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* [PATCH v3 1/6] powerpc/nohash: Refactor update of BDI2000 pointers in switch_mmu_context()
@ 2021-06-03  9:29 ` Christophe Leroy
  0 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-06-03  9:29 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linux-kernel, linuxppc-dev

Instead of duplicating the update of BDI2000 pointers in
set_context(), do it directly from switch_mmu_context().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v3: Do it only for nohash platforms, book3s/32 will have its own as part of converting switch_mmu_context() to C.
---
 arch/powerpc/kernel/head_40x.S       | 14 --------------
 arch/powerpc/kernel/head_44x.S       | 16 ----------------
 arch/powerpc/kernel/head_8xx.S       |  7 -------
 arch/powerpc/kernel/head_book3s_32.S |  6 ------
 arch/powerpc/kernel/head_fsl_booke.S | 16 ----------------
 arch/powerpc/mm/nohash/8xx.c         |  6 ------
 arch/powerpc/mm/nohash/mmu_context.c |  8 ++++++++
 arch/powerpc/mm/nohash/tlb_low.S     |  8 --------
 8 files changed, 8 insertions(+), 73 deletions(-)

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index e1360b88b6cb..7ef1bbc23bed 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -703,14 +703,6 @@ _GLOBAL(abort)
         mtspr   SPRN_DBCR0,r13
 
 _GLOBAL(set_context)
-
-#ifdef CONFIG_BDI_SWITCH
-	/* Context switch the PTE pointer for the Abatron BDI2000.
-	 * The PGDIR is the second parameter.
-	 */
-	lis	r5, abatron_pteptrs@ha
-	stw	r4, abatron_pteptrs@l + 0x4(r5)
-#endif
 	sync
 	mtspr	SPRN_PID,r3
 	isync				/* Need an isync to flush shadow */
@@ -731,9 +723,3 @@ EXPORT_SYMBOL(empty_zero_page)
 	.globl	swapper_pg_dir
 swapper_pg_dir:
 	.space	PGD_TABLE_SIZE
-
-/* Room for two PTE pointers, usually the kernel and current user pointers
- * to their respective root page table.
- */
-abatron_pteptrs:
-	.space	8
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 5c106ac36626..57509d90e409 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -781,15 +781,6 @@ _GLOBAL(__fixup_440A_mcheck)
 	blr
 
 _GLOBAL(set_context)
-
-#ifdef CONFIG_BDI_SWITCH
-	/* Context switch the PTE pointer for the Abatron BDI2000.
-	 * The PGDIR is the second parameter.
-	 */
-	lis	r5, abatron_pteptrs@h
-	ori	r5, r5, abatron_pteptrs@l
-	stw	r4, 0x4(r5)
-#endif
 	mtspr	SPRN_PID,r3
 	isync			/* Force context change */
 	blr
@@ -1259,13 +1250,6 @@ EXPORT_SYMBOL(empty_zero_page)
 swapper_pg_dir:
 	.space	PGD_TABLE_SIZE
 
-/*
- * Room for two PTE pointers, usually the kernel and current user pointers
- * to their respective root page table.
- */
-abatron_pteptrs:
-	.space	8
-
 #ifdef CONFIG_SMP
 	.align	12
 temp_boot_stack:
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 7d445e4342c0..817df9fe7fb3 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -804,10 +804,3 @@ EXPORT_SYMBOL(empty_zero_page)
 	.globl	swapper_pg_dir
 swapper_pg_dir:
 	.space	PGD_TABLE_SIZE
-
-/* Room for two PTE table pointers, usually the kernel and current user
- * pointer to their respective root page table (pgdir).
- */
-	.globl	abatron_pteptrs
-abatron_pteptrs:
-	.space	8
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 326262030279..32c27dac9b80 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -1282,9 +1282,3 @@ EXPORT_SYMBOL(empty_zero_page)
 	.globl	swapper_pg_dir
 swapper_pg_dir:
 	.space	PGD_TABLE_SIZE
-
-/* Room for two PTE pointers, usually the kernel and current user pointers
- * to their respective root page table.
- */
-abatron_pteptrs:
-	.space	8
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index a1a5c3f10dc4..590f34cc5bb2 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -986,15 +986,6 @@ _GLOBAL(abort)
 	isync
 
 _GLOBAL(set_context)
-
-#ifdef CONFIG_BDI_SWITCH
-	/* Context switch the PTE pointer for the Abatron BDI2000.
-	 * The PGDIR is the second parameter.
-	 */
-	lis	r5, abatron_pteptrs@h
-	ori	r5, r5, abatron_pteptrs@l
-	stw	r4, 0x4(r5)
-#endif
 	mtspr	SPRN_PID,r3
 	isync			/* Force context change */
 	blr
@@ -1242,10 +1233,3 @@ EXPORT_SYMBOL(empty_zero_page)
 	.globl	swapper_pg_dir
 swapper_pg_dir:
 	.space	PGD_TABLE_SIZE
-
-/*
- * Room for two PTE pointers, usually the kernel and current user pointers
- * to their respective root page table.
- */
-abatron_pteptrs:
-	.space	8
diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index 71bfdbedacee..f749acba5473 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -224,12 +224,6 @@ void set_context(unsigned long id, pgd_t *pgd)
 {
 	s16 offset = (s16)(__pa(swapper_pg_dir));
 
-	/* Context switch the PTE pointer for the Abatron BDI2000.
-	 * The PGDIR is passed as second argument.
-	 */
-	if (IS_ENABLED(CONFIG_BDI_SWITCH))
-		abatron_pteptrs[1] = pgd;
-
 	/* Register M_TWB will contain base address of level 1 table minus the
 	 * lower part of the kernel PGDIR base address, so that all accesses to
 	 * level 1 table are done relative to lower part of kernel PGDIR base
diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index aac81c9f84a5..eae48635a9ac 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -50,6 +50,12 @@
 
 #include <mm/mmu_decl.h>
 
+/*
+ * Room for two PTE table pointers, usually the kernel and current user
+ * pointer to their respective root page table (pgdir).
+ */
+void *abatron_pteptrs[2];
+
 /*
  * The MPC8xx has only 16 contexts. We rotate through them on each task switch.
  * A better way would be to keep track of tasks that own contexts, and implement
@@ -357,6 +363,8 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 
 	/* Flick the MMU and release lock */
 	pr_hardcont(" -> %d\n", id);
+	if (IS_ENABLED(CONFIG_BDI_SWITCH))
+		abatron_pteptrs[1] = next->pgd;
 	set_context(id, next->pgd);
 	raw_spin_unlock(&context_lock);
 }
diff --git a/arch/powerpc/mm/nohash/tlb_low.S b/arch/powerpc/mm/nohash/tlb_low.S
index 68797e072f55..b3d0f0127828 100644
--- a/arch/powerpc/mm/nohash/tlb_low.S
+++ b/arch/powerpc/mm/nohash/tlb_low.S
@@ -362,14 +362,6 @@ _GLOBAL(_tlbivax_bcast)
 	blr
 
 _GLOBAL(set_context)
-#ifdef CONFIG_BDI_SWITCH
-	/* Context switch the PTE pointer for the Abatron BDI2000.
-	 * The PGDIR is the second parameter.
-	 */
-	lis	r5, abatron_pteptrs@h
-	ori	r5, r5, abatron_pteptrs@l
-	stw	r4, 0x4(r5)
-#endif
 	mtspr	SPRN_PID,r3
 	isync			/* Force context change */
 	blr
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread
* [PATCH v3 1/6] powerpc/nohash: Refactor update of BDI2000 pointers in switch_mmu_context()
@ 2021-06-03  9:29 ` Christophe Leroy
  0 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-06-03  9:29 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linuxppc-dev, linux-kernel

Instead of duplicating the update of BDI2000 pointers in
set_context(), do it directly from switch_mmu_context().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v3: Do it only for nohash platforms, book3s/32 will have its own as part of converting switch_mmu_context() to C.
---
 arch/powerpc/kernel/head_40x.S       | 14 --------------
 arch/powerpc/kernel/head_44x.S       | 16 ----------------
 arch/powerpc/kernel/head_8xx.S       |  7 -------
 arch/powerpc/kernel/head_book3s_32.S |  6 ------
 arch/powerpc/kernel/head_fsl_booke.S | 16 ----------------
 arch/powerpc/mm/nohash/8xx.c         |  6 ------
 arch/powerpc/mm/nohash/mmu_context.c |  8 ++++++++
 arch/powerpc/mm/nohash/tlb_low.S     |  8 --------
 8 files changed, 8 insertions(+), 73 deletions(-)

