Re: [PATCH V2 4/4] edac, amd64_edac: Add F15h M60h support

From: Aravind Gopalakrishnan
Date: Wed Oct 29 2014 - 11:30:26 EST

On 10/10/2014 12:49 PM, Borislav Petkov wrote:
On Mon, Oct 06, 2014 at 07:04:40PM -0500, Aravind Gopalakrishnan wrote:
This patch adds support for ECC error decoding for F15h M60h processor.
Aside from the usual changes, the patch adds support for some new features
in the processor:
- DDR4(unbuffered, registered); LRDIMM DDR3 support
- relevant debug messages have been modified/added to report these
memory types
- new dbam_to_cs mappers
- if (F15h M60h && LRDIMM); we need a 'multiplier' value to find
cs_size. This multiplier value is obtained from the per-dimm
DCSM register. So, change the interface to accept a 'cs_mask_nr'
value to facilitate this calculation
- new determine_memory_type low_ops
- introduced to remove too many if-else conditions in
determine_memory_type().
- This is now called early in read_mc_regs() to cache dram_type

Misc cleanup:
- amd64_pci_table[] is condensed by using PCI_VDEVICE macro.

Testing details:
Tested the patch by injecting 'ECC' type errors using mce_amd_inj
and error decoding works fine.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@xxxxxxx>
---
Changes in V2
- Cache dram_type in amd64_pvt structure (per Boris suggestion)
- Introduce per-family low_ops for determine_memory_type() to reduce
number of if-else statements
- Call this early in read_mc_regs() to cache dram_type
- The debug messages are moved around a bit as a result to print
dram_type immediately

drivers/edac/amd64_edac.c | 253 ++++++++++++++++++++++++++++++++--------------
drivers/edac/amd64_edac.h | 16 ++-
2 files changed, 188 insertions(+), 81 deletions(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index bbd6514..6cc3243 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -692,9 +692,18 @@ static void debug_dump_dramcfg_low(struct amd64_pvt *pvt, u32 dclr, int chan)
{
edac_dbg(1, "F2x%d90 (DRAM Cfg Low): 0x%08x\n", chan, dclr);
- edac_dbg(1, " DIMM type: %sbuffered; all DIMMs support ECC: %s\n",
- (dclr & BIT(16)) ? "un" : "",
- (dclr & BIT(19)) ? "yes" : "no");
+ if (pvt->dram_type == MEM_LRDDR3) {
+ u32 dcsm = pvt->csels[chan].csmasks[0];
+ /*
+ * It's assumed all LRDIMMs in a DCT are going to be of
+ * same 'type' until proven otherwise. So, use a cs
+ * value of '0' here to get dcsm value.
+ */
+ edac_dbg(1, " LRDIMM %dx rank multiply\n", (dcsm & 0x3));
+ }
+
+ edac_dbg(1, "All DIMMs support ECC:%s\n",
+ (dclr & BIT(19)) ? "yes" : "no");
edac_dbg(1, " PAR/ERR parity: %s\n",
(dclr & BIT(8)) ? "enabled" : "disabled");
@@ -756,7 +765,7 @@ static void prep_chip_selects(struct amd64_pvt *pvt)
if (pvt->fam == 0xf && pvt->ext_model < K8_REV_F) {
pvt->csels[0].b_cnt = pvt->csels[1].b_cnt = 8;
pvt->csels[0].m_cnt = pvt->csels[1].m_cnt = 8;
- } else if (pvt->fam == 0x15 && pvt->model >= 0x30) {
+ } else if (pvt->fam == 0x15 && pvt->model == 0x30) {
pvt->csels[0].b_cnt = pvt->csels[1].b_cnt = 4;
pvt->csels[0].m_cnt = pvt->csels[1].m_cnt = 2;
} else {
@@ -813,25 +822,57 @@ static void read_dct_base_mask(struct amd64_pvt *pvt)
}
}
-static enum mem_type determine_memory_type(struct amd64_pvt *pvt, int cs)
+void determine_memory_type_k8(struct amd64_pvt *pvt)
{
- enum mem_type type;
-
- /* F15h supports only DDR3 */
- if (pvt->fam >= 0x15)
- type = (pvt->dclr0 & BIT(16)) ? MEM_DDR3 : MEM_RDDR3;
- else if (pvt->fam == 0x10 || pvt->ext_model >= K8_REV_F) {
+ if (pvt->ext_model >= K8_REV_F) {
if (pvt->dchr0 & DDR3_MODE)
- type = (pvt->dclr0 & BIT(16)) ? MEM_DDR3 : MEM_RDDR3;
+ pvt->dram_type = (pvt->dclr0 & BIT(16)) ?
+ MEM_DDR3 : MEM_RDDR3;
else
- type = (pvt->dclr0 & BIT(16)) ? MEM_DDR2 : MEM_RDDR2;
+ pvt->dram_type = (pvt->dclr0 & BIT(16)) ?
+ MEM_DDR2 : MEM_RDDR2;
If you want to do separate ->determine_memory_type() per family, you can
at least avoid code duplication here above ^^^ by doing

