[PATCH 0/3] Use scratch registers when MIPS_PGD_C0_CONTEXT is not set

[PATCH 0/3] Use scratch registers when MIPS_PGD_C0_CONTEXT is not set

[Jayachandran C]

This is the updated patchset that fixes issues reported during the last
merge to upstream-sfr.

The first patch is a new change that moves the TLB handlers from arrays
in .data to functions defined in tlb-funcs.S to fix the microMIPS issue
reported.
(http://www.linux-mips.org/archives/linux-mips/2013-06/msg00415.html)

The second patch has the changes to use scratch registers when
MIPS_PGD_C0_CONTEXT is not defined - this has not changed.

The third has a fix for the compile error  on IP27 platform.
(http://www.linux-mips.org/archives/linux-mips/2013-06/msg00399.html)

Jonas already has posted http://patchwork.linux-mips.org/patch/5539/ for
the other issue (crash on bcm63xx and mti platforms)

JC.

Jayachandran C (3):
  MIPS: Move generated code to .text for microMIPS
  MIPS: mm: Use scratch for PGD when !CONFIG_MIPS_PGD_C0_CONTEXT
  MIPS: Move definition of SMP processor id register to header file

 arch/mips/include/asm/mmu_context.h |   28 ++---
 arch/mips/include/asm/stackframe.h  |   24 +---
 arch/mips/include/asm/thread_info.h |   33 +++++-
 arch/mips/mm/Makefile               |    2 +-
 arch/mips/mm/tlb-funcs.S            |   37 ++++++
 arch/mips/mm/tlbex.c                |  224 ++++++++++++++++-------------------
 6 files changed, 187 insertions(+), 161 deletions(-)
 create mode 100644 arch/mips/mm/tlb-funcs.S

-- 
1.7.9.5

[PATCH 1/3] MIPS: Move generated code to .text for microMIPS

[Jayachandran C]

Prepare of a next patch which will call tlbmiss_handler_setup_pgd on
microMIPS. MicroMIPS complains if the called code s not in the .text
section. To fix this we generate code into space reserved in
arch/mips/mm/tlb-funcs.S

While there, move the rest of the generated functions (handle_tlbl,
handle_tlbs, handle_tlbm) to the same file.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
---
 arch/mips/include/asm/mmu_context.h |    6 +--
 arch/mips/mm/Makefile               |    2 +-
 arch/mips/mm/tlb-funcs.S            |   37 +++++++++++++++
 arch/mips/mm/tlbex.c                |   84 ++++++++++++++++++-----------------
 4 files changed, 83 insertions(+), 46 deletions(-)
 create mode 100644 arch/mips/mm/tlb-funcs.S

diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h
index 516e6e9..3b29079 100644
--- a/arch/mips/include/asm/mmu_context.h
+++ b/arch/mips/include/asm/mmu_context.h
@@ -28,11 +28,7 @@
 
 #define TLBMISS_HANDLER_SETUP_PGD(pgd)					\
 do {									\
-	void (*tlbmiss_handler_setup_pgd)(unsigned long);		\
-	extern u32 tlbmiss_handler_setup_pgd_array[16];			\
-									\
-	tlbmiss_handler_setup_pgd =					\
-		(__typeof__(tlbmiss_handler_setup_pgd)) tlbmiss_handler_setup_pgd_array; \
+	extern void tlbmiss_handler_setup_pgd(unsigned long);		\
 	tlbmiss_handler_setup_pgd((unsigned long)(pgd));		\
 } while (0)
 
diff --git a/arch/mips/mm/Makefile b/arch/mips/mm/Makefile
index e87aae1..7f4f93a 100644
--- a/arch/mips/mm/Makefile
+++ b/arch/mips/mm/Makefile
@@ -4,7 +4,7 @@
 
 obj-y				+= cache.o dma-default.o extable.o fault.o \
 				   gup.o init.o mmap.o page.o page-funcs.o \
-				   tlbex.o tlbex-fault.o uasm-mips.o
+				   tlbex.o tlbex-fault.o tlb-funcs.o uasm-mips.o
 
 obj-$(CONFIG_32BIT)		+= ioremap.o pgtable-32.o
 obj-$(CONFIG_64BIT)		+= pgtable-64.o
diff --git a/arch/mips/mm/tlb-funcs.S b/arch/mips/mm/tlb-funcs.S
new file mode 100644
index 0000000..30a494d
--- /dev/null
+++ b/arch/mips/mm/tlb-funcs.S
@@ -0,0 +1,37 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Micro-assembler generated tlb handler functions.
+ *
+ * Copyright (C) 2013  Broadcom Corporation.
+ *
+ * Based on mm/page-funcs.c
+ * Copyright (C) 2012  MIPS Technologies, Inc.
+ * Copyright (C) 2012  Ralf Baechle <ralf@linux-mips.org>
+ */
+#include <asm/asm.h>
+#include <asm/regdef.h>
+
+#define FASTPATH_SIZE	128
+
+LEAF(tlbmiss_handler_setup_pgd)
+	.space		16 * 4
+END(tlbmiss_handler_setup_pgd)
+EXPORT(tlbmiss_handler_setup_pgd_end)
+
+LEAF(handle_tlbm)
+	.space		FASTPATH_SIZE * 4
+END(handle_tlbm)
+EXPORT(handle_tlbm_end)
+
+LEAF(handle_tlbs)
+	.space		FASTPATH_SIZE * 4
+END(handle_tlbs)
+EXPORT(handle_tlbs_end)
+
+LEAF(handle_tlbl)
+	.space		FASTPATH_SIZE * 4
+END(handle_tlbl)
+EXPORT(handle_tlbl_end)
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index f1eabe7..b5e9363 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -1455,27 +1455,25 @@ static void __cpuinit build_r4000_tlb_refill_handler(void)
 	dump_handler("r4000_tlb_refill", (u32 *)ebase, 64);
 }
 