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index e1360b88b6cb..7ef1bbc23bed 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -703,14 +703,6 @@ _GLOBAL(abort)
         mtspr   SPRN_DBCR0,r13
 
 _GLOBAL(set_context)
-
-#ifdef CONFIG_BDI_SWITCH
-	/* Context switch the PTE pointer for the Abatron BDI2000.
-	 * The PGDIR is the second parameter.
-	 */
-	lis	r5, abatron_pteptrs@ha
-	stw	r4, abatron_pteptrs@l + 0x4(r5)
-#endif
 	sync
 	mtspr	SPRN_PID,r3
 	isync				/* Need an isync to flush shadow */
@@ -731,9 +723,3 @@ EXPORT_SYMBOL(empty_zero_page)
 	.globl	swapper_pg_dir
 swapper_pg_dir:
 	.space	PGD_TABLE_SIZE
-
-/* Room for two PTE pointers, usually the kernel and current user pointers
- * to their respective root page table.
- */
-abatron_pteptrs:
-	.space	8
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 5c106ac36626..57509d90e409 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -781,15 +781,6 @@ _GLOBAL(__fixup_440A_mcheck)
 	blr
 
 _GLOBAL(set_context)
-
-#ifdef CONFIG_BDI_SWITCH
-	/* Context switch the PTE pointer for the Abatron BDI2000.
-	 * The PGDIR is the second parameter.
-	 */
-	lis	r5, abatron_pteptrs@h
-	ori	r5, r5, abatron_pteptrs@l
-	stw	r4, 0x4(r5)
-#endif
 	mtspr	SPRN_PID,r3
 	isync			/* Force context change */
 	blr
@@ -1259,13 +1250,6 @@ EXPORT_SYMBOL(empty_zero_page)
 swapper_pg_dir:
 	.space	PGD_TABLE_SIZE
 
-/*
- * Room for two PTE pointers, usually the kernel and current user pointers
- * to their respective root page table.
- */
-abatron_pteptrs:
-	.space	8
-
 #ifdef CONFIG_SMP
 	.align	12
 temp_boot_stack:
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 7d445e4342c0..817df9fe7fb3 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -804,10 +804,3 @@ EXPORT_SYMBOL(empty_zero_page)
 	.globl	swapper_pg_dir
 swapper_pg_dir:
 	.space	PGD_TABLE_SIZE
-
-/* Room for two PTE table pointers, usually the kernel and current user
- * pointer to their respective root page table (pgdir).
- */
-	.globl	abatron_pteptrs
-abatron_pteptrs:
-	.space	8
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 326262030279..32c27dac9b80 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -1282,9 +1282,3 @@ EXPORT_SYMBOL(empty_zero_page)
 	.globl	swapper_pg_dir
 swapper_pg_dir:
 	.space	PGD_TABLE_SIZE
-
-/* Room for two PTE pointers, usually the kernel and current user pointers
- * to their respective root page table.
- */
-abatron_pteptrs:
-	.space	8
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index a1a5c3f10dc4..590f34cc5bb2 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -986,15 +986,6 @@ _GLOBAL(abort)
 	isync
 
 _GLOBAL(set_context)
-
-#ifdef CONFIG_BDI_SWITCH
-	/* Context switch the PTE pointer for the Abatron BDI2000.
-	 * The PGDIR is the second parameter.
-	 */
-	lis	r5, abatron_pteptrs@h
-	ori	r5, r5, abatron_pteptrs@l
-	stw	r4, 0x4(r5)
-#endif
 	mtspr	SPRN_PID,r3
 	isync			/* Force context change */
 	blr
@@ -1242,10 +1233,3 @@ EXPORT_SYMBOL(empty_zero_page)
 	.globl	swapper_pg_dir
 swapper_pg_dir:
 	.space	PGD_TABLE_SIZE
-
-/*
- * Room for two PTE pointers, usually the kernel and current user pointers
- * to their respective root page table.
- */
-abatron_pteptrs:
-	.space	8
diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index 71bfdbedacee..f749acba5473 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -224,12 +224,6 @@ void set_context(unsigned long id, pgd_t *pgd)
 {
 	s16 offset = (s16)(__pa(swapper_pg_dir));
 
-	/* Context switch the PTE pointer for the Abatron BDI2000.
-	 * The PGDIR is passed as second argument.
-	 */
-	if (IS_ENABLED(CONFIG_BDI_SWITCH))
-		abatron_pteptrs[1] = pgd;
-
 	/* Register M_TWB will contain base address of level 1 table minus the
 	 * lower part of the kernel PGDIR base address, so that all accesses to
 	 * level 1 table are done relative to lower part of kernel PGDIR base
diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index aac81c9f84a5..eae48635a9ac 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -50,6 +50,12 @@
 
 #include <mm/mmu_decl.h>
 
+/*
+ * Room for two PTE table pointers, usually the kernel and current user
+ * pointer to their respective root page table (pgdir).
+ */
+void *abatron_pteptrs[2];
+
 /*
  * The MPC8xx has only 16 contexts. We rotate through them on each task switch.
  * A better way would be to keep track of tasks that own contexts, and implement
@@ -357,6 +363,8 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 
 	/* Flick the MMU and release lock */
 	pr_hardcont(" -> %d\n", id);
+	if (IS_ENABLED(CONFIG_BDI_SWITCH))
+		abatron_pteptrs[1] = next->pgd;
 	set_context(id, next->pgd);
 	raw_spin_unlock(&context_lock);
 }
diff --git a/arch/powerpc/mm/nohash/tlb_low.S b/arch/powerpc/mm/nohash/tlb_low.S
index 68797e072f55..b3d0f0127828 100644
--- a/arch/powerpc/mm/nohash/tlb_low.S
+++ b/arch/powerpc/mm/nohash/tlb_low.S
@@ -362,14 +362,6 @@ _GLOBAL(_tlbivax_bcast)
 	blr
 
 _GLOBAL(set_context)
-#ifdef CONFIG_BDI_SWITCH
-	/* Context switch the PTE pointer for the Abatron BDI2000.
-	 * The PGDIR is the second parameter.
-	 */
-	lis	r5, abatron_pteptrs@h
-	ori	r5, r5, abatron_pteptrs@l
-	stw	r4, 0x4(r5)
-#endif
 	mtspr	SPRN_PID,r3
 	isync			/* Force context change */
 	blr
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread
* [PATCH v3 2/6] powerpc/nohash: Convert set_context() to C
  2021-06-03  9:29 ` Christophe Leroy
@ 2021-06-03  9:29   ` Christophe Leroy
  -1 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-06-03  9:29 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linux-kernel, linuxppc-dev

ppc8xx already has set_context() in C.

Other ones have it in assembly. The only thing it does is to
write the context id into SPRN_PID.

Do it in C.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v3: Fixed whitespace before tab
---
 arch/powerpc/include/asm/mmu_context.h |  1 -
 arch/powerpc/kernel/head_40x.S         |  7 -------
 arch/powerpc/kernel/head_44x.S         |  5 -----
 arch/powerpc/kernel/head_fsl_booke.S   |  5 -----
 arch/powerpc/mm/nohash/8xx.c           | 25 -------------------------
 arch/powerpc/mm/nohash/mmu_context.c   | 24 ++++++++++++++++++++++++
 arch/powerpc/mm/nohash/tlb_low.S       |  5 -----
 7 files changed, 24 insertions(+), 48 deletions(-)

diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 4bc45d3ed8b0..ef6df2681582 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -57,7 +57,6 @@ static inline bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa,
 static inline void mm_iommu_init(struct mm_struct *mm) { }
 #endif
 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
-extern void set_context(unsigned long id, pgd_t *pgd);
 
 #ifdef CONFIG_PPC_BOOK3S_64
 extern void radix__switch_mmu_context(struct mm_struct *prev,
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 7ef1bbc23bed..2717aa860cae 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -702,13 +702,6 @@ _GLOBAL(abort)
         oris    r13,r13,DBCR0_RST_SYSTEM@h
         mtspr   SPRN_DBCR0,r13
 
