* [PATCH 1/2] powerpc/32s: Refactor update of user segment registers
@ 2021-05-05 9:28 ` Christophe Leroy
0 siblings, 0 replies; 4+ messages in thread
From: Christophe Leroy @ 2021-05-05 9:28 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
Cc: linux-kernel, linuxppc-dev
KUEP implements the update of user segment registers.
Move it into mmu-hash.h in order to use it from other places.
And inline kuep_lock() and kuep_unlock() and remove kuep.c
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/book3s/32/mmu-hash.h | 27 +++++++++++++
arch/powerpc/include/asm/kup.h | 11 ++++-
arch/powerpc/mm/book3s32/Makefile | 1 -
arch/powerpc/mm/book3s32/kuep.c | 40 -------------------
4 files changed, 36 insertions(+), 43 deletions(-)
delete mode 100644 arch/powerpc/mm/book3s32/kuep.c
diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index b85f8e114a9c..cc0284bbac86 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -102,6 +102,33 @@ extern s32 patch__hash_page_B, patch__hash_page_C;
extern s32 patch__flush_hash_A0, patch__flush_hash_A1, patch__flush_hash_A2;
extern s32 patch__flush_hash_B;
+#include <asm/reg.h>
+#include <asm/task_size_32.h>
+
+#define 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 update_user_segments(u32 val)
+{
+ int val1 = val;
+ int val2 = (val + 0x111) & 0xf0ffffff;
+
+ UPDATE_TWO_USER_SEGMENTS(0);
+ UPDATE_TWO_USER_SEGMENTS(2);
+ UPDATE_TWO_USER_SEGMENTS(4);
+ UPDATE_TWO_USER_SEGMENTS(6);
+ UPDATE_TWO_USER_SEGMENTS(8);
+ UPDATE_TWO_USER_SEGMENTS(10);
+ UPDATE_TWO_USER_SEGMENTS(12);
+ UPDATE_TWO_USER_SEGMENTS(14);
+}
+
#endif /* !__ASSEMBLY__ */
/* We happily ignore the smaller BATs on 601, we don't actually use
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index ec96232529ac..1da9fed5c321 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -47,8 +47,15 @@ static inline void setup_kuep(bool disabled) { }
#endif /* CONFIG_PPC_KUEP */
#if defined(CONFIG_PPC_KUEP) && defined(CONFIG_PPC_BOOK3S_32)
-void kuep_lock(void);
-void kuep_unlock(void);
+static inline void kuep_lock(void)
+{
+ update_user_segments(mfsr(0) | SR_NX);
+}
+
+static inline void kuep_unlock(void)
+{
+ update_user_segments(mfsr(0) & ~SR_NX);
+}
#else
static inline void kuep_lock(void) { }
static inline void kuep_unlock(void) { }
diff --git a/arch/powerpc/mm/book3s32/Makefile b/arch/powerpc/mm/book3s32/Makefile
index 7f0c8a78ba0c..446d9de88ce4 100644
--- a/arch/powerpc/mm/book3s32/Makefile
+++ b/arch/powerpc/mm/book3s32/Makefile
@@ -9,4 +9,3 @@ 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
deleted file mode 100644
index 8ed1b8634839..000000000000
--- a/arch/powerpc/mm/book3s32/kuep.c
+++ /dev/null
@@ -1,40 +0,0 @@
-// 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);
-}
--
2.25.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 1/2] powerpc/32s: Refactor update of user segment registers
@ 2021-05-05 9:28 ` Christophe Leroy
0 siblings, 0 replies; 4+ messages in thread
From: Christophe Leroy @ 2021-05-05 9:28 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
Cc: linuxppc-dev, linux-kernel
KUEP implements the update of user segment registers.
Move it into mmu-hash.h in order to use it from other places.
