From 2d1c645cc50b8f5a718b24bad9eb3931e7105d12 Mon Sep 17 00:00:00 2001
From: Marc Gauthier <marc@tensilica.com>
Date: Sat, 5 Jan 2013 04:57:17 +0400
Subject: xtensa: dispatch medium-priority interrupts

Add support for dispatching medium-priority interrupts, that is,
interrupts of priority levels 2 to EXCM_LEVEL. IRQ handling may be
preempted by higher priority IRQ.

Signed-off-by: Marc Gauthier <marc@tensilica.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
---
 arch/xtensa/kernel/entry.S       | 55 +++++++++++++++++++++++++-------
 arch/xtensa/kernel/head.S        |  9 +++---
 arch/xtensa/kernel/setup.c       | 42 +++++++++++++++++++++++++
 arch/xtensa/kernel/traps.c       | 55 ++++++++++++++++++++++----------
 arch/xtensa/kernel/vectors.S     | 57 ++++++++++++++++++++++++++++++++-
 arch/xtensa/kernel/vmlinux.lds.S | 68 ++++++++++++++++++++++++++++++++++++++--
 6 files changed, 250 insertions(+), 36 deletions(-)

(limited to 'arch/xtensa/kernel')

diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 3777fec85e7c..0ace2acbbad0 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -7,7 +7,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2004-2007 by Tensilica Inc.
+ * Copyright (C) 2004 - 2008 by Tensilica Inc.
  *
  * Chris Zankel <chris@zankel.net>
  *
@@ -349,15 +349,16 @@ common_exception:
 	 * so we can allow exceptions and interrupts (*) again.
 	 * Set PS(EXCM = 0, UM = 0, RING = 0, OWB = 0, WOE = 1, INTLEVEL = X)
 	 *
-	 * (*) We only allow interrupts if PS.INTLEVEL was not set to 1 before
-	 *     (interrupts disabled) and if this exception is not an interrupt.
+	 * (*) We only allow interrupts of higher priority than current IRQ
 	 */
 
 	rsr	a3, ps
 	addi	a0, a0, -4
 	movi	a2, 1
-	extui	a3, a3, 0, 1		# a3 = PS.INTLEVEL[0]
-	moveqz	a3, a2, a0		# a3 = 1 iff interrupt exception
+	extui	a3, a3, PS_INTLEVEL_SHIFT, PS_INTLEVEL_WIDTH
+					# a3 = PS.INTLEVEL
+	movnez	a2, a3, a3		# a2 = 1: level-1, > 1: high priority
+	moveqz	a3, a2, a0		# a3 = IRQ level iff interrupt
 	movi	a2, 1 << PS_WOE_BIT
 	or	a3, a3, a2
 	rsr	a0, exccause
@@ -641,19 +642,51 @@ common_exception_exit:
 
 	l32i	a0, a1, PT_DEPC
 	l32i	a3, a1, PT_AREG3
+	_bltui	a0, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f
+
+	wsr	a0, depc
 	l32i	a2, a1, PT_AREG2
-	_bgeui	a0, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f
+	l32i	a0, a1, PT_AREG0
+	l32i	a1, a1, PT_AREG1
+	rfde
 
+1:
 	/* Restore a0...a3 and return */
 
+	rsr	a0, ps
+	extui	a2, a0, PS_INTLEVEL_SHIFT, PS_INTLEVEL_WIDTH
+	movi	a0, 2f
+	slli	a2, a2, 4
+	add	a0, a2, a0
+	l32i	a2, a1, PT_AREG2
+	jx	a0
+
+	.macro	irq_exit_level level
+	.align	16
+	.if	XCHAL_EXCM_LEVEL >= \level
+	l32i	a0, a1, PT_PC
+	wsr	a0, epc\level
 	l32i	a0, a1, PT_AREG0
 	l32i	a1, a1, PT_AREG1
-	rfe
+	rfi	\level
+	.endif
+	.endm
 
-1:	wsr	a0, depc
+	.align	16
+2:
 	l32i	a0, a1, PT_AREG0
 	l32i	a1, a1, PT_AREG1
-	rfde
+	rfe
+
+	.align	16
+	/* no rfi for level-1 irq, handled by rfe above*/
+	nop
+
+	irq_exit_level 2
+	irq_exit_level 3
+	irq_exit_level 4
+	irq_exit_level 5
+	irq_exit_level 6
 
 ENDPROC(kernel_exception)
 
