| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 025/210] EDAC/sb_edac: Fix computation of channel address | Date | Sun, 10 Apr 2016 11:34:06 -0700 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Tony Luck <tony.luck@intel.com>
commit eb1af3b71f9d83e45f2fd2fd649356e98e1c582c upstream.
Large memory Haswell-EX systems with multiple DIMMs per channel were sometimes reporting the wrong DIMM.
Found three problems:
1) Debug printouts for socket and channel interleave were not interpreting the register fields correctly. The socket interleave field is a 2^X value (0=1, 1=2, 2=4, 3=8). The channel interleave is X+1 (0=1, 1=2, 2=3. 3=4).
2) Actual use of the socket interleave value didn't interpret as 2^X
3) Conversion of address to channel address was complicated, and wrong.
Signed-off-by: Tony Luck <tony.luck@intel.com> Acked-by: Aristeu Rozanski <arozansk@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-edac@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/edac/sb_edac.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-)
--- a/drivers/edac/sb_edac.c +++ b/drivers/edac/sb_edac.c @@ -1117,8 +1117,8 @@ static void get_memory_layout(const stru edac_dbg(0, "TAD#%d: up to %u.%03u GB (0x%016Lx), socket interleave %d, memory interleave %d, TGT: %d, %d, %d, %d, reg=0x%08x\n", n_tads, gb, (mb*1000)/1024, ((u64)tmp_mb) << 20L, - (u32)TAD_SOCK(reg), - (u32)TAD_CH(reg), + (u32)(1 << TAD_SOCK(reg)), + (u32)TAD_CH(reg) + 1, (u32)TAD_TGT0(reg), (u32)TAD_TGT1(reg), (u32)TAD_TGT2(reg), @@ -1396,7 +1396,7 @@ static int get_memory_error_data(struct } ch_way = TAD_CH(reg) + 1; - sck_way = TAD_SOCK(reg) + 1; + sck_way = 1 << TAD_SOCK(reg); if (ch_way == 3) idx = addr >> 6; @@ -1453,7 +1453,7 @@ static int get_memory_error_data(struct n_tads, addr, limit, - (u32)TAD_SOCK(reg), + sck_way, ch_way, offset, idx, @@ -1468,18 +1468,12 @@ static int get_memory_error_data(struct offset, addr); return -EINVAL; } - addr -= offset; - /* Store the low bits [0:6] of the addr */ - ch_addr = addr & 0x7f; - /* Remove socket wayness and remove 6 bits */ - addr >>= 6; - addr = div_u64(addr, sck_xch); -#if 0 - /* Divide by channel way */ - addr = addr / ch_way; -#endif - /* Recover the last 6 bits */ - ch_addr |= addr << 6; + + ch_addr = addr - offset; + ch_addr >>= (6 + shiftup); + ch_addr /= ch_way * sck_way; + ch_addr <<= (6 + shiftup); + ch_addr |= addr & ((1 << (6 + shiftup)) - 1); /* * Step 3) Decode rank
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