[PATCH v3 1/3] nfit, address-range-scrub: determine one platform max_ars value

From: Dan Williams
Date: Sat Apr 07 2018 - 11:56:01 EST


acpi_nfit_query_poison() is awkward in that it requires an nfit_spa
argument in order to determine what max_ars value to use. Instead probe
for the minimum max_ars across all scrub-capable ranges in the system
and drop the nfit_spa argument.

This enables a larger rework / simplification of the ARS state machine
whereby the status can be retrieved once and then iterated over all
address ranges to reap completions.

Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/acpi/nfit/core.c | 78 ++++++++++++++++++++++++----------------------
drivers/acpi/nfit/nfit.h | 2 +
2 files changed, 41 insertions(+), 39 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 9c56022c216f..866853abebea 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -2494,16 +2494,16 @@ static int ars_get_status(struct acpi_nfit_desc *acpi_desc)
int rc, cmd_rc;

rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_STATUS, ars_status,
- acpi_desc->ars_status_size, &cmd_rc);
+ acpi_desc->max_ars, &cmd_rc);
if (rc < 0)
return rc;
return cmd_rc;
}

-static int ars_status_process_records(struct acpi_nfit_desc *acpi_desc,
- struct nd_cmd_ars_status *ars_status)
+static int ars_status_process_records(struct acpi_nfit_desc *acpi_desc)
{
struct nvdimm_bus *nvdimm_bus = acpi_desc->nvdimm_bus;
+ struct nd_cmd_ars_status *ars_status = acpi_desc->ars_status;
int rc;
u32 i;

@@ -2739,60 +2739,35 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
return rc;
}

-static int ars_status_alloc(struct acpi_nfit_desc *acpi_desc,
- u32 max_ars)
+static int ars_status_alloc(struct acpi_nfit_desc *acpi_desc)
{
struct device *dev = acpi_desc->dev;
struct nd_cmd_ars_status *ars_status;

- if (acpi_desc->ars_status && acpi_desc->ars_status_size >= max_ars) {
- memset(acpi_desc->ars_status, 0, acpi_desc->ars_status_size);
+ if (acpi_desc->ars_status) {
+ memset(acpi_desc->ars_status, 0, acpi_desc->max_ars);
return 0;
}

- if (acpi_desc->ars_status)
- devm_kfree(dev, acpi_desc->ars_status);
- acpi_desc->ars_status = NULL;
- ars_status = devm_kzalloc(dev, max_ars, GFP_KERNEL);
+ ars_status = devm_kzalloc(dev, acpi_desc->max_ars, GFP_KERNEL);
if (!ars_status)
return -ENOMEM;
acpi_desc->ars_status = ars_status;
- acpi_desc->ars_status_size = max_ars;
return 0;
}

-static int acpi_nfit_query_poison(struct acpi_nfit_desc *acpi_desc,
- struct nfit_spa *nfit_spa)
+static int acpi_nfit_query_poison(struct acpi_nfit_desc *acpi_desc)
{
- struct acpi_nfit_system_address *spa = nfit_spa->spa;
int rc;

- if (!nfit_spa->max_ars) {
- struct nd_cmd_ars_cap ars_cap;
-
- memset(&ars_cap, 0, sizeof(ars_cap));
- rc = ars_get_cap(acpi_desc, &ars_cap, nfit_spa);
- if (rc < 0)
- return rc;
- nfit_spa->max_ars = ars_cap.max_ars_out;
- nfit_spa->clear_err_unit = ars_cap.clear_err_unit;
- /* check that the supported scrub types match the spa type */
- if (nfit_spa_type(spa) == NFIT_SPA_VOLATILE &&
- ((ars_cap.status >> 16) & ND_ARS_VOLATILE) == 0)
- return -ENOTTY;
- else if (nfit_spa_type(spa) == NFIT_SPA_PM &&
- ((ars_cap.status >> 16) & ND_ARS_PERSISTENT) == 0)
- return -ENOTTY;
- }
-
- if (ars_status_alloc(acpi_desc, nfit_spa->max_ars))
+ if (ars_status_alloc(acpi_desc))
return -ENOMEM;

rc = ars_get_status(acpi_desc);
if (rc < 0 && rc != -ENOSPC)
return rc;

