Messages in this thread | | | Subject | Re: [PATCH V4 01/10] acpi: apei: read ack upon ghes record consumption | From | Suzuki K Poulose <> | Date | Mon, 24 Oct 2016 09:51:47 +0100 |
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On 21/10/16 18:30, Tyler Baicar wrote: > A RAS (Reliability, Availability, Serviceability) controller > may be a separate processor running in parallel with OS > execution, and may generate error records for consumption by > the OS. If the RAS controller produces multiple error records, > then they may be overwritten before the OS has consumed them. > > The Generic Hardware Error Source (GHES) v2 structure > introduces the capability for the OS to acknowledge the > consumption of the error record generated by the RAS > controller. A RAS controller supporting GHESv2 shall wait for > the acknowledgment before writing a new error record, thus > eliminating the race condition. > > Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org> > Signed-off-by: Richard Ruigrok <rruigrok@codeaurora.org> > Signed-off-by: Tyler Baicar <tbaicar@codeaurora.org> > Signed-off-by: Naveen Kaje <nkaje@codeaurora.org> > --- > drivers/acpi/apei/ghes.c | 42 ++++++++++++++++++++++++++++++++++++++++++ > drivers/acpi/apei/hest.c | 7 +++++-- > include/acpi/ghes.h | 5 ++++- > 3 files changed, 51 insertions(+), 3 deletions(-) > > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c > index 60746ef..7d020b0 100644 > --- a/drivers/acpi/apei/ghes.c > +++ b/drivers/acpi/apei/ghes.c > @@ -45,6 +45,7 @@ > #include <linux/aer.h> > #include <linux/nmi.h> > > +#include <acpi/actbl1.h> > #include <acpi/ghes.h> > #include <acpi/apei.h> > #include <asm/tlbflush.h> > @@ -79,6 +80,10 @@ > ((struct acpi_hest_generic_status *) \ > ((struct ghes_estatus_node *)(estatus_node) + 1)) > > +#define HEST_TYPE_GENERIC_V2(ghes) \ > + ((struct acpi_hest_header *)ghes->generic)->type == \ > + ACPI_HEST_TYPE_GENERIC_ERROR_V2 > + > /* > * This driver isn't really modular, however for the time being, > * continuing to use module_param is the easiest way to remain > @@ -248,7 +253,15 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic) > ghes = kzalloc(sizeof(*ghes), GFP_KERNEL); > if (!ghes) > return ERR_PTR(-ENOMEM); > + > ghes->generic = generic; > + if (HEST_TYPE_GENERIC_V2(ghes)) { > + rc = apei_map_generic_address( > + &ghes->generic_v2->read_ack_register); > + if (rc) > + goto err_unmap;
I think should be goto err_free, see more below.
> + } > + > rc = apei_map_generic_address(&generic->error_status_address); > if (rc) > goto err_free; > @@ -270,6 +283,9 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic) > > err_unmap: > apei_unmap_generic_address(&generic->error_status_address); > + if (HEST_TYPE_GENERIC_V2(ghes)) > + apei_unmap_generic_address( > + &ghes->generic_v2->read_ack_register);
We might end up trying to unmap (error_status_address) which is not mapped if we hit the error in mapping read_ack_register. The read_ack_register unmap hunk should be moved below to err_free.
> err_free: > kfree(ghes); > return ERR_PTR(rc); > @@ -279,6 +295,9 @@ static void ghes_fini(struct ghes *ghes) > { > kfree(ghes->estatus); > apei_unmap_generic_address(&ghes->generic->error_status_address); > + if (HEST_TYPE_GENERIC_V2(ghes)) > + apei_unmap_generic_address( > + &ghes->generic_v2->read_ack_register); > } > > static inline int ghes_severity(int severity) > @@ -648,6 +667,23 @@ static void ghes_estatus_cache_add( > rcu_read_unlock(); > } >
> +static int ghes_do_read_ack(struct acpi_hest_generic_v2 *generic_v2)
nit: We are actually writing something to the read_ack_register. The names read_ack_register (which may be as per standard) and more importantly the function name (ghes_do_read_ack) sounds a bit misleading.
Rest looks fine to me.
Suzuki
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