@@ -753,7 +786,7 @@ ENTRY(unrecoverable_exception)
 	wsr	a1, windowbase
 	rsync
 
-	movi	a1, (1 << PS_WOE_BIT) | 1
+	movi	a1, (1 << PS_WOE_BIT) | LOCKLEVEL
 	wsr	a1, ps
 	rsync
 
@@ -1474,7 +1507,7 @@ ENTRY(_spill_registers)
 	l32i	a1, a3, EXC_TABLE_KSTK
 	wsr	a3, excsave1
 
-	movi	a4, (1 << PS_WOE_BIT) | 1
+	movi	a4, (1 << PS_WOE_BIT) | LOCKLEVEL
 	wsr	a4, ps
 	rsync
 
diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S
index 91d9095284de..df88f98737f4 100644
--- a/arch/xtensa/kernel/head.S
+++ b/arch/xtensa/kernel/head.S
@@ -7,7 +7,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2001 - 2005 Tensilica Inc.
+ * Copyright (C) 2001 - 2008 Tensilica Inc.
  *
  * Chris Zankel <chris@zankel.net>
  * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca>
@@ -128,14 +128,14 @@ ENTRY(_startup)
 	wsr	a0, cpenable
 #endif
 
-	/* Set PS.INTLEVEL=1, PS.WOE=0, kernel stack, PS.EXCM=0
+	/* Set PS.INTLEVEL=LOCKLEVEL, PS.WOE=0, kernel stack, PS.EXCM=0
 	 *
 	 * Note: PS.EXCM must be cleared before using any loop
 	 *	 instructions; otherwise, they are silently disabled, and
 	 * 	 at most one iteration of the loop is executed.
 	 */
 
-	movi	a1, 1
+	movi	a1, LOCKLEVEL
 	wsr	a1, ps
 	rsync
 
@@ -211,7 +211,8 @@ ENTRY(_startup)
 	movi	a1, init_thread_union
 	addi	a1, a1, KERNEL_STACK_SIZE
 
-	movi	a2, 0x00040001		# WOE=1, INTLEVEL=1, UM=0
+	movi	a2, (1 << PS_WOE_BIT) | LOCKLEVEL
+					# WOE=1, INTLEVEL=LOCKLEVEL, UM=0
 	wsr	a2, ps			# (enable reg-windows; progmode stack)
 	rsync
 
diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index 24c1a57abb40..6dd25ecde3f5 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -328,6 +328,27 @@ extern char _UserExceptionVector_literal_start;
 extern char _UserExceptionVector_text_end;
 extern char _DoubleExceptionVector_literal_start;
 extern char _DoubleExceptionVector_text_end;
+#if XCHAL_EXCM_LEVEL >= 2
+extern char _Level2InterruptVector_text_start;
+extern char _Level2InterruptVector_text_end;
+#endif
+#if XCHAL_EXCM_LEVEL >= 3
+extern char _Level3InterruptVector_text_start;
+extern char _Level3InterruptVector_text_end;
+#endif
+#if XCHAL_EXCM_LEVEL >= 4
+extern char _Level4InterruptVector_text_start;
+extern char _Level4InterruptVector_text_end;
+#endif
+#if XCHAL_EXCM_LEVEL >= 5
+extern char _Level5InterruptVector_text_start;
+extern char _Level5InterruptVector_text_end;
+#endif
+#if XCHAL_EXCM_LEVEL >= 6
+extern char _Level6InterruptVector_text_start;
+extern char _Level6InterruptVector_text_end;
+#endif
+
 
 
 #ifdef CONFIG_S32C1I_SELFTEST
@@ -482,6 +503,27 @@ void __init setup_arch(char **cmdline_p)
 	mem_reserve(__pa(&_DoubleExceptionVector_literal_start),
 		    __pa(&_DoubleExceptionVector_text_end), 0);
 
+#if XCHAL_EXCM_LEVEL >= 2
+	mem_reserve(__pa(&_Level2InterruptVector_text_start),
+		    __pa(&_Level2InterruptVector_text_end), 0);
+#endif
+#if XCHAL_EXCM_LEVEL >= 3
+	mem_reserve(__pa(&_Level3InterruptVector_text_start),
+		    __pa(&_Level3InterruptVector_text_end), 0);
+#endif
+#if XCHAL_EXCM_LEVEL >= 4
+	mem_reserve(__pa(&_Level4InterruptVector_text_start),
+		    __pa(&_Level4InterruptVector_text_end), 0);
+#endif
+#if XCHAL_EXCM_LEVEL >= 5
+	mem_reserve(__pa(&_Level5InterruptVector_text_start),
+		    __pa(&_Level5InterruptVector_text_end), 0);
+#endif
+#if XCHAL_EXCM_LEVEL >= 6
+	mem_reserve(__pa(&_Level6InterruptVector_text_start),
+		    __pa(&_Level6InterruptVector_text_end), 0);
+#endif
+
 	bootmem_init();
 
