changeset 17d8d0a624a0 in /z/repo/gem5
details: http://repo.gem5.org/gem5?cmd=changeset;node=17d8d0a624a0
description:
mem: Move DRAM interleaving check to init
This patch fixes a bug where the DRAM controller tried to access the
system cacheline size before the system pointer was initialised. It
also fixes a bug where the granularity is 0 (no interleaving).
diffstat:
src/mem/dram_ctrl.cc | 81 ++++++++++++++++++++++++++-------------------------
1 files changed, 41 insertions(+), 40 deletions(-)
diffs (105 lines):
diff -r cd95d4d51659 -r 17d8d0a624a0 src/mem/dram_ctrl.cc
--- a/src/mem/dram_ctrl.cc Sat Jan 10 18:06:43 2015 -0600
+++ b/src/mem/dram_ctrl.cc Tue Jan 20 08:11:55 2015 -0500
@@ -69,7 +69,7 @@
burstSize((devicesPerRank * burstLength * deviceBusWidth) / 8),
rowBufferSize(devicesPerRank * deviceRowBufferSize),
columnsPerRowBuffer(rowBufferSize / burstSize),
- columnsPerStripe(range.granularity() / burstSize),
+ columnsPerStripe(range.interleaved() ? range.granularity() / burstSize :
1),
ranksPerChannel(p->ranks_per_channel),
bankGroupsPerRank(p->bank_groups_per_rank),
bankGroupArch(p->bank_groups_per_rank > 0),
@@ -153,45 +153,6 @@
rowsPerBank = capacity / (rowBufferSize * banksPerRank * ranksPerChannel);
- // a bit of sanity checks on the interleaving
- if (range.interleaved()) {
- if (channels != range.stripes())
- fatal("%s has %d interleaved address stripes but %d channel(s)\n",
- name(), range.stripes(), channels);
-
- if (addrMapping == Enums::RoRaBaChCo) {
- if (rowBufferSize != range.granularity()) {
- fatal("Channel interleaving of %s doesn't match RoRaBaChCo "
- "address map\n", name());
- }
- } else if (addrMapping == Enums::RoRaBaCoCh ||
- addrMapping == Enums::RoCoRaBaCh) {
- // for the interleavings with channel bits in the bottom,
- // if the system uses a channel striping granularity that
- // is larger than the DRAM burst size, then map the
- // sequential accesses within a stripe to a number of
- // columns in the DRAM, effectively placing some of the
- // lower-order column bits as the least-significant bits
- // of the address (above the ones denoting the burst size)
- assert(columnsPerStripe >= 1);
-
- // channel striping has to be done at a granularity that
- // is equal or larger to a cache line
- if (system()->cacheLineSize() > range.granularity()) {
- fatal("Channel interleaving of %s must be at least as large "
- "as the cache line size\n", name());
- }
-
- // ...and equal or smaller than the row-buffer size
- if (rowBufferSize < range.granularity()) {
- fatal("Channel interleaving of %s must be at most as large "
- "as the row-buffer size\n", name());
- }
- // this is essentially the check above, so just to be sure
- assert(columnsPerStripe <= columnsPerRowBuffer);
- }
- }
-
// some basic sanity checks
if (tREFI <= tRP || tREFI <= tRFC) {
fatal("tREFI (%d) must be larger than tRP (%d) and tRFC (%d)\n",
@@ -239,6 +200,46 @@
} else {
port.sendRangeChange();
}
+
+ // a bit of sanity checks on the interleaving, save it for here to
+ // ensure that the system pointer is initialised
+ if (range.interleaved()) {
+ if (channels != range.stripes())
+ fatal("%s has %d interleaved address stripes but %d channel(s)\n",
+ name(), range.stripes(), channels);
+
+ if (addrMapping == Enums::RoRaBaChCo) {
+ if (rowBufferSize != range.granularity()) {
+ fatal("Channel interleaving of %s doesn't match RoRaBaChCo "
+ "address map\n", name());
+ }
+ } else if (addrMapping == Enums::RoRaBaCoCh ||
+ addrMapping == Enums::RoCoRaBaCh) {
+ // for the interleavings with channel bits in the bottom,
+ // if the system uses a channel striping granularity that
+ // is larger than the DRAM burst size, then map the
+ // sequential accesses within a stripe to a number of
+ // columns in the DRAM, effectively placing some of the
+ // lower-order column bits as the least-significant bits
+ // of the address (above the ones denoting the burst size)
+ assert(columnsPerStripe >= 1);
+
+ // channel striping has to be done at a granularity that
+ // is equal or larger to a cache line
+ if (system()->cacheLineSize() > range.granularity()) {
+ fatal("Channel interleaving of %s must be at least as large "
+ "as the cache line size\n", name());
+ }
+
+ // ...and equal or smaller than the row-buffer size
+ if (rowBufferSize < range.granularity()) {
+ fatal("Channel interleaving of %s must be at most as large "
+ "as the row-buffer size\n", name());
+ }
+ // this is essentially the check above, so just to be sure
+ assert(columnsPerStripe <= columnsPerRowBuffer);
+ }
+ }
}
void
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