[PATCH 1/5] FRV: Handle update_mmu_cache() being called when current->mm is NULL

[PATCH 1/5] FRV: Handle update_mmu_cache() being called when current->mm is NULL

[David Howells]

From: David Howells <dhowells@redhat.com>

Handle update_mmu_cache() being called when current->mm is NULL.

We cache static TLB mappings for the current page table in DAMPR4 and DAMPR5
on the theory that the next data lookup is likely to be in the same general
region, and thus is likely to be mapped by the same page table.  However, we
can't get this information if we can't access the appropriate mm_struct.

If current->mm is NULL, we just clear the cache in the knowledge that the TLB
miss handlers will load it.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 Makefile                  |   11 ++++++-----
 include/asm-frv/pgtable.h |   19 ++++++++++++++-----
 2 files changed, 20 insertions(+), 10 deletions(-)


diff --git a/Makefile b/Makefile
index fec2a12..54d4fb2 100644
--- a/Makefile
+++ b/Makefile
@@ -501,11 +501,12 @@ endif # $(dot-config)
 # Defaults vmlinux but it is usually overridden in the arch makefile
 all: vmlinux
 
-ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
-KBUILD_CFLAGS	+= -Os
-else
-KBUILD_CFLAGS	+= -O2
-endif
+#ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
+#KBUILD_CFLAGS	+= -Os
+#else
+#KBUILD_CFLAGS	+= -O2
+#endif
+KBUILD_CFLAGS	+= -O1
 
 # Force gcc to behave correct even for buggy distributions
 # Arch Makefiles may override this setting
diff --git a/include/asm-frv/pgtable.h b/include/asm-frv/pgtable.h
index 6c0682e..4e21904 100644
--- a/include/asm-frv/pgtable.h
+++ b/include/asm-frv/pgtable.h
@@ -507,13 +507,22 @@ static inline int pte_file(pte_t pte)
  */
 static inline void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t pte)
 {
+	struct mm_struct *mm;
 	unsigned long ampr;
-	pgd_t *pge = pgd_offset(current->mm, address);
-	pud_t *pue = pud_offset(pge, address);
-	pmd_t *pme = pmd_offset(pue, address);
 
-	ampr = pme->ste[0] & 0xffffff00;
-	ampr |= xAMPRx_L | xAMPRx_SS_16Kb | xAMPRx_S | xAMPRx_C | xAMPRx_V;
+	mm = current->mm;
+	if (mm) {
+		pgd_t *pge = pgd_offset(mm, address);
+		pud_t *pue = pud_offset(pge, address);
+		pmd_t *pme = pmd_offset(pue, address);
+
+		ampr = pme->ste[0] & 0xffffff00;
+		ampr |= xAMPRx_L | xAMPRx_SS_16Kb | xAMPRx_S | xAMPRx_C |
+			xAMPRx_V;
+	} else {
+		address = ULONG_MAX;
+		ampr = 0;
+	}
 
 	asm volatile("movgs %0,scr0\n"
 		     "movgs %0,scr1\n"

[PATCH 2/5] FRV: Move STACK_TOP_MAX up

[David Howells]

From: David Howells <dhowells@redhat.com>

Move STACK_TOP_MAX up so that we don't try moving the stack above it as that
causes setup_arg_pages() to malfunction.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 include/asm-frv/mem-layout.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)


diff --git a/include/asm-frv/mem-layout.h b/include/asm-frv/mem-layout.h
index 8353225..734a1d0 100644
--- a/include/asm-frv/mem-layout.h
+++ b/include/asm-frv/mem-layout.h
@@ -60,7 +60,7 @@
  */
 #define BRK_BASE			__UL(2 * 1024 * 1024 + PAGE_SIZE)
 #define STACK_TOP			__UL(2 * 1024 * 1024)
-#define STACK_TOP_MAX	STACK_TOP
+#define STACK_TOP_MAX			__UL(0xc0000000)
 
 /* userspace process size */
 #ifdef CONFIG_MMU

[PATCH 3/5] FRV: Add support for emulation of userspace atomic ops

[David Howells]