-/*
- * 128 instructions for the fastpath handler is generous and should
- * never be exceeded.
- */
-#define FASTPATH_SIZE 128
+extern u32 handle_tlbl[], handle_tlbl_end[];
+extern u32 handle_tlbs[], handle_tlbs_end[];
+extern u32 handle_tlbm[], handle_tlbm_end[];
 
-u32 handle_tlbl[FASTPATH_SIZE] __cacheline_aligned;
-u32 handle_tlbs[FASTPATH_SIZE] __cacheline_aligned;
-u32 handle_tlbm[FASTPATH_SIZE] __cacheline_aligned;
 #ifdef CONFIG_MIPS_PGD_C0_CONTEXT
-u32 tlbmiss_handler_setup_pgd_array[16] __cacheline_aligned;
+extern u32 tlbmiss_handler_setup_pgd[], tlbmiss_handler_setup_pgd_end[];
 
 static void __cpuinit build_r4000_setup_pgd(void)
 {
 	const int a0 = 4;
 	const int a1 = 5;
 	u32 *p = tlbmiss_handler_setup_pgd_array;
+	const int tlbmiss_handler_setup_pgd_size =
+		tlbmiss_handler_setup_pgd_end - tlbmiss_handler_setup_pgd;
 	struct uasm_label *l = labels;
 	struct uasm_reloc *r = relocs;
 
-	memset(tlbmiss_handler_setup_pgd_array, 0, sizeof(tlbmiss_handler_setup_pgd_array));
+	memset(tlbmiss_handler_setup_pgd, 0, tlbmiss_handler_setup_pgd_size *
+					sizeof(tlbmiss_handler_setup_pgd[0]));
 	memset(labels, 0, sizeof(labels));
 	memset(relocs, 0, sizeof(relocs));
 
@@ -1503,15 +1501,15 @@ static void __cpuinit build_r4000_setup_pgd(void)
 		uasm_i_jr(&p, 31);
 		UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
 	}
-	if (p - tlbmiss_handler_setup_pgd_array > ARRAY_SIZE(tlbmiss_handler_setup_pgd_array))
-		panic("tlbmiss_handler_setup_pgd_array space exceeded");
+	if (p >= tlbmiss_handler_setup_pgd_end)
+		panic("tlbmiss_handler_setup_pgd space exceeded");
+
 	uasm_resolve_relocs(relocs, labels);
-	pr_debug("Wrote tlbmiss_handler_setup_pgd_array (%u instructions).\n",
-		 (unsigned int)(p - tlbmiss_handler_setup_pgd_array));
+	pr_debug("Wrote tlbmiss_handler_setup_pgd (%u instructions).\n",
+		 (unsigned int)(p - tlbmiss_handler_setup_pgd));
 
-	dump_handler("tlbmiss_handler",
-		     tlbmiss_handler_setup_pgd_array,
-		     ARRAY_SIZE(tlbmiss_handler_setup_pgd_array));
+	dump_handler("tlbmiss_handler", tlbmiss_handler_setup_pgd,
+					tlbmiss_handler_setup_pgd_size);
 }
 #endif
 
@@ -1756,10 +1754,11 @@ build_r3000_tlbchange_handler_head(u32 **p, unsigned int pte,
 static void __cpuinit build_r3000_tlb_load_handler(void)
 {
 	u32 *p = handle_tlbl;
+	const int handle_tlbl_size = handle_tlbl_end - handle_tlbl;
 	struct uasm_label *l = labels;
 	struct uasm_reloc *r = relocs;
 
-	memset(handle_tlbl, 0, sizeof(handle_tlbl));
+	memset(handle_tlbl, 0, handle_tlbl_size * sizeof(handle_tlbl[0]));
 	memset(labels, 0, sizeof(labels));
 	memset(relocs, 0, sizeof(relocs));
 
@@ -1773,23 +1772,24 @@ static void __cpuinit build_r3000_tlb_load_handler(void)
 	uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
 	uasm_i_nop(&p);
 
-	if ((p - handle_tlbl) > FASTPATH_SIZE)
+	if (p >= handle_tlbl_end)
 		panic("TLB load handler fastpath space exceeded");
 
 	uasm_resolve_relocs(relocs, labels);
 	pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
 		 (unsigned int)(p - handle_tlbl));
 
-	dump_handler("r3000_tlb_load", handle_tlbl, ARRAY_SIZE(handle_tlbl));
+	dump_handler("r3000_tlb_load", handle_tlbl, handle_tlbl_size);
 }
 
 static void __cpuinit build_r3000_tlb_store_handler(void)
 {
 	u32 *p = handle_tlbs;
+	const int handle_tlbs_size = handle_tlbs_end - handle_tlbs;
 	struct uasm_label *l = labels;
 	struct uasm_reloc *r = relocs;
 
-	memset(handle_tlbs, 0, sizeof(handle_tlbs));
+	memset(handle_tlbs, 0, handle_tlbs_size * sizeof(handle_tlbs[0]));
 	memset(labels, 0, sizeof(labels));
 	memset(relocs, 0, sizeof(relocs));
 
@@ -1803,23 +1803,24 @@ static void __cpuinit build_r3000_tlb_store_handler(void)
 	uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
 	uasm_i_nop(&p);
 
-	if ((p - handle_tlbs) > FASTPATH_SIZE)
+	if (p >= handle_tlbs)
 		panic("TLB store handler fastpath space exceeded");
 
 	uasm_resolve_relocs(relocs, labels);
 	pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
 		 (unsigned int)(p - handle_tlbs));
 
