From faa6d21153fd11e139dd880044521389b34a24f2 Mon Sep 17 00:00:00 2001
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Date: Tue, 3 Sep 2019 18:04:52 +0530
Subject: [PATCH] powerpc/nvdimm: use H_SCM_QUERY hcall on H_OVERLAP error
References: bsc#1175284
Patch-mainline: v5.4-rc1
Git-commit: faa6d21153fd11e139dd880044521389b34a24f2
Right now we force an unbind of SCM memory at drcindex on H_OVERLAP error.
This really slows down operations like kexec where we get the H_OVERLAP
error because we don't go through a full hypervisor re init.
H_OVERLAP error for a H_SCM_BIND_MEM hcall indicates that SCM memory at
drc index is already bound. Since we don't specify a logical memory
address for bind hcall, we can use the H_SCM_QUERY hcall to query
the already bound logical address.
Boot time difference with and without patch is:
[ 5.583617] IOMMU table initialized, virtual merging enabled
[ 5.603041] papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Retrying bind after unbinding
[ 301.514221] papr_scm ibm,persistent-memory:ibm,pmemory@44108001: Retrying bind after unbinding
[ 340.057238] hv-24x7: read 1530 catalog entries, created 537 event attrs (0 failures), 275 descs
after fix
[ 5.101572] IOMMU table initialized, virtual merging enabled
[ 5.116984] papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Querying SCM details
[ 5.117223] papr_scm ibm,persistent-memory:ibm,pmemory@44108001: Querying SCM details
[ 5.120530] hv-24x7: read 1530 catalog entries, created 537 event attrs (0 failures), 275 descs
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190903123452.28620-2-aneesh.kumar@linux.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/platforms/pseries/papr_scm.c | 48 +++++++++++++++++++----
1 file changed, 40 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
index 3bef4d298ac6..61883291defc 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -65,10 +65,8 @@ static int drc_pmem_bind(struct papr_scm_priv *p)
cond_resched();
} while (rc == H_BUSY);
- if (rc) {
- dev_err(&p->pdev->dev, "bind err: %lld\n", rc);
+ if (rc)
return rc;
- }
p->bound_addr = saved;
dev_dbg(&p->pdev->dev, "bound drc 0x%x to %pR\n", p->drc_index, &p->res);
@@ -110,6 +108,42 @@ static void drc_pmem_unbind(struct papr_scm_priv *p)
return;
}
+static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
+{
+ unsigned long start_addr;
+ unsigned long end_addr;
+ unsigned long ret[PLPAR_HCALL_BUFSIZE];
+ int64_t rc;
+
+
+ rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
+ p->drc_index, 0);
+ if (rc)
+ goto err_out;
+ start_addr = ret[0];
+
+ /* Make sure the full region is bound. */
+ rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
+ p->drc_index, p->blocks - 1);
+ if (rc)
+ goto err_out;
+ end_addr = ret[0];
+
+ if ((end_addr - start_addr) != ((p->blocks - 1) * p->block_size))
+ goto err_out;
+
+ p->bound_addr = start_addr;
+ dev_dbg(&p->pdev->dev, "bound drc 0x%x to %pR\n", p->drc_index, &p->res);
+ return rc;
+
+err_out:
+ dev_info(&p->pdev->dev,
+ "Failed to query, trying an unbind followed by bind");
+ drc_pmem_unbind(p);
+ return drc_pmem_bind(p);
+}
+
+
static int papr_scm_meta_get(struct papr_scm_priv *p,
struct nd_cmd_get_config_data_hdr *hdr)
{
@@ -430,13 +464,11 @@ static int papr_scm_probe(struct platform_device *pdev)
rc = drc_pmem_bind(p);
/* If phyp says drc memory still bound then force unbound and retry */
- if (rc == H_OVERLAP) {
- dev_warn(&pdev->dev, "Retrying bind after unbinding\n");
- drc_pmem_unbind(p);
- rc = drc_pmem_bind(p);
- }
+ if (rc == H_OVERLAP)
+ rc = drc_pmem_query_n_bind(p);
if (rc != H_SUCCESS) {
+ dev_err(&p->pdev->dev, "bind err: %d\n", rc);
rc = -ENXIO;
goto err;
}
--
2.26.2