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authorAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>2019-09-03 18:04:52 +0530
committerMichael Ellerman <mpe@ellerman.id.au>2019-09-25 08:32:59 +1000
commitfaa6d21153fd11e139dd880044521389b34a24f2 (patch)
tree34449539d8880b65cfb1e6b3a62c4bd866a0f5aa /arch/powerpc
parent4111cdef0e871c0f7c8874b19ee68a3671f7d63e (diff)
downloadlinux-faa6d21153fd11e139dd880044521389b34a24f2.tar.bz2
powerpc/nvdimm: use H_SCM_QUERY hcall on H_OVERLAP error
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
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/platforms/pseries/papr_scm.c48
1 files 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;
}