 #ifdef CONFIG_OF
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index 01e0111bf787..9b5c345d2b4f 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -193,28 +193,49 @@ void do_multihit(struct pt_regs *regs, unsigned long exccause)
 }
 
 /*
- * Level-1 interrupt.
- * We currently have no priority encoding.
+ * IRQ handler.
+ * PS.INTLEVEL is the current IRQ priority level.
  */
 
-unsigned long ignored_level1_interrupts;
 extern void do_IRQ(int, struct pt_regs *);
 
-void do_interrupt (struct pt_regs *regs)
+void do_interrupt(struct pt_regs *regs)
 {
-	unsigned long intread = get_sr (interrupt);
-	unsigned long intenable = get_sr (intenable);
-	int i, mask;
-
-	/* Handle all interrupts (no priorities).
-	 * (Clear the interrupt before processing, in case it's
-	 *  edge-triggered or software-generated)
-	 */
+	static const unsigned int_level_mask[] = {
+		0,
+		XCHAL_INTLEVEL1_MASK,
+		XCHAL_INTLEVEL2_MASK,
+		XCHAL_INTLEVEL3_MASK,
+		XCHAL_INTLEVEL4_MASK,
+		XCHAL_INTLEVEL5_MASK,
+		XCHAL_INTLEVEL6_MASK,
+		XCHAL_INTLEVEL7_MASK,
+	};
+	unsigned level = get_sr(ps) & PS_INTLEVEL_MASK;
+
+	if (WARN_ON_ONCE(level >= ARRAY_SIZE(int_level_mask)))
+		return;
 
-	for (i=0, mask = 1; i < XCHAL_NUM_INTERRUPTS; i++, mask <<= 1) {
-		if (mask & (intread & intenable)) {
-			set_sr (mask, intclear);
-			do_IRQ (i,regs);
+	for (;;) {
+		unsigned intread = get_sr(interrupt);
+		unsigned intenable = get_sr(intenable);
+		unsigned int_at_level = intread & intenable &
+			int_level_mask[level];
+
+		if (!int_at_level)
+			return;
+
+		/*
+		 * Clear the interrupt before processing, in case it's
+		 *  edge-triggered or software-generated
+		 */
+		while (int_at_level) {
+			unsigned i = __ffs(int_at_level);
+			unsigned mask = 1 << i;
+
+			int_at_level ^= mask;
+			set_sr(mask, intclear);
+			do_IRQ(i, regs);
 		}
 	}
 }
@@ -397,7 +418,7 @@ static inline void spill_registers(void)
 	unsigned int a0, ps;
 
 	__asm__ __volatile__ (
-		"movi	a14, " __stringify(PS_EXCM_BIT | 1) "\n\t"
+		"movi	a14, " __stringify(PS_EXCM_BIT | LOCKLEVEL) "\n\t"
 		"mov	a12, a0\n\t"
 		"rsr	a13, sar\n\t"
 		"xsr	a14, ps\n\t"
diff --git a/arch/xtensa/kernel/vectors.S b/arch/xtensa/kernel/vectors.S
index 68df35f66ce3..82109b42e240 100644
--- a/arch/xtensa/kernel/vectors.S
+++ b/arch/xtensa/kernel/vectors.S
@@ -10,7 +10,7 @@
  * Public License.  See the file "COPYING" in the main directory of
  * this archive for more details.
  *
- * Copyright (C) 2005 Tensilica, Inc.
+ * Copyright (C) 2005 - 2008 Tensilica, Inc.
  *
  * Chris Zankel <chris@zankel.net>
  *
@@ -366,6 +366,41 @@ ENTRY(_DebugInterruptVector)
 ENDPROC(_DebugInterruptVector)
 
