[PATCH] CRIS update: SMP

Patches to support SMP.

* Each CPU has its own current_pgd.
* flush_tlb_range is implemented as flush_tlb_mm.
* Atomic operations implemented with spinlocks.
* Semaphores implemented with spinlocks.

Signed-off-by: Mikael Starvik <starvik@axis.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/cris/arch-v10/mm/fault.c

@@ -14,6 +14,7 @@
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 #include <asm/arch/svinto.h>
+#include <asm/mmu_context.h>
 
 /* debug of low-level TLB reload */
 #undef DEBUG
@@ -24,8 +25,6 @@
 #define D(x)
 #endif
 
-extern volatile pgd_t *current_pgd;
-
 extern const struct exception_table_entry
 	*search_exception_tables(unsigned long addr);
 
@@ -46,7 +45,7 @@ handle_mmu_bus_fault(struct pt_regs *regs)
 	int page_id;
 	int acc, inv;
 #endif
-	pgd_t* pgd = (pgd_t*)current_pgd;
+	pgd_t* pgd = (pgd_t*)per_cpu(current_pgd, smp_processor_id());
 	pmd_t *pmd;
 	pte_t pte;
 	int miss, we, writeac;
@@ -94,24 +93,3 @@ handle_mmu_bus_fault(struct pt_regs *regs)
 	*R_TLB_LO = pte_val(pte);
 	local_irq_restore(flags);
 }
-
-/* Called from arch/cris/mm/fault.c to find fixup code. */
-int
-find_fixup_code(struct pt_regs *regs)
-{
-	const struct exception_table_entry *fixup;
-
-	if ((fixup = search_exception_tables(regs->irp)) != 0) {
-		/* Adjust the instruction pointer in the stackframe. */
-		regs->irp = fixup->fixup;
-
-		/* 
-		 * Don't return by restoring the CPU state, so switch
-		 * frame-type. 
-		 */
-		regs->frametype = CRIS_FRAME_NORMAL;
-		return 1;
-	}
-
-	return 0;
-}

arch/cris/arch-v10/mm/init.c

@@ -42,7 +42,7 @@ paging_init(void)
 	 *  switch_mm)
 	 */
 
-	current_pgd = init_mm.pgd;
+	per_cpu(current_pgd, smp_processor_id()) = init_mm.pgd;
 
 	/* initialise the TLB (tlb.c) */
 

arch/cris/arch-v10/mm/tlb.c

@@ -139,53 +139,6 @@ flush_tlb_page(struct vm_area_struct *vma,
 	local_irq_restore(flags);
 }
 
-/* invalidate a page range */
-
-void
-flush_tlb_range(struct vm_area_struct *vma, 
-		unsigned long start,
-		unsigned long end)
-{
-	struct mm_struct *mm = vma->vm_mm;
-	int page_id = mm->context.page_id;
-	int i;
-	unsigned long flags;
-
-	D(printk("tlb: flush range %p<->%p in context %d (%p)\n",
-		 start, end, page_id, mm));
-
-	if(page_id == NO_CONTEXT)
-		return;
-
-	start &= PAGE_MASK;  /* probably not necessary */
-	end &= PAGE_MASK;    /* dito */
-
-	/* invalidate those TLB entries that match both the mm context
-	 * and the virtual address range
-	 */
-
-	local_save_flags(flags);
-	local_irq_disable();
-	for(i = 0; i < NUM_TLB_ENTRIES; i++) {
-		unsigned long tlb_hi, vpn;
-		*R_TLB_SELECT = IO_FIELD(R_TLB_SELECT, index, i);
-		tlb_hi = *R_TLB_HI;
-		vpn = tlb_hi & PAGE_MASK;
-		if (IO_EXTRACT(R_TLB_HI, page_id, tlb_hi) == page_id &&
-		    vpn >= start && vpn < end) {
-			*R_TLB_HI = ( IO_FIELD(R_TLB_HI, page_id, INVALID_PAGEID ) |
-				      IO_FIELD(R_TLB_HI, vpn,     i & 0xf ) );
-
-			*R_TLB_LO = ( IO_STATE(R_TLB_LO, global,no  ) |
-				      IO_STATE(R_TLB_LO, valid, no  ) |
-				      IO_STATE(R_TLB_LO, kernel,no  ) |
-				      IO_STATE(R_TLB_LO, we,    no  ) |
-				      IO_FIELD(R_TLB_LO, pfn,   0   ) );
-		}
-	}
-	local_irq_restore(flags);
-}
-
 /* dump the entire TLB for debug purposes */
 