From: David Howells <dhowells@redhat.com>

Use traps 120-126 to emulate atomic cmpxchg32, xchg32, and XOR-, OR-, AND-, SUB-
and ADD-to-memory operations for userspace.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 arch/frv/kernel/entry-table.S |    8 +
 arch/frv/kernel/entry.S       |   20 ++++
 arch/frv/kernel/traps.c       |  227 +++++++++++++++++++++++++++++++++++++++++
 include/asm-frv/spr-regs.h    |   14 +++
 4 files changed, 268 insertions(+), 1 deletions(-)


diff --git a/arch/frv/kernel/entry-table.S b/arch/frv/kernel/entry-table.S
index d3b9253..bf35f33 100644
--- a/arch/frv/kernel/entry-table.S
+++ b/arch/frv/kernel/entry-table.S
@@ -316,8 +316,14 @@ __trap_fixup_kernel_data_tlb_miss:
 	.section	.trap.vector
 	.org		TBR_TT_TRAP0 >> 2
 	.long		system_call
-	.rept		126
+	.rept		119
 	.long		__entry_unsupported_trap
 	.endr
+
+	# userspace atomic op emulation, traps 120-126
+	.rept		7
+	.long		__entry_atomic_op
+	.endr
+	
 	.org		TBR_TT_BREAK >> 2
 	.long		__entry_debug_exception
diff --git a/arch/frv/kernel/entry.S b/arch/frv/kernel/entry.S
index f36d7f4..b8a4b94 100644
--- a/arch/frv/kernel/entry.S
+++ b/arch/frv/kernel/entry.S
@@ -656,6 +656,26 @@ __entry_debug_exception:
 
 ###############################################################################
 #
+# handle atomic operation emulation for userspace
+#
+###############################################################################
+	.globl		__entry_atomic_op
+__entry_atomic_op:
+	LEDS		0x6012
+	sethi.p		%hi(atomic_operation),gr5
+	setlo		%lo(atomic_operation),gr5
+	movsg		esfr1,gr8
+	movsg		epcr0,gr9
+	movsg		esr0,gr10
+
+	# now that we've accessed the exception regs, we can enable exceptions
+	movsg		psr,gr4
+	ori		gr4,#PSR_ET,gr4
+	movgs		gr4,psr
+	jmpl		@(gr5,gr0)	; call atomic_operation(esfr1,epcr0,esr0)
+
+###############################################################################
+#
 # handle media exception
 #
 ###############################################################################
diff --git a/arch/frv/kernel/traps.c b/arch/frv/kernel/traps.c
index 2e6098c..2f7e668 100644
--- a/arch/frv/kernel/traps.c
+++ b/arch/frv/kernel/traps.c
@@ -102,6 +102,233 @@ asmlinkage void illegal_instruction(unsigned long esfr1, unsigned long epcr0, un
 