 
+
+/*
+ * Medium priority level interrupt vectors
+ *
+ * Each takes less than 16 (0x10) bytes, no literals, by placing
+ * the extra 8 bytes that would otherwise be required in the window
+ * vectors area where there is space.  With relocatable vectors,
+ * all vectors are within ~ 4 kB range of each other, so we can
+ * simply jump (J) to another vector without having to use JX.
+ *
+ * common_exception code gets current IRQ level in PS.INTLEVEL
+ * and preserves it for the IRQ handling time.
+ */
+
+	.macro	irq_entry_level level
+
+	.if	XCHAL_EXCM_LEVEL >= \level
+	.section .Level\level\()InterruptVector.text, "ax"
+ENTRY(_Level\level\()InterruptVector)
+	wsr	a0, epc1
+	rsr	a0, epc\level
+	xsr	a0, epc1
+					# branch to user or kernel vector
+	j	_SimulateUserKernelVectorException
+	.endif
+
+	.endm
+
+	irq_entry_level 2
+	irq_entry_level 3
+	irq_entry_level 4
+	irq_entry_level 5
+	irq_entry_level 6
+
+
 /* Window overflow and underflow handlers.
  * The handlers must be 64 bytes apart, first starting with the underflow
  * handlers underflow-4 to underflow-12, then the overflow handlers
@@ -396,6 +431,26 @@ ENTRY_ALIGN64(_WindowOverflow4)
 ENDPROC(_WindowOverflow4)
 
 
+#if XCHAL_EXCM_LEVEL >= 2
+	/*  Not a window vector - but a convenient location
+	 *  (where we know there's space) for continuation of
+	 *  medium priority interrupt dispatch code.
+	 *  On entry here, a0 contains PS, and EPC2 contains saved a0:
+	 */
+	.align 4
+_SimulateUserKernelVectorException:
+	wsr	a0, excsave2
+	movi	a0, 4			# LEVEL1_INTERRUPT cause
+	wsr	a0, exccause
+	rsr	a0, ps
+	bbsi.l	a0, PS_UM_BIT, 1f	# branch if user mode
+	rsr	a0, excsave2		# restore a0
+	j	_KernelExceptionVector	# simulate kernel vector exception
+1:	rsr	a0, excsave2		# restore a0
+	j	_UserExceptionVector	# simulate user vector exception
+#endif
+
+
 /* 4-Register Window Underflow Vector (Handler) */
 
 ENTRY_ALIGN64(_WindowUnderflow4)
diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S
index 255154f820b7..14695240536d 100644
--- a/arch/xtensa/kernel/vmlinux.lds.S
+++ b/arch/xtensa/kernel/vmlinux.lds.S
@@ -7,7 +7,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2001 - 2005 Tensilica Inc.
+ * Copyright (C) 2001 - 2008 Tensilica Inc.
  *
  * Chris Zankel <chris@zankel.net>
  * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca>
@@ -134,6 +134,26 @@ SECTIONS
 