-_GLOBAL(set_context)
-	sync
-	mtspr	SPRN_PID,r3
-	isync				/* Need an isync to flush shadow */
-					/* TLBs after changing PID */
-	blr
-
 /* We put a few things here that have to be page-aligned. This stuff
  * goes at the beginning of the data segment, which is page-aligned.
  */
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 57509d90e409..c5bec6a9864b 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -780,11 +780,6 @@ _GLOBAL(__fixup_440A_mcheck)
 	sync
 	blr
 
-_GLOBAL(set_context)
-	mtspr	SPRN_PID,r3
-	isync			/* Force context change */
-	blr
-
 /*
  * Init CPU state. This is called at boot time or for secondary CPUs
  * to setup initial TLB entries, setup IVORs, etc...
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 590f34cc5bb2..ab718fd5e2a2 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -985,11 +985,6 @@ _GLOBAL(abort)
 	mtspr	SPRN_DBCR0,r13
 	isync
 
-_GLOBAL(set_context)
-	mtspr	SPRN_PID,r3
-	isync			/* Force context change */
-	blr
-
 #ifdef CONFIG_SMP
 /* When we get here, r24 needs to hold the CPU # */
 	.globl __secondary_start
diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index f749acba5473..65e4c8b92657 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -212,31 +212,6 @@ void __init setup_initial_memory_limit(phys_addr_t first_memblock_base,
 	memblock_set_current_limit(min_t(u64, first_memblock_size, SZ_32M));
 }
 
-/*
- * Set up to use a given MMU context.
- * id is context number, pgd is PGD pointer.
- *
- * We place the physical address of the new task page directory loaded
- * into the MMU base register, and set the ASID compare register with
- * the new "context."
- */
-void set_context(unsigned long id, pgd_t *pgd)
-{
-	s16 offset = (s16)(__pa(swapper_pg_dir));
-
-	/* Register M_TWB will contain base address of level 1 table minus the
-	 * lower part of the kernel PGDIR base address, so that all accesses to
-	 * level 1 table are done relative to lower part of kernel PGDIR base
-	 * address.
-	 */
-	mtspr(SPRN_M_TWB, __pa(pgd) - offset);
-
-	/* Update context */
-	mtspr(SPRN_M_CASID, id - 1);
-	/* sync */
-	mb();
-}
-
 #ifdef CONFIG_PPC_KUEP
 void __init setup_kuep(bool disabled)
 {
diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index eae48635a9ac..75dafec50d19 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -264,6 +264,30 @@ static void context_check_map(void)
 static void context_check_map(void) { }
 #endif
 
+static void set_context(unsigned long id, pgd_t *pgd)
+{
+	if (IS_ENABLED(CONFIG_PPC_8xx)) {
+		s16 offset = (s16)(__pa(swapper_pg_dir));
+
+		/* Register M_TWB will contain base address of level 1 table minus the
+		 * lower part of the kernel PGDIR base address, so that all accesses to
+		 * level 1 table are done relative to lower part of kernel PGDIR base
+		 * address.
+		 */
+		mtspr(SPRN_M_TWB, __pa(pgd) - offset);
+
+		/* Update context */
+		mtspr(SPRN_M_CASID, id - 1);
+		/* sync */
+		mb();
+	} else {
+		if (IS_ENABLED(CONFIG_40x))
+			mb();	/* sync */
+		mtspr(SPRN_PID, id);
+		isync();
+	}
+}
+
 void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 			struct task_struct *tsk)
 {
diff --git a/arch/powerpc/mm/nohash/tlb_low.S b/arch/powerpc/mm/nohash/tlb_low.S
index b3d0f0127828..4613bf8e9aae 100644
--- a/arch/powerpc/mm/nohash/tlb_low.S
+++ b/arch/powerpc/mm/nohash/tlb_low.S
@@ -360,11 +360,6 @@ _GLOBAL(_tlbivax_bcast)
 	sync
 	wrtee	r10
 	blr
-
-_GLOBAL(set_context)
-	mtspr	SPRN_PID,r3
-	isync			/* Force context change */
-	blr
 #else
 #error Unsupported processor type !
 #endif
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread
* [PATCH v3 2/6] powerpc/nohash: Convert set_context() to C
@ 2021-06-03  9:29   ` Christophe Leroy
  0 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-06-03  9:29 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linuxppc-dev, linux-kernel

ppc8xx already has set_context() in C.

Other ones have it in assembly. The only thing it does is to
write the context id into SPRN_PID.

Do it in C.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v3: Fixed whitespace before tab
---
 arch/powerpc/include/asm/mmu_context.h |  1 -
 arch/powerpc/kernel/head_40x.S         |  7 -------
 arch/powerpc/kernel/head_44x.S         |  5 -----
 arch/powerpc/kernel/head_fsl_booke.S   |  5 -----
 arch/powerpc/mm/nohash/8xx.c           | 25 -------------------------
 arch/powerpc/mm/nohash/mmu_context.c   | 24 ++++++++++++++++++++++++
 arch/powerpc/mm/nohash/tlb_low.S       |  5 -----
 7 files changed, 24 insertions(+), 48 deletions(-)

diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 4bc45d3ed8b0..ef6df2681582 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -57,7 +57,6 @@ static inline bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa,
 static inline void mm_iommu_init(struct mm_struct *mm) { }
 #endif
 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
-extern void set_context(unsigned long id, pgd_t *pgd);
 
 #ifdef CONFIG_PPC_BOOK3S_64
 extern void radix__switch_mmu_context(struct mm_struct *prev,
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 7ef1bbc23bed..2717aa860cae 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -702,13 +702,6 @@ _GLOBAL(abort)
         oris    r13,r13,DBCR0_RST_SYSTEM@h
         mtspr   SPRN_DBCR0,r13
 
-_GLOBAL(set_context)
-	sync
-	mtspr	SPRN_PID,r3
-	isync				/* Need an isync to flush shadow */
-					/* TLBs after changing PID */
-	blr
-
 /* We put a few things here that have to be page-aligned. This stuff
  * goes at the beginning of the data segment, which is page-aligned.
  */
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 57509d90e409..c5bec6a9864b 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -780,11 +780,6 @@ _GLOBAL(__fixup_440A_mcheck)
 	sync
 	blr
 
-_GLOBAL(set_context)
-	mtspr	SPRN_PID,r3
-	isync			/* Force context change */
-	blr
-
 /*
  * Init CPU state. This is called at boot time or for secondary CPUs
  * to setup initial TLB entries, setup IVORs, etc...
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 590f34cc5bb2..ab718fd5e2a2 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -985,11 +985,6 @@ _GLOBAL(abort)
 	mtspr	SPRN_DBCR0,r13
 	isync
 
-_GLOBAL(set_context)
-	mtspr	SPRN_PID,r3
-	isync			/* Force context change */
-	blr
-
 #ifdef CONFIG_SMP
 /* When we get here, r24 needs to hold the CPU # */
 	.globl __secondary_start
diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index f749acba5473..65e4c8b92657 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -212,31 +212,6 @@ void __init setup_initial_memory_limit(phys_addr_t first_memblock_base,
 	memblock_set_current_limit(min_t(u64, first_memblock_size, SZ_32M));
 }
 
-/*
- * Set up to use a given MMU context.
- * id is context number, pgd is PGD pointer.
- *
- * We place the physical address of the new task page directory loaded
- * into the MMU base register, and set the ASID compare register with
- * the new "context."
- */
-void set_context(unsigned long id, pgd_t *pgd)
-{
-	s16 offset = (s16)(__pa(swapper_pg_dir));
-
-	/* Register M_TWB will contain base address of level 1 table minus the
-	 * lower part of the kernel PGDIR base address, so that all accesses to
-	 * level 1 table are done relative to lower part of kernel PGDIR base
-	 * address.
-	 */
-	mtspr(SPRN_M_TWB, __pa(pgd) - offset);
-
-	/* Update context */
-	mtspr(SPRN_M_CASID, id - 1);
-	/* sync */
-	mb();
-}
-
 #ifdef CONFIG_PPC_KUEP
 void __init setup_kuep(bool disabled)
 {
diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index eae48635a9ac..75dafec50d19 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -264,6 +264,30 @@ static void context_check_map(void)
 static void context_check_map(void) { }
 #endif
 