 #if 0
@@ -237,7 +190,7 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next,
 	 * the pgd.
 	 */
 
-	current_pgd = next->pgd;
+	per_cpu(current_pgd, smp_processor_id()) = next->pgd;
 
 	/* switch context in the MMU */
 

include/asm-cris/arch-v10/atomic.h

@@ -0,0 +1,7 @@
+#ifndef __ASM_CRIS_ARCH_ATOMIC__
+#define __ASM_CRIS_ARCH_ATOMIC__
+
+#define cris_atomic_save(addr, flags) local_irq_save(flags);
+#define cris_atomic_restore(addr, flags) local_irq_restore(flags);
+
+#endif

include/asm-cris/atomic.h

@@ -4,21 +4,14 @@
 #define __ASM_CRIS_ATOMIC__
 
 #include <asm/system.h>
+#include <asm/arch/atomic.h>
 
 /*
  * Atomic operations that C can't guarantee us.  Useful for
  * resource counting etc..
  */
 
-/*
- * Make sure gcc doesn't try to be clever and move things around
- * on us. We need to use _exactly_ the address the user gave us,
- * not some alias that contains the same information.
- */
-
-#define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x)
-
-typedef struct { int counter; } atomic_t;
+typedef struct { volatile int counter; } atomic_t;
 
 #define ATOMIC_INIT(i)  { (i) }
 
@@ -30,29 +23,26 @@ typedef struct { int counter; } atomic_t;
 extern __inline__ void atomic_add(int i, volatile atomic_t *v)
 {
 	unsigned long flags;
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(v, flags);
 	v->counter += i;
-	local_irq_restore(flags);
+	cris_atomic_restore(v, flags);
 }
 
 extern __inline__ void atomic_sub(int i, volatile atomic_t *v)
 {
 	unsigned long flags;
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(v, flags);
 	v->counter -= i;
-	local_irq_restore(flags);
+	cris_atomic_restore(v, flags);
 }
 
 extern __inline__ int atomic_add_return(int i, volatile atomic_t *v)
 {
 	unsigned long flags;
 	int retval;
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(v, flags);
 	retval = (v->counter += i);
-	local_irq_restore(flags);
+	cris_atomic_restore(v, flags);
 	return retval;
 }
 
@@ -62,82 +52,74 @@ extern __inline__ int atomic_sub_return(int i, volatile atomic_t *v)
 {
 	unsigned long flags;
 	int retval;
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(v, flags);
 	retval = (v->counter -= i);
-	local_irq_restore(flags);
+	cris_atomic_restore(v, flags);
 	return retval;
 }
 
 extern __inline__ int atomic_sub_and_test(int i, volatile atomic_t *v)
 {
 	int retval;
 	unsigned long flags;
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(v, flags);
 	retval = (v->counter -= i) == 0;
-	local_irq_restore(flags);
+	cris_atomic_restore(v, flags);
 	return retval;
 }
 
 extern __inline__ void atomic_inc(volatile atomic_t *v)
 {
 	unsigned long flags;
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(v, flags);
 	(v->counter)++;
-	local_irq_restore(flags);
+	cris_atomic_restore(v, flags);
 }
 
 extern __inline__ void atomic_dec(volatile atomic_t *v)
 {
 	unsigned long flags;
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(v, flags);
 	(v->counter)--;
-	local_irq_restore(flags);
+	cris_atomic_restore(v, flags);
 }
 
 extern __inline__ int atomic_inc_return(volatile atomic_t *v)
 {
 	unsigned long flags;
 	int retval;
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(v, flags);
 	retval = (v->counter)++;
-	local_irq_restore(flags);
+	cris_atomic_restore(v, flags);
 	return retval;
 }
 
 extern __inline__ int atomic_dec_return(volatile atomic_t *v)
 {
 	unsigned long flags;
 	int retval;
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(v, flags);
 	retval = (v->counter)--;
-	local_irq_restore(flags);
+	cris_atomic_restore(v, flags);
 	return retval;
 }
 extern __inline__ int atomic_dec_and_test(volatile atomic_t *v)
 {
 	int retval;
 	unsigned long flags;
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(v, flags);
 	retval = --(v->counter) == 0;
-	local_irq_restore(flags);
+	cris_atomic_restore(v, flags);
 	return retval;
 }
 
 extern __inline__ int atomic_inc_and_test(volatile atomic_t *v)
 {
 	int retval;
 	unsigned long flags;
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(v, flags);
 	retval = ++(v->counter) == 0;
-	local_irq_restore(flags);
+	cris_atomic_restore(v, flags);
 	return retval;
 }
 

include/asm-cris/mmu_context.h

@@ -15,7 +15,7 @@ extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  * registers like cr3 on the i386
  */
 