     RELOCATE_ENTRY(_WindowVectors_text,
 		   .WindowVectors.text);
+#if XCHAL_EXCM_LEVEL >= 2
+    RELOCATE_ENTRY(_Level2InterruptVector_text,
+		   .Level2InterruptVector.text);
+#endif
+#if XCHAL_EXCM_LEVEL >= 3
+    RELOCATE_ENTRY(_Level3InterruptVector_text,
+		   .Level3InterruptVector.text);
+#endif
+#if XCHAL_EXCM_LEVEL >= 4
+    RELOCATE_ENTRY(_Level4InterruptVector_text,
+		   .Level4InterruptVector.text);
+#endif
+#if XCHAL_EXCM_LEVEL >= 5
+    RELOCATE_ENTRY(_Level5InterruptVector_text,
+		   .Level5InterruptVector.text);
+#endif
+#if XCHAL_EXCM_LEVEL >= 6
+    RELOCATE_ENTRY(_Level6InterruptVector_text,
+		   .Level6InterruptVector.text);
+#endif
     RELOCATE_ENTRY(_KernelExceptionVector_text,
 		   .KernelExceptionVector.text);
     RELOCATE_ENTRY(_UserExceptionVector_text,
@@ -177,11 +197,53 @@ SECTIONS
 		  XCHAL_DEBUG_VECTOR_VADDR,
 		  4,
 		  .DebugInterruptVector.literal)
+#undef LAST
+#define LAST	.DebugInterruptVector.text
+#if XCHAL_EXCM_LEVEL >= 2
+  SECTION_VECTOR (_Level2InterruptVector_text,
+		  .Level2InterruptVector.text,
+		  XCHAL_INTLEVEL2_VECTOR_VADDR,
+		  SIZEOF(LAST), LAST)
+# undef LAST
+# define LAST	.Level2InterruptVector.text
+#endif
+#if XCHAL_EXCM_LEVEL >= 3
+  SECTION_VECTOR (_Level3InterruptVector_text,
+		  .Level3InterruptVector.text,
+		  XCHAL_INTLEVEL3_VECTOR_VADDR,
+		  SIZEOF(LAST), LAST)
+# undef LAST
+# define LAST	.Level3InterruptVector.text
+#endif
+#if XCHAL_EXCM_LEVEL >= 4
+  SECTION_VECTOR (_Level4InterruptVector_text,
+		  .Level4InterruptVector.text,
+		  XCHAL_INTLEVEL4_VECTOR_VADDR,
+		  SIZEOF(LAST), LAST)
+# undef LAST
+# define LAST	.Level4InterruptVector.text
+#endif
+#if XCHAL_EXCM_LEVEL >= 5
+  SECTION_VECTOR (_Level5InterruptVector_text,
+		  .Level5InterruptVector.text,
+		  XCHAL_INTLEVEL5_VECTOR_VADDR,
+		  SIZEOF(LAST), LAST)
+# undef LAST
+# define LAST	.Level5InterruptVector.text
+#endif
+#if XCHAL_EXCM_LEVEL >= 6
+  SECTION_VECTOR (_Level6InterruptVector_text,
+		  .Level6InterruptVector.text,
+		  XCHAL_INTLEVEL6_VECTOR_VADDR,
+		  SIZEOF(LAST), LAST)
+# undef LAST
+# define LAST	.Level6InterruptVector.text
+#endif
   SECTION_VECTOR (_KernelExceptionVector_literal,
 		  .KernelExceptionVector.literal,
 		  XCHAL_KERNEL_VECTOR_VADDR - 4,
-		  SIZEOF(.DebugInterruptVector.text),
-		  .DebugInterruptVector.text)
+		  SIZEOF(LAST), LAST)
+#undef LAST
   SECTION_VECTOR (_KernelExceptionVector_text,
 		  .KernelExceptionVector.text,
 		  XCHAL_KERNEL_VECTOR_VADDR,
-- 
cgit v1.2.1


From de73b6b1bd7480301c8e8fbe58184448b1757945 Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Sat, 22 Dec 2012 06:35:04 +0400
Subject: xtensa: avoid mmap cache aliasing

Provide arch_get_unmapped_area function aligning shared memory mapping
addresses to the biggest of the page size or the cache way size. That
guarantees that corresponding virtual addresses of shared mappings are
cached by the same cache sets.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
---
 arch/xtensa/kernel/syscall.c | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

(limited to 'arch/xtensa/kernel')

diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c
index 54fa8425cee2..5d3f7a119ed1 100644
--- a/arch/xtensa/kernel/syscall.c
+++ b/arch/xtensa/kernel/syscall.c
@@ -36,6 +36,10 @@ syscall_t sys_call_table[__NR_syscall_count] /* FIXME __cacheline_aligned */= {
 #include <uapi/asm/unistd.h>
 };
 
+#define COLOUR_ALIGN(addr, pgoff) \
+	((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \
+	 (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1)))
+
 asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg)
 {
 	unsigned long ret;
@@ -52,3 +56,40 @@ asmlinkage long xtensa_fadvise64_64(int fd, int advice,
 {
 	return sys_fadvise64_64(fd, offset, len, advice);
 }
+
+unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
+		unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+	struct vm_area_struct *vmm;
+
+	if (flags & MAP_FIXED) {
+		/* We do not accept a shared mapping if it would violate
+		 * cache aliasing constraints.
+		 */
+		if ((flags & MAP_SHARED) &&
+				((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
+			return -EINVAL;
+		return addr;
+	}
+
+	if (len > TASK_SIZE)
+		return -ENOMEM;
+	if (!addr)
+		addr = TASK_UNMAPPED_BASE;
+
+	if (flags & MAP_SHARED)
+		addr = COLOUR_ALIGN(addr, pgoff);
+	else
+		addr = PAGE_ALIGN(addr);
+
+	for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
+		/* At this point:  (!vmm || addr < vmm->vm_end). */
+		if (TASK_SIZE - len < addr)
+			return -ENOMEM;
+		if (!vmm || addr + len <= vmm->vm_start)
+			return addr;
+		addr = vmm->vm_end;
+		if (flags & MAP_SHARED)
+			addr = COLOUR_ALIGN(addr, pgoff);
+	}
+}
-- 
cgit v1.2.1