And inline kuep_lock() and kuep_unlock() and remove kuep.c
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/book3s/32/mmu-hash.h | 27 +++++++++++++
arch/powerpc/include/asm/kup.h | 11 ++++-
arch/powerpc/mm/book3s32/Makefile | 1 -
arch/powerpc/mm/book3s32/kuep.c | 40 -------------------
4 files changed, 36 insertions(+), 43 deletions(-)
delete mode 100644 arch/powerpc/mm/book3s32/kuep.c
diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index b85f8e114a9c..cc0284bbac86 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -102,6 +102,33 @@ extern s32 patch__hash_page_B, patch__hash_page_C;
extern s32 patch__flush_hash_A0, patch__flush_hash_A1, patch__flush_hash_A2;
extern s32 patch__flush_hash_B;
+#include <asm/reg.h>
+#include <asm/task_size_32.h>
+
+#define 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 update_user_segments(u32 val)
+{
+ int val1 = val;
+ int val2 = (val + 0x111) & 0xf0ffffff;
+
+ UPDATE_TWO_USER_SEGMENTS(0);
+ UPDATE_TWO_USER_SEGMENTS(2);
+ UPDATE_TWO_USER_SEGMENTS(4);
+ UPDATE_TWO_USER_SEGMENTS(6);
+ UPDATE_TWO_USER_SEGMENTS(8);
+ UPDATE_TWO_USER_SEGMENTS(10);
+ UPDATE_TWO_USER_SEGMENTS(12);
+ UPDATE_TWO_USER_SEGMENTS(14);
+}
+
#endif /* !__ASSEMBLY__ */
/* We happily ignore the smaller BATs on 601, we don't actually use
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index ec96232529ac..1da9fed5c321 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -47,8 +47,15 @@ static inline void setup_kuep(bool disabled) { }
#endif /* CONFIG_PPC_KUEP */
#if defined(CONFIG_PPC_KUEP) && defined(CONFIG_PPC_BOOK3S_32)
-void kuep_lock(void);
-void kuep_unlock(void);
+static inline void kuep_lock(void)
+{
+ update_user_segments(mfsr(0) | SR_NX);
+}
+
+static inline void kuep_unlock(void)
+{
+ update_user_segments(mfsr(0) & ~SR_NX);
+}
#else
static inline void kuep_lock(void) { }
static inline void kuep_unlock(void) { }
diff --git a/arch/powerpc/mm/book3s32/Makefile b/arch/powerpc/mm/book3s32/Makefile
index 7f0c8a78ba0c..446d9de88ce4 100644
--- a/arch/powerpc/mm/book3s32/Makefile
+++ b/arch/powerpc/mm/book3s32/Makefile
@@ -9,4 +9,3 @@ 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
deleted file mode 100644
index 8ed1b8634839..000000000000
--- a/arch/powerpc/mm/book3s32/kuep.c
+++ /dev/null
@@ -1,40 +0,0 @@
-// 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);
-}
--
2.25.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] powerpc/32s: Convert switch_mmu_context() to C
2021-05-05 9:28 ` Christophe Leroy
@ 2021-05-05 9:28 ` Christophe Leroy
-1 siblings, 0 replies; 4+ messages in thread
From: Christophe Leroy @ 2021-05-05 9:28 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
Cc: linux-kernel, linuxppc-dev
switch_mmu_context() does things that can easily be done in C.
For updating user segments, we have update_user_segments().
As mentionned in commit b5efec00b671 ("powerpc/32s: Move KUEP
locking/unlocking in C"), update_user_segments() has the loop
unrolled which is a significant performance gain.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/asm-offsets.c | 5 ---
arch/powerpc/kernel/head_book3s_32.S | 53 +-------------------------
arch/powerpc/mm/book3s32/mmu_context.c | 27 +++++++++++++
3 files changed, 28 insertions(+), 57 deletions(-)
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 28af4efb4587..459829805177 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -86,7 +86,6 @@ int main(void)
OFFSET(PACA_CANARY, paca_struct, canary);
#endif
#endif
- OFFSET(MMCONTEXTID, mm_struct, context.id);
#ifdef CONFIG_PPC64
DEFINE(SIGSEGV, SIGSEGV);
DEFINE(NMI_MASK, NMI_MASK);
@@ -368,10 +367,6 @@ int main(void)
#endif
#endif
-#ifndef CONFIG_PPC64
- OFFSET(MM_PGD, mm_struct, pgd);
-#endif /* ! CONFIG_PPC64 */
-
/* About the CPU features table */
OFFSET(CPU_SPEC_FEATURES, cpu_spec, cpu_features);
OFFSET(CPU_SPEC_SETUP, cpu_spec, cpu_setup);
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 065178f19a3d..c1d2f0d1d6b2 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -1023,58 +1023,6 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_HPTE_TABLE)
mtspr SPRN_SRR1,r4
rfi
-/*
- * void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
- *
- * Set up the segment registers for a new context.
- */
-_ENTRY(switch_mmu_context)
- lwz r3,MMCONTEXTID(r4)
- cmpwi cr0,r3,0
- blt- 4f
- mulli r3,r3,897 /* multiply context by skew factor */
- rlwinm r3,r3,4,8,27 /* VSID = (context & 0xfffff) << 4 */
-#ifdef CONFIG_PPC_KUEP
- oris r3, r3, SR_NX@h /* Set Nx */
-#endif
-#ifdef CONFIG_PPC_KUAP
- oris r3, r3, SR_KS@h /* Set Ks */
-#endif
- li r0,NUM_USER_SEGMENTS
- mtctr r0
-
-#ifdef CONFIG_BDI_SWITCH
- /* Context switch the PTE pointer for the Abatron BDI2000.