 /*****************************************************************************/
 /*
+ * handle atomic operations with errors
+ * - arguments in gr8, gr9, gr10
+ * - original memory value placed in gr5
+ * - replacement memory value placed in gr9
+ */
+asmlinkage void atomic_operation(unsigned long esfr1, unsigned long epcr0,
+				 unsigned long esr0)
+{
+	static DEFINE_SPINLOCK(atomic_op_lock);
+	unsigned long x, y, z, *p;
+	mm_segment_t oldfs;
+	siginfo_t info;
+	int ret;
+
+	y = 0;
+	z = 0;
+
+	oldfs = get_fs();
+	if (!user_mode(__frame))
+		set_fs(KERNEL_DS);
+
+	switch (__frame->tbr & TBR_TT) {
+		/* TIRA gr0,#120
+		 * u32 __atomic_user_cmpxchg32(u32 *ptr, u32 test, u32 new)
+		 */
+	case TBR_TT_ATOMIC_CMPXCHG32:
+		p = (unsigned long *) __frame->gr8;
+		x = __frame->gr9;
+		y = __frame->gr10;
+
+		for (;;) {
+			ret = get_user(z, p);
+			if (ret < 0)
+				goto error;
+
+			if (z != x)
+				goto done;
+
+			spin_lock_irq(&atomic_op_lock);
+
+			if (__get_user(z, p) == 0) {
+				if (z != x)
+					goto done2;
+
+				if (__put_user(y, p) == 0)
+					goto done2;
+				goto error2;
+			}
+
+			spin_unlock_irq(&atomic_op_lock);
+		}
+
+		/* TIRA gr0,#121
+		 * u32 __atomic_kernel_xchg32(void *v, u32 new)
+		 */
+	case TBR_TT_ATOMIC_XCHG32:
+		p = (unsigned long *) __frame->gr8;
+		y = __frame->gr9;
+
+		for (;;) {
+			ret = get_user(z, p);
+			if (ret < 0)
+				goto error;
+
+			spin_lock_irq(&atomic_op_lock);
+
+			if (__get_user(z, p) == 0) {
+				if (__put_user(y, p) == 0)
+					goto done2;
+				goto error2;
+			}
+
+			spin_unlock_irq(&atomic_op_lock);
+		}
+
+		/* TIRA gr0,#122
+		 * ulong __atomic_kernel_XOR_return(ulong i, ulong *v)
+		 */
+	case TBR_TT_ATOMIC_XOR:
+		p = (unsigned long *) __frame->gr8;
+		x = __frame->gr9;
+
+		for (;;) {
+			ret = get_user(z, p);
+			if (ret < 0)
+				goto error;
+
+			spin_lock_irq(&atomic_op_lock);
+
+			if (__get_user(z, p) == 0) {
+				y = x ^ z;
+				if (__put_user(y, p) == 0)
+					goto done2;
+				goto error2;
+			}
+
+			spin_unlock_irq(&atomic_op_lock);
+		}
+
+		/* TIRA gr0,#123
+		 * ulong __atomic_kernel_OR_return(ulong i, ulong *v)
+		 */
+	case TBR_TT_ATOMIC_OR:
+		p = (unsigned long *) __frame->gr8;
+		x = __frame->gr9;
+
+		for (;;) {
+			ret = get_user(z, p);
+			if (ret < 0)
+				goto error;
+
+			spin_lock_irq(&atomic_op_lock);
+
+			if (__get_user(z, p) == 0) {
+				y = x ^ z;
+				if (__put_user(y, p) == 0)
+					goto done2;
+				goto error2;
+			}
+
+			spin_unlock_irq(&atomic_op_lock);
+		}
+
+		/* TIRA gr0,#124
+		 * ulong __atomic_kernel_AND_return(ulong i, ulong *v)
