SMP for 32-bit kernel, support for Sibyte SB1. Patch from Justin

with minor changes by me.

8 files changed, 143 insertions, 17 deletions

diff --git a/include/asm-mips/hardirq.h b/include/asm-mips/hardirq.h
index 3896706c7..28340dff3 100644
--- a/include/asm-mips/hardirq.h
+++ b/include/asm-mips/hardirq.h
@@ -12,6 +12,7 @@
 #include <linux/config.h>
 #include <linux/threads.h>
 #include <linux/irq.h>
+#include <linux/spinlock.h>
 
 /* entry.S is sensitive to the offsets of these fields */
 typedef struct {
@@ -44,7 +45,53 @@ typedef struct {
 
 #else
 
-#error No habla MIPS SMP
+#include <asm/atomic.h>
+#include <linux/spinlock.h>
+#include <asm/smp.h>
+
+extern int global_irq_holder;
+extern spinlock_t global_irq_lock;
+
+static inline int irqs_running (void)
+{
+	int i;
+
+	for (i = 0; i < smp_num_cpus; i++)
+		if (local_irq_count(i))
+			return 1;
+	return 0;
+}
+
+static inline void release_irqlock(int cpu)
+{
+	/* if we didn't own the irq lock, just ignore.. */
+	if (global_irq_holder == cpu) {
+		global_irq_holder = NO_PROC_ID;
+		spin_unlock(&global_irq_lock);
+	}
+}
+
+static inline int hardirq_trylock(int cpu)
+{
+	return !local_irq_count(cpu) && !spin_is_locked(&global_irq_lock);
+}
+
+#define hardirq_endlock(cpu)	do { } while (0)
+
+static inline void irq_enter(int cpu, int irq)
+{
+	++local_irq_count(cpu);
+
+	while (spin_is_locked(&global_irq_lock))
+		barrier();
+}
+
+static inline void irq_exit(int cpu, int irq)
+{
+	--local_irq_count(cpu);
+}
+
+extern void synchronize_irq(void);
 
 #endif /* CONFIG_SMP */
 #endif /* _ASM_HARDIRQ_H */
diff --git a/include/asm-mips/mmu_context.h b/include/asm-mips/mmu_context.h
index 5912b9966..775e2d370 100644
--- a/include/asm-mips/mmu_context.h
+++ b/include/asm-mips/mmu_context.h
@@ -1,5 +1,4 @@
-/* $Id: mmu_context.h,v 1.7 2000/02/04 07:40:53 ralf Exp $
- *
+/*
  * Switch a MMU context.
  *
  * This file is subject to the terms and conditions of the GNU General Public
@@ -13,11 +12,12 @@
 #define _ASM_MMU_CONTEXT_H
 
 #include <linux/config.h>
+#include <linux/slab.h>
 #include <asm/pgalloc.h>
 
 /* Fuck.  The f-word is here so you can grep for it :-)  */
 extern unsigned long asid_cache;
-extern pgd_t *current_pgd;
+extern pgd_t *current_pgd[];
 
 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_R3912)
 
@@ -60,7 +60,19 @@ get_new_mmu_context(struct mm_struct *mm, unsigned long asid)
 extern inline int
 init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 {
+#ifndef CONFIG_SMP
 	mm->context = 0;
+#else
+	mm->context = (unsigned long)kmalloc(smp_num_cpus * 
+				sizeof(unsigned long), GFP_KERNEL);
+	/*
+ 	 * Init the "context" values so that a tlbpid allocation 
+	 * happens on the first switch.
+ 	 */
+	if (mm->context == 0)
+		return -ENOMEM;
+	memset((void *)mm->context, 0, smp_num_cpus * sizeof(unsigned long));
+#endif
 	return 0;
 }
 
@@ -73,7 +85,7 @@ extern inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 	if ((next->context ^ asid) & ASID_VERSION_MASK)
 		get_new_mmu_context(next, asid);
 
-	current_pgd = next->pgd;
+	current_pgd[cpu] = next->pgd;
 	set_entryhi(next->context);
 }
 
@@ -96,7 +108,7 @@ activate_mm(struct mm_struct *prev, struct mm_struct *next)
 	/* Unconditionally get a new ASID.  */
 	get_new_mmu_context(next, asid_cache);
 
-	current_pgd = next->pgd;
+	current_pgd[smp_processor_id()] = next->pgd;
 	set_entryhi(next->context);
 }
 
diff --git a/include/asm-mips/pgalloc.h b/include/asm-mips/pgalloc.h
index 4f8c74dcf..0fa39f666 100644
--- a/include/asm-mips/pgalloc.h
+++ b/include/asm-mips/pgalloc.h
@@ -10,6 +10,7 @@
 #define _ASM_PGALLOC_H
 
 #include <linux/config.h>
+#include <linux/mm.h>
 
 /* TLB flushing:
  *
@@ -177,6 +178,7 @@ extern inline void pmd_free(pmd_t * pmd)
 
 extern inline pmd_t * pmd_alloc(pgd_t * pgd, unsigned long address)
 {
+	/* Two level page tables.  This level is a nop */
 	return (pmd_t *) pgd;
 }
 
diff --git a/include/asm-mips/processor.h b/include/asm-mips/processor.h
index d658a010e..b0273cca1 100644
--- a/include/asm-mips/processor.h
+++ b/include/asm-mips/processor.h
@@ -29,6 +29,7 @@
 #include <asm/system.h>
 
 struct mips_cpuinfo {
+	unsigned long udelay_val;
 	unsigned long *pgd_quick;
 	unsigned long *pte_quick;
 	unsigned long pgtable_cache_sz;
diff --git a/include/asm-mips/smp.h b/include/asm-mips/smp.h
index 601826429..831dccafd 100644
--- a/include/asm-mips/smp.h
+++ b/include/asm-mips/smp.h
@@ -1,6 +1,36 @@
 #ifndef __ASM_MIPS_SMP_H
 #define __ASM_MIPS_SMP_H
 