From 2d6f82fee45a52359012948306587eba704cf35b Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Sun, 3 Feb 2013 05:39:22 +0400
Subject: xtensa: move spill_registers to traps.h

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
---
 arch/xtensa/kernel/traps.c | 21 +--------------------
 1 file changed, 1 insertion(+), 20 deletions(-)

(limited to 'arch/xtensa/kernel')

diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index 9b5c345d2b4f..5e0f81a65186 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -37,6 +37,7 @@
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 #include <asm/processor.h>
+#include <asm/traps.h>
 
 #ifdef CONFIG_KGDB
 extern int gdb_enter;
@@ -413,26 +414,6 @@ static __always_inline unsigned long *stack_pointer(struct task_struct *task)
 	return sp;
 }
 
-static inline void spill_registers(void)
-{
-	unsigned int a0, ps;
-
-	__asm__ __volatile__ (
-		"movi	a14, " __stringify(PS_EXCM_BIT | LOCKLEVEL) "\n\t"
-		"mov	a12, a0\n\t"
-		"rsr	a13, sar\n\t"
-		"xsr	a14, ps\n\t"
-		"movi	a0, _spill_registers\n\t"
-		"rsync\n\t"
-		"callx0 a0\n\t"
-		"mov	a0, a12\n\t"
-		"wsr	a13, sar\n\t"
-		"wsr	a14, ps\n\t"
-		:: "a" (&a0), "a" (&ps)
-		: "a2", "a3", "a4", "a7", "a11", "a12", "a13", "a14", "a15",
-		  "memory");
-}
-
 void show_trace(struct task_struct *task, unsigned long *sp)
 {
 	unsigned long a0, a1, pc;
-- 
cgit v1.2.1


From e6ffe17ec45dd763ee8278246a112562f64a4ef2 Mon Sep 17 00:00:00 2001
From: dann <dann@xtensa-linux.org>
Date: Wed, 21 May 2008 17:43:50 -0700
Subject: xtensa: add support for oprofile

Support call graph profiling.
Keep upper two bits of PC unchanged through backtrace rather than take
them from sp (a1). The stack pointer is usually in the same GB (same
upper 2 bits) as PC, but technically doesn't always have to be (and
might not in the future, when taking full advantage of MMU v3).

Signed-off-by: Dan Nicolaescu <dann@xtensa-linux.org>
Signed-off-by: Pete Delaney <piet@tensilica.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
---
 arch/xtensa/kernel/entry.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'arch/xtensa/kernel')

diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 0ace2acbbad0..70d5a9e33573 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -399,7 +399,7 @@ common_exception:
 	callx4	a4
 
 	/* Jump here for exception exit */
-
+	.global common_exception_return
 common_exception_return:
 
 	/* Jump if we are returning from kernel exceptions. */
-- 
cgit v1.2.1


From 4b2bb03f108a6e68c28de2763268571ef569c6e8 Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Mon, 14 Jan 2013 10:38:02 +0400
Subject: xtensa: complete ptrace handling of register windows

Compute WindowBase and WindowMask registers correctly on ptrace calls.
Work done earlier by Maxim, Christian and Marc.

Signed-off-by: Marc Gauthier <marc@tensilica.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
---
 arch/xtensa/kernel/ptrace.c | 33 ++++++++++++++++++++-------------
 1 file changed, 20 insertions(+), 13 deletions(-)

(limited to 'arch/xtensa/kernel')

diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
index 61fb2e9e9035..a8b0d5795571 100644
--- a/arch/xtensa/kernel/ptrace.c
+++ b/arch/xtensa/kernel/ptrace.c
@@ -53,9 +53,8 @@ int ptrace_getregs(struct task_struct *child, void __user *uregs)
 {
 	struct pt_regs *regs = task_pt_regs(child);
 	xtensa_gregset_t __user *gregset = uregs;
-	unsigned long wm = regs->wmask;
 	unsigned long wb = regs->windowbase;
-	int live, i;
+	int i;
 
 	if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
 		return -EIO;
@@ -68,12 +67,9 @@ int ptrace_getregs(struct task_struct *child, void __user *uregs)
 	__put_user(regs->windowstart, &gregset->windowstart);
 	__put_user(regs->windowbase, &gregset->windowbase);
 
