[PATCHv2 28/59] keys/mktme: Move the MKTME payload into a cache aligned structure

["Kirill A. Shutemov" <kirill@shutemov.name>]

From: Alison Schofield <alison.schofield@intel.com>

In preparation for programming the key into the hardware, move
the key payload into a cache aligned structure. This alignment
is a requirement of the MKTME hardware.

Use the slab allocator to have this structure readily available.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 security/keys/mktme_keys.c | 37 +++++++++++++++++++++++++++++++++++--
 1 file changed, 35 insertions(+), 2 deletions(-)

diff --git a/security/keys/mktme_keys.c b/security/keys/mktme_keys.c
index 10fcdbf5a08f..8ac75b1e6188 100644
--- a/security/keys/mktme_keys.c
+++ b/security/keys/mktme_keys.c
@@ -16,6 +16,7 @@
 
 static DEFINE_SPINLOCK(mktme_lock);
 static unsigned int mktme_available_keyids;  /* Free Hardware KeyIDs */
+static struct kmem_cache *mktme_prog_cache;  /* Hardware programming cache */
 
 enum mktme_keyid_state {
 	KEYID_AVAILABLE,	/* Available to be assigned */
@@ -79,6 +80,25 @@ static const match_table_t mktme_token = {
 	{OPT_ERROR, NULL}
 };
 
+/* Copy the payload to the HW programming structure and program this KeyID */
+static int mktme_program_keyid(int keyid, u32 payload)
+{
+	struct mktme_key_program *kprog = NULL;
+	int ret;
+
+	kprog = kmem_cache_zalloc(mktme_prog_cache, GFP_KERNEL);
+	if (!kprog)
+		return -ENOMEM;
+
+	/* Hardware programming requires cached aligned struct */
+	kprog->keyid = keyid;
+	kprog->keyid_ctrl = payload;
+
+	ret = MKTME_PROG_SUCCESS;	/* Future programming call */
+	kmem_cache_free(mktme_prog_cache, kprog);
+	return ret;
+}
+
 /* Key Service Method called when a Userspace Key is garbage collected. */
 static void mktme_destroy_key(struct key *key)
 {
@@ -93,6 +113,7 @@ static void mktme_destroy_key(struct key *key)
 /* Key Service Method to create a new key. Payload is preparsed. */
 int mktme_instantiate_key(struct key *key, struct key_preparsed_payload *prep)
 {
+	u32 *payload = prep->payload.data[0];
 	unsigned long flags;
 	int keyid;
 
@@ -101,7 +122,14 @@ int mktme_instantiate_key(struct key *key, struct key_preparsed_payload *prep)
 	spin_unlock_irqrestore(&mktme_lock, flags);
 	if (!keyid)
 		return -ENOKEY;
-	return 0;
+
+	if (!mktme_program_keyid(keyid, *payload))
+		return MKTME_PROG_SUCCESS;
+
+	spin_lock_irqsave(&mktme_lock, flags);
+	mktme_release_keyid(keyid);
+	spin_unlock_irqrestore(&mktme_lock, flags);
+	return -ENOKEY;
 }
 
 /* Make sure arguments are correct for the TYPE of key requested */
@@ -245,10 +273,15 @@ static int __init init_mktme(void)
 	if (!mktme_map)
 		return -ENOMEM;
 
+	/* Used to program the hardware key tables */
+	mktme_prog_cache = KMEM_CACHE(mktme_key_program, SLAB_PANIC);
+	if (!mktme_prog_cache)
+		goto free_map;
+
 	ret = register_key_type(&key_type_mktme);
 	if (!ret)
 		return ret;			/* SUCCESS */
-
+free_map:
 	kvfree(mktme_map);
 
 	return -ENOMEM;
-- 
2.21.0