From 0d7fc080ba139a2a639d3732616403ccddfa2d36 Mon Sep 17 00:00:00 2001 From: Vaibhav Jain Date: Sat, 29 Jun 2019 21:36:09 +0530 Subject: [PATCH] powerpc/papr_scm: Update drc_pmem_unbind() to use H_SCM_UNBIND_ALL The new hcall named H_SCM_UNBIND_ALL has been introduce that can unbind all or specific scm memory assigned to an lpar. This is more efficient than using H_SCM_UNBIND_MEM as currently we don't support partial unbind of scm memory. Hence this patch proposes following changes to drc_pmem_unbind(): * Update drc_pmem_unbind() to replace hcall H_SCM_UNBIND_MEM to H_SCM_UNBIND_ALL. * Update drc_pmem_unbind() to handles cases when PHYP asks the guest kernel to wait for specific amount of time before retrying the hcall via the 'LONG_BUSY' return value. * Ensure appropriate error code is returned back from the function in case of an error. Reviewed-by: Oliver O'Halloran Signed-off-by: Vaibhav Jain Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190629160610.23402-3-vaibhav@linux.ibm.com --- arch/powerpc/platforms/pseries/papr_scm.c | 29 +++++++++++++++++------ 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c index c8ec670ee924..82568a7e0a7c 100644 --- a/arch/powerpc/platforms/pseries/papr_scm.c +++ b/arch/powerpc/platforms/pseries/papr_scm.c @@ -11,6 +11,7 @@ #include #include #include +#include #include @@ -78,22 +79,36 @@ static int drc_pmem_bind(struct papr_scm_priv *p) static int drc_pmem_unbind(struct papr_scm_priv *p) { unsigned long ret[PLPAR_HCALL_BUFSIZE]; - uint64_t rc, token; + uint64_t token = 0; + int64_t rc; - token = 0; + dev_dbg(&p->pdev->dev, "unbind drc %x\n", p->drc_index); - /* NB: unbind has the same retry requirements mentioned above */ + /* NB: unbind has the same retry requirements as drc_pmem_bind() */ do { - rc = plpar_hcall(H_SCM_UNBIND_MEM, ret, p->drc_index, - p->bound_addr, p->blocks, token); + + /* Unbind of all SCM resources associated with drcIndex */ + rc = plpar_hcall(H_SCM_UNBIND_ALL, ret, H_UNBIND_SCOPE_DRC, + p->drc_index, token); token = ret[0]; - cond_resched(); + + /* Check if we are stalled for some time */ + if (H_IS_LONG_BUSY(rc)) { + msleep(get_longbusy_msecs(rc)); + rc = H_BUSY; + } else if (rc == H_BUSY) { + cond_resched(); + } + } while (rc == H_BUSY); if (rc) dev_err(&p->pdev->dev, "unbind error: %lld\n", rc); + else + dev_dbg(&p->pdev->dev, "unbind drc %x complete\n", + p->drc_index); - return !!rc; + return rc == H_SUCCESS ? 0 : -ENXIO; } static int papr_scm_meta_get(struct papr_scm_priv *p,