+		 */
+	case TBR_TT_ATOMIC_AND:
+		p = (unsigned long *) __frame->gr8;
+		x = __frame->gr9;
+
+		for (;;) {
+			ret = get_user(z, p);
+			if (ret < 0)
+				goto error;
+
+			spin_lock_irq(&atomic_op_lock);
+
+			if (__get_user(z, p) == 0) {
+				y = x & z;
+				if (__put_user(y, p) == 0)
+					goto done2;
+				goto error2;
+			}
+
+			spin_unlock_irq(&atomic_op_lock);
+		}
+
+		/* TIRA gr0,#125
+		 * int __atomic_user_sub_return(atomic_t *v, int i)
+		 */
+	case TBR_TT_ATOMIC_SUB:
+		p = (unsigned long *) __frame->gr8;
+		x = __frame->gr9;
+
+		for (;;) {
+			ret = get_user(z, p);
+			if (ret < 0)
+				goto error;
+
+			spin_lock_irq(&atomic_op_lock);
+
+			if (__get_user(z, p) == 0) {
+				y = z - x;
+				if (__put_user(y, p) == 0)
+					goto done2;
+				goto error2;
+			}
+
+			spin_unlock_irq(&atomic_op_lock);
+		}
+
+		/* TIRA gr0,#126
+		 * int __atomic_user_add_return(atomic_t *v, int i)
+		 */
+	case TBR_TT_ATOMIC_ADD:
+		p = (unsigned long *) __frame->gr8;
+		x = __frame->gr9;
+
+		for (;;) {
+			ret = get_user(z, p);
+			if (ret < 0)
+				goto error;
+
+			spin_lock_irq(&atomic_op_lock);
+
+			if (__get_user(z, p) == 0) {
+				y = z + x;
+				if (__put_user(y, p) == 0)
+					goto done2;
+				goto error2;
+			}
+
+			spin_unlock_irq(&atomic_op_lock);
+		}
+
+	default:
+		BUG();
+	}
+
+done2:
+	spin_unlock_irq(&atomic_op_lock);
+done:
+	if (!user_mode(__frame))
+		set_fs(oldfs);
+	__frame->gr5 = z;
+	__frame->gr9 = y;
+	return;
+
+error2:
+	spin_unlock_irq(&atomic_op_lock);
+error:
+	if (!user_mode(__frame))
+		set_fs(oldfs);
+	__frame->pc -= 4;
+
+	die_if_kernel("-- Atomic Op Error --\n");
+
+	info.si_signo	= SIGSEGV;
+	info.si_code	= SEGV_ACCERR;
+	info.si_errno	= 0;
+	info.si_addr	= (void *) __frame->pc;
+
+	force_sig_info(info.si_signo, &info, current);
+}
+
+/*****************************************************************************/
+/*
  *
  */
 asmlinkage void media_exception(unsigned long msr0, unsigned long msr1)
diff --git a/include/asm-frv/spr-regs.h b/include/asm-frv/spr-regs.h
index c2a541e..01e6af5 100644
--- a/include/asm-frv/spr-regs.h
+++ b/include/asm-frv/spr-regs.h
@@ -99,9 +99,23 @@
 #define TBR_TT_TRAP1		(0x81 << 4)
 #define TBR_TT_TRAP2		(0x82 << 4)
 #define TBR_TT_TRAP3		(0x83 << 4)
+#define TBR_TT_TRAP120		(0xf8 << 4)
+#define TBR_TT_TRAP121		(0xf9 << 4)
+#define TBR_TT_TRAP122		(0xfa << 4)
+#define TBR_TT_TRAP123		(0xfb << 4)
+#define TBR_TT_TRAP124		(0xfc << 4)
+#define TBR_TT_TRAP125		(0xfd << 4)
 #define TBR_TT_TRAP126		(0xfe << 4)
 #define TBR_TT_BREAK		(0xff << 4)
 