+static void set_context(unsigned long id, pgd_t *pgd)
+{
+	if (IS_ENABLED(CONFIG_PPC_8xx)) {
+		s16 offset = (s16)(__pa(swapper_pg_dir));
+
+		/* Register M_TWB will contain base address of level 1 table minus the
+		 * lower part of the kernel PGDIR base address, so that all accesses to
+		 * level 1 table are done relative to lower part of kernel PGDIR base
+		 * address.
+		 */
+		mtspr(SPRN_M_TWB, __pa(pgd) - offset);
+
+		/* Update context */
+		mtspr(SPRN_M_CASID, id - 1);
+		/* sync */
+		mb();
+	} else {
+		if (IS_ENABLED(CONFIG_40x))
+			mb();	/* sync */
+		mtspr(SPRN_PID, id);
+		isync();
+	}
+}
+
 void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 			struct task_struct *tsk)
 {
diff --git a/arch/powerpc/mm/nohash/tlb_low.S b/arch/powerpc/mm/nohash/tlb_low.S
index b3d0f0127828..4613bf8e9aae 100644
--- a/arch/powerpc/mm/nohash/tlb_low.S
+++ b/arch/powerpc/mm/nohash/tlb_low.S
@@ -360,11 +360,6 @@ _GLOBAL(_tlbivax_bcast)
 	sync
 	wrtee	r10
 	blr
-
-_GLOBAL(set_context)
-	mtspr	SPRN_PID,r3
-	isync			/* Force context change */
-	blr
 #else
 #error Unsupported processor type !
 #endif
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread
* [PATCH v3 3/6] powerpc/nohash: Remove CONFIG_SMP #ifdefery in mmu_context.h
  2021-06-03  9:29 ` Christophe Leroy
@ 2021-06-03  9:29   ` Christophe Leroy
  -1 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-06-03  9:29 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linux-kernel, linuxppc-dev

Everything can be done even when CONFIG_SMP is not selected.

Just use IS_ENABLED() where relevant and rely on GCC to
opt out unneeded code and variables when CONFIG_SMP is not set.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/mmu_context.c | 66 ++++++++++------------------
 1 file changed, 24 insertions(+), 42 deletions(-)

diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index 75dafec50d19..437940d191d6 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -47,6 +47,7 @@
 
 #include <asm/mmu_context.h>
 #include <asm/tlbflush.h>
+#include <asm/smp.h>
 
 #include <mm/mmu_decl.h>
 
@@ -86,9 +87,7 @@ void *abatron_pteptrs[2];
 
 static unsigned int next_context, nr_free_contexts;
 static unsigned long *context_map;
-#ifdef CONFIG_SMP
 static unsigned long *stale_map[NR_CPUS];
-#endif
 static struct mm_struct **context_mm;
 static DEFINE_RAW_SPINLOCK(context_lock);
 
@@ -111,7 +110,6 @@ static DEFINE_RAW_SPINLOCK(context_lock);
  * the stale map as we can just flush the local CPU
  *  -- benh
  */
-#ifdef CONFIG_SMP
 static unsigned int steal_context_smp(unsigned int id)
 {
 	struct mm_struct *mm;
@@ -164,14 +162,11 @@ static unsigned int steal_context_smp(unsigned int id)
 	/* This will cause the caller to try again */
 	return MMU_NO_CONTEXT;
 }
-#endif  /* CONFIG_SMP */
 
 static unsigned int steal_all_contexts(void)
 {
 	struct mm_struct *mm;
-#ifdef CONFIG_SMP
 	int cpu = smp_processor_id();
-#endif
 	unsigned int id;
 
 	for (id = FIRST_CONTEXT; id <= LAST_CONTEXT; id++) {
@@ -189,9 +184,8 @@ static unsigned int steal_all_contexts(void)
 			mm->context.active = 0;
 #endif
 		}
-#ifdef CONFIG_SMP
-		__clear_bit(id, stale_map[cpu]);
-#endif
+		if (IS_ENABLED(CONFIG_SMP))
+			__clear_bit(id, stale_map[cpu]);
 	}
 
 	/* Flush the TLB for all contexts (not to be used on SMP) */
@@ -210,9 +204,7 @@ static unsigned int steal_all_contexts(void)
 static unsigned int steal_context_up(unsigned int id)
 {
 	struct mm_struct *mm;
-#ifdef CONFIG_SMP
 	int cpu = smp_processor_id();
-#endif
 
 	/* Pick up the victim mm */
 	mm = context_mm[id];
@@ -226,9 +218,8 @@ static unsigned int steal_context_up(unsigned int id)
 	mm->context.id = MMU_NO_CONTEXT;
 
 	/* XXX This clear should ultimately be part of local_flush_tlb_mm */
-#ifdef CONFIG_SMP
-	__clear_bit(id, stale_map[cpu]);
-#endif
+	if (IS_ENABLED(CONFIG_SMP))
+		__clear_bit(id, stale_map[cpu]);
 
 	return id;
 }
@@ -292,9 +283,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 			struct task_struct *tsk)
 {
 	unsigned int id;
-#ifdef CONFIG_SMP
 	unsigned int i, cpu = smp_processor_id();
-#endif
 	unsigned long *map;
 
 	/* No lockless fast path .. yet */
@@ -303,17 +292,17 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	pr_hard("[%d] activating context for mm @%p, active=%d, id=%d",
 		cpu, next, next->context.active, next->context.id);
 
-#ifdef CONFIG_SMP
-	/* Mark us active and the previous one not anymore */
-	next->context.active++;
-	if (prev) {
-		pr_hardcont(" (old=0x%p a=%d)", prev, prev->context.active);
-		WARN_ON(prev->context.active < 1);
-		prev->context.active--;
+	if (IS_ENABLED(CONFIG_SMP)) {
+		/* Mark us active and the previous one not anymore */
+		next->context.active++;
+		if (prev) {
+			pr_hardcont(" (old=0x%p a=%d)", prev, prev->context.active);
+			WARN_ON(prev->context.active < 1);
+			prev->context.active--;
+		}
 	}
 
  again:
-#endif /* CONFIG_SMP */
 
 	/* If we already have a valid assigned context, skip all that */
 	id = next->context.id;
@@ -334,14 +323,12 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 
 	/* No more free contexts, let's try to steal one */
 	if (nr_free_contexts == 0) {
-#ifdef CONFIG_SMP
 		if (num_online_cpus() > 1) {
 			id = steal_context_smp(id);
 			if (id == MMU_NO_CONTEXT)
 				goto again;
 			goto stolen;
 		}
-#endif /* CONFIG_SMP */
 		if (IS_ENABLED(CONFIG_PPC_8xx))
 			id = steal_all_contexts();
 		else
@@ -368,8 +355,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	/* If that context got marked stale on this CPU, then flush the
 	 * local TLB for it and unmark it before we use it
 	 */
-#ifdef CONFIG_SMP
-	if (test_bit(id, stale_map[cpu])) {
+	if (IS_ENABLED(CONFIG_SMP) && test_bit(id, stale_map[cpu])) {
 		pr_hardcont(" | stale flush %d [%d..%d]",
 			    id, cpu_first_thread_sibling(cpu),
 			    cpu_last_thread_sibling(cpu));
@@ -383,7 +369,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 				__clear_bit(id, stale_map[i]);
 		}
 	}
-#endif
 
 	/* Flick the MMU and release lock */
 	pr_hardcont(" -> %d\n", id);
@@ -442,7 +427,6 @@ void destroy_context(struct mm_struct *mm)
 	raw_spin_unlock_irqrestore(&context_lock, flags);
 }
 
-#ifdef CONFIG_SMP
 static int mmu_ctx_cpu_prepare(unsigned int cpu)
 {
 	/* We don't touch CPU 0 map, it's allocated at aboot and kept
@@ -472,8 +456,6 @@ static int mmu_ctx_cpu_dead(unsigned int cpu)
 	return 0;
 }
 
-#endif /* CONFIG_SMP */
-
 /*
  * Initialize the context management stuff.
  */
@@ -497,16 +479,16 @@ void __init mmu_context_init(void)
 	if (!context_mm)
 		panic("%s: Failed to allocate %zu bytes\n", __func__,
 		      sizeof(void *) * (LAST_CONTEXT + 1));
-#ifdef CONFIG_SMP
-	stale_map[boot_cpuid] = memblock_alloc(CTX_MAP_SIZE, SMP_CACHE_BYTES);
-	if (!stale_map[boot_cpuid])
-		panic("%s: Failed to allocate %zu bytes\n", __func__,
-		      CTX_MAP_SIZE);
-
-	cpuhp_setup_state_nocalls(CPUHP_POWERPC_MMU_CTX_PREPARE,
-				  "powerpc/mmu/ctx:prepare",
-				  mmu_ctx_cpu_prepare, mmu_ctx_cpu_dead);
-#endif
+	if (IS_ENABLED(CONFIG_SMP)) {
+		stale_map[boot_cpuid] = memblock_alloc(CTX_MAP_SIZE, SMP_CACHE_BYTES);
+		if (!stale_map[boot_cpuid])
+			panic("%s: Failed to allocate %zu bytes\n", __func__,
+			      CTX_MAP_SIZE);
+
+		cpuhp_setup_state_nocalls(CPUHP_POWERPC_MMU_CTX_PREPARE,
+					  "powerpc/mmu/ctx:prepare",
+					  mmu_ctx_cpu_prepare, mmu_ctx_cpu_dead);
+	}
 
 	printk(KERN_INFO
 	       "MMU: Allocated %zu bytes of context maps for %d contexts\n",
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread
* [PATCH v3 3/6] powerpc/nohash: Remove CONFIG_SMP #ifdefery in mmu_context.h
@ 2021-06-03  9:29   ` Christophe Leroy
  0 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-06-03  9:29 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linuxppc-dev, linux-kernel

Everything can be done even when CONFIG_SMP is not selected.

