Use the fpu_kern_enter() interface to properly separate usermode FPU

context from in-kernel execution of padlock instructions and to handle
spurious FPUDNA exceptions that sometime are raised when doing padlock
calculations.

Globally mark crypto(9) kthread as using FPU.

Reviewed by:	pjd
Hardware provided by:	Sentex Communications
Tested by:	  pho
PR:    amd64/135014
MFC after:    1 month

1 files changed, 12 insertions, 2 deletions

diff --git a/sys/crypto/via/padlock_cipher.c b/sys/crypto/via/padlock_cipher.c
index 8195584..0ae26c8 100644
--- a/sys/crypto/via/padlock_cipher.c
+++ b/sys/crypto/via/padlock_cipher.c
@@ -53,6 +53,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/module.h>
 #include <sys/malloc.h>
 #include <sys/libkern.h>
+#include <sys/pcpu.h>
 #include <sys/uio.h>
 
 #include <opencrypto/cryptodev.h>
@@ -201,9 +202,10 @@ padlock_cipher_process(struct padlock_session *ses, struct cryptodesc *enccrd,
     struct cryptop *crp)
 {
 	union padlock_cw *cw;
+	struct thread *td;
 	u_char *buf, *abuf;
 	uint32_t *key;
-	int allocated;
+	int allocated, error;
 
 	buf = padlock_cipher_alloc(enccrd, crp, &allocated);
 	if (buf == NULL)
@@ -247,9 +249,16 @@ padlock_cipher_process(struct padlock_session *ses, struct cryptodesc *enccrd,
 		    enccrd->crd_len, abuf);
 	}
 
+	td = curthread;
+	error = fpu_kern_enter(td, &ses->ses_fpu_ctx, FPU_KERN_NORMAL);
+	if (error != 0)
+		goto out;
+
 	padlock_cbc(abuf, abuf, enccrd->crd_len / AES_BLOCK_LEN, key, cw,
 	    ses->ses_iv);
 
+	fpu_kern_leave(td, &ses->ses_fpu_ctx);
+
 	if (allocated) {
 		crypto_copyback(crp->crp_flags, crp->crp_buf, enccrd->crd_skip,
 		    enccrd->crd_len, abuf);
@@ -262,9 +271,10 @@ padlock_cipher_process(struct padlock_session *ses, struct cryptodesc *enccrd,
 		    AES_BLOCK_LEN, ses->ses_iv);
 	}
 
+ out:
 	if (allocated) {
 		bzero(buf, enccrd->crd_len + 16);
 		free(buf, M_PADLOCK);
 	}
-	return (0);
+	return (error);
 }