- * The PGDIR is passed as second argument.
- */
- lwz r4, MM_PGD(r4)
- lis r5, abatron_pteptrs@ha
- stw r4, abatron_pteptrs@l + 0x4(r5)
-#endif
-BEGIN_MMU_FTR_SECTION
-#ifndef CONFIG_BDI_SWITCH
- lwz r4, MM_PGD(r4)
-#endif
- tophys(r4, r4)
- rlwinm r4, r4, 4, 0xffff01ff
- mtspr SPRN_SDR1, r4
-END_MMU_FTR_SECTION_IFCLR(MMU_FTR_HPTE_TABLE)
- li r4,0
- isync
-3:
- mtsrin r3,r4
- addi r3,r3,0x111 /* next VSID */
- rlwinm r3,r3,0,8,3 /* clear out any overflow from VSID field */
- addis r4,r4,0x1000 /* address of next segment */
- bdnz 3b
- sync
- isync
- blr
-4: trap
- EMIT_BUG_ENTRY 4b,__FILE__,__LINE__,0
- blr
-EXPORT_SYMBOL(switch_mmu_context)
-
/*
* An undocumented "feature" of 604e requires that the v bit
* be cleared before changing BAT values.
@@ -1312,5 +1260,6 @@ swapper_pg_dir:
/* Room for two PTE pointers, usually the kernel and current user pointers
* to their respective root page table.
*/
+ .globl abatron_pteptrs
abatron_pteptrs:
.space 8
diff --git a/arch/powerpc/mm/book3s32/mmu_context.c b/arch/powerpc/mm/book3s32/mmu_context.c
index 218996e40a8e..3fcac03b125f 100644
--- a/arch/powerpc/mm/book3s32/mmu_context.c
+++ b/arch/powerpc/mm/book3s32/mmu_context.c
@@ -111,3 +111,30 @@ void __init mmu_context_init(void)
context_map[0] = (1 << FIRST_CONTEXT) - 1;
next_mmu_context = FIRST_CONTEXT;
}
+
+void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
+{
+ unsigned long id = next->context.id;
+ unsigned long val;
+
+ if (!id)
+ panic("mm_struct %p has no context ID", next);
+
+ isync();
+
+ val = ((id * 897) & 0xfffff) << 4;
+ if (IS_ENABLED(CONFIG_PPC_KUEP))
+ val |= SR_NX;
+ if (IS_ENABLED(CONFIG_PPC_KUAP))
+ val |= SR_KS;
+
+ update_user_segments(val);
+ mb(); /* sync */
+ isync();
+
+ if (IS_ENABLED(CONFIG_BDI_SWITCH))
+ abatron_pteptrs[1] = next->pgd;
+
+ if (!mmu_has_feature(MMU_FTR_HPTE_TABLE))
+ mtspr(SPRN_SDR1, rol32(__pa(next->pgd), 4) & 0xffff01ff);
+}
--
2.25.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] powerpc/32s: Convert switch_mmu_context() to C
@ 2021-05-05 9:28 ` Christophe Leroy
0 siblings, 0 replies; 4+ messages in thread
From: Christophe Leroy @ 2021-05-05 9:28 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
Cc: linuxppc-dev, linux-kernel
switch_mmu_context() does things that can easily be done in C.
For updating user segments, we have update_user_segments().
As mentionned in commit b5efec00b671 ("powerpc/32s: Move KUEP
locking/unlocking in C"), update_user_segments() has the loop
unrolled which is a significant performance gain.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/asm-offsets.c | 5 ---
arch/powerpc/kernel/head_book3s_32.S | 53 +-------------------------
arch/powerpc/mm/book3s32/mmu_context.c | 27 +++++++++++++
3 files changed, 28 insertions(+), 57 deletions(-)
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 28af4efb4587..459829805177 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -86,7 +86,6 @@ int main(void)
OFFSET(PACA_CANARY, paca_struct, canary);
#endif
#endif
- OFFSET(MMCONTEXTID, mm_struct, context.id);
#ifdef CONFIG_PPC64
DEFINE(SIGSEGV, SIGSEGV);
DEFINE(NMI_MASK, NMI_MASK);
@@ -368,10 +367,6 @@ int main(void)
#endif
#endif
-#ifndef CONFIG_PPC64
- OFFSET(MM_PGD, mm_struct, pgd);
-#endif /* ! CONFIG_PPC64 */
-
/* About the CPU features table */
OFFSET(CPU_SPEC_FEATURES, cpu_spec, cpu_features);
OFFSET(CPU_SPEC_SETUP, cpu_spec, cpu_setup);
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 065178f19a3d..c1d2f0d1d6b2 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -1023,58 +1023,6 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_HPTE_TABLE)
mtspr SPRN_SRR1,r4
rfi
-/*
- * void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
- *
- * Set up the segment registers for a new context.
