[PATCH 5/5] acpi, nfit: limit ->flush_probe() to initialization work

From: Dan Williams
Date: Fri Apr 14 2017 - 13:04:34 EST


The nvdimm probe flushing mechanism gives userspace a sync point where
it knows all asynchronous driver probe sequences have completed.
However, it need not wait for other asynchronous actions, like
on-demand address-range-scrub. Track the init work separately from other
work in the workqueue, and only flush the former.

Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/acpi/nfit/core.c | 13 ++++++++++---
drivers/acpi/nfit/nfit.h | 1 +
2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 06738df477db..17cac9d369e0 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -738,7 +738,7 @@ static void nfit_mem_init_bdw(struct acpi_nfit_desc *acpi_desc,
}
}

-static int nfit_mem_dcr_init(struct acpi_nfit_desc *acpi_desc,
+static int __nfit_mem_init(struct acpi_nfit_desc *acpi_desc,
struct acpi_nfit_system_address *spa)
{
struct nfit_mem *nfit_mem, *found;
@@ -898,7 +898,7 @@ static int nfit_mem_init(struct acpi_nfit_desc *acpi_desc)
* BDWs are optional.
*/
list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
- rc = nfit_mem_dcr_init(acpi_desc, nfit_spa->spa);
+ rc = __nfit_mem_init(acpi_desc, nfit_spa->spa);
if (rc)
return rc;
}
@@ -908,7 +908,7 @@ static int nfit_mem_init(struct acpi_nfit_desc *acpi_desc)
* SPA entries above. Find and register all the unmapped DIMMs
* for reporting and recovery purposes.
*/
- rc = nfit_mem_dcr_init(acpi_desc, NULL);
+ rc = __nfit_mem_init(acpi_desc, NULL);
if (rc)
return rc;

@@ -2568,6 +2568,7 @@ static void acpi_nfit_scrub(struct work_struct *work)
acpi_nfit_register_region(acpi_desc, nfit_spa);
}
}
+ acpi_desc->init_complete = 1;

list_for_each_entry(nfit_spa, &acpi_desc->spas, list)
acpi_nfit_async_scrub(acpi_desc, nfit_spa);
@@ -2771,6 +2772,12 @@ static int acpi_nfit_flush_probe(struct nvdimm_bus_descriptor *nd_desc)
device_lock(dev);
device_unlock(dev);

+ /* bounce the init_mutex to make init_complete valid */
+ mutex_lock(&acpi_desc->init_mutex);
+ mutex_unlock(&acpi_desc->init_mutex);
+ if (acpi_desc->init_complete)
+ return 0;
+
/*
* Scrub work could take 10s of seconds, userspace may give up so we
* need to be interruptible while waiting.
diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h
index fc29c2e9832e..256829597585 100644
--- a/drivers/acpi/nfit/nfit.h
+++ b/drivers/acpi/nfit/nfit.h
@@ -163,6 +163,7 @@ struct acpi_nfit_desc {
unsigned int scrub_count;
unsigned int scrub_mode;
unsigned int cancel:1;
+ unsigned int init_complete:1;
unsigned long dimm_cmd_force_en;
unsigned long bus_cmd_force_en;
int (*blk_do_io)(struct nd_blk_region *ndbr, resource_size_t dpa,