Just use IS_ENABLED() where relevant and rely on GCC to
opt out unneeded code and variables when CONFIG_SMP is not set.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/mmu_context.c | 66 ++++++++++------------------
 1 file changed, 24 insertions(+), 42 deletions(-)

diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index 75dafec50d19..437940d191d6 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -47,6 +47,7 @@
 
 #include <asm/mmu_context.h>
 #include <asm/tlbflush.h>
+#include <asm/smp.h>
 
 #include <mm/mmu_decl.h>
 
@@ -86,9 +87,7 @@ void *abatron_pteptrs[2];
 
 static unsigned int next_context, nr_free_contexts;
 static unsigned long *context_map;
-#ifdef CONFIG_SMP
 static unsigned long *stale_map[NR_CPUS];
-#endif
 static struct mm_struct **context_mm;
 static DEFINE_RAW_SPINLOCK(context_lock);
 
@@ -111,7 +110,6 @@ static DEFINE_RAW_SPINLOCK(context_lock);
  * the stale map as we can just flush the local CPU
  *  -- benh
  */
-#ifdef CONFIG_SMP
 static unsigned int steal_context_smp(unsigned int id)
 {
 	struct mm_struct *mm;
@@ -164,14 +162,11 @@ static unsigned int steal_context_smp(unsigned int id)
 	/* This will cause the caller to try again */
 	return MMU_NO_CONTEXT;
 }
-#endif  /* CONFIG_SMP */
 
 static unsigned int steal_all_contexts(void)
 {
 	struct mm_struct *mm;
-#ifdef CONFIG_SMP
 	int cpu = smp_processor_id();
-#endif
 	unsigned int id;
 
 	for (id = FIRST_CONTEXT; id <= LAST_CONTEXT; id++) {
@@ -189,9 +184,8 @@ static unsigned int steal_all_contexts(void)
 			mm->context.active = 0;
 #endif
 		}
-#ifdef CONFIG_SMP
-		__clear_bit(id, stale_map[cpu]);
-#endif
+		if (IS_ENABLED(CONFIG_SMP))
+			__clear_bit(id, stale_map[cpu]);
 	}
 
 	/* Flush the TLB for all contexts (not to be used on SMP) */
@@ -210,9 +204,7 @@ static unsigned int steal_all_contexts(void)
 static unsigned int steal_context_up(unsigned int id)
 {
 	struct mm_struct *mm;
-#ifdef CONFIG_SMP
 	int cpu = smp_processor_id();
-#endif
 
 	/* Pick up the victim mm */
 	mm = context_mm[id];
@@ -226,9 +218,8 @@ static unsigned int steal_context_up(unsigned int id)
 	mm->context.id = MMU_NO_CONTEXT;
 
 	/* XXX This clear should ultimately be part of local_flush_tlb_mm */
-#ifdef CONFIG_SMP
-	__clear_bit(id, stale_map[cpu]);
-#endif
+	if (IS_ENABLED(CONFIG_SMP))
+		__clear_bit(id, stale_map[cpu]);
 
 	return id;
 }
@@ -292,9 +283,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 			struct task_struct *tsk)
 {
 	unsigned int id;
-#ifdef CONFIG_SMP
 	unsigned int i, cpu = smp_processor_id();
-#endif
 	unsigned long *map;
 
 	/* No lockless fast path .. yet */
@@ -303,17 +292,17 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	pr_hard("[%d] activating context for mm @%p, active=%d, id=%d",
 		cpu, next, next->context.active, next->context.id);
 
-#ifdef CONFIG_SMP
-	/* Mark us active and the previous one not anymore */
-	next->context.active++;
-	if (prev) {
-		pr_hardcont(" (old=0x%p a=%d)", prev, prev->context.active);
-		WARN_ON(prev->context.active < 1);
-		prev->context.active--;
+	if (IS_ENABLED(CONFIG_SMP)) {
+		/* Mark us active and the previous one not anymore */
+		next->context.active++;
+		if (prev) {
+			pr_hardcont(" (old=0x%p a=%d)", prev, prev->context.active);
+			WARN_ON(prev->context.active < 1);
+			prev->context.active--;
+		}
 	}
 
  again:
-#endif /* CONFIG_SMP */
 
 	/* If we already have a valid assigned context, skip all that */
 	id = next->context.id;
@@ -334,14 +323,12 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 
 	/* No more free contexts, let's try to steal one */
 	if (nr_free_contexts == 0) {
-#ifdef CONFIG_SMP
 		if (num_online_cpus() > 1) {
 			id = steal_context_smp(id);
 			if (id == MMU_NO_CONTEXT)
 				goto again;
 			goto stolen;
 		}
-#endif /* CONFIG_SMP */
 		if (IS_ENABLED(CONFIG_PPC_8xx))
 			id = steal_all_contexts();
 		else
@@ -368,8 +355,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	/* If that context got marked stale on this CPU, then flush the
 	 * local TLB for it and unmark it before we use it
 	 */
-#ifdef CONFIG_SMP
-	if (test_bit(id, stale_map[cpu])) {
+	if (IS_ENABLED(CONFIG_SMP) && test_bit(id, stale_map[cpu])) {
 		pr_hardcont(" | stale flush %d [%d..%d]",
 			    id, cpu_first_thread_sibling(cpu),
 			    cpu_last_thread_sibling(cpu));
@@ -383,7 +369,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 				__clear_bit(id, stale_map[i]);
 		}
 	}
-#endif
 
 	/* Flick the MMU and release lock */
 	pr_hardcont(" -> %d\n", id);
@@ -442,7 +427,6 @@ void destroy_context(struct mm_struct *mm)
 	raw_spin_unlock_irqrestore(&context_lock, flags);
 }
 
-#ifdef CONFIG_SMP
 static int mmu_ctx_cpu_prepare(unsigned int cpu)
 {
 	/* We don't touch CPU 0 map, it's allocated at aboot and kept
@@ -472,8 +456,6 @@ static int mmu_ctx_cpu_dead(unsigned int cpu)
 	return 0;
 }
 
-#endif /* CONFIG_SMP */
-
 /*
  * Initialize the context management stuff.
  */
@@ -497,16 +479,16 @@ void __init mmu_context_init(void)
 	if (!context_mm)
 		panic("%s: Failed to allocate %zu bytes\n", __func__,
 		      sizeof(void *) * (LAST_CONTEXT + 1));
-#ifdef CONFIG_SMP
-	stale_map[boot_cpuid] = memblock_alloc(CTX_MAP_SIZE, SMP_CACHE_BYTES);
-	if (!stale_map[boot_cpuid])
-		panic("%s: Failed to allocate %zu bytes\n", __func__,
-		      CTX_MAP_SIZE);
-
-	cpuhp_setup_state_nocalls(CPUHP_POWERPC_MMU_CTX_PREPARE,
-				  "powerpc/mmu/ctx:prepare",
-				  mmu_ctx_cpu_prepare, mmu_ctx_cpu_dead);
-#endif
+	if (IS_ENABLED(CONFIG_SMP)) {
+		stale_map[boot_cpuid] = memblock_alloc(CTX_MAP_SIZE, SMP_CACHE_BYTES);
+		if (!stale_map[boot_cpuid])
+			panic("%s: Failed to allocate %zu bytes\n", __func__,
+			      CTX_MAP_SIZE);
+
+		cpuhp_setup_state_nocalls(CPUHP_POWERPC_MMU_CTX_PREPARE,
+					  "powerpc/mmu/ctx:prepare",
+					  mmu_ctx_cpu_prepare, mmu_ctx_cpu_dead);
+	}
 
 	printk(KERN_INFO
 	       "MMU: Allocated %zu bytes of context maps for %d contexts\n",
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread
* [PATCH v3 4/6] powerpc/nohash: Remove DEBUG_MAP_CONSISTENCY
  2021-06-03  9:29 ` Christophe Leroy
@ 2021-06-03  9:29   ` Christophe Leroy
  -1 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-06-03  9:29 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linux-kernel, linuxppc-dev

mmu_context handling has been there for years, so we
would know if there was problems with maps.

