linux-kernel - [PATCH v3 22/23] dax/hmem: Introduce dax_hmem.region

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 31 Jul 2020 20:27:01 -0700
From:   Dan Williams <dan.j.williams@...el.com>
To:     akpm@...ux-foundation.org
Cc:     Joao Martins <joao.m.martins@...cle.com>, peterz@...radead.org,
        vishal.l.verma@...el.com, dave.hansen@...ux.intel.com,
        ard.biesheuvel@...aro.org, vishal.l.verma@...el.com,
        linux-mm@...ck.org, linux-nvdimm@...ts.01.org,
        joao.m.martins@...cle.com, linux-kernel@...r.kernel.org,
        linux-acpi@...r.kernel.org, dri-devel@...ts.freedesktop.org
Subject: [PATCH v3 22/23] dax/hmem: Introduce dax_hmem.region_idle parameter

From: Joao Martins <joao.m.martins@...cle.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@...cle.com>
Link: https://lore.kernel.org/r/20200716172913.19658-4-joao.m.martins@oracle.com
Signed-off-by: Dan Williams <dan.j.williams@...el.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))