-	dump_handler("r3000_tlb_store", handle_tlbs, ARRAY_SIZE(handle_tlbs));
+	dump_handler("r3000_tlb_store", handle_tlbs, handle_tlbs_size);
 }
 
 static void __cpuinit build_r3000_tlb_modify_handler(void)
 {
 	u32 *p = handle_tlbm;
+	const int handle_tlbm_size = handle_tlbm_end - handle_tlbm;
 	struct uasm_label *l = labels;
 	struct uasm_reloc *r = relocs;
 
-	memset(handle_tlbm, 0, sizeof(handle_tlbm));
+	memset(handle_tlbm, 0, handle_tlbm_size * sizeof(handle_tlbm[0]));
 	memset(labels, 0, sizeof(labels));
 	memset(relocs, 0, sizeof(relocs));
 
@@ -1833,14 +1834,14 @@ static void __cpuinit build_r3000_tlb_modify_handler(void)
 	uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
 	uasm_i_nop(&p);
 
-	if ((p - handle_tlbm) > FASTPATH_SIZE)
+	if (p >= handle_tlbm_end)
 		panic("TLB modify handler fastpath space exceeded");
 
 	uasm_resolve_relocs(relocs, labels);
 	pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
 		 (unsigned int)(p - handle_tlbm));
 
-	dump_handler("r3000_tlb_modify", handle_tlbm, ARRAY_SIZE(handle_tlbm));
+	dump_handler("r3000_tlb_modify", handle_tlbm, handle_tlbm_size);
 }
 #endif /* CONFIG_MIPS_PGD_C0_CONTEXT */
 
@@ -1904,11 +1905,12 @@ build_r4000_tlbchange_handler_tail(u32 **p, struct uasm_label **l,
 static void __cpuinit build_r4000_tlb_load_handler(void)
 {
 	u32 *p = handle_tlbl;
+	const int handle_tlbl_size = handle_tlbl_end - handle_tlbl;
 	struct uasm_label *l = labels;
 	struct uasm_reloc *r = relocs;
 	struct work_registers wr;
 
-	memset(handle_tlbl, 0, sizeof(handle_tlbl));
+	memset(handle_tlbl, 0, handle_tlbl_size * sizeof(handle_tlbl[0]));
 	memset(labels, 0, sizeof(labels));
 	memset(relocs, 0, sizeof(relocs));
 
@@ -2073,24 +2075,25 @@ static void __cpuinit build_r4000_tlb_load_handler(void)
 	uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
 	uasm_i_nop(&p);
 
-	if ((p - handle_tlbl) > FASTPATH_SIZE)
+	if (p >= handle_tlbl_end)
 		panic("TLB load handler fastpath space exceeded");
 
 	uasm_resolve_relocs(relocs, labels);
 	pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
 		 (unsigned int)(p - handle_tlbl));
 
-	dump_handler("r4000_tlb_load", handle_tlbl, ARRAY_SIZE(handle_tlbl));
+	dump_handler("r4000_tlb_load", handle_tlbl, handle_tlbl_size);
 }
 
 static void __cpuinit build_r4000_tlb_store_handler(void)
 {
 	u32 *p = handle_tlbs;
+	const int handle_tlbs_size = handle_tlbs_end - handle_tlbs;
 	struct uasm_label *l = labels;
 	struct uasm_reloc *r = relocs;
 	struct work_registers wr;
 
-	memset(handle_tlbs, 0, sizeof(handle_tlbs));
+	memset(handle_tlbs, 0, handle_tlbs_size * sizeof(handle_tlbs[0]));
 	memset(labels, 0, sizeof(labels));
 	memset(relocs, 0, sizeof(relocs));
 
@@ -2127,24 +2130,25 @@ static void __cpuinit build_r4000_tlb_store_handler(void)
 	uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
 	uasm_i_nop(&p);
 
-	if ((p - handle_tlbs) > FASTPATH_SIZE)
+	if (p >= handle_tlbs_end)
 		panic("TLB store handler fastpath space exceeded");
 
 	uasm_resolve_relocs(relocs, labels);
 	pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
 		 (unsigned int)(p - handle_tlbs));
 
-	dump_handler("r4000_tlb_store", handle_tlbs, ARRAY_SIZE(handle_tlbs));
+	dump_handler("r4000_tlb_store", handle_tlbs, handle_tlbs_size);
 }
 
 static void __cpuinit build_r4000_tlb_modify_handler(void)
 {
 	u32 *p = handle_tlbm;
+	const int handle_tlbm_size = handle_tlbm_end - handle_tlbm;
 	struct uasm_label *l = labels;
 	struct uasm_reloc *r = relocs;
 	struct work_registers wr;
 
-	memset(handle_tlbm, 0, sizeof(handle_tlbm));
+	memset(handle_tlbm, 0, handle_tlbm_size * sizeof(handle_tlbm[0]));
 	memset(labels, 0, sizeof(labels));
 	memset(relocs, 0, sizeof(relocs));
 
@@ -2182,14 +2186,14 @@ static void __cpuinit build_r4000_tlb_modify_handler(void)
 	uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
 	uasm_i_nop(&p);
 
-	if ((p - handle_tlbm) > FASTPATH_SIZE)
+	if (p >= handle_tlbm_end)
 		panic("TLB modify handler fastpath space exceeded");
 
 	uasm_resolve_relocs(relocs, labels);
 	pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
 		 (unsigned int)(p - handle_tlbm));
 