-extern volatile pgd_t *current_pgd;   /* defined in arch/cris/mm/fault.c */
+extern volatile DEFINE_PER_CPU(pgd_t *,current_pgd); /* defined in arch/cris/mm/fault.c */
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {

include/asm-cris/semaphore.h

@@ -72,10 +72,9 @@ extern inline void down(struct semaphore * sem)
 	might_sleep();
 
 	/* atomically decrement the semaphores count, and if its negative, we wait */
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(sem, flags);
 	failed = --(sem->count.counter) < 0;
-	local_irq_restore(flags);
+	cris_atomic_restore(sem, flags);
 	if(failed) {
 		__down(sem);
 	}
@@ -95,10 +94,9 @@ extern inline int down_interruptible(struct semaphore * sem)
 	might_sleep();
 
 	/* atomically decrement the semaphores count, and if its negative, we wait */
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(sem, flags);
 	failed = --(sem->count.counter) < 0;
-	local_irq_restore(flags);
+	cris_atomic_restore(sem, flags);
 	if(failed)
 		failed = __down_interruptible(sem);
 	return(failed);
@@ -109,13 +107,13 @@ extern inline int down_trylock(struct semaphore * sem)
 	unsigned long flags;
 	int failed;
 
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(sem, flags);
 	failed = --(sem->count.counter) < 0;
-	local_irq_restore(flags);
+	cris_atomic_restore(sem, flags);
 	if(failed)
 		failed = __down_trylock(sem);
 	return(failed);
+
 }
 
 /*
@@ -130,10 +128,9 @@ extern inline void up(struct semaphore * sem)
 	int wakeup;
 
 	/* atomically increment the semaphores count, and if it was negative, we wake people */
-	local_save_flags(flags);
-	local_irq_disable();
+	cris_atomic_save(sem, flags);
 	wakeup = ++(sem->count.counter) <= 0;
-	local_irq_restore(flags);
+	cris_atomic_restore(sem, flags);
 	if(wakeup) {
 		__up(sem);
 	}

include/asm-cris/smp.h

@@ -1,4 +1,11 @@
 #ifndef __ASM_SMP_H
 #define __ASM_SMP_H
 
+#include <linux/cpumask.h>
+
+extern cpumask_t phys_cpu_present_map;
+#define cpu_possible_map phys_cpu_present_map
+
+#define __smp_processor_id() (current_thread_info()->cpu)
+
 #endif

include/asm-cris/spinlock.h

@@ -0,0 +1 @@
+#include <asm/arch/spinlock.h>

include/asm-cris/tlbflush.h

@@ -18,13 +18,26 @@
  *
  */
 
+extern void __flush_tlb_all(void);
+extern void __flush_tlb_mm(struct mm_struct *mm);
+extern void __flush_tlb_page(struct vm_area_struct *vma,
+			   unsigned long addr);
+
+#ifdef CONFIG_SMP
 extern void flush_tlb_all(void);
 extern void flush_tlb_mm(struct mm_struct *mm);
 extern void flush_tlb_page(struct vm_area_struct *vma, 
 			   unsigned long addr);
-extern void flush_tlb_range(struct vm_area_struct *vma,
-			    unsigned long start,
-			    unsigned long end);
+#else
+#define flush_tlb_all __flush_tlb_all
+#define flush_tlb_mm __flush_tlb_mm
+#define flush_tlb_page __flush_tlb_page
+#endif
+
+static inline void flush_tlb_range(struct vm_area_struct * vma, unsigned long start, unsigned long end)
+{
+	flush_tlb_mm(vma->vm_mm);
+}
 
 extern inline void flush_tlb_pgtables(struct mm_struct *mm,
                                       unsigned long start, unsigned long end)