DEBUG_MAP_CONSISTENCY is not user selectable, remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/mmu_context.c | 47 +---------------------------
 1 file changed, 1 insertion(+), 46 deletions(-)

diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index 437940d191d6..78369580b9ff 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -21,7 +21,6 @@
  *     also clear mm->cpu_vm_mask bits when processes are migrated
  */
 
-//#define DEBUG_MAP_CONSISTENCY
 //#define DEBUG_CLAMP_LAST_CONTEXT   31
 //#define DEBUG_HARDER
 
@@ -180,9 +179,6 @@ static unsigned int steal_all_contexts(void)
 		if (id != FIRST_CONTEXT) {
 			context_mm[id] = NULL;
 			__clear_bit(id, context_map);
-#ifdef DEBUG_MAP_CONSISTENCY
-			mm->context.active = 0;
-#endif
 		}
 		if (IS_ENABLED(CONFIG_SMP))
 			__clear_bit(id, stale_map[cpu]);
@@ -224,37 +220,6 @@ static unsigned int steal_context_up(unsigned int id)
 	return id;
 }
 
-#ifdef DEBUG_MAP_CONSISTENCY
-static void context_check_map(void)
-{
-	unsigned int id, nrf, nact;
-
-	nrf = nact = 0;
-	for (id = FIRST_CONTEXT; id <= LAST_CONTEXT; id++) {
-		int used = test_bit(id, context_map);
-		if (!used)
-			nrf++;
-		if (used != (context_mm[id] != NULL))
-			pr_err("MMU: Context %d is %s and MM is %p !\n",
-			       id, used ? "used" : "free", context_mm[id]);
-		if (context_mm[id] != NULL)
-			nact += context_mm[id]->context.active;
-	}
-	if (nrf != nr_free_contexts) {
-		pr_err("MMU: Free context count out of sync ! (%d vs %d)\n",
-		       nr_free_contexts, nrf);
-		nr_free_contexts = nrf;
-	}
-	if (nact > num_online_cpus())
-		pr_err("MMU: More active contexts than CPUs ! (%d vs %d)\n",
-		       nact, num_online_cpus());
-	if (FIRST_CONTEXT > 0 && !test_bit(0, context_map))
-		pr_err("MMU: Context 0 has been freed !!!\n");
-}
-#else
-static void context_check_map(void) { }
-#endif
-
 static void set_context(unsigned long id, pgd_t *pgd)
 {
 	if (IS_ENABLED(CONFIG_PPC_8xx)) {
@@ -306,14 +271,8 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 
 	/* If we already have a valid assigned context, skip all that */
 	id = next->context.id;
-	if (likely(id != MMU_NO_CONTEXT)) {
-#ifdef DEBUG_MAP_CONSISTENCY
-		if (context_mm[id] != next)
-			pr_err("MMU: mm 0x%p has id %d but context_mm[%d] says 0x%p\n",
-			       next, id, id, context_mm[id]);
-#endif
+	if (likely(id != MMU_NO_CONTEXT))
 		goto ctxt_ok;
-	}
 
 	/* We really don't have a context, let's try to acquire one */
 	id = next_context;
@@ -349,7 +308,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	next->context.id = id;
 	pr_hardcont(" | new id=%d,nrf=%d", id, nr_free_contexts);
 
-	context_check_map();
  ctxt_ok:
 
 	/* If that context got marked stale on this CPU, then flush the
@@ -418,9 +376,6 @@ void destroy_context(struct mm_struct *mm)
 	if (id != MMU_NO_CONTEXT) {
 		__clear_bit(id, context_map);
 		mm->context.id = MMU_NO_CONTEXT;
-#ifdef DEBUG_MAP_CONSISTENCY
-		mm->context.active = 0;
-#endif
 		context_mm[id] = NULL;
 		nr_free_contexts++;
 	}
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread
* [PATCH v3 4/6] powerpc/nohash: Remove DEBUG_MAP_CONSISTENCY
@ 2021-06-03  9:29   ` Christophe Leroy
  0 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-06-03  9:29 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linuxppc-dev, linux-kernel

mmu_context handling has been there for years, so we
would know if there was problems with maps.

DEBUG_MAP_CONSISTENCY is not user selectable, remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/mmu_context.c | 47 +---------------------------
 1 file changed, 1 insertion(+), 46 deletions(-)

diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index 437940d191d6..78369580b9ff 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -21,7 +21,6 @@
  *     also clear mm->cpu_vm_mask bits when processes are migrated
  */
 
-//#define DEBUG_MAP_CONSISTENCY
 //#define DEBUG_CLAMP_LAST_CONTEXT   31
 //#define DEBUG_HARDER
 
@@ -180,9 +179,6 @@ static unsigned int steal_all_contexts(void)
 		if (id != FIRST_CONTEXT) {
 			context_mm[id] = NULL;
 			__clear_bit(id, context_map);
-#ifdef DEBUG_MAP_CONSISTENCY
-			mm->context.active = 0;
-#endif
 		}
 		if (IS_ENABLED(CONFIG_SMP))
 			__clear_bit(id, stale_map[cpu]);
@@ -224,37 +220,6 @@ static unsigned int steal_context_up(unsigned int id)
 	return id;
 }
 
-#ifdef DEBUG_MAP_CONSISTENCY
-static void context_check_map(void)
-{
-	unsigned int id, nrf, nact;
-
-	nrf = nact = 0;
-	for (id = FIRST_CONTEXT; id <= LAST_CONTEXT; id++) {
-		int used = test_bit(id, context_map);
-		if (!used)
-			nrf++;
-		if (used != (context_mm[id] != NULL))
-			pr_err("MMU: Context %d is %s and MM is %p !\n",
-			       id, used ? "used" : "free", context_mm[id]);
-		if (context_mm[id] != NULL)
-			nact += context_mm[id]->context.active;
-	}
-	if (nrf != nr_free_contexts) {
-		pr_err("MMU: Free context count out of sync ! (%d vs %d)\n",
-		       nr_free_contexts, nrf);
-		nr_free_contexts = nrf;
-	}
-	if (nact > num_online_cpus())
-		pr_err("MMU: More active contexts than CPUs ! (%d vs %d)\n",
-		       nact, num_online_cpus());
-	if (FIRST_CONTEXT > 0 && !test_bit(0, context_map))
-		pr_err("MMU: Context 0 has been freed !!!\n");
-}
-#else
-static void context_check_map(void) { }
-#endif
-
 static void set_context(unsigned long id, pgd_t *pgd)
 {
 	if (IS_ENABLED(CONFIG_PPC_8xx)) {
@@ -306,14 +271,8 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 
 	/* If we already have a valid assigned context, skip all that */
 	id = next->context.id;
-	if (likely(id != MMU_NO_CONTEXT)) {
-#ifdef DEBUG_MAP_CONSISTENCY
-		if (context_mm[id] != next)
-			pr_err("MMU: mm 0x%p has id %d but context_mm[%d] says 0x%p\n",
-			       next, id, id, context_mm[id]);
-#endif
+	if (likely(id != MMU_NO_CONTEXT))
 		goto ctxt_ok;
-	}
 
 	/* We really don't have a context, let's try to acquire one */
 	id = next_context;
@@ -349,7 +308,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	next->context.id = id;
 	pr_hardcont(" | new id=%d,nrf=%d", id, nr_free_contexts);
 
-	context_check_map();
  ctxt_ok:
 
 	/* If that context got marked stale on this CPU, then flush the
@@ -418,9 +376,6 @@ void destroy_context(struct mm_struct *mm)
 	if (id != MMU_NO_CONTEXT) {
 		__clear_bit(id, context_map);
 		mm->context.id = MMU_NO_CONTEXT;
-#ifdef DEBUG_MAP_CONSISTENCY
-		mm->context.active = 0;
-#endif
 		context_mm[id] = NULL;
 		nr_free_contexts++;
 	}
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread
* [PATCH v3 5/6] powerpc/nohash: Remove DEBUG_CLAMP_LAST_CONTEXT
  2021-06-03  9:29 ` Christophe Leroy
@ 2021-06-03  9:29   ` Christophe Leroy
  -1 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-06-03  9:29 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linux-kernel, linuxppc-dev

DEBUG_CLAMP_LAST_CONTEXT was there in the old days to reduce
number of contexts in order to ease debugging implementation
of context switching, but that's been quite stable during
years now.

