From: Mauro Carvalho Chehab <mchehab@redhat.com> Cc: linux-acpi@vger.kernel.org, Huang Ying <ying.huang@intel.com>, Tony Luck <tony.luck@intel.com>, Mauro Carvalho Chehab <mchehab@redhat.com>, Linux Edac Mailing List <linux-edac@vger.kernel.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org> Subject: [PATCH EDAC 01/13] edac: lock module owner to avoid error report conflicts Date: Fri, 15 Feb 2013 10:44:49 -0200 [thread overview] Message-ID: <7bcfdab898ef7b1d24431ca01d5895f1d4659f89.1360931635.git.mchehab@redhat.com> (raw) In-Reply-To: <cover.1360931635.git.mchehab@redhat.com> APEI GHES and i7core_edac/sb_edac currently can be loaded at the same time, but those are Highlander modules: "There can be only one". There are two reasons for that: 1) Each driver assumes that it is the only one registering at the EDAC core, as it is driver's responsibility to number the memory controllers, and all of them start from 0; 2) If BIOS is handling the memory errors, the OS can't also be doing it, as one will mangle with the other. So, we need to add an module owner's lock at the EDAC core, in order to avoid having two different modules handling memory errors at the same time. The best way for doing this lock seems to use the driver's name, as this is unique, and won't require changes on every driver. Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> --- drivers/edac/edac_mc.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c index fb219bc..8e58b1c 100644 --- a/drivers/edac/edac_mc.c +++ b/drivers/edac/edac_mc.c @@ -42,6 +42,12 @@ static DEFINE_MUTEX(mem_ctls_mutex); static LIST_HEAD(mc_devices); +/* + * Used to lock EDAC MC to just one module, avoiding two drivers e. g. + * apei/ghes and i7core_edac to be used at the same time. + */ +static void const *edac_mc_owner; + unsigned edac_dimm_info_location(struct dimm_info *dimm, char *buf, unsigned len) { @@ -659,9 +665,9 @@ fail1: return 1; } -static void del_mc_from_global_list(struct mem_ctl_info *mci) +static int del_mc_from_global_list(struct mem_ctl_info *mci) { - atomic_dec(&edac_handlers); + int handlers = atomic_dec_return(&edac_handlers); list_del_rcu(&mci->link); /* these are for safe removal of devices from global list while @@ -669,6 +675,8 @@ static void del_mc_from_global_list(struct mem_ctl_info *mci) */ synchronize_rcu(); INIT_LIST_HEAD(&mci->link); + + return handlers; } /** @@ -712,6 +720,7 @@ EXPORT_SYMBOL(edac_mc_find); /* FIXME - should a warning be printed if no error detection? correction? */ int edac_mc_add_mc(struct mem_ctl_info *mci) { + int ret = -EINVAL; edac_dbg(0, "\n"); #ifdef CONFIG_EDAC_DEBUG @@ -742,6 +751,11 @@ int edac_mc_add_mc(struct mem_ctl_info *mci) #endif mutex_lock(&mem_ctls_mutex); + if (edac_mc_owner && edac_mc_owner != mci->mod_name) { + ret = -EPERM; + goto fail0; + } + if (add_mc_to_global_list(mci)) goto fail0; @@ -768,6 +782,8 @@ int edac_mc_add_mc(struct mem_ctl_info *mci) edac_mc_printk(mci, KERN_INFO, "Giving out device to '%s' '%s':" " DEV %s\n", mci->mod_name, mci->ctl_name, edac_dev_name(mci)); + edac_mc_owner = mci->mod_name; + mutex_unlock(&mem_ctls_mutex); return 0; @@ -776,7 +792,7 @@ fail1: fail0: mutex_unlock(&mem_ctls_mutex); - return 1; + return ret; } EXPORT_SYMBOL_GPL(edac_mc_add_mc); @@ -802,7 +818,9 @@ struct mem_ctl_info *edac_mc_del_mc(struct device *dev) return NULL; } - del_mc_from_global_list(mci); + if (!del_mc_from_global_list(mci)) { + edac_mc_owner = NULL; + } mutex_unlock(&mem_ctls_mutex); /* flush workq processes */ -- 1.8.1.2