-	dump_handler("r4000_tlb_modify", handle_tlbm, ARRAY_SIZE(handle_tlbm));
+	dump_handler("r4000_tlb_modify", handle_tlbm, handle_tlbm_size);
 }
 
 void __cpuinit build_tlb_refill_handler(void)
@@ -2261,13 +2265,13 @@ void __cpuinit build_tlb_refill_handler(void)
 void __cpuinit flush_tlb_handlers(void)
 {
 	local_flush_icache_range((unsigned long)handle_tlbl,
-			   (unsigned long)handle_tlbl + sizeof(handle_tlbl));
+			   (unsigned long)handle_tlbl_end);
 	local_flush_icache_range((unsigned long)handle_tlbs,
-			   (unsigned long)handle_tlbs + sizeof(handle_tlbs));
+			   (unsigned long)handle_tlbs_end);
 	local_flush_icache_range((unsigned long)handle_tlbm,
-			   (unsigned long)handle_tlbm + sizeof(handle_tlbm));
+			   (unsigned long)handle_tlbm_end);
 #ifdef CONFIG_MIPS_PGD_C0_CONTEXT
-	local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd_array,
-			   (unsigned long)tlbmiss_handler_setup_pgd_array + sizeof(handle_tlbm));
+	local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd,
+			   (unsigned long)tlbmiss_handler_setup_pgd_end);
 #endif
 }
-- 
1.7.9.5

[PATCH 2/3] MIPS: mm: Use scratch for PGD when !CONFIG_MIPS_PGD_C0_CONTEXT

[Jayachandran C]

Allow usage of scratch register for current pgd even when
MIPS_PGD_C0_CONTEXT is not configured. MIPS_PGD_C0_CONTEXT is set
for 64r2 platforms to indicate availability of Xcontext for saving
cpuid, thus freeing Context to be used for saving PGD. This option
was also tied to using a scratch register for storing PGD.

This commit will allow usage of scratch register to store the current
pgd if one can be allocated for the platform, even when
MIPS_PGD_C0_CONTEXT is not set. The cpuid will be kept in the CP0
Context register in this case.

The code to store the current pgd for the TLB miss handler is now
generated in all cases. When scratch register is available, the PGD
is also stored in the scratch register.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
---
 arch/mips/include/asm/mmu_context.h |    6 +-
 arch/mips/mm/tlbex.c                |  147 ++++++++++++++++++++++-------------
 2 files changed, 92 insertions(+), 61 deletions(-)

diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h
index 3b29079..c846d45 100644
--- a/arch/mips/include/asm/mmu_context.h
+++ b/arch/mips/include/asm/mmu_context.h
@@ -24,14 +24,13 @@
 #endif /* SMTC */
 #include <asm-generic/mm_hooks.h>
 
-#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
-
 #define TLBMISS_HANDLER_SETUP_PGD(pgd)					\
 do {									\
 	extern void tlbmiss_handler_setup_pgd(unsigned long);		\
 	tlbmiss_handler_setup_pgd((unsigned long)(pgd));		\
 } while (0)
 
+#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
 #define TLBMISS_HANDLER_SETUP()						\
 	do {								\
 		TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);		\
@@ -47,9 +46,6 @@ do {									\
  */
 extern unsigned long pgd_current[];
 
-#define TLBMISS_HANDLER_SETUP_PGD(pgd) \
-	pgd_current[smp_processor_id()] = (unsigned long)(pgd)
-
 #ifdef CONFIG_32BIT
 #define TLBMISS_HANDLER_SETUP()						\
 	write_c0_context((unsigned long) smp_processor_id() << 25);	\
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index b5e9363..dcec1c0 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -825,11 +825,11 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
 	}
 	/* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */
 
-#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
 	if (pgd_reg != -1) {
 		/* pgd is in pgd_reg */
 		UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
 	} else {
+#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
 		/*
 		 * &pgd << 11 stored in CONTEXT [23..63].
 		 */
@@ -841,30 +841,30 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
 		/* 1 0	1 0 1  << 6  xkphys cached */
 		uasm_i_ori(p, ptr, ptr, 0x540);
 		uasm_i_drotr(p, ptr, ptr, 11);
-	}
 #elif defined(CONFIG_SMP)
-# ifdef	 CONFIG_MIPS_MT_SMTC
-	/*
-	 * SMTC uses TCBind value as "CPU" index
-	 */
-	uasm_i_mfc0(p, ptr, C0_TCBIND);
-	uasm_i_dsrl_safe(p, ptr, ptr, 19);
+# ifdef CONFIG_MIPS_MT_SMTC
+		/*
+		 * SMTC uses TCBind value as "CPU" index
+		 */
+		uasm_i_mfc0(p, ptr, C0_TCBIND);
+		uasm_i_dsrl_safe(p, ptr, ptr, 19);
 # else
-	/*
-	 * 64 bit SMP running in XKPHYS has smp_processor_id() << 3
-	 * stored in CONTEXT.
-	 */
-	uasm_i_dmfc0(p, ptr, C0_CONTEXT);
-	uasm_i_dsrl_safe(p, ptr, ptr, 23);
+		/*
+		 * 64 bit SMP running in XKPHYS has smp_processor_id() << 3
+		 * stored in CONTEXT.
+		 */
+		uasm_i_dmfc0(p, ptr, C0_CONTEXT);
+		uasm_i_dsrl_safe(p, ptr, ptr, 23);
 # endif
-	UASM_i_LA_mostly(p, tmp, pgdc);
-	uasm_i_daddu(p, ptr, ptr, tmp);
-	uasm_i_dmfc0(p, tmp, C0_BADVADDR);
-	uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
+		UASM_i_LA_mostly(p, tmp, pgdc);
+		uasm_i_daddu(p, ptr, ptr, tmp);
+		uasm_i_dmfc0(p, tmp, C0_BADVADDR);
+		uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
 #else
-	UASM_i_LA_mostly(p, ptr, pgdc);
-	uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
+		UASM_i_LA_mostly(p, ptr, pgdc);
+		uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
 #endif
+	}
 
 	uasm_l_vmalloc_done(l, *p);
 
@@ -959,31 +959,37 @@ build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
 static void __cpuinit __maybe_unused
 build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
 {
-	long pgdc = (long)pgd_current;
+	if (pgd_reg != -1) {
+		/* pgd is in pgd_reg */
+		uasm_i_mfc0(p, ptr, c0_kscratch(), pgd_reg);
+		uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
+	} else {
+		long pgdc = (long)pgd_current;
 
