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authorVaibhav Jain <vaibhav@linux.ibm.com>2019-06-29 21:36:10 +0530
committerMichael Ellerman <mpe@ellerman.id.au>2019-07-22 23:31:00 +1000
commit3a855b7ac7d5021674aa3e1cc9d3bfd6b604e9c0 (patch)
treeae04913f24c6fcae47a3a1b7eca58bd94b067406 /arch/powerpc/platforms
parent0d7fc080ba139a2a639d3732616403ccddfa2d36 (diff)
powerpc/papr_scm: Force a scm-unbind if initial scm-bind fails
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> Reviewed-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190629160610.23402-4-vaibhav@linux.ibm.com
Diffstat (limited to 'arch/powerpc/platforms')
-rw-r--r--arch/powerpc/platforms/pseries/papr_scm.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
index 82568a7e0a7c..2c07908359b2 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -44,8 +44,9 @@ 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
@@ -65,6 +66,10 @@ 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;
}
@@ -404,6 +409,14 @@ 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 says drc memory still bound then 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;