WARNING: multiple messages have this Message-ID (diff)
From: Mauro Carvalho Chehab <mchehab@redhat.com> To: unlisted-recipients:; (no To-header on input) Cc: linux-acpi@vger.kernel.org, Huang Ying <ying.huang@intel.com>, Tony Luck <tony.luck@intel.com>, Mauro Carvalho Chehab <mchehab@redhat.com>, Linux Edac Mailing List <linux-edac@vger.kernel.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org> Subject: [PATCH EDAC 01/13] edac: lock module owner to avoid error report conflicts Date: Fri, 15 Feb 2013 10:44:49 -0200 [thread overview] Message-ID: <7bcfdab898ef7b1d24431ca01d5895f1d4659f89.1360931635.git.mchehab@redhat.com> (raw) In-Reply-To: <cover.1360931635.git.mchehab@redhat.com> APEI GHES and i7core_edac/sb_edac currently can be loaded at the same time, but those are Highlander modules: "There can be only one". There are two reasons for that: 1) Each driver assumes that it is the only one registering at the EDAC core, as it is driver's responsibility to number the memory controllers, and all of them start from 0; 2) If BIOS is handling the memory errors, the OS can't also be doing it, as one will mangle with the other. So, we need to add an module owner's lock at the EDAC core, in order to avoid having two different modules handling memory errors at the same time. The best way for doing this lock seems to use the driver's name, as this is unique, and won't require changes on every driver. Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> --- drivers/edac/edac_mc.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c index fb219bc..8e58b1c 100644 --- a/drivers/edac/edac_mc.c +++ b/drivers/edac/edac_mc.c @@ -42,6 +42,12 @@ static DEFINE_MUTEX(mem_ctls_mutex); static LIST_HEAD(mc_devices); +/* + * Used to lock EDAC MC to just one module, avoiding two drivers e. g. + * apei/ghes and i7core_edac to be used at the same time. + */ +static void const *edac_mc_owner; + unsigned edac_dimm_info_location(struct dimm_info *dimm, char *buf, unsigned len) { @@ -659,9 +665,9 @@ fail1: return 1; } -static void del_mc_from_global_list(struct mem_ctl_info *mci) +static int del_mc_from_global_list(struct mem_ctl_info *mci) { - atomic_dec(&edac_handlers); + int handlers = atomic_dec_return(&edac_handlers); list_del_rcu(&mci->link); /* these are for safe removal of devices from global list while @@ -669,6 +675,8 @@ static void del_mc_from_global_list(struct mem_ctl_info *mci) */ synchronize_rcu(); INIT_LIST_HEAD(&mci->link); + + return handlers; } /** @@ -712,6 +720,7 @@ EXPORT_SYMBOL(edac_mc_find); /* FIXME - should a warning be printed if no error detection? correction? */ int edac_mc_add_mc(struct mem_ctl_info *mci) { + int ret = -EINVAL; edac_dbg(0, "\n"); #ifdef CONFIG_EDAC_DEBUG @@ -742,6 +751,11 @@ int edac_mc_add_mc(struct mem_ctl_info *mci) #endif mutex_lock(&mem_ctls_mutex); + if (edac_mc_owner && edac_mc_owner != mci->mod_name) { + ret = -EPERM; + goto fail0; + } + if (add_mc_to_global_list(mci)) goto fail0; @@ -768,6 +782,8 @@ int edac_mc_add_mc(struct mem_ctl_info *mci) edac_mc_printk(mci, KERN_INFO, "Giving out device to '%s' '%s':" " DEV %s\n", mci->mod_name, mci->ctl_name, edac_dev_name(mci)); + edac_mc_owner = mci->mod_name; + mutex_unlock(&mem_ctls_mutex); return 0; @@ -776,7 +792,7 @@ fail1: fail0: mutex_unlock(&mem_ctls_mutex); - return 1; + return ret; } EXPORT_SYMBOL_GPL(edac_mc_add_mc); @@ -802,7 +818,9 @@ struct mem_ctl_info *edac_mc_del_mc(struct device *dev) return NULL; } - del_mc_from_global_list(mci); + if (!del_mc_from_global_list(mci)) { + edac_mc_owner = NULL; + } mutex_unlock(&mem_ctls_mutex); /* flush workq processes */ -- 1.8.1.2
