[Cbe-oss-dev] [PATCH] fix cbe_cpufreq for legacy SLOF tree.

[Jean-Christophe Dubois]

On some legacy SLOF tree the generic code is unable to ioremap some Cell BE 
registers. Therefore the "generic"" functions are returning a NULL pointer, 
triggering a crash on such platforms.

Let's handle this more gracefully.

Signed-off-by: Jean-Christophe DUBOIS <jcd at tribudubois.net>

Index: linux-2.6.22-rc4/arch/powerpc/platforms/cell/cbe_cpufreq_pervasive.c
===================================================================
--- linux-2.6.22-rc4.orig/arch/powerpc/platforms/cell/cbe_cpufreq_pervasive.c
+++ linux-2.6.22-rc4/arch/powerpc/platforms/cell/cbe_cpufreq_pervasive.c
@@ -68,6 +68,13 @@ int cbe_cpufreq_set_pmode(int cpu, unsig
 	mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
 	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
 
+
+	if (!mic_tm_regs || !pmd_regs) {
+		WARN_ON_ONCE(!mic_tm_regs || !pmd_regs);
+		local_irq_restore(flags);
+		return -1;
+	}
+
 	pr_debug("pm register is mapped at %p\n", &pmd_regs->pmcr);
 	pr_debug("mic register is mapped at %p\n", &mic_tm_regs->slow_fast_timer_0);
 
@@ -114,6 +121,12 @@ int cbe_cpufreq_get_pmode(int cpu)
 	struct cbe_pmd_regs __iomem *pmd_regs;
 
 	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
+
+	if (!pmd_regs) {
+		WARN_ON_ONCE(!pmd_regs);
+		return -1;
+	}
+
 	ret = in_be64(&pmd_regs->pmsr) & 0x07;
 
 	return ret;
Index: linux-2.6.22-rc4/arch/powerpc/platforms/cell/cbe_cpufreq.c
===================================================================
--- linux-2.6.22-rc4.orig/arch/powerpc/platforms/cell/cbe_cpufreq.c
+++ linux-2.6.22-rc4/arch/powerpc/platforms/cell/cbe_cpufreq.c
@@ -96,6 +96,11 @@ static int cbe_cpufreq_cpu_init(struct c
 	cur_pmode = cbe_cpufreq_get_pmode(policy->cpu);
 	pr_debug("current pmode is at %d\n",cur_pmode);
 
+	if (cur_pmode == -1) {
+		WARN_ON_ONCE(cur_pmode == -1);
+		return -EINVAL;
+	}
+
 	policy->cur = cbe_freqs[cur_pmode].frequency;
 
 #ifdef CONFIG_SMP
@@ -155,7 +160,11 @@ static int cbe_cpufreq_target(struct cpu
 
 	rc = set_pmode(policy->cpu, cbe_pmode_new);
 
-	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+	if (rc != -1)
+		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+	else
+		WARN_ON_ONCE(rc == -1);
+
 	mutex_unlock(&cbe_switch_mutex);
 
 	return rc;