As it is not user selectable, remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/mmu_context.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index 78369580b9ff..d9f590b9e636 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -21,7 +21,6 @@
  *     also clear mm->cpu_vm_mask bits when processes are migrated
  */
 
-//#define DEBUG_CLAMP_LAST_CONTEXT   31
 //#define DEBUG_HARDER
 
 /* We don't use DEBUG because it tends to be compiled in always nowadays
@@ -74,9 +73,7 @@ void *abatron_pteptrs[2];
  * -- BenH
  */
 #define FIRST_CONTEXT 1
-#ifdef DEBUG_CLAMP_LAST_CONTEXT
-#define LAST_CONTEXT DEBUG_CLAMP_LAST_CONTEXT
-#elif defined(CONFIG_PPC_8xx)
+#if defined(CONFIG_PPC_8xx)
 #define LAST_CONTEXT 16
 #elif defined(CONFIG_PPC_47x)
 #define LAST_CONTEXT 65535
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread
* [PATCH v3 5/6] powerpc/nohash: Remove DEBUG_CLAMP_LAST_CONTEXT
@ 2021-06-03  9:29   ` Christophe Leroy
  0 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-06-03  9:29 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linuxppc-dev, linux-kernel

DEBUG_CLAMP_LAST_CONTEXT was there in the old days to reduce
number of contexts in order to ease debugging implementation
of context switching, but that's been quite stable during
years now.

As it is not user selectable, remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/mmu_context.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index 78369580b9ff..d9f590b9e636 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -21,7 +21,6 @@
  *     also clear mm->cpu_vm_mask bits when processes are migrated
  */
 
-//#define DEBUG_CLAMP_LAST_CONTEXT   31
 //#define DEBUG_HARDER
 
 /* We don't use DEBUG because it tends to be compiled in always nowadays
@@ -74,9 +73,7 @@ void *abatron_pteptrs[2];
  * -- BenH
  */
 #define FIRST_CONTEXT 1
-#ifdef DEBUG_CLAMP_LAST_CONTEXT
-#define LAST_CONTEXT DEBUG_CLAMP_LAST_CONTEXT
-#elif defined(CONFIG_PPC_8xx)
+#if defined(CONFIG_PPC_8xx)
 #define LAST_CONTEXT 16
 #elif defined(CONFIG_PPC_47x)
 #define LAST_CONTEXT 65535
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread
* [PATCH v3 6/6] powerpc/nohash: Remove DEBUG_HARDER
  2021-06-03  9:29 ` Christophe Leroy
@ 2021-06-03  9:29   ` Christophe Leroy
  -1 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-06-03  9:29 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linux-kernel, linuxppc-dev

DEBUG_HARDER is not user selectable.

Remove it together with related messages.

Also remove two pr_devel() messages that should
likely have been pr_hard().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/mmu_context.c | 32 ----------------------------
 1 file changed, 32 deletions(-)

diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index d9f590b9e636..920b5b8c770d 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -21,19 +21,6 @@
  *     also clear mm->cpu_vm_mask bits when processes are migrated
  */
 
-//#define DEBUG_HARDER
-
-/* We don't use DEBUG because it tends to be compiled in always nowadays
- * and this would generate way too much output
- */
-#ifdef DEBUG_HARDER
-#define pr_hard(args...)	printk(KERN_DEBUG args)
-#define pr_hardcont(args...)	printk(KERN_CONT args)
-#else
-#define pr_hard(args...)	do { } while(0)
-#define pr_hardcont(args...)	do { } while(0)
-#endif
-
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/init.h>
@@ -127,7 +114,6 @@ static unsigned int steal_context_smp(unsigned int id)
 				id = FIRST_CONTEXT;
 			continue;
 		}
-		pr_hardcont(" | steal %d from 0x%p", id, mm);
 
 		/* Mark this mm has having no context anymore */
 		mm->context.id = MMU_NO_CONTEXT;
@@ -169,8 +155,6 @@ static unsigned int steal_all_contexts(void)
 		/* Pick up the victim mm */
 		mm = context_mm[id];
 
-		pr_hardcont(" | steal %d from 0x%p", id, mm);
-
 		/* Mark this mm as having no context anymore */
 		mm->context.id = MMU_NO_CONTEXT;
 		if (id != FIRST_CONTEXT) {
@@ -202,8 +186,6 @@ static unsigned int steal_context_up(unsigned int id)
 	/* Pick up the victim mm */
 	mm = context_mm[id];
 
-	pr_hardcont(" | steal %d from 0x%p", id, mm);
-
 	/* Flush the TLB for that context */
 	local_flush_tlb_mm(mm);
 
@@ -251,14 +233,10 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	/* No lockless fast path .. yet */
 	raw_spin_lock(&context_lock);
 
-	pr_hard("[%d] activating context for mm @%p, active=%d, id=%d",
-		cpu, next, next->context.active, next->context.id);
-
 	if (IS_ENABLED(CONFIG_SMP)) {
 		/* Mark us active and the previous one not anymore */
 		next->context.active++;
 		if (prev) {
-			pr_hardcont(" (old=0x%p a=%d)", prev, prev->context.active);
 			WARN_ON(prev->context.active < 1);
 			prev->context.active--;
 		}
@@ -303,7 +281,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	next_context = id + 1;
 	context_mm[id] = next;
 	next->context.id = id;
-	pr_hardcont(" | new id=%d,nrf=%d", id, nr_free_contexts);
 
  ctxt_ok:
 
@@ -311,10 +288,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	 * local TLB for it and unmark it before we use it
 	 */
 	if (IS_ENABLED(CONFIG_SMP) && test_bit(id, stale_map[cpu])) {
-		pr_hardcont(" | stale flush %d [%d..%d]",
-			    id, cpu_first_thread_sibling(cpu),
-			    cpu_last_thread_sibling(cpu));
-
 		local_flush_tlb_mm(next);
 
 		/* XXX This clear should ultimately be part of local_flush_tlb_mm */
@@ -326,7 +299,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	}
 
 	/* Flick the MMU and release lock */
-	pr_hardcont(" -> %d\n", id);
 	if (IS_ENABLED(CONFIG_BDI_SWITCH))
 		abatron_pteptrs[1] = next->pgd;
 	set_context(id, next->pgd);
@@ -338,8 +310,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
  */
 int init_new_context(struct task_struct *t, struct mm_struct *mm)
 {
-	pr_hard("initing context for mm @%p\n", mm);
-
 	/*
 	 * We have MMU_NO_CONTEXT set to be ~0. Hence check
 	 * explicitly against context.id == 0. This ensures that we properly
@@ -387,7 +357,6 @@ static int mmu_ctx_cpu_prepare(unsigned int cpu)
 	if (cpu == boot_cpuid)
 		return 0;
 
-	pr_devel("MMU: Allocating stale context map for CPU %d\n", cpu);
 	stale_map[cpu] = kzalloc(CTX_MAP_SIZE, GFP_KERNEL);
 	return 0;
 }
@@ -398,7 +367,6 @@ static int mmu_ctx_cpu_dead(unsigned int cpu)
 	if (cpu == boot_cpuid)
 		return 0;
 
-	pr_devel("MMU: Freeing stale context map for CPU %d\n", cpu);
 	kfree(stale_map[cpu]);
 	stale_map[cpu] = NULL;
 
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread
* [PATCH v3 6/6] powerpc/nohash: Remove DEBUG_HARDER
@ 2021-06-03  9:29   ` Christophe Leroy
  0 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-06-03  9:29 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linuxppc-dev, linux-kernel

DEBUG_HARDER is not user selectable.