return determine_memory_type_f10(pvt);

for the K8-revF and later at least.

Or, you can do a nice clean switch/case and keep the logic for the
memory type in one function. See which one looks cleaner but from where
I'm standing, the per-family pointers are a bit too much for this case,
IMHO.

Oh, btw, they all should be static declarations, of course.

} else {
- type = (pvt->dclr0 & BIT(18)) ? MEM_DDR : MEM_RDDR;
+ pvt->dram_type = (pvt->dclr0 & BIT(18)) ? MEM_DDR : MEM_RDDR;
}
+}
- amd64_info("CS%d: %s\n", cs, edac_mem_types[type]);
+void determine_memory_type_f10(struct amd64_pvt *pvt)
+{
+ if (pvt->dchr0 & DDR3_MODE)
+ pvt->dram_type = (pvt->dclr0 & BIT(16)) ?
+ MEM_DDR3 : MEM_RDDR3;
+ else
+ pvt->dram_type = (pvt->dclr0 & BIT(16)) ?
+ MEM_DDR2 : MEM_RDDR2;
+}
- return type;
+void determine_memory_type_f15(struct amd64_pvt *pvt)
+{
+ if (pvt->model == 0x60) {
+ /*
+ * We use a Chip Select value of '0' to obtain dcsm.
+ * Theoretically, it is possible to populate LRDIMMs
+ * of different 'Rank' value on a DCT. But this is
+ * not a common case. So, it's reasonable to assume
+ * all DIMMs are going to be of same 'type' until
+ * proven otherwise.
+ */
+ u32 dram_ctrl;
+ u32 dcsm = pvt->csels[0].csmasks[0];
+
+ amd64_read_dct_pci_cfg(pvt, 0, DRAM_CONTROL,
+ &dram_ctrl);
+ pvt->dram_type = (((dram_ctrl >> 8) & 0x7) == 0x2) ? MEM_DDR4 :
+ (pvt->dclr0 & BIT(16)) ? MEM_DDR3 :
+ (dcsm & 0x3) ? MEM_LRDDR3 : MEM_RDDR3;
This is pretty unreadable, please do a simpler if-else instead.

Ok, will do.

+ } else {
+ pvt->dram_type = (pvt->dclr0 & BIT(16)) ? MEM_DDR3 : MEM_RDDR3;
+ }
+}
+
+void determine_memory_type_f16(struct amd64_pvt *pvt)
+{
+ pvt->dram_type = (pvt->dclr0 & BIT(16)) ? MEM_DDR3 : MEM_RDDR3;
This line tends to repeat a lot - the switch/case version starts to
sound much better all of a sudden... :-)



switch-case is fine too (although it'll probably be one big function..).
I thought per-family pointers might be more manageable; anyway, I'll re-implement this as a switch-case and send as V3.

Thanks,
-Aravind
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