[PATCH v3 1/5] crypto: ccp: Get a free page to use while fetching initial nonce

Mario Limonciello
2023-08-29T17:34:47Z

dbc_dev_init() gets a free page from `GFP_KERNEL`, but if that page has
any data in it the first nonce request will fail.
This prevents dynamic boost control from probing. To fix this, explicitly
request a zeroed page with `__GFP_ZERO` to ensure first nonce fetch works.

Fixes: c04cf9e14f10 ("crypto: ccp - Add support for fetching a nonce for dynamic boost control")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
drivers/crypto/ccp/dbc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/crypto/ccp/dbc.c b/drivers/crypto/ccp/dbc.c
index 839ea14b9a85..6f33149ef80d 100644
--- a/drivers/crypto/ccp/dbc.c
+++ b/drivers/crypto/ccp/dbc.c
@@ -205,7 +205,7 @@ int dbc_dev_init(struct psp_device *psp)
return -ENOMEM;

BUILD_BUG_ON(sizeof(union dbc_buffer) > PAGE_SIZE);
- dbc_dev->mbox = (void *)devm_get_free_pages(dev, GFP_KERNEL, 0);
+ dbc_dev->mbox = (void *)devm_get_free_pages(dev, GFP_KERNEL | __GFP_ZERO, 0);
if (!dbc_dev->mbox) {
ret = -ENOMEM;
goto cleanup_dev;
--
2.34.1