[PATCH v3 22/23] dax/hmem: Introduce dax_hmem.region_idle parameter

Dan Williams
2020-08-01T03:43:22Z

From: Joao Martins <joao.m.martins@oracle.com>

Introduce a new module parameter for dax_hmem which
initializes all region devices as free, rather than allocating
a pagemap for the region by default.

All hmem devices created with dax_hmem.region_idle=1 will have full
available size for creating dynamic dax devices.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Link: https://lore.kernel.org/r/20200716172913.19658-4-joao.m.martins@oracle.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/dax/hmem/hmem.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
index 1a3347bb6143..1bf040dbc834 100644
--- a/drivers/dax/hmem/hmem.c
+++ b/drivers/dax/hmem/hmem.c
@@ -5,6 +5,9 @@
#include <linux/pfn_t.h>
#include "../bus.h"

+static bool region_idle;
+module_param_named(region_idle, region_idle, bool, 0644);
+
static int dax_hmem_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -30,7 +33,7 @@ static int dax_hmem_probe(struct platform_device *pdev)
data = (struct dev_dax_data) {
.dax_region = dax_region,
.id = -1,
- .size = resource_size(res),
+ .size = region_idle ? 0 : resource_size(res),
};
dev_dax = devm_create_dev_dax(&data);
if (IS_ERR(dev_dax))