next prev parent reply other threads:[~2013-02-15 12:44 UTC|newest] Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-02-15 12:44 [PATCH EDAC 00/13] Add a driver to report Firmware first errors (via GHES) Mauro Carvalho Chehab 2013-02-15 12:44 ` Mauro Carvalho Chehab 2013-02-15 12:44 ` Mauro Carvalho Chehab [this message] 2013-02-15 12:44 ` [PATCH EDAC 01/13] edac: lock module owner to avoid error report conflicts Mauro Carvalho Chehab 2013-02-15 12:44 ` [PATCH EDAC 02/13] ghes: move structures/enum to a header file Mauro Carvalho Chehab 2013-02-15 12:44 ` Mauro Carvalho Chehab 2013-02-15 12:44 ` [PATCH EDAC 03/13] ghes: add the needed hooks for EDAC error report Mauro Carvalho Chehab 2013-02-15 12:44 ` Mauro Carvalho Chehab 2013-02-21 1:26 ` Huang Ying 2013-02-21 12:04 ` Mauro Carvalho Chehab 2013-02-22 0:45 ` Huang Ying 2013-02-22 8:50 ` Mauro Carvalho Chehab 2013-02-22 8:57 ` Mauro Carvalho Chehab 2013-02-25 0:25 ` Huang Ying 2013-02-15 12:44 ` [PATCH EDAC 04/13] edac: add a new memory layer type Mauro Carvalho Chehab 2013-02-15 12:44 ` Mauro Carvalho Chehab 2013-02-15 12:44 ` [PATCH EDAC 05/13] ghes_edac: Register at EDAC core the BIOS report Mauro Carvalho Chehab 2013-02-15 12:44 ` Mauro Carvalho Chehab 2013-02-15 12:44 ` [PATCH EDAC 06/13] ghes_edac: Allow registering more than once Mauro Carvalho Chehab 2013-02-15 12:44 ` Mauro Carvalho Chehab 2013-02-15 12:44 ` [PATCH EDAC 07/13] edac: add support for raw error reports Mauro Carvalho Chehab 2013-02-15 12:44 ` Mauro Carvalho Chehab 2013-02-15 14:13 ` Borislav Petkov 2013-02-15 15:25 ` Mauro Carvalho Chehab 2013-02-15 15:41 ` Borislav Petkov 2013-02-15 15:49 ` Mauro Carvalho Chehab 2013-02-15 16:02 ` Borislav Petkov 2013-02-15 18:20 ` Mauro Carvalho Chehab 2013-02-16 16:57 ` Borislav Petkov 2013-02-16 16:57 ` Borislav Petkov 2013-02-17 10:44 ` Mauro Carvalho Chehab 2013-02-17 10:44 ` Mauro Carvalho Chehab 2013-02-18 13:52 ` Borislav Petkov 2013-02-18 15:24 ` Mauro Carvalho Chehab 2013-02-19 11:56 ` Mauro Carvalho Chehab 2013-02-15 12:44 ` [PATCH EDAC 08/13] ghes_edac: add support for reporting errors via EDAC Mauro Carvalho Chehab 2013-02-15 12:44 ` Mauro Carvalho Chehab 2013-02-15 12:44 ` [PATCH EDAC 09/13] ghes_edac: do a better job of filling EDAC DIMM info Mauro Carvalho Chehab 2013-02-15 12:44 ` Mauro Carvalho Chehab 2013-02-15 12:44 ` [PATCH EDAC 10/13] edac: better report error conditions in debug mode Mauro Carvalho Chehab 2013-02-15 12:44 ` Mauro Carvalho Chehab 2013-02-15 12:44 ` [PATCH EDAC 11/13] edac: initialize the core earlier Mauro Carvalho Chehab 2013-02-15 12:44 ` Mauro Carvalho Chehab 2013-02-15 12:45 ` [PATCH EDAC 12/13] ghes_edac.c: Don't credit the same memory dimm twice Mauro Carvalho Chehab 2013-02-15 12:45 ` Mauro Carvalho Chehab 2013-02-15 12:45 ` [PATCH EDAC 13/13] ghes_edac: Improve driver's printk messages Mauro Carvalho Chehab 2013-02-15 12:45 ` Mauro Carvalho Chehab 2013-02-15 16:38 ` Joe Perches 2013-02-15 17:33 ` Mauro Carvalho Chehab
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