Re: [PATCH v3 37/41] powerpc/32s: Move KUEP locking/unlocking in C
From: Christophe Leroy <hidden>
Date: 2021-03-27 17:25:54
Also in:
lkml
Le 12/03/2021 à 13:50, Christophe Leroy a écrit :
This can be done in C, do it. Unrolling the loop gains approx. 15% performance. From now on, prepare_transfer_to_handler() is only for interrupts from kernel. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/include/asm/book3s/32/kup.h | 31 ------------------- arch/powerpc/include/asm/interrupt.h | 6 +++- arch/powerpc/include/asm/kup.h | 8 +++++ arch/powerpc/kernel/entry_32.S | 16 ---------- arch/powerpc/kernel/head_32.h | 3 ++ arch/powerpc/kernel/head_booke.h | 3 ++ arch/powerpc/kernel/interrupt.c | 4 +++ arch/powerpc/mm/book3s32/Makefile | 1 + arch/powerpc/mm/book3s32/kuep.c | 38 ++++++++++++++++++++++++ 9 files changed, 62 insertions(+), 48 deletions(-) create mode 100644 arch/powerpc/mm/book3s32/kuep.c
quoted hunk ↗ jump to hunk
diff --git a/arch/powerpc/mm/book3s32/kuep.c b/arch/powerpc/mm/book3s32/kuep.c new file mode 100644 index 000000000000..c70532568a28 --- /dev/null +++ b/arch/powerpc/mm/book3s32/kuep.c@@ -0,0 +1,38 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +#include <asm/reg.h> +#include <asm/task_size_32.h> +#include <asm/mmu.h>
Need to add <asm/kup.h> to make Robot happy (missing prototypes of kuep_lock() and kuep_unlock())
+
+#define KUEP_UPDATE_TWO_USER_SEGMENTS(n) do { \
+ if (TASK_SIZE > ((n) << 28)) \
+ mtsr(val1, (n) << 28); \
+ if (TASK_SIZE > (((n) + 1) << 28)) \
+ mtsr(val2, ((n) + 1) << 28); \
+ val1 = (val1 + 0x222) & 0xf0ffffff; \
+ val2 = (val2 + 0x222) & 0xf0ffffff; \
+} while (0)
+
+static __always_inline void kuep_update(u32 val)
+{
+ int val1 = val;
+ int val2 = (val + 0x111) & 0xf0ffffff;
+
+ KUEP_UPDATE_TWO_USER_SEGMENTS(0);
+ KUEP_UPDATE_TWO_USER_SEGMENTS(2);
+ KUEP_UPDATE_TWO_USER_SEGMENTS(4);
+ KUEP_UPDATE_TWO_USER_SEGMENTS(6);
+ KUEP_UPDATE_TWO_USER_SEGMENTS(8);
+ KUEP_UPDATE_TWO_USER_SEGMENTS(10);
+ KUEP_UPDATE_TWO_USER_SEGMENTS(12);
+ KUEP_UPDATE_TWO_USER_SEGMENTS(14);
+}
+
+void kuep_lock(void)
+{
+ kuep_update(mfsr(0) | SR_NX);
+}
+
+void kuep_unlock(void)
+{
+ kuep_update(mfsr(0) & ~SR_NX);
+}