-	/* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
+		/* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
 #ifdef CONFIG_SMP
-#ifdef	CONFIG_MIPS_MT_SMTC
-	/*
-	 * SMTC uses TCBind value as "CPU" index
-	 */
-	uasm_i_mfc0(p, ptr, C0_TCBIND);
-	UASM_i_LA_mostly(p, tmp, pgdc);
-	uasm_i_srl(p, ptr, ptr, 19);
-#else
-	/*
-	 * smp_processor_id() << 3 is stored in CONTEXT.
-	 */
-	uasm_i_mfc0(p, ptr, C0_CONTEXT);
-	UASM_i_LA_mostly(p, tmp, pgdc);
-	uasm_i_srl(p, ptr, ptr, 23);
-#endif
-	uasm_i_addu(p, ptr, tmp, ptr);
+# ifdef CONFIG_MIPS_MT_SMTC
+		/*
+		 * SMTC uses TCBind value as "CPU" index
+		 */
+		uasm_i_mfc0(p, ptr, C0_TCBIND);
+		UASM_i_LA_mostly(p, tmp, pgdc);
+		uasm_i_srl(p, ptr, ptr, 19);
+# else
+		/*
+		 * smp_processor_id() << 3 is stored in CONTEXT.
+		 */
+		uasm_i_mfc0(p, ptr, C0_CONTEXT);
+		UASM_i_LA_mostly(p, tmp, pgdc);
+		uasm_i_srl(p, ptr, ptr, 23);
+# endif
+		uasm_i_addu(p, ptr, tmp, ptr);
 #else
-	UASM_i_LA_mostly(p, ptr, pgdc);
+		UASM_i_LA_mostly(p, ptr, pgdc);
 #endif
-	uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
-	uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
+		uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
+		uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
+	}
 	uasm_i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */
 	uasm_i_sll(p, tmp, tmp, PGD_T_LOG2);
 	uasm_i_addu(p, ptr, ptr, tmp); /* add in pgd offset */
@@ -1458,28 +1464,30 @@ static void __cpuinit build_r4000_tlb_refill_handler(void)
 extern u32 handle_tlbl[], handle_tlbl_end[];
 extern u32 handle_tlbs[], handle_tlbs_end[];
 extern u32 handle_tlbm[], handle_tlbm_end[];
-
-#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
 extern u32 tlbmiss_handler_setup_pgd[], tlbmiss_handler_setup_pgd_end[];
 
-static void __cpuinit build_r4000_setup_pgd(void)
+static void __cpuinit build_setup_pgd(void)
 {
 	const int a0 = 4;
-	const int a1 = 5;
-	u32 *p = tlbmiss_handler_setup_pgd_array;
+	const int __maybe_unused a1 = 5;
+	const int __maybe_unused a2 = 6;
+	u32 *p = tlbmiss_handler_setup_pgd;
 	const int tlbmiss_handler_setup_pgd_size =
 		tlbmiss_handler_setup_pgd_end - tlbmiss_handler_setup_pgd;
-	struct uasm_label *l = labels;
-	struct uasm_reloc *r = relocs;
+#ifndef CONFIG_MIPS_PGD_C0_CONTEXT
+	long pgdc = (long)pgd_current;
+#endif
 
 	memset(tlbmiss_handler_setup_pgd, 0, tlbmiss_handler_setup_pgd_size *
 					sizeof(tlbmiss_handler_setup_pgd[0]));
 	memset(labels, 0, sizeof(labels));
 	memset(relocs, 0, sizeof(relocs));
-
 	pgd_reg = allocate_kscratch();
-
+#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
 	if (pgd_reg == -1) {
+		struct uasm_label *l = labels;
+		struct uasm_reloc *r = relocs;
+
 		/* PGD << 11 in c0_Context */
 		/*
 		 * If it is a ckseg0 address, convert to a physical
@@ -1501,6 +1509,37 @@ static void __cpuinit build_r4000_setup_pgd(void)
 		uasm_i_jr(&p, 31);
 		UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
 	}
+#else
+	/* Save PGD to pgd_current[smp_processor_id()] */
+#if defined(CONFIG_SMP)
+# ifdef CONFIG_MIPS_MT_SMTC
+	/*
+	 * SMTC uses TCBind value as "CPU" index
+	 */
+	uasm_i_mfc0(&p, a1, C0_TCBIND);
+	UASM_i_SRL_SAFE(&p, a1, a1, 19);
+# else
+	/*
+	 * smp_processor_id() is in CONTEXT
+	 */
+	UASM_i_MFC0(&p, a1, C0_CONTEXT);
+	UASM_i_SRL_SAFE(&p, a1, a1, 23);
+# endif
+	UASM_i_LA_mostly(&p, a2, pgdc);
+	UASM_i_ADDU(&p, a2, a2, a1);
+	UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
+#else
+	UASM_i_LA_mostly(&p, a2, pgdc);
+	UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
+#endif /* SMP */
+	uasm_i_jr(&p, 31);
+
+	/* if pgd_reg is allocated, save PGD also to scratch register */
+	if (pgd_reg != -1)
+		UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
+	else
+		uasm_i_nop(&p);
+#endif
 	if (p >= tlbmiss_handler_setup_pgd_end)
 		panic("tlbmiss_handler_setup_pgd space exceeded");
 