-	live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16;
-
-	for (i = 0; i < live; i++)
-		__put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS));
-	for (i = XCHAL_NUM_AREGS - (wm >> 4) * 4; i < XCHAL_NUM_AREGS; i++)
-		__put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS));
+	for (i = 0; i < XCHAL_NUM_AREGS; i++)
+		__put_user(regs->areg[i],
+				gregset->a + ((wb * 4 + i) % XCHAL_NUM_AREGS));
 
 	return 0;
 }
@@ -84,7 +80,7 @@ int ptrace_setregs(struct task_struct *child, void __user *uregs)
 	xtensa_gregset_t *gregset = uregs;
 	const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK;
 	unsigned long ps;
-	unsigned long wb;
+	unsigned long wb, ws;
 
 	if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
 		return -EIO;
@@ -94,7 +90,7 @@ int ptrace_setregs(struct task_struct *child, void __user *uregs)
 	__get_user(regs->lbeg, &gregset->lbeg);
 	__get_user(regs->lend, &gregset->lend);
 	__get_user(regs->lcount, &gregset->lcount);
-	__get_user(regs->windowstart, &gregset->windowstart);
+	__get_user(ws, &gregset->windowstart);
 	__get_user(wb, &gregset->windowbase);
 
 	regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT);
@@ -102,13 +98,24 @@ int ptrace_setregs(struct task_struct *child, void __user *uregs)
 	if (wb >= XCHAL_NUM_AREGS / 4)
 		return -EFAULT;
 
-	regs->windowbase = wb;
+	if (wb != regs->windowbase || ws != regs->windowstart) {
+		unsigned long rotws, wmask;
+
+		rotws = (((ws | (ws << WSBITS)) >> wb) &
+				((1 << WSBITS) - 1)) & ~1;
+		wmask = ((rotws ? WSBITS + 1 - ffs(rotws) : 0) << 4) |
+			(rotws & 0xF) | 1;
+		regs->windowbase = wb;
+		regs->windowstart = ws;
+		regs->wmask = wmask;
+	}
 
 	if (wb != 0 &&  __copy_from_user(regs->areg + XCHAL_NUM_AREGS - wb * 4,
-					 gregset->a, wb * 16))
+				gregset->a, wb * 16))
 		return -EFAULT;
 
-	if (__copy_from_user(regs->areg, gregset->a + wb*4, (WSBITS-wb) * 16))
+	if (__copy_from_user(regs->areg, gregset->a + wb * 4,
+				(WSBITS - wb) * 16))
 		return -EFAULT;
 
 	return 0;
-- 
cgit v1.2.1


From c50842df47970eab459f13490c152aac85fc02f2 Mon Sep 17 00:00:00 2001
From: Chris Zankel <chris@zankel.net>
Date: Sat, 23 Feb 2013 19:35:57 -0800
Subject: xtensa: add support for TLS

The Xtensa architecture provides a global register called THREADPTR
for the purpose of Thread Local Storage (TLS) support. This allows us
to use a fairly simple implementation, keeping the thread pointer in
the regset and simply saving and restoring it upon entering/exiting
the from user space.

Signed-off-by: Chris Zankel <chris@zankel.net>
---
 arch/xtensa/kernel/asm-offsets.c |  1 +
 arch/xtensa/kernel/entry.S       | 12 +++++++++++-
 arch/xtensa/kernel/process.c     |  5 +++--
 arch/xtensa/kernel/ptrace.c      |  2 ++
 arch/xtensa/kernel/signal.c      |  6 ++++--
 5 files changed, 21 insertions(+), 5 deletions(-)

(limited to 'arch/xtensa/kernel')

diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c
index 0701fad170db..1915c7c889ba 100644
--- a/arch/xtensa/kernel/asm-offsets.c
+++ b/arch/xtensa/kernel/asm-offsets.c
@@ -42,6 +42,7 @@ int main(void)
 	DEFINE(PT_ICOUNTLEVEL, offsetof (struct pt_regs, icountlevel));
 	DEFINE(PT_SYSCALL, offsetof (struct pt_regs, syscall));
 	DEFINE(PT_SCOMPARE1, offsetof(struct pt_regs, scompare1));
+	DEFINE(PT_THREADPTR, offsetof(struct pt_regs, threadptr));
 	DEFINE(PT_AREG, offsetof (struct pt_regs, areg[0]));
 	DEFINE(PT_AREG0, offsetof (struct pt_regs, areg[0]));
 	DEFINE(PT_AREG1, offsetof (struct pt_regs, areg[1]));
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 70d5a9e33573..63845f950792 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -130,6 +130,11 @@ _user_exception:
 	s32i	a3, a1, PT_SAR
 	s32i	a2, a1, PT_ICOUNTLEVEL
 