- if (ars_status_process_records(acpi_desc, acpi_desc->ars_status))
+ if (ars_status_process_records(acpi_desc))
return -ENOMEM;

return 0;
@@ -2824,7 +2799,7 @@ static void acpi_nfit_async_scrub(struct acpi_nfit_desc *acpi_desc,

if (acpi_desc->cancel)
break;
- rc = acpi_nfit_query_poison(acpi_desc, nfit_spa);
+ rc = acpi_nfit_query_poison(acpi_desc);
if (rc == -ENOTTY)
break;
if (rc == -EBUSY && !tmo) {
@@ -2925,7 +2900,7 @@ static void acpi_nfit_scrub(struct work_struct *work)
*/
rc = 0;
} else
- rc = acpi_nfit_query_poison(acpi_desc, nfit_spa);
+ rc = acpi_nfit_query_poison(acpi_desc);

if (rc == -ENOTTY) {
/* no ars capability, just register spa and move on */
@@ -3018,6 +2993,31 @@ static void acpi_nfit_scrub(struct work_struct *work)
mutex_unlock(&acpi_desc->init_mutex);
}

+static void acpi_nfit_init_ars(struct acpi_nfit_desc *acpi_desc,
+ struct nfit_spa *nfit_spa)
+{
+ int type = nfit_spa_type(nfit_spa->spa);
+ struct nd_cmd_ars_cap ars_cap;
+ int rc;
+
+ memset(&ars_cap, 0, sizeof(ars_cap));
+ rc = ars_get_cap(acpi_desc, &ars_cap, nfit_spa);
+ if (rc < 0)
+ return;
+ /* check that the supported scrub types match the spa type */
+ if (type == NFIT_SPA_VOLATILE && ((ars_cap.status >> 16)
+ & ND_ARS_VOLATILE) == 0)
+ return;
+ if (type == NFIT_SPA_PM && ((ars_cap.status >> 16)
+ & ND_ARS_PERSISTENT) == 0)
+ return;
+
+ nfit_spa->max_ars = ars_cap.max_ars_out;
+ nfit_spa->clear_err_unit = ars_cap.clear_err_unit;
+ acpi_desc->max_ars = max(nfit_spa->max_ars, acpi_desc->max_ars);
+}
+
+
static int acpi_nfit_register_regions(struct acpi_nfit_desc *acpi_desc)
{
struct nfit_spa *nfit_spa;
@@ -3026,8 +3026,10 @@ static int acpi_nfit_register_regions(struct acpi_nfit_desc *acpi_desc)
int rc, type = nfit_spa_type(nfit_spa->spa);

/* PMEM and VMEM will be registered by the ARS workqueue */
- if (type == NFIT_SPA_PM || type == NFIT_SPA_VOLATILE)
+ if (type == NFIT_SPA_PM || type == NFIT_SPA_VOLATILE) {
+ acpi_nfit_init_ars(acpi_desc, nfit_spa);
continue;
+ }
/* BLK apertures belong to BLK region registration below */
if (type == NFIT_SPA_BDW)
continue;
diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h
index 2b97e5f76bdf..45e7949986a8 100644
--- a/drivers/acpi/nfit/nfit.h
+++ b/drivers/acpi/nfit/nfit.h
@@ -197,10 +197,10 @@ struct acpi_nfit_desc {
struct device *dev;
u8 ars_start_flags;
struct nd_cmd_ars_status *ars_status;
- size_t ars_status_size;
struct work_struct work;
struct list_head list;
struct kernfs_node *scrub_count_state;
+ unsigned int max_ars;
unsigned int scrub_count;
unsigned int scrub_mode;
unsigned int cancel:1;