@@ -1511,7 +1550,6 @@ static void __cpuinit build_r4000_setup_pgd(void)
 	dump_handler("tlbmiss_handler", tlbmiss_handler_setup_pgd,
 					tlbmiss_handler_setup_pgd_size);
 }
-#endif
 
 static void __cpuinit
 iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr)
@@ -2225,6 +2263,7 @@ void __cpuinit build_tlb_refill_handler(void)
 		if (!run_once) {
 			if (!cpu_has_local_ebase)
 				build_r3000_tlb_refill_handler();
+			build_setup_pgd();
 			build_r3000_tlb_load_handler();
 			build_r3000_tlb_store_handler();
 			build_r3000_tlb_modify_handler();
@@ -2247,9 +2286,7 @@ void __cpuinit build_tlb_refill_handler(void)
 	default:
 		if (!run_once) {
 			scratch_reg = allocate_kscratch();
-#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
-			build_r4000_setup_pgd();
-#endif
+			build_setup_pgd();
 			build_r4000_tlb_load_handler();
 			build_r4000_tlb_store_handler();
 			build_r4000_tlb_modify_handler();
@@ -2270,8 +2307,6 @@ void __cpuinit flush_tlb_handlers(void)
 			   (unsigned long)handle_tlbs_end);
 	local_flush_icache_range((unsigned long)handle_tlbm,
 			   (unsigned long)handle_tlbm_end);
-#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
 	local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd,
 			   (unsigned long)tlbmiss_handler_setup_pgd_end);
-#endif
 }
-- 
1.7.9.5

[PATCH 3/3] MIPS: Move definition of SMP processor id register to header file

[Jayachandran C]

The definition of the CP0 register used to save the smp processor
id is repicated in many files, move them all to thread_info.h.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
---
 arch/mips/include/asm/mmu_context.h |   16 +++-----
 arch/mips/include/asm/stackframe.h  |   24 +++--------
 arch/mips/include/asm/thread_info.h |   33 ++++++++++++++-
 arch/mips/mm/tlbex.c                |   75 +++++------------------------------
 4 files changed, 53 insertions(+), 95 deletions(-)

diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h
index c846d45..e277bba 100644
--- a/arch/mips/include/asm/mmu_context.h
+++ b/arch/mips/include/asm/mmu_context.h
@@ -34,10 +34,11 @@ do {									\
 #define TLBMISS_HANDLER_SETUP()						\
 	do {								\
 		TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);		\
-		write_c0_xcontext((unsigned long) smp_processor_id() << 51); \
+		write_c0_xcontext((unsigned long) smp_processor_id() <<	\
+						SMP_CPUID_REGSHIFT);	\
 	} while (0)
 
-#else /* CONFIG_MIPS_PGD_C0_CONTEXT: using  pgd_current*/
+#else /* !CONFIG_MIPS_PGD_C0_CONTEXT: using  pgd_current*/
 
 /*
  * For the fast tlb miss handlers, we keep a per cpu array of pointers
@@ -46,18 +47,11 @@ do {									\
  */
 extern unsigned long pgd_current[];
 
-#ifdef CONFIG_32BIT
 #define TLBMISS_HANDLER_SETUP()						\
-	write_c0_context((unsigned long) smp_processor_id() << 25);	\
+	write_c0_context((unsigned long) smp_processor_id() <<		\
+						SMP_CPUID_REGSHIFT);	\
 	back_to_back_c0_hazard();					\
 	TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
-#endif
-#ifdef CONFIG_64BIT
-#define TLBMISS_HANDLER_SETUP()						\
-	write_c0_context((unsigned long) smp_processor_id() << 26);	\
-	back_to_back_c0_hazard();					\
-	TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
-#endif
 #endif /* CONFIG_MIPS_PGD_C0_CONTEXT*/
 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
 
diff --git a/arch/mips/include/asm/stackframe.h b/arch/mips/include/asm/stackframe.h
index a89d1b1..1728933 100644
--- a/arch/mips/include/asm/stackframe.h
+++ b/arch/mips/include/asm/stackframe.h
@@ -17,6 +17,7 @@
 #include <asm/asmmacro.h>
 #include <asm/mipsregs.h>
 #include <asm/asm-offsets.h>
+#include <asm/thread_info.h>
 
 /*
  * For SMTC kernel, global IE should be left set, and interrupts
@@ -85,21 +86,8 @@
 		.endm
 
 #ifdef CONFIG_SMP
-#ifdef CONFIG_MIPS_MT_SMTC
-#define PTEBASE_SHIFT	19	/* TCBIND */
-#define CPU_ID_REG CP0_TCBIND
-#define CPU_ID_MFC0 mfc0
-#elif defined(CONFIG_MIPS_PGD_C0_CONTEXT)
-#define PTEBASE_SHIFT	48	/* XCONTEXT */
-#define CPU_ID_REG CP0_XCONTEXT
-#define CPU_ID_MFC0 MFC0
-#else
-#define PTEBASE_SHIFT	23	/* CONTEXT */
-#define CPU_ID_REG CP0_CONTEXT
-#define CPU_ID_MFC0 MFC0
-#endif
 		.macro	get_saved_sp	/* SMP variation */
-		CPU_ID_MFC0	k0, CPU_ID_REG
+		ASM_CPUID_MFC0	k0, ASM_SMP_CPUID_REG
 #if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
 		lui	k1, %hi(kernelsp)
 #else
@@ -109,17 +97,17 @@
 		daddiu	k1, %hi(kernelsp)
 		dsll	k1, 16
 #endif
-		LONG_SRL	k0, PTEBASE_SHIFT
+		LONG_SRL	k0, SMP_CPUID_PTRSHIFT
 		LONG_ADDU	k1, k0
 		LONG_L	k1, %lo(kernelsp)(k1)
 		.endm
 
 		.macro	set_saved_sp stackp temp temp2
-		CPU_ID_MFC0	\temp, CPU_ID_REG
-		LONG_SRL	\temp, PTEBASE_SHIFT
+		ASM_CPUID_MFC0	\temp, ASM_SMP_CPUID_REG
+		LONG_SRL	\temp, SMP_CPUID_PTRSHIFT
 		LONG_S	\stackp, kernelsp(\temp)
 		.endm
-#else
+#else /* !CONFIG_SMP */
 		.macro	get_saved_sp	/* Uniprocessor variation */
 #ifdef CONFIG_CPU_JUMP_WORKAROUNDS
 		/*
diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h
index 61215a3..e0c8cf3 100644
--- a/arch/mips/include/asm/thread_info.h
+++ b/arch/mips/include/asm/thread_info.h
@@ -147,6 +147,37 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_ALLWORK_MASK	(_TIF_NOHZ | _TIF_WORK_MASK |		\
 				 _TIF_WORK_SYSCALL_EXIT)
 