+#define TBR_TT_ATOMIC_CMPXCHG32	TBR_TT_TRAP120
+#define TBR_TT_ATOMIC_XCHG32	TBR_TT_TRAP121
+#define TBR_TT_ATOMIC_XOR	TBR_TT_TRAP122
+#define TBR_TT_ATOMIC_OR	TBR_TT_TRAP123
+#define TBR_TT_ATOMIC_AND	TBR_TT_TRAP124
+#define TBR_TT_ATOMIC_SUB	TBR_TT_TRAP125
+#define TBR_TT_ATOMIC_ADD	TBR_TT_TRAP126
+
 #define __get_TBR()	({ unsigned long x; asm volatile("movsg tbr,%0" : "=r"(x)); x; })
 
 /*

[PATCH 4/5] FRV: Make NOMMU-mode work with base addresses other than 0xC0000000

[David Howells]

From: David Howells <dhowells@redhat.com>

Make NOMMU-mode work with base addresses other than 0xC0000000 by:

 (1) Giving the code that sets up the protection registers the right address
     in __sdram_base.  Rather than being hard coded to 0xC0000000, the value
     of __page_offset is obtained from the linker script.

 (2) Eliminate the check in __switch_to() that verifies the current thread
     info is in the 0xCxxxxxxx region.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 arch/frv/kernel/head.inc    |    2 +-
 arch/frv/kernel/switch_to.S |    7 -------
 2 files changed, 1 insertions(+), 8 deletions(-)


diff --git a/arch/frv/kernel/head.inc b/arch/frv/kernel/head.inc
index d424cd2..bff6662 100644
--- a/arch/frv/kernel/head.inc
+++ b/arch/frv/kernel/head.inc
@@ -46,5 +46,5 @@
 #ifdef CONFIG_MMU
 __sdram_base = 0x00000000		/* base address to which SDRAM relocated */
 #else
-__sdram_base = 0xc0000000		/* base address to which SDRAM relocated */
+__sdram_base = __page_offset		/* base address to which SDRAM relocated */
 #endif
diff --git a/arch/frv/kernel/switch_to.S b/arch/frv/kernel/switch_to.S
index b5275fa..b066686 100644
--- a/arch/frv/kernel/switch_to.S
+++ b/arch/frv/kernel/switch_to.S
@@ -102,13 +102,6 @@ __switch_to:
 	movgs		gr14,lr
 	bar
 
-	srli		gr15,#28,gr5
-	subicc		gr5,#0xc,gr0,icc0
-	beq		icc0,#0,111f
-	break
-	nop
-111:
-
 	# jump to __switch_back or ret_from_fork as appropriate
 	# - move prev to GR8
 	movgs		gr4,psr

[PATCH 5/5] FRV: Don't make smp_{r, w, }mb() interpolate MEMBAR when CONFIG_SMP=n

[David Howells]

From: David Howells <dhowells@redhat.com>

Don't make smp_{r,w,}mb() interpolate a MEMBAR instruction when CONFIG_SMP=n as
SMP memory barries on UP systems should interpolate a compiler barrier only.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 include/asm-frv/system.h |   21 +++++++++++++++------
 1 files changed, 15 insertions(+), 6 deletions(-)


diff --git a/include/asm-frv/system.h b/include/asm-frv/system.h
index 2c57f47..30a67a9 100644
--- a/include/asm-frv/system.h
+++ b/include/asm-frv/system.h
@@ -179,14 +179,23 @@ do {							\
 #define mb()			asm volatile ("membar" : : :"memory")
 #define rmb()			asm volatile ("membar" : : :"memory")
 #define wmb()			asm volatile ("membar" : : :"memory")
-#define set_mb(var, value)	do { var = value; mb(); } while (0)
+#define read_barrier_depends()	barrier()
 
-#define smp_mb()		mb()
-#define smp_rmb()		rmb()
-#define smp_wmb()		wmb()
-
-#define read_barrier_depends()		do {} while(0)
+#ifdef CONFIG_SMP
+#define smp_mb()			mb()
+#define smp_rmb()			rmb()
+#define smp_wmb()			wmb()
 #define smp_read_barrier_depends()	read_barrier_depends()
+#define set_mb(var, value) \
+	do { xchg(&var, (value)); } while (0)
+#else
+#define smp_mb()			barrier()
+#define smp_rmb()			barrier()
+#define smp_wmb()			barrier()
+#define smp_read_barrier_depends()	do {} while(0)
+#define set_mb(var, value) \
+	do { var = (value); barrier(); } while (0)
+#endif
 
 #define HARD_RESET_NOW()			\
 do {						\

Re: [PATCH 1/5] FRV: Handle update_mmu_cache() being called when current->mm is NULL

[David Howells]

David Howells <dhowells@redhat.com> wrote:

> --- a/Makefile
> +++ b/Makefile
> @@ -501,11 +501,12 @@ endif # $(dot-config)
>  # Defaults vmlinux but it is usually overridden in the arch makefile
>  all: vmlinux
>  
> -ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
> -KBUILD_CFLAGS	+= -Os
> -else
> -KBUILD_CFLAGS	+= -O2
> -endif
> +#ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
> +#KBUILD_CFLAGS	+= -Os
> +#else
> +#KBUILD_CFLAGS	+= -O2
> +#endif
> +KBUILD_CFLAGS	+= -O1

Oops.  Don't use this patch.  I forgot to delete this bit.

David