+#include <linux/config.h>
+#include <asm/spinlock.h>
+#include <asm/atomic.h>
+#include <asm/current.h>
+
+#ifdef CONFIG_SMP
+
+
+/* Mappings are straight across.  If we want
+   to add support for disabling cpus and such,
+   we'll have to do what the mips64 port does here */
 #define cpu_logical_map(cpu)	(cpu)
+#define cpu_number_map(cpu)     (cpu)
+
+#define smp_processor_id()  (current->processor)
+
+
+/* I've no idea what the real meaning of this is */
+#define PROC_CHANGE_PENALTY	20
+
+#define NO_PROC_ID	(-1)
+
+struct smp_fn_call_struct {
+	spinlock_t lock;
+	atomic_t   finished;
+	void (*fn)(void *);
+	void *data;
+};
+
+extern struct smp_fn_call_struct smp_fn_call;
 
+#endif /* CONFIG_SMP */
 #endif /* __ASM_MIPS_SMP_H */
diff --git a/include/asm-mips/spinlock.h b/include/asm-mips/spinlock.h
index 4ac282bbc..61ebfa660 100644
--- a/include/asm-mips/spinlock.h
+++ b/include/asm-mips/spinlock.h
@@ -21,6 +21,9 @@ typedef struct {
 
 #define spin_lock_init(x)	do { (x)->lock = 0; } while(0);
 
+#define spin_is_locked(x)	((x)->lock != 0)
+#define spin_unlock_wait(x)	({ do { barrier(); } while ((x)->lock); })
+
 /*
  * Simple spin lock operations.  There are two variants, one clears IRQ's
  * on the local processor, one does not.
diff --git a/include/asm-mips/stackframe.h b/include/asm-mips/stackframe.h
index 2f436e79f..127654aab 100644
--- a/include/asm-mips/stackframe.h
+++ b/include/asm-mips/stackframe.h
@@ -8,6 +8,9 @@
 #ifndef __ASM_MIPS_STACKFRAME_H
 #define __ASM_MIPS_STACKFRAME_H
 
+#include <asm/addrspace.h>
+#include <asm/mipsregs.h>
+#include <asm/processor.h>
 #include <asm/asm.h>
 #include <asm/offset.h>
 #include <linux/config.h>
@@ -70,6 +73,22 @@ __asm__ (                                                               \
 /* Used in declaration of save_static functions.  */
 #define static_unused static __attribute__((unused))
 
+
+#ifdef CONFIG_SMP
+#  define GET_SAVED_SP                                   \
+                mfc0    k0, CP0_CONTEXT;                 \
+                lui     k1, %hi(kernelsp);               \
+                srl     k0, k0, 23;                      \
+		sll     k0, k0, 2;                       \
+                addu    k1, k0;                          \
+                lw      k1, %lo(kernelsp)(k1);        
+
+#else
+#  define GET_SAVED_SP                                   \
+		lui	k1, %hi(kernelsp);               \
+		lw	k1, %lo(kernelsp)(k1);           
+#endif
+ 
 #define SAVE_SOME                                        \
 		.set	push;                            \
 		.set	reorder;                         \
@@ -80,13 +99,12 @@ __asm__ (                                                               \
 		 move	k1, sp;                          \
 		.set	reorder;                         \
 		/* Called from user mode, new stack. */  \
-		lui	k1, %hi(kernelsp);               \
-		lw	k1, %lo(kernelsp)(k1);           \
+                GET_SAVED_SP                             \
 8:                                                       \
 		move	k0, sp;                          \
 		subu	sp, k1, PT_SIZE;                 \
 		sw	k0, PT_R29(sp);                  \
-		sw	$3, PT_R3(sp);                   \
+                sw	$3, PT_R3(sp);                   \
 		sw	$0, PT_R0(sp);			 \
 		mfc0	v1, CP0_STATUS;                  \
 		sw	$2, PT_R2(sp);                   \
diff --git a/include/asm-mips/system.h b/include/asm-mips/system.h
index 68117be89..1c1c8c575 100644
--- a/include/asm-mips/system.h
+++ b/include/asm-mips/system.h
@@ -115,14 +115,27 @@ do {									\
 		: "$1", "memory");					\
 } while(0)
 
-/*
- * Non-SMP versions ...
- */
-#define sti() __sti()
-#define cli() __cli()
-#define save_flags(x) __save_flags(x)
-#define save_and_cli(x) __save_and_cli(x)
-#define restore_flags(x) __restore_flags(x)
+#ifdef CONFIG_SMP
+
+extern void __global_sti(void);
+extern void __global_cli(void);
+extern unsigned long __global_save_flags(void);
+extern void __global_restore_flags(unsigned long);
+#  define sti() __global_sti()
+#  define cli() __global_cli() 
+#  define save_flags(x) do { x = __global_save_flags(); } while (0)
+#  define restore_flags(x) __global_restore_flags(x)
+#  define save_and_cli(x) do { save_flags(x); cli(); } while(0)
+
+#else /* Single processor */
+
+#  define sti() __sti()
+#  define cli() __cli()
+#  define save_flags(x) __save_flags(x)
+#  define save_and_cli(x) __save_and_cli(x)
+#  define restore_flags(x) __restore_flags(x)
+
+#endif /* SMP */
 
 /* For spinlocks etc */
 #define local_irq_save(x)	__save_and_cli(x);