From: Vaibhav Jain <vaibhav@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
Oliver O'Halloran <oohall@gmail.com>,
Vaibhav Jain <vaibhav@linux.ibm.com>,
Laurent Dufour <ldufour@linux.vnet.ibm.com>,
David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH v2 3/3] powerpc/papr_scm: Force a scm-unbind if initial scm-bind fails
Date: Tue, 25 Jun 2019 17:57:09 +0530 [thread overview]
Message-ID: <20190625122709.11846-4-vaibhav@linux.ibm.com> (raw)
In-Reply-To: <20190625122709.11846-1-vaibhav@linux.ibm.com>
In some cases initial bind of scm memory for an lpar can fail if
previously it wasn't released using a scm-unbind hcall. This situation
can arise due to panic of the previous kernel or forced lpar
fadump. In such cases the H_SCM_BIND_MEM return a H_OVERLAP error.
To mitigate such cases the patch updates papr_scm_probe() to force a
call to drc_pmem_unbind() in case the initial bind of scm memory fails
with EBUSY error. In case scm-bind operation again fails after the
forced scm-unbind then we follow the existing error path. We also
update drc_pmem_bind() to handle the H_OVERLAP error returned by phyp
and indicate it as a EBUSY error back to the caller.
Suggested-by: "Oliver O'Halloran" <oohall@gmail.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
---
Change-log:
v2:
* Moved the retry code from drc_pmem_bind() to papr_scm_probe()
[Oliver]
* Changed the type of variable 'rc' in drc_pmem_bind() to
int64_t. [Oliver]
---
arch/powerpc/platforms/pseries/papr_scm.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
index a4e1674bb15c..2c90cbe88313 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -43,8 +43,9 @@ struct papr_scm_priv {
static int drc_pmem_bind(struct papr_scm_priv *p)
{
unsigned long ret[PLPAR_HCALL_BUFSIZE];
- uint64_t rc, token;
uint64_t saved = 0;
+ uint64_t token;
+ int64_t rc;
/*
* When the hypervisor cannot map all the requested memory in a single
@@ -64,6 +65,10 @@ static int drc_pmem_bind(struct papr_scm_priv *p)
} while (rc == H_BUSY);
if (rc) {
+ /* H_OVERLAP needs a separate error path */
+ if (rc == H_OVERLAP)
+ return -EBUSY;
+
dev_err(&p->pdev->dev, "bind err: %lld\n", rc);
return -ENXIO;
}
@@ -331,6 +336,14 @@ static int papr_scm_probe(struct platform_device *pdev)
/* request the hypervisor to bind this region to somewhere in memory */
rc = drc_pmem_bind(p);
+
+ /* If phyp reports drc memory still bound the force unbound and retry */
+ if (rc == -EBUSY) {
+ dev_warn(&pdev->dev, "Retrying bind after unbinding\n");
+ drc_pmem_unbind(p);
+ rc = drc_pmem_bind(p);
+ }
+
if (rc)
goto err;
--
2.21.0
next prev parent reply other threads:[~2019-06-25 12:41 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-25 12:27 [PATCH v2 0/3] powerpc/papr_scm: Workaround for failure of drc bind after kexec Vaibhav Jain
2019-06-25 12:27 ` [PATCH v2 1/3] powerpc/pseries: Update SCM hcall op-codes in hvcall.h Vaibhav Jain
2019-06-26 3:17 ` Oliver O'Halloran
2019-06-25 12:27 ` [PATCH v2 2/3] powerpc/papr_scm: Update drc_pmem_unbind() to use H_SCM_UNBIND_ALL Vaibhav Jain
2019-06-25 20:35 ` kbuild test robot
2019-06-26 3:47 ` Oliver O'Halloran
2019-06-25 12:27 ` Vaibhav Jain [this message]
2019-06-26 3:24 ` [PATCH v2 3/3] powerpc/papr_scm: Force a scm-unbind if initial scm-bind fails Oliver O'Halloran
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