[PATCH nft-testing v3 1/2] netfilter: nft_set_pipapo*: Move FPU handling to pipapo_get_avx2()

[Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>]

Move kernel_fpu_begin_mask()/ _end() to pipapo_get_avx2() where it is
required.
This is a preparation for adding local_lock_t to struct
nft_pipapo_scratch in order to protect the __map pointer. The lock can
not be acquired in preemption disabled context which is what
kernel_fpu_begin*() does.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
 net/netfilter/nft_set_pipapo.c      |  2 --
 net/netfilter/nft_set_pipapo_avx2.c | 15 +++++++++------
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index 515eb64bff9f8..1a1ba0b47696e 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -528,9 +528,7 @@ static struct nft_pipapo_elem *pipapo_get(const struct nft_pipapo_match *m,
 #if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
 	if (boot_cpu_has(X86_FEATURE_AVX2) && boot_cpu_has(X86_FEATURE_AVX) &&
 	    irq_fpu_usable()) {
-		kernel_fpu_begin_mask(0);
 		e = pipapo_get_avx2(m, data, genmask, tstamp);
-		kernel_fpu_end();
 		local_bh_enable();
 		return e;
 	}
diff --git a/net/netfilter/nft_set_pipapo_avx2.c b/net/netfilter/nft_set_pipapo_avx2.c
index a584ffff73769..951868a904a25 100644
--- a/net/netfilter/nft_set_pipapo_avx2.c
+++ b/net/netfilter/nft_set_pipapo_avx2.c
@@ -1170,6 +1170,12 @@ struct nft_pipapo_elem *pipapo_get_avx2(const struct nft_pipapo_match *m,
 
 	pipapo_resmap_init_avx2(m, res);
 
+	/* Note that we don't need a valid MXCSR state for any of the
+	 * operations we use here, so pass 0 as mask and spare a LDMXCSR
+	 * instruction.
+	 */
+	kernel_fpu_begin_mask(0);
+
 	nft_pipapo_avx2_prepare();
 
 next_match:
@@ -1221,6 +1227,7 @@ struct nft_pipapo_elem *pipapo_get_avx2(const struct nft_pipapo_match *m,
 
 		if (ret < 0) {
 			scratch->map_index = map_index;
+			kernel_fpu_end();
 			return NULL;
 		}
 
@@ -1233,6 +1240,7 @@ struct nft_pipapo_elem *pipapo_get_avx2(const struct nft_pipapo_match *m,
 				goto next_match;
 
 			scratch->map_index = map_index;
+			kernel_fpu_end();
 			return e;
 		}
 
@@ -1241,6 +1249,7 @@ struct nft_pipapo_elem *pipapo_get_avx2(const struct nft_pipapo_match *m,
 		data += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
 	}
 
+	kernel_fpu_end();
 	return NULL;
 }
 
@@ -1280,13 +1289,7 @@ nft_pipapo_avx2_lookup(const struct net *net, const struct nft_set *set,
 
 	m = rcu_dereference(priv->match);
 
-	/* Note that we don't need a valid MXCSR state for any of the
-	 * operations we use here, so pass 0 as mask and spare a LDMXCSR
-	 * instruction.
-	 */
-	kernel_fpu_begin_mask(0);
 	e = pipapo_get_avx2(m, rp, genmask, get_jiffies_64());
-	kernel_fpu_end();
 	local_bh_enable();
 
 	return e ? &e->ext : NULL;
-- 
2.50.1