Blackfin arch: SMP supporting patchset: Blackfin kernel and memory management code

Blackfin dual core BF561 processor can support SMP like features.
https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like

In this patch, we provide SMP extend to Blackfin kernel and memory management code

Singed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

1 files changed, 26 insertions, 30 deletions

diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c
index bef025b0744..af7cc43630d 100644
--- a/arch/blackfin/kernel/traps.c
+++ b/arch/blackfin/kernel/traps.c
@@ -75,16 +75,6 @@ void __init trap_init(void)
 	CSYNC();
 }
 
-/*
- * Used to save the RETX, SEQSTAT, I/D CPLB FAULT ADDR
- * values across the transition from exception to IRQ5.
- * We put these in L1, so they are going to be in a valid
- * location during exception context
- */
-__attribute__((l1_data))
-unsigned long saved_retx, saved_seqstat,
-	saved_icplb_fault_addr, saved_dcplb_fault_addr;
-
 static void decode_address(char *buf, unsigned long address)
 {
 #ifdef CONFIG_DEBUG_VERBOSE
@@ -211,18 +201,18 @@ asmlinkage void double_fault_c(struct pt_regs *fp)
 	printk(KERN_EMERG "\n" KERN_EMERG "Double Fault\n");
 #ifdef CONFIG_DEBUG_DOUBLEFAULT_PRINT
 	if (((long)fp->seqstat &  SEQSTAT_EXCAUSE) == VEC_UNCOV) {
+		unsigned int cpu = smp_processor_id();
 		char buf[150];
-		decode_address(buf, saved_retx);
+		decode_address(buf, cpu_pda[cpu].retx);
 		printk(KERN_EMERG "While handling exception (EXCAUSE = 0x%x) at %s:\n",
-			(int)saved_seqstat & SEQSTAT_EXCAUSE, buf);
-		decode_address(buf, saved_dcplb_fault_addr);
+			(unsigned int)cpu_pda[cpu].seqstat & SEQSTAT_EXCAUSE, buf);
+		decode_address(buf, cpu_pda[cpu].dcplb_fault_addr);
 		printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %s\n", buf);
-		decode_address(buf, saved_icplb_fault_addr);
+		decode_address(buf, cpu_pda[cpu].icplb_fault_addr);
 		printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %s\n", buf);
 
 		decode_address(buf, fp->retx);
-		printk(KERN_NOTICE "The instruction at %s caused a double exception\n",
-			buf);
+		printk(KERN_NOTICE "The instruction at %s caused a double exception\n", buf);
 	} else
 #endif
 	{
@@ -240,6 +230,9 @@ asmlinkage void trap_c(struct pt_regs *fp)
 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
 	int j;
 #endif
+#ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
+	unsigned int cpu = smp_processor_id();
+#endif
 	int sig = 0;
 	siginfo_t info;
 	unsigned long trapnr = fp->seqstat & SEQSTAT_EXCAUSE;
@@ -417,7 +410,7 @@ asmlinkage void trap_c(struct pt_regs *fp)
 		info.si_code = ILL_CPLB_MULHIT;
 		sig = SIGSEGV;
 #ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
-		if (saved_dcplb_fault_addr < FIXED_CODE_START)
+		if (cpu_pda[cpu].dcplb_fault_addr < FIXED_CODE_START)
 			verbose_printk(KERN_NOTICE "NULL pointer access\n");
 		else
 #endif
@@ -471,7 +464,7 @@ asmlinkage void trap_c(struct pt_regs *fp)
 		info.si_code = ILL_CPLB_MULHIT;
 		sig = SIGSEGV;
 #ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
-		if (saved_icplb_fault_addr < FIXED_CODE_START)
+		if (cpu_pda[cpu].icplb_fault_addr < FIXED_CODE_START)
 			verbose_printk(KERN_NOTICE "Jump to NULL address\n");
 		else
 #endif
@@ -960,6 +953,7 @@ void dump_bfin_process(struct pt_regs *fp)
 		else
 			verbose_printk(KERN_NOTICE "COMM= invalid\n");
 
+		printk(KERN_NOTICE "CPU = %d\n", current_thread_info()->cpu);
 		if (!((unsigned long)current->mm & 0x3) && (unsigned long)current->mm >= FIXED_CODE_START)
 			verbose_printk(KERN_NOTICE  "TEXT = 0x%p-0x%p        DATA = 0x%p-0x%p\n"
 				KERN_NOTICE " BSS = 0x%p-0x%p  USER-STACK = 0x%p\n"
@@ -1053,6 +1047,7 @@ void show_regs(struct pt_regs *fp)
 	struct irqaction *action;
 	unsigned int i;
 	unsigned long flags;
+	unsigned int cpu = smp_processor_id();
 
 	verbose_printk(KERN_NOTICE "\n" KERN_NOTICE "SEQUENCER STATUS:\t\t%s\n", print_tainted());
 	verbose_printk(KERN_NOTICE " SEQSTAT: %08lx  IPEND: %04lx  SYSCFG: %04lx\n",
@@ -1112,9 +1107,9 @@ unlock:
 
 	if (((long)fp->seqstat &  SEQSTAT_EXCAUSE) &&
 	    (((long)fp->seqstat & SEQSTAT_EXCAUSE) != VEC_HWERR)) {
-		decode_address(buf, saved_dcplb_fault_addr);
+		decode_address(buf, cpu_pda[cpu].dcplb_fault_addr);
 		verbose_printk(KERN_NOTICE "DCPLB_FAULT_ADDR: %s\n", buf);
-		decode_address(buf, saved_icplb_fault_addr);
+		decode_address(buf, cpu_pda[cpu].icplb_fault_addr);
 		verbose_printk(KERN_NOTICE "ICPLB_FAULT_ADDR: %s\n", buf);
 	}
 
@@ -1153,20 +1148,21 @@ unlock:
 asmlinkage int sys_bfin_spinlock(int *spinlock)__attribute__((l1_text));
 #endif
 
-asmlinkage int sys_bfin_spinlock(int *spinlock)
+static DEFINE_SPINLOCK(bfin_spinlock_lock);
+
+asmlinkage int sys_bfin_spinlock(int *p)
 {
-	int ret = 0;
-	int tmp = 0;
+	int ret, tmp = 0;
 
-	local_irq_disable();
-	ret = get_user(tmp, spinlock);
-	if (ret == 0) {
-		if (tmp)
+	spin_lock(&bfin_spinlock_lock);	/* This would also hold kernel preemption. */
+	ret = get_user(tmp, p);
+	if (likely(ret == 0)) {
+		if (unlikely(tmp))
 			ret = 1;
-		tmp = 1;
-		put_user(tmp, spinlock);
+		else
+			put_user(1, p);
 	}
-	local_irq_enable();
+	spin_unlock(&bfin_spinlock_lock);
 	return ret;
 }