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authorChristophe Leroy <christophe.leroy@csgroup.eu>2021-03-12 15:50:47 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2021-03-29 05:22:10 +0300
commitb5efec00b671c5d7e9cb9e73a1d4925dd6ce8dcd (patch)
tree99a5ab07a508cab6ee4943fd8b8d689b7c7c8e1a /arch/powerpc/mm/book3s32
parenta2b3e09ae41c71d27d9b8da9baf31e0d9a97b864 (diff)
downloadlinux-b5efec00b671c5d7e9cb9e73a1d4925dd6ce8dcd.tar.xz
powerpc/32s: Move KUEP locking/unlocking in C
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 <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4eadd873927e9a73c3d1dfe2f9497353465514cf.1615552867.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/mm/book3s32')
-rw-r--r--arch/powerpc/mm/book3s32/Makefile1
-rw-r--r--arch/powerpc/mm/book3s32/kuep.c40
2 files changed, 41 insertions, 0 deletions
diff --git a/arch/powerpc/mm/book3s32/Makefile b/arch/powerpc/mm/book3s32/Makefile
index 446d9de88ce4..7f0c8a78ba0c 100644
--- a/arch/powerpc/mm/book3s32/Makefile
+++ b/arch/powerpc/mm/book3s32/Makefile
@@ -9,3 +9,4 @@ endif
obj-y += mmu.o mmu_context.o
obj-$(CONFIG_PPC_BOOK3S_603) += nohash_low.o
obj-$(CONFIG_PPC_BOOK3S_604) += hash_low.o tlb.o
+obj-$(CONFIG_PPC_KUEP) += kuep.o
diff --git a/arch/powerpc/mm/book3s32/kuep.c b/arch/powerpc/mm/book3s32/kuep.c
new file mode 100644
index 000000000000..8ed1b8634839
--- /dev/null
+++ b/arch/powerpc/mm/book3s32/kuep.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <asm/kup.h>
+#include <asm/reg.h>
+#include <asm/task_size_32.h>
+#include <asm/mmu.h>
+
+#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);
+}