[PATCH 4.5 037/200] x86 EDAC, sb_edac.c: Take account of channel hashing when needed

Greg Kroah-Hartman
2016-05-03T00:36:23Z

From: Tony Luck <tony.luck@intel.com>

commit ea5dfb5fae81939f777ca569d8cfb599252da2e8 upstream.

Haswell and Broadwell can be configured to hash the channel
interleave function using bits [27:12] of the physical address.

On those processor models we must check to see if hashing is
enabled (bit21 of the HASWELL_HASYSDEFEATURE2 register) and
act accordingly.

Based on a patch by patrickg <patrickg@supermicro.com>

Tested-by: Patrick Geary <patrickg@supermicro.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Aristeu Rozanski <arozansk@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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 | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)

--- a/drivers/edac/sb_edac.c
+++ b/drivers/edac/sb_edac.c
@@ -362,6 +362,7 @@ struct sbridge_pvt {

/* Memory type detection */
bool is_mirrored, is_lockstep, is_close_pg;
+ bool is_chan_hash;

/* Fifo double buffers */
struct mce mce_entry[MCE_LOG_LEN];
@@ -1060,6 +1061,20 @@ static inline u8 sad_pkg_ha(u8 pkg)
return (pkg >> 2) & 0x1;
}

+static int haswell_chan_hash(int idx, u64 addr)
+{
+ int i;
+
+ /*
+ * XOR even bits from 12:26 to bit0 of idx,
+ * odd bits from 13:27 to bit1
+ */
+ for (i = 12; i < 28; i += 2)
+ idx ^= (addr >> i) & 3;
+
+ return idx;
+}
+
/****************************************************************************
Memory check routines
****************************************************************************/
@@ -1616,6 +1631,10 @@ static int get_dimm_config(struct mem_ct
KNL_MAX_CHANNELS : NUM_CHANNELS;
u64 knl_mc_sizes[KNL_MAX_CHANNELS];

+ if (pvt->info.type == HASWELL || pvt->info.type == BROADWELL) {
+ pci_read_config_dword(pvt->pci_ha0, HASWELL_HASYSDEFEATURE2, &reg);
+ pvt->is_chan_hash = GET_BITFIELD(reg, 21, 21);
+ }
if (pvt->info.type == HASWELL || pvt->info.type == BROADWELL ||
pvt->info.type == KNIGHTS_LANDING)
pci_read_config_dword(pvt->pci_sad1, SAD_TARGET, &reg);
@@ -2122,8 +2141,11 @@ static int get_memory_error_data(struct

if (ch_way == 3)
idx = addr >> 6;
- else
+ else {
idx = (addr >> (6 + sck_way + shiftup)) & 0x3;
+ if (pvt->is_chan_hash)
+ idx = haswell_chan_hash(idx, addr);
+ }
idx = idx % ch_way;

/*