+#if XCHAL_HAVE_THREADPTR
+	rur	a2, threadptr
+	s32i	a2, a1, PT_THREADPTR
+#endif
+
 	/* Rotate ws so that the current windowbase is at bit0. */
 	/* Assume ws = xxwww1yyyy. Rotate ws right, so that a2 = yyyyxxwww1 */
 
@@ -510,6 +515,11 @@ user_exception_exit:
 	 *	 (if we have restored WSBITS-1 frames).
 	 */
 
+#if XCHAL_HAVE_THREADPTR
+	l32i	a3, a1, PT_THREADPTR
+	wur	a3, threadptr
+#endif
+
 2:	j	common_exception_exit
 
 	/* This is the kernel exception exit.
@@ -1955,7 +1965,7 @@ ENTRY(_switch_to)
 	s32i	a6, a3, EXC_TABLE_FIXUP
 	s32i	a7, a3, EXC_TABLE_KSTK
 
-	/* restore context of the task that 'next' addresses */
+	/* restore context of the task 'next' */
 
 	l32i	a0, a13, THREAD_RA	# restore return address
 	l32i	a1, a13, THREAD_SP	# restore stack pointer
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index 0dd5784416d3..5cd82e9f601c 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -259,9 +259,10 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
 			memcpy(&childregs->areg[XCHAL_NUM_AREGS - len/4],
 			       &regs->areg[XCHAL_NUM_AREGS - len/4], len);
 		}
-// FIXME: we need to set THREADPTR in thread_info...
+
+		/* The thread pointer is passed in the '4th argument' (= a5) */
 		if (clone_flags & CLONE_SETTLS)
-			childregs->areg[2] = childregs->areg[6];
+			childregs->threadptr = childregs->areg[5];
 	} else {
 		p->thread.ra = MAKE_RA_FOR_CALL(
 				(unsigned long)ret_from_kernel_thread, 1);
diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
index a8b0d5795571..562fac664751 100644
--- a/arch/xtensa/kernel/ptrace.c
+++ b/arch/xtensa/kernel/ptrace.c
@@ -66,6 +66,7 @@ int ptrace_getregs(struct task_struct *child, void __user *uregs)
 	__put_user(regs->lcount, &gregset->lcount);
 	__put_user(regs->windowstart, &gregset->windowstart);
 	__put_user(regs->windowbase, &gregset->windowbase);
+	__put_user(regs->threadptr, &gregset->threadptr);
 
 	for (i = 0; i < XCHAL_NUM_AREGS; i++)
 		__put_user(regs->areg[i],
@@ -92,6 +93,7 @@ int ptrace_setregs(struct task_struct *child, void __user *uregs)
 	__get_user(regs->lcount, &gregset->lcount);
 	__get_user(ws, &gregset->windowstart);
 	__get_user(wb, &gregset->windowbase);
+	__get_user(regs->threadptr, &gregset->threadptr);
 
 	regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT);
 
diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c
index de34d6be91cd..6952d8959236 100644
--- a/arch/xtensa/kernel/signal.c
+++ b/arch/xtensa/kernel/signal.c
@@ -337,7 +337,7 @@ static int setup_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	struct rt_sigframe *frame;
 	int err = 0;
 	int signal;
-	unsigned long sp, ra;
+	unsigned long sp, ra, tp;
 
 	sp = regs->areg[1];
 
@@ -395,7 +395,8 @@ static int setup_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	 * Return context not modified until this point.
 	 */
 
-	/* Set up registers for signal handler */
+	/* Set up registers for signal handler; preserve the threadptr */
+	tp = regs->threadptr;
 	start_thread(regs, (unsigned long) ka->sa.sa_handler,
 		     (unsigned long) frame);
 
@@ -406,6 +407,7 @@ static int setup_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	regs->areg[6] = (unsigned long) signal;
 	regs->areg[7] = (unsigned long) &frame->info;
 	regs->areg[8] = (unsigned long) &frame->uc;
+	regs->threadptr = tp;
 
 	/* Set access mode to USER_DS.  Nomenclature is outdated, but
 	 * functionality is used in uaccess.h
-- 
cgit v1.2.1