bytesValidEnd = func_offset + overlap_size;
+ } else {
+ // Some bytes have already been copied. Use bytesValid
+ // indices and offset values to figure out how much data
+ // to copy and where to copy it to.
+
+ // Indice overlap conditions to check
+ int a = func_offset - bytesValidStart;
+ int b = (func_offset + overlap_size) - bytesValidEnd;
+ int c = func_offset - bytesValidEnd;
+ int d = (func_offset + overlap_size) - bytesValidStart;
+
+ if (a >= 0 && b <= 0) {
+ // bytes already in pkt data array are superset of
+ // found bytes, will not copy any bytes
+ overlap_size = 0;
+ } else if (a < 0 && d >= 0 && b <= 0) {
+ // found bytes will move bytesValidStart towards 0
+ overlap_size = bytesValidStart - func_offset;
+ bytesValidStart = func_offset;
+ } else if (b > 0 && c <= 0 && a >= 0) {
+ // found bytes will move bytesValidEnd
+ // towards end of pkt data array
+ overlap_size =
+ (func_offset + overlap_size) - bytesValidEnd;
+ val_offset += bytesValidEnd - func_offset;
+ func_offset = bytesValidEnd;
+ bytesValidEnd += overlap_size;
+ } else if (a < 0 && b > 0) {
+ // Found bytes are superset of copied range. Will move
+ // bytesValidStart towards 0 and bytesValidEnd towards
+ // end of pkt data array. Need to break copy into two
+ // pieces so as to not overwrite previously found data.
+
+ // copy the first half
+ uint8_t *dest = getPtr<uint8_t>() + func_offset;
+ uint8_t *src = data + val_offset;
+ memcpy(dest, src, (bytesValidStart - func_offset));
+
+ // re-calc the offsets and indices to do the copy
+ // required for the second half
+ val_offset += (bytesValidEnd - func_offset);
+ bytesValidStart = func_offset;
+ overlap_size =
+ (func_offset + overlap_size) - bytesValidEnd;
+ func_offset = bytesValidEnd;
+ bytesValidEnd += overlap_size;
+ } else if ((c > 0 && b > 0)
+ || (a < 0 && d < 0)) {
+ // region to be copied is discontiguous! Not supported.
+ panic("BUG: Discontiguous bytes found"
+ "for functional copying!");
+ }
+ }
+ assert(bytesValidEnd <= getSize());
+
+ // copy partial data into the packet's data array
+ uint8_t *dest = getPtr<uint8_t>() + func_offset;
+ uint8_t *src = data + val_offset;
+ memcpy(dest, src, overlap_size);
+
+ // check if we're done filling the functional access
+ bool done = (bytesValidStart == 0) && (bytesValidEnd == getSize());
+ return done;
}
} else if (isWrite()) {
if (offset >= 0) {