-#endif /* __KERNEL__ */
+/*
+ * We stash processor id into a COP0 register to retrieve it fast
+ * at kernel exception entry.
+ */
+#if defined(CONFIG_MIPS_MT_SMTC)
+#define SMP_CPUID_REG		2, 2	/* TCBIND */
+#define ASM_SMP_CPUID_REG	$2, 2
+#define SMP_CPUID_PTRSHIFT	19
+#elif defined(CONFIG_MIPS_PGD_C0_CONTEXT)
+#define SMP_CPUID_REG		20, 0	/* XCONTEXT */
+#define ASM_SMP_CPUID_REG	$20
+#define SMP_CPUID_PTRSHIFT	48
+#else
+#define SMP_CPUID_REG		4, 0	/* CONTEXT */
+#define ASM_SMP_CPUID_REG	$4
+#define SMP_CPUID_PTRSHIFT	23
+#endif
 
+#ifdef CONFIG_64BIT
+#define SMP_CPUID_REGSHIFT	(SMP_CPUID_PTRSHIFT + 3)
+#else
+#define SMP_CPUID_REGSHIFT	(SMP_CPUID_PTRSHIFT + 2)
+#endif
+
+#ifdef CONFIG_MIPS_MT_SMTC
+#define ASM_CPUID_MFC0		mfc0
+#define UASM_i_CPUID_MFC0	uasm_i_mfc0
+#else
+#define ASM_CPUID_MFC0		MFC0
+#define UASM_i_CPUID_MFC0	UASM_i_MFC0
+#endif
+
+#endif /* __KERNEL__ */
 #endif /* _ASM_THREAD_INFO_H */
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index dcec1c0..1cc06fd 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -341,10 +341,6 @@ static struct work_registers __cpuinit build_get_work_registers(u32 **p)
 {
 	struct work_registers r;
 
-	int smp_processor_id_reg;
-	int smp_processor_id_sel;
-	int smp_processor_id_shift;
-
 	if (scratch_reg >= 0) {
 		/* Save in CPU local C0_KScratch? */
 		UASM_i_MTC0(p, 1, c0_kscratch(), scratch_reg);
@@ -355,25 +351,9 @@ static struct work_registers __cpuinit build_get_work_registers(u32 **p)
 	}
 
 	if (num_possible_cpus() > 1) {
-#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
-		smp_processor_id_shift = 51;
-		smp_processor_id_reg = 20; /* XContext */
-		smp_processor_id_sel = 0;
-#else
-# ifdef CONFIG_32BIT
-		smp_processor_id_shift = 25;
-		smp_processor_id_reg = 4; /* Context */
-		smp_processor_id_sel = 0;
-# endif
-# ifdef CONFIG_64BIT
-		smp_processor_id_shift = 26;
-		smp_processor_id_reg = 4; /* Context */
-		smp_processor_id_sel = 0;
-# endif
-#endif
 		/* Get smp_processor_id */
-		UASM_i_MFC0(p, K0, smp_processor_id_reg, smp_processor_id_sel);
-		UASM_i_SRL_SAFE(p, K0, K0, smp_processor_id_shift);
+		UASM_i_CPUID_MFC0(p, K0, SMP_CPUID_REG);
+		UASM_i_SRL_SAFE(p, K0, K0, SMP_CPUID_REGSHIFT);
 
 		/* handler_reg_save index in K0 */
 		UASM_i_SLL(p, K0, K0, ilog2(sizeof(struct tlb_reg_save)));
@@ -829,7 +809,7 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
 		/* pgd is in pgd_reg */
 		UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
 	} else {
-#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
+#if defined(CONFIG_MIPS_PGD_C0_CONTEXT)
 		/*
 		 * &pgd << 11 stored in CONTEXT [23..63].
 		 */
@@ -842,20 +822,8 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
 		uasm_i_ori(p, ptr, ptr, 0x540);
 		uasm_i_drotr(p, ptr, ptr, 11);
 #elif defined(CONFIG_SMP)
-# ifdef CONFIG_MIPS_MT_SMTC
-		/*
-		 * SMTC uses TCBind value as "CPU" index
-		 */
-		uasm_i_mfc0(p, ptr, C0_TCBIND);
-		uasm_i_dsrl_safe(p, ptr, ptr, 19);
-# else
-		/*
-		 * 64 bit SMP running in XKPHYS has smp_processor_id() << 3
-		 * stored in CONTEXT.
-		 */
-		uasm_i_dmfc0(p, ptr, C0_CONTEXT);
-		uasm_i_dsrl_safe(p, ptr, ptr, 23);
-# endif
+		UASM_i_CPUID_MFC0(p, ptr, SMP_CPUID_REG);
+		uasm_i_dsrl_safe(p, ptr, ptr, SMP_CPUID_PTRSHIFT);
 		UASM_i_LA_mostly(p, tmp, pgdc);
 		uasm_i_daddu(p, ptr, ptr, tmp);
 		uasm_i_dmfc0(p, tmp, C0_BADVADDR);
@@ -968,21 +936,9 @@ build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
 