- */
-_ENTRY(switch_mmu_context)
- lwz r3,MMCONTEXTID(r4)
- cmpwi cr0,r3,0
- blt- 4f
- mulli r3,r3,897 /* multiply context by skew factor */
- rlwinm r3,r3,4,8,27 /* VSID = (context & 0xfffff) << 4 */
-#ifdef CONFIG_PPC_KUEP
- oris r3, r3, SR_NX@h /* Set Nx */
-#endif
-#ifdef CONFIG_PPC_KUAP
- oris r3, r3, SR_KS@h /* Set Ks */
-#endif
- li r0,NUM_USER_SEGMENTS
- mtctr r0
-
-#ifdef CONFIG_BDI_SWITCH
- /* Context switch the PTE pointer for the Abatron BDI2000.
- * The PGDIR is passed as second argument.
- */
- lwz r4, MM_PGD(r4)
- lis r5, abatron_pteptrs@ha
- stw r4, abatron_pteptrs@l + 0x4(r5)
-#endif
-BEGIN_MMU_FTR_SECTION
-#ifndef CONFIG_BDI_SWITCH
- lwz r4, MM_PGD(r4)
-#endif
- tophys(r4, r4)
- rlwinm r4, r4, 4, 0xffff01ff
- mtspr SPRN_SDR1, r4
-END_MMU_FTR_SECTION_IFCLR(MMU_FTR_HPTE_TABLE)
- li r4,0
- isync
-3:
- mtsrin r3,r4
- addi r3,r3,0x111 /* next VSID */
- rlwinm r3,r3,0,8,3 /* clear out any overflow from VSID field */
- addis r4,r4,0x1000 /* address of next segment */
- bdnz 3b
- sync
- isync
- blr
-4: trap
- EMIT_BUG_ENTRY 4b,__FILE__,__LINE__,0
- blr
-EXPORT_SYMBOL(switch_mmu_context)
-
/*
* An undocumented "feature" of 604e requires that the v bit
* be cleared before changing BAT values.
@@ -1312,5 +1260,6 @@ swapper_pg_dir:
/* Room for two PTE pointers, usually the kernel and current user pointers
* to their respective root page table.
*/
+ .globl abatron_pteptrs
abatron_pteptrs:
.space 8
diff --git a/arch/powerpc/mm/book3s32/mmu_context.c b/arch/powerpc/mm/book3s32/mmu_context.c
index 218996e40a8e..3fcac03b125f 100644
--- a/arch/powerpc/mm/book3s32/mmu_context.c
+++ b/arch/powerpc/mm/book3s32/mmu_context.c
@@ -111,3 +111,30 @@ void __init mmu_context_init(void)
context_map[0] = (1 << FIRST_CONTEXT) - 1;
next_mmu_context = FIRST_CONTEXT;
}
+
+void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
+{
+ unsigned long id = next->context.id;
+ unsigned long val;
+
+ if (!id)
+ panic("mm_struct %p has no context ID", next);
+
+ isync();
+
+ val = ((id * 897) & 0xfffff) << 4;
+ if (IS_ENABLED(CONFIG_PPC_KUEP))
+ val |= SR_NX;
+ if (IS_ENABLED(CONFIG_PPC_KUAP))
+ val |= SR_KS;
+
+ update_user_segments(val);
+ mb(); /* sync */
+ isync();
+
+ if (IS_ENABLED(CONFIG_BDI_SWITCH))
+ abatron_pteptrs[1] = next->pgd;
+
+ if (!mmu_has_feature(MMU_FTR_HPTE_TABLE))
+ mtspr(SPRN_SDR1, rol32(__pa(next->pgd), 4) & 0xffff01ff);
+}
--
2.25.0
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2021-05-05 9:28 [PATCH 1/2] powerpc/32s: Refactor update of user segment registers Christophe Leroy
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2021-05-05 9:28 ` [PATCH 2/2] powerpc/32s: Convert switch_mmu_context() to C Christophe Leroy
2021-05-05 9:28 ` Christophe Leroy
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