Messages in this thread Patch in this message | | | Subject | [Patch] AMD64_EDAC: Fix amd64_map_to_dcs_mask | From | Keith Mannthey <> | Date | Thu, 17 Sep 2009 19:09:41 -0700 |
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I tested 2.6.31 and the mainline amd64_edac driver. Once errors were getting reported I noticed that a good amount of valid looking system addressed were not being correctly decoded to the csrow level. I was only able to correctly decode errors on channel 0 of a given csrow. Errors on channel 1 were unable to be mapped.
After some digging I realized that the there was an issue with handling of Dram Chip Select Masks. Specifically that amd64_map_to_dcs_mask was returning incorrect values on my Rev F based system. See AMD #32559, 4.5.4, starting on pg 90 for a Rev F explanation of the correct mapping of DRAM CS Base and DRAM CS Mask regs. This lead to the code below. I can provide further explanation if needed.
I have tested this code on Rev F based system with ecc debug dimms and fully expect it to work on earlier and later cpus. I am now able to correctly decode and map errors to csrows rows on this system.
Submitted-by: Keith Mannthey<kmannth@us.ibm.com> ---
diff -urN linux-2.6.31/drivers/edac/amd64_edac.c linux-2.6.31-fixed/drivers/edac/amd64_edac.c --- linux-2.6.31/drivers/edac/amd64_edac.c 2009-09-09 15:13:59.000000000 -0700 +++ linux-2.6.31-fixed/drivers/edac/amd64_edac.c 2009-09-17 22:32:09.000000000 -0700 @@ -1,6 +1,8 @@ -#include "amd64_edac.h" +#include <linux/log2.h> #include <asm/k8.h> +#include "amd64_edac.h" + static struct edac_pci_ctl_info *amd64_ctl_pci; static int report_gart_errors; @@ -132,7 +134,7 @@ /* Map from a CSROW entry to the mask entry that operates on it */ static inline u32 amd64_map_to_dcs_mask(struct amd64_pvt *pvt, int csrow) { - return csrow >> (pvt->num_dcsm >> 3); + return csrow >> (8 >> (ilog2(pvt->num_dcsm)+1)); } /* return the 'base' address the i'th CS entry of the 'dct' DRAM controller */ diff -urN linux-2.6.31/drivers/edac/amd64_edac.h linux-2.6.31-fixed/drivers/edac/amd64_edac.h --- linux-2.6.31/drivers/edac/amd64_edac.h 2009-09-17 22:22:18.000000000 -0700 +++ linux-2.6.31-fixed/drivers/edac/amd64_edac.h 2009-09-17 22:48:50.000000000 -0700 @@ -526,7 +526,7 @@ /* * The following fields are set at (load) run time, after CPU revision * has been determined, since the dct_base and dct_mask registers vary - * based on revision + * based on revision. num_dcsm is assumed to be a power of 2. */ u32 dcsb_base; /* DCSB base bits */ u32 dcsm_mask; /* DCSM mask bits */
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