Remove it together with related messages.

Also remove two pr_devel() messages that should
likely have been pr_hard().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/mmu_context.c | 32 ----------------------------
 1 file changed, 32 deletions(-)

diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index d9f590b9e636..920b5b8c770d 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -21,19 +21,6 @@
  *     also clear mm->cpu_vm_mask bits when processes are migrated
  */
 
-//#define DEBUG_HARDER
-
-/* We don't use DEBUG because it tends to be compiled in always nowadays
- * and this would generate way too much output
- */
-#ifdef DEBUG_HARDER
-#define pr_hard(args...)	printk(KERN_DEBUG args)
-#define pr_hardcont(args...)	printk(KERN_CONT args)
-#else
-#define pr_hard(args...)	do { } while(0)
-#define pr_hardcont(args...)	do { } while(0)
-#endif
-
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/init.h>
@@ -127,7 +114,6 @@ static unsigned int steal_context_smp(unsigned int id)
 				id = FIRST_CONTEXT;
 			continue;
 		}
-		pr_hardcont(" | steal %d from 0x%p", id, mm);
 
 		/* Mark this mm has having no context anymore */
 		mm->context.id = MMU_NO_CONTEXT;
@@ -169,8 +155,6 @@ static unsigned int steal_all_contexts(void)
 		/* Pick up the victim mm */
 		mm = context_mm[id];
 
-		pr_hardcont(" | steal %d from 0x%p", id, mm);
-
 		/* Mark this mm as having no context anymore */
 		mm->context.id = MMU_NO_CONTEXT;
 		if (id != FIRST_CONTEXT) {
@@ -202,8 +186,6 @@ static unsigned int steal_context_up(unsigned int id)
 	/* Pick up the victim mm */
 	mm = context_mm[id];
 
-	pr_hardcont(" | steal %d from 0x%p", id, mm);
-
 	/* Flush the TLB for that context */
 	local_flush_tlb_mm(mm);
 
@@ -251,14 +233,10 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	/* No lockless fast path .. yet */
 	raw_spin_lock(&context_lock);
 
-	pr_hard("[%d] activating context for mm @%p, active=%d, id=%d",
-		cpu, next, next->context.active, next->context.id);
-
 	if (IS_ENABLED(CONFIG_SMP)) {
 		/* Mark us active and the previous one not anymore */
 		next->context.active++;
 		if (prev) {
-			pr_hardcont(" (old=0x%p a=%d)", prev, prev->context.active);
 			WARN_ON(prev->context.active < 1);
 			prev->context.active--;
 		}
@@ -303,7 +281,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	next_context = id + 1;
 	context_mm[id] = next;
 	next->context.id = id;
-	pr_hardcont(" | new id=%d,nrf=%d", id, nr_free_contexts);
 
  ctxt_ok:
 
@@ -311,10 +288,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	 * local TLB for it and unmark it before we use it
 	 */
 	if (IS_ENABLED(CONFIG_SMP) && test_bit(id, stale_map[cpu])) {
-		pr_hardcont(" | stale flush %d [%d..%d]",
-			    id, cpu_first_thread_sibling(cpu),
-			    cpu_last_thread_sibling(cpu));
-
 		local_flush_tlb_mm(next);
 
 		/* XXX This clear should ultimately be part of local_flush_tlb_mm */
@@ -326,7 +299,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
 	}
 
 	/* Flick the MMU and release lock */
-	pr_hardcont(" -> %d\n", id);
 	if (IS_ENABLED(CONFIG_BDI_SWITCH))
 		abatron_pteptrs[1] = next->pgd;
 	set_context(id, next->pgd);
@@ -338,8 +310,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
  */
 int init_new_context(struct task_struct *t, struct mm_struct *mm)
 {
-	pr_hard("initing context for mm @%p\n", mm);
-
 	/*
 	 * We have MMU_NO_CONTEXT set to be ~0. Hence check
 	 * explicitly against context.id == 0. This ensures that we properly
@@ -387,7 +357,6 @@ static int mmu_ctx_cpu_prepare(unsigned int cpu)
 	if (cpu == boot_cpuid)
 		return 0;
 
-	pr_devel("MMU: Allocating stale context map for CPU %d\n", cpu);
 	stale_map[cpu] = kzalloc(CTX_MAP_SIZE, GFP_KERNEL);
 	return 0;
 }
@@ -398,7 +367,6 @@ static int mmu_ctx_cpu_dead(unsigned int cpu)
 	if (cpu == boot_cpuid)
 		return 0;
 
-	pr_devel("MMU: Freeing stale context map for CPU %d\n", cpu);
 	kfree(stale_map[cpu]);
 	stale_map[cpu] = NULL;
 
-- 
2.25.0


^ permalink raw reply related	[flat|nested] 13+ messages in thread
* Re: [PATCH v3 1/6] powerpc/nohash: Refactor update of BDI2000 pointers in switch_mmu_context()
  2021-06-03  9:29 ` Christophe Leroy
                   ` (5 preceding siblings ...)
  (?)
@ 2021-06-18  3:51 ` Michael Ellerman
  -1 siblings, 0 replies; 13+ messages in thread
From: Michael Ellerman @ 2021-06-18  3:51 UTC (permalink / raw)
  To: Paul Mackerras, Michael Ellerman, Benjamin Herrenschmidt,
	Christophe Leroy
  Cc: linuxppc-dev, linux-kernel

On Thu, 3 Jun 2021 09:29:02 +0000 (UTC), Christophe Leroy wrote:
> Instead of duplicating the update of BDI2000 pointers in
> set_context(), do it directly from switch_mmu_context().

Applied to powerpc/next.

[1/6] powerpc/nohash: Refactor update of BDI2000 pointers in switch_mmu_context()
      https://git.kernel.org/powerpc/c/25910260ff69fa0c37e26541aac4e8f978e1f17f
[2/6] powerpc/nohash: Convert set_context() to C
      https://git.kernel.org/powerpc/c/a56ab7c7290f5922363d1ee11bbafc4da2b9bf51
[3/6] powerpc/nohash: Remove CONFIG_SMP #ifdefery in mmu_context.h
      https://git.kernel.org/powerpc/c/c13066e53aabd8f268f051d267270765e10343aa
[4/6] powerpc/nohash: Remove DEBUG_MAP_CONSISTENCY
      https://git.kernel.org/powerpc/c/dac3db1edf8b4c75859f07789f577322f2a51e3a
[5/6] powerpc/nohash: Remove DEBUG_CLAMP_LAST_CONTEXT
      https://git.kernel.org/powerpc/c/a36c0faf3dbc429d5ddcb941afe38dd6fe6c5901
[6/6] powerpc/nohash: Remove DEBUG_HARDER
      https://git.kernel.org/powerpc/c/e2c043163d44f7b3a9e65d9161af72b647b18451

cheers

^ permalink raw reply	[flat|nested] 13+ messages in thread
end of thread, other threads:[~2021-06-18  4:23 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-06-03  9:29 [PATCH v3 1/6] powerpc/nohash: Refactor update of BDI2000 pointers in switch_mmu_context() Christophe Leroy
2021-06-03  9:29 ` Christophe Leroy
2021-06-03  9:29 ` [PATCH v3 2/6] powerpc/nohash: Convert set_context() to C Christophe Leroy
2021-06-03  9:29   ` Christophe Leroy
2021-06-03  9:29 ` [PATCH v3 3/6] powerpc/nohash: Remove CONFIG_SMP #ifdefery in mmu_context.h Christophe Leroy
2021-06-03  9:29   ` Christophe Leroy
2021-06-03  9:29 ` [PATCH v3 4/6] powerpc/nohash: Remove DEBUG_MAP_CONSISTENCY Christophe Leroy
2021-06-03  9:29   ` Christophe Leroy
2021-06-03  9:29 ` [PATCH v3 5/6] powerpc/nohash: Remove DEBUG_CLAMP_LAST_CONTEXT Christophe Leroy
2021-06-03  9:29   ` Christophe Leroy
2021-06-03  9:29 ` [PATCH v3 6/6] powerpc/nohash: Remove DEBUG_HARDER Christophe Leroy
2021-06-03  9:29   ` Christophe Leroy
2021-06-18  3:51 ` [PATCH v3 1/6] powerpc/nohash: Refactor update of BDI2000 pointers in switch_mmu_context() Michael Ellerman

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