From: Robert Richter <rrichter@marvell.com>
To: Borislav Petkov <bp@alien8.de>, James Morse <james.morse@arm.com>,
"Mauro Carvalho Chehab" <mchehab@kernel.org>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Robert Richter <rrichter@marvell.com>
Subject: [PATCH v2 01/24] EDAC, mc: Fix grain_bits calculation
Date: Mon, 24 Jun 2019 15:08:55 +0000 [thread overview]
Message-ID: <20190624150758.6695-2-rrichter@marvell.com> (raw)
In-Reply-To: <20190624150758.6695-1-rrichter@marvell.com>
The grain in edac is defined as "minimum granularity for an error
report, in bytes". The following calculation of the grain_bits in
edac_mc is wrong:
grain_bits = fls_long(e->grain) + 1;
Where grain_bits is defined as:
grain = 1 << grain_bits
Example:
grain = 8 # 64 bit (8 bytes)
grain_bits = fls_long(8) + 1
grain_bits = 4 + 1 = 5
grain = 1 << grain_bits
grain = 1 << 5 = 32
Replacing it with the correct calculation:
grain_bits = fls_long(e->grain - 1);
The example gives now:
grain_bits = fls_long(8 - 1)
grain_bits = fls_long(8 - 1)
grain_bits = 3
grain = 1 << 3 = 8
Note: We need to check if the hardware reports a reasonable grain != 0
and fallback with a warn_once and 1 byte granularity otherwise.
Signed-off-by: Robert Richter <rrichter@marvell.com>
---
drivers/edac/edac_mc.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 64922c8fa7e3..45cac74ab833 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -1235,9 +1235,15 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
if (p > e->location)
*(p - 1) = '\0';
- /* Report the error via the trace interface */
- grain_bits = fls_long(e->grain) + 1;
+ /*
+ * We expect the hw to report a reasonable grain, fallback to
+ * 1 byte granularity otherwise.
+ */
+ if (WARN_ON_ONCE(!e->grain))
+ e->grain = 1;
+ grain_bits = fls_long(e->grain - 1);
+ /* Report the error via the trace interface */
if (IS_ENABLED(CONFIG_RAS))
trace_mc_event(type, e->msg, e->label, e->error_count,
mci->mc_idx, e->top_layer, e->mid_layer,
--
2.20.1
next prev parent reply other threads:[~2019-06-24 15:09 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-24 15:08 [PATCH v2 00/24] EDAC, mc, ghes: Fixes and updates to improve memory error reporting Robert Richter
2019-06-24 15:08 ` Robert Richter [this message]
2019-08-03 10:08 ` [PATCH v2 01/24] EDAC, mc: Fix grain_bits calculation Borislav Petkov
2019-06-24 15:08 ` [PATCH v2 02/24] EDAC, ghes: Fix grain calculation Robert Richter
2019-08-09 13:15 ` Borislav Petkov
2019-08-12 6:42 ` Robert Richter
2019-08-12 7:32 ` Borislav Petkov
2019-08-12 12:05 ` Robert Richter
2019-08-12 12:38 ` Borislav Petkov
2019-06-24 15:08 ` [PATCH v2 03/24] EDAC, ghes: Remove pvt->detail_location string Robert Richter
2019-08-02 17:04 ` James Morse
2019-08-07 9:00 ` Robert Richter
2019-08-13 8:09 ` Borislav Petkov
2019-06-24 15:09 ` [PATCH v2 04/24] EDAC, ghes: Unify trace_mc_event() code with edac_mc driver Robert Richter
2019-06-24 15:09 ` [PATCH v2 05/24] EDAC, mc: Fix and improve sysfs init functions Robert Richter
2019-08-13 8:26 ` Borislav Petkov
2019-06-24 15:09 ` [PATCH v2 06/24] EDAC: Kill EDAC_DIMM_PTR() macro Robert Richter
2019-08-13 14:59 ` Borislav Petkov
2019-08-27 12:20 ` Robert Richter
2019-06-24 15:09 ` [PATCH v2 07/24] EDAC: Kill EDAC_DIMM_OFF() macro Robert Richter
2019-08-14 14:52 ` Borislav Petkov
2019-06-24 15:09 ` [PATCH v2 08/24] EDAC: Introduce mci_for_each_dimm() iterator Robert Richter
2019-08-14 15:18 ` Borislav Petkov
2019-08-28 8:18 ` Robert Richter
2019-06-24 15:09 ` [PATCH v2 09/24] EDAC, mc: Cleanup _edac_mc_free() code Robert Richter
2019-08-14 16:31 ` Borislav Petkov
2019-06-24 15:09 ` [PATCH v2 10/24] EDAC, mc: Remove per layer counters Robert Richter
2019-08-16 9:24 ` Borislav Petkov
2019-06-24 15:09 ` [PATCH v2 11/24] EDAC, mc: Rework edac_raw_mc_handle_error() to use struct dimm_info Robert Richter
2019-06-24 15:09 ` [PATCH v2 12/24] EDAC, ghes: Use standard kernel macros for page calculations Robert Richter
2019-08-02 17:04 ` James Morse
2019-08-07 9:52 ` Robert Richter
2019-06-24 15:09 ` [PATCH v2 13/24] EDAC, ghes: Add support for legacy API counters Robert Richter
2019-08-16 9:55 ` Borislav Petkov
2019-08-30 9:35 ` Robert Richter
2019-06-24 15:09 ` [PATCH v2 14/24] EDAC, ghes: Rework memory hierarchy detection Robert Richter
2019-08-20 8:56 ` Borislav Petkov
2019-06-24 15:09 ` [PATCH v2 15/24] EDAC, ghes: Extract numa node information for each dimm Robert Richter
2019-08-02 17:05 ` James Morse
2019-08-09 13:09 ` Robert Richter
2019-06-24 15:09 ` [PATCH v2 16/24] EDAC, ghes: Moving code around ghes_edac_register() Robert Richter
2019-06-24 15:09 ` [PATCH v2 17/24] EDAC, ghes: Create one memory controller device per node Robert Richter
2019-06-24 15:09 ` [PATCH v2 18/24] EDAC, ghes: Fill sysfs with the DMI DIMM label information Robert Richter
2019-06-24 15:09 ` [PATCH v2 19/24] EDAC, mc: Introduce edac_mc_alloc_by_dimm() for per dimm allocation Robert Richter
2019-06-24 15:09 ` [PATCH v2 20/24] EDAC, ghes: Identify dimm by node, card, module and handle Robert Richter
2019-06-24 15:09 ` [PATCH v2 21/24] EDAC, ghes: Enable per-layer reporting based on card/module Robert Richter
2019-06-24 15:09 ` [PATCH v2 22/24] EDAC, ghes: Move struct member smbios_handle to struct ghes_dimm_info Robert Richter
2019-06-24 15:09 ` [PATCH v2 23/24] EDAC, Documentation: Describe CPER module definition and DIMM ranks Robert Richter
2019-06-24 15:09 ` [PATCH v2 24/24] EDAC, ghes: Disable legacy API for ARM64 Robert Richter
2019-06-26 9:33 ` James Morse
2019-06-26 10:11 ` Robert Richter
2019-08-02 7:58 ` [PATCH v2 00/24] EDAC, mc, ghes: Fixes and updates to improve memory error reporting Robert Richter
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