 		/* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
 #ifdef CONFIG_SMP
-# ifdef CONFIG_MIPS_MT_SMTC
-		/*
-		 * SMTC uses TCBind value as "CPU" index
-		 */
-		uasm_i_mfc0(p, ptr, C0_TCBIND);
+		uasm_i_mfc0(p, ptr, SMP_CPUID_REG);
 		UASM_i_LA_mostly(p, tmp, pgdc);
-		uasm_i_srl(p, ptr, ptr, 19);
-# else
-		/*
-		 * smp_processor_id() << 3 is stored in CONTEXT.
-		 */
-		uasm_i_mfc0(p, ptr, C0_CONTEXT);
-		UASM_i_LA_mostly(p, tmp, pgdc);
-		uasm_i_srl(p, ptr, ptr, 23);
-# endif
+		uasm_i_srl(p, ptr, ptr, SMP_CPUID_PTRSHIFT);
 		uasm_i_addu(p, ptr, tmp, ptr);
 #else
 		UASM_i_LA_mostly(p, ptr, pgdc);
@@ -1510,21 +1466,10 @@ static void __cpuinit build_setup_pgd(void)
 		UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
 	}
 #else
+#ifdef CONFIG_SMP
 	/* Save PGD to pgd_current[smp_processor_id()] */
-#if defined(CONFIG_SMP)
-# ifdef CONFIG_MIPS_MT_SMTC
-	/*
-	 * SMTC uses TCBind value as "CPU" index
-	 */
-	uasm_i_mfc0(&p, a1, C0_TCBIND);
-	UASM_i_SRL_SAFE(&p, a1, a1, 19);
-# else
-	/*
-	 * smp_processor_id() is in CONTEXT
-	 */
-	UASM_i_MFC0(&p, a1, C0_CONTEXT);
-	UASM_i_SRL_SAFE(&p, a1, a1, 23);
-# endif
+	UASM_i_CPUID_MFC0(&p, a1, SMP_CPUID_REG);
+	UASM_i_SRL_SAFE(&p, a1, a1, SMP_CPUID_PTRSHIFT);
 	UASM_i_LA_mostly(&p, a2, pgdc);
 	UASM_i_ADDU(&p, a2, a2, a1);
 	UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
-- 
1.7.9.5

Re: [PATCH 0/3] Use scratch registers when MIPS_PGD_C0_CONTEXT is not set

[Ralf Baechle]

On Sun, Jun 23, 2013 at 11:46:18PM +0530, Jayachandran C wrote:

Applied.  Thanks,

  Ralf

Re: [PATCH 0/3] Use scratch registers when MIPS_PGD_C0_CONTEXT is not set

[Steven J. Hill]

On 06/23/2013 01:16 PM, Jayachandran C wrote:
>
> Jayachandran C (3):
>    MIPS: Move generated code to .text for microMIPS
>    MIPS: mm: Use scratch for PGD when !CONFIG_MIPS_PGD_C0_CONTEXT
>    MIPS: Move definition of SMP processor id register to header file
>
>   arch/mips/include/asm/mmu_context.h |   28 ++---
>   arch/mips/include/asm/stackframe.h  |   24 +---
>   arch/mips/include/asm/thread_info.h |   33 +++++-
>   arch/mips/mm/Makefile               |    2 +-
>   arch/mips/mm/tlb-funcs.S            |   37 ++++++
>   arch/mips/mm/tlbex.c                |  224 ++++++++++++++++-------------------
>   6 files changed, 187 insertions(+), 161 deletions(-)
>   create mode 100644 arch/mips/mm/tlb-funcs.S
>
The microMIPS kernel compiles, but fails to boot. It stops at:

    Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)

and does not go any further. I will look at this later this evening.

-Steve

Re: [PATCH 0/3] Use scratch registers when MIPS_PGD_C0_CONTEXT is not set

[Steven J. Hill]

On 06/23/2013 01:16 PM, Jayachandran C wrote:
>
> Jayachandran C (3):
>    MIPS: Move generated code to .text for microMIPS
>    MIPS: mm: Use scratch for PGD when !CONFIG_MIPS_PGD_C0_CONTEXT
>    MIPS: Move definition of SMP processor id register to header file
>
>   arch/mips/include/asm/mmu_context.h |   28 ++---
>   arch/mips/include/asm/stackframe.h  |   24 +---
>   arch/mips/include/asm/thread_info.h |   33 +++++-
>   arch/mips/mm/Makefile               |    2 +-
>   arch/mips/mm/tlb-funcs.S            |   37 ++++++
>   arch/mips/mm/tlbex.c                |  224 ++++++++++++++++-------------------
>   6 files changed, 187 insertions(+), 161 deletions(-)
>   create mode 100644 arch/mips/mm/tlb-funcs.S
>
The microMIPS kernel compiles, but fails to boot. It stops at:

    Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)

and does not go any further. I will look at this later this evening.

-Steve

Re: [PATCH 0/3] Use scratch registers when MIPS_PGD_C0_CONTEXT is not set

[Ralf Baechle]

On Wed, Jun 26, 2013 at 06:31:07PM -0500, Steven J. Hill wrote:

> >Jayachandran C (3):
> >   MIPS: Move generated code to .text for microMIPS
> >   MIPS: mm: Use scratch for PGD when !CONFIG_MIPS_PGD_C0_CONTEXT
> >   MIPS: Move definition of SMP processor id register to header file
> >
> >  arch/mips/include/asm/mmu_context.h |   28 ++---
> >  arch/mips/include/asm/stackframe.h  |   24 +---
> >  arch/mips/include/asm/thread_info.h |   33 +++++-
> >  arch/mips/mm/Makefile               |    2 +-
> >  arch/mips/mm/tlb-funcs.S            |   37 ++++++
> >  arch/mips/mm/tlbex.c                |  224 ++++++++++++++++-------------------
> >  6 files changed, 187 insertions(+), 161 deletions(-)
> >  create mode 100644 arch/mips/mm/tlb-funcs.S
> >
> The microMIPS kernel compiles, but fails to boot. It stops at:
> 
>    Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)
> 
> and does not go any further. I will look at this later this evening.

I'll leave the series applied for now then.

  Ralf