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From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Scott Wood <oss@buserror.net>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v5 16/23] powerpc/8xx: rewrite set_context() in C
Date: Wed,  3 Feb 2016 23:54:27 +0100 (CET)	[thread overview]
Message-ID: <59bd0cb31204c68d15a8d7a3df3dfbf8412a546d.1454538978.git.christophe.leroy@c-s.fr> (raw)
In-Reply-To: <cover.1454538974.git.christophe.leroy@c-s.fr>

There is no real need to have set_context() in assembly.
Now that we have mtspr() handling CPU6 ERRATA directly, we
can rewrite set_context() in C language for easier maintenance.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
v2: no change
v3: no change
v4: no change
v5: no change

 arch/powerpc/kernel/head_8xx.S | 44 ------------------------------------------
 arch/powerpc/mm/8xx_mmu.c      | 34 ++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 44 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 637f8e9..bb2b657 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -968,50 +968,6 @@ initial_mmu:
 
 
 /*
- * Set up to use a given MMU context.
- * r3 is context number, r4 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."
- */
-_GLOBAL(set_context)
-
-#ifdef CONFIG_BDI_SWITCH
-	/* Context switch the PTE pointer for the Abatron BDI2000.
-	 * The PGDIR is passed as second argument.
-	 */
-	lis	r5, KERNELBASE@h
-	lwz	r5, 0xf0(r5)
-	stw	r4, 0x4(r5)
-#endif
-
-	/* Register M_TW 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.
-	 */
-	li	r5, (swapper_pg_dir-PAGE_OFFSET)@l
-	sub	r4, r4, r5
-	tophys	(r4, r4)
-#ifdef CONFIG_8xx_CPU6
-	lis	r6, cpu6_errata_word@h
-	ori	r6, r6, cpu6_errata_word@l
-	li	r7, 0x3f80
-	stw	r7, 12(r6)
-	lwz	r7, 12(r6)
-#endif
-	mtspr	SPRN_M_TW, r4		/* Update pointeur to level 1 table */
-#ifdef CONFIG_8xx_CPU6
-	li	r7, 0x3380
-	stw	r7, 12(r6)
-	lwz	r7, 12(r6)
-#endif
-	mtspr	SPRN_M_CASID, r3	/* Update context */
-	SYNC
-	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/mm/8xx_mmu.c b/arch/powerpc/mm/8xx_mmu.c
index 6965575..8701e4d 100644
--- a/arch/powerpc/mm/8xx_mmu.c
+++ b/arch/powerpc/mm/8xx_mmu.c
@@ -147,3 +147,37 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 	memblock_set_current_limit(min_t(u64, first_memblock_size,
 					 initial_memory_size));
 }
+
+/*
+ * 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));
+
+#ifdef CONFIG_BDI_SWITCH
+	pgd_t	**ptr = *(pgd_t ***)(KERNELBASE + 0xf0);
+
+	/* Context switch the PTE pointer for the Abatron BDI2000.
+	 * The PGDIR is passed as second argument.
+	 */
+	*(ptr + 1) = pgd;
+#endif
+
+	/* Register M_TW 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_TW, __pa(pgd) - offset);
+
+	/* Update context */
+	mtspr(SPRN_M_CASID, id);
+	/* sync */
+	mb();
+}
-- 
2.1.0

  parent reply	other threads:[~2016-02-03 22:57 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-03 22:53 [PATCH v5 00/23] powerpc/8xx: Use large pages for RAM and IMMR and other improvments Christophe Leroy
2016-02-03 22:53 ` [PATCH v5 01/23] powerpc/8xx: Save r3 all the time in DTLB miss handler Christophe Leroy
2016-02-03 22:53 ` [PATCH v5 02/23] powerpc/8xx: Map linear kernel RAM with 8M pages Christophe Leroy
2016-02-03 22:53 ` [PATCH v5 03/23] powerpc: Update documentation for noltlbs kernel parameter Christophe Leroy
2016-02-03 22:53 ` [PATCH v5 04/23] powerpc/8xx: move setup_initial_memory_limit() into 8xx_mmu.c Christophe Leroy
2016-02-03 22:53 ` [PATCH v5 05/23] powerpc32: Fix pte_offset_kernel() to return NULL for bad pages Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 06/23] powerpc32: refactor x_mapped_by_bats() and x_mapped_by_tlbcam() together Christophe Leroy
2016-02-07  9:42   ` kbuild test robot
2016-02-03 22:54 ` [PATCH v5 07/23] powerpc/8xx: Fix vaddr for IMMR early remap Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 08/23] powerpc/8xx: Map IMMR area with 512k page at a fixed address Christophe Leroy
2016-02-04  9:58   ` kbuild test robot
2016-02-03 22:54 ` [PATCH v5 09/23] powerpc/8xx: CONFIG_PIN_TLB unneeded for CONFIG_PPC_EARLY_DEBUG_CPM Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 10/23] powerpc/8xx: map more RAM at startup when needed Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 11/23] powerpc32: Remove useless/wrong MMU:setio progress message Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 12/23] powerpc32: remove ioremap_base Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 13/23] powerpc/8xx: Add missing SPRN defines into reg_8xx.h Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 14/23] powerpc/8xx: Handle CPU6 ERRATA directly in mtspr() macro Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 15/23] powerpc/8xx: remove special handling of CPU6 errata in set_dec() Christophe Leroy
2016-02-03 22:54 ` Christophe Leroy [this message]
2016-02-03 22:54 ` [PATCH v5 17/23] powerpc/8xx: rewrite flush_instruction_cache() in C Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 18/23] powerpc: add inline functions for cache related instructions Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 19/23] powerpc32: Remove clear_pages() and define clear_page() inline Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 20/23] powerpc32: move xxxxx_dcache_range() functions inline Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 21/23] powerpc: Simplify test in __dma_sync() Christophe Leroy
2016-02-04 11:37   ` Denis Kirjanov
2016-02-04 13:42     ` Christophe Leroy
2016-02-05  7:52       ` Denis Kirjanov
2016-02-05  7:56         ` Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 22/23] powerpc32: small optimisation in flush_icache_range() Christophe Leroy
2016-02-03 22:54 ` [PATCH v5 23/23] powerpc32: Remove one insn in mulhdu Christophe Leroy

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