Re: [PATCH 4/4] EDAC: Convert AMD EDAC pieces to use RAS printk buffer

Mauro Carvalho Chehab
2012-03-02T14:53:28Z

Em 02-03-2012 11:25, Borislav Petkov escreveu:
> From: Borislav Petkov <borislav.petkov@amd.com>
>
> This is an initial version of the patch which converts MCE decoding
> facilities to use the RAS printk buffer. When there's no userspace agent
> running (i.e., /sys/devices/system/ras/agent == 0), we fall back to the
> default printk's into dmesg which is what we've been doing so far.
>
> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
> ---
> drivers/edac/amd64_edac.c | 8 ++-
> drivers/edac/edac_mc.c | 42 ++++++---
> drivers/edac/mce_amd.c | 217 ++++++++++++++++++++++++---------------------
> 3 files changed, 149 insertions(+), 118 deletions(-)
>
> diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
> index 08413377a43b..29e153c57e33 100644
> --- a/drivers/edac/amd64_edac.c
> +++ b/drivers/edac/amd64_edac.c
> @@ -1,6 +1,7 @@
> -#include "amd64_edac.h"
> #include <asm/amd_nb.h>
> +#include <asm/ras.h>
>
> +#include "amd64_edac.h"
> static struct edac_pci_ctl_info *amd64_ctl_pci;
>
> static int report_gart_errors;
> @@ -1901,7 +1902,10 @@ static void amd64_handle_ce(struct mem_ctl_info *mci, struct mce *m)
> sys_addr = get_error_address(m);
> syndrome = extract_syndrome(m->status);
>
> - amd64_mc_err(mci, "CE ERROR_ADDRESS= 0x%llx\n", sys_addr);
> + if (ras_agent)
> + ras_printk(PR_EMERG, "ERR_ADDR: 0x%llx", sys_addr);
> + else
> + amd64_mc_err(mci, "CE ERROR_ADDRESS= 0x%llx\n", sys_addr);
>
> pvt->ops->map_sysaddr_to_csrow(mci, sys_addr, syndrome);
> }
> diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
> index ca6c04d350ee..3b3db477b5d0 100644
> --- a/drivers/edac/edac_mc.c
> +++ b/drivers/edac/edac_mc.c
> @@ -30,8 +30,10 @@
> #include <asm/uaccess.h>
> #include <asm/page.h>
> #include <asm/edac.h>
> +#include <asm/ras.h>
> #include "edac_core.h"
> #include "edac_module.h"
> +#include "mce_amd.h"
>
> /* lock to memory controller's control array */
> static DEFINE_MUTEX(mem_ctls_mutex);
> @@ -701,14 +703,22 @@ void edac_mc_handle_ce(struct mem_ctl_info *mci,
> return;
> }
>
> - if (edac_mc_get_log_ce())
> - /* FIXME - put in DIMM location */
> - edac_mc_printk(mci, KERN_WARNING,
> - "CE page 0x%lx, offset 0x%lx, grain %d, syndrome "
> - "0x%lx, row %d, channel %d, label \"%s\": %s\n",
> - page_frame_number, offset_in_page,
> - mci->csrows[row].grain, syndrome, row, channel,
> - mci->csrows[row].channels[channel].label, msg);
> + if (edac_mc_get_log_ce()) {
> + if (ras_agent)
> + ras_printk(PR_CONT, ", row: %d, channel: %d\n",
> + row, channel);
> + else
> + /* FIXME - put in DIMM location */
> + edac_mc_printk(mci, KERN_WARNING,
> + "CE page 0x%lx, offset 0x%lx, grain %d,"
> + " syndrome 0x%lx, row %d, channel %d,"
> + " label \"%s\": %s\n",
> + page_frame_number, offset_in_page,
> + mci->csrows[row].grain, syndrome,
> + row, channel,
> + mci->csrows[row].channels[channel].label,
> + msg);
> + }

As I've commented already, This piece of the code is not ok, due
to several reasons:

- the "ras_agent" helper functions is used only for amd64_edac. There's
no reason for use it elsewhere;

- the code here is adding the location only for CE errors. The location
of the error is also pertinent for the other types of errors;

- on my patches, this function disappears, being replaced by a single
function, that can be used to report all types of memory errors;

- non MCA drivers should also generate tracepoints;

- it is a way easier to add just one call to the tracepoint function here, than
to spread on all drivers.

As it is shown at:
http://git.kernel.org/?p=linux/kernel/git/mchehab/linux-edac.git;a=commitdiff_plain;h=4eb2a29419c1fefd76c8dbcd308b84a4b52faf4d

Once we made an agreement with regards to the tracepoint function,
a change similar to what it was proposed there, e. g.:

diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 37d2c97..2dca0e3 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -899,7 +899,7 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
const int layer2,
const char *msg,
const char *other_detail,
- const void *mcelog)
+ const void *arch_log)
{
unsigned long remapped_page;
/* FIXME: too much for stack: move it to some pre-alocated area */
@@ -1033,8 +1047,17 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
"page 0x%lx offset 0x%lx grain %d\n",
page_frame_number, offset_in_page, grain);

+#ifdef CONFIG_X86
+ if (arch_log)
+ trace_mc_error_mce(type, mci->mc_idx, msg, label, location,
+ detail, other_detail, arch_log);
+ else
+ trace_mc_error(type, mci->mc_idx, msg, label, location,
+ detail, other_detail);
+#else
trace_mc_error(type, mci->mc_idx, msg, label, location,
detail, other_detail);
+#endif

if (type == HW_EVENT_ERR_CORRECTED) {
if (edac_mc_get_log_ce())

is enough to generate traces for all existing drivers.

Regards,
Mauro