diff mbox

[V2,2/2] cpc925_edac: support single-processor configurations

Message ID 1306059295-25806-2-git-send-email-dbaryshkov@gmail.com (mailing list archive)
State Superseded
Headers show

Commit Message

Dmitry Baryshkov May 22, 2011, 10:14 a.m. UTC 
If second CPU is not enabled, CPC925 EDAC driver will spill out warnings
about errors on second Processor Interface. Support masking that out,
by detecting at runtime which CPUs are present in device tree.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Harry Ciao <qingtao.cao@windriver.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
---
 drivers/edac/cpc925_edac.c |   52 ++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 52 insertions(+), 0 deletions(-)

Comments

Segher Boessenkool May 23, 2011, 3:50 p.m. UTC | #1 
> If second CPU is not enabled, CPC925 EDAC driver will spill out 
> warnings
> about errors on second Processor Interface. Support masking that out,
> by detecting at runtime which CPUs are present in device tree.
>
> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> Cc: Harry Ciao <qingtao.cao@windriver.com>
> Cc: Doug Thompson <dougthompson@xmission.com>
> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>

Acked-by: Segher Boessenkool <segher@kernel.crashing.org>

Minor stuff...

> +	/* Get first CPU node */

Comment doesn't match code.

> +	for (cpunode = NULL;
> +	     (cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {

Use a while loop instead?

> +		const u32 *reg = of_get_property(cpunode, "reg", NULL);
> +
> +		if (!strcmp(cpunode->type, "cpu") && reg != NULL)
> +			mask &= ~APIMASK_ADI(*reg);
> +	}

You might want to check if the "reg" value is < 2, you get C undefined
behaviour if it is too big (not that that should happen), and it's 
clearer
code anyway.

> +	cpumask = cpc925_cpu_getmask();

You could choose a function name that makes more clear these are the
processor _interfaces_ that are _not_ used :-)

You could cache this value as well.


Segher
diff mbox

Patch

diff --git a/drivers/edac/cpc925_edac.c b/drivers/edac/cpc925_edac.c
index 837ad8f..0b466af 100644
--- a/drivers/edac/cpc925_edac.c
+++ b/drivers/edac/cpc925_edac.c
@@ -90,6 +90,7 @@  enum apimask_bits {
 	ECC_MASK_ENABLE = (APIMASK_ECC_UE_H | APIMASK_ECC_CE_H |
 			   APIMASK_ECC_UE_L | APIMASK_ECC_CE_L),
 };
+#define APIMASK_ADI(n)		CPC925_BIT(((n)+1))
 
 /************************************************************
  *	Processor Interface Exception Register (APIEXCP)
@@ -581,16 +582,64 @@  static void cpc925_mc_check(struct mem_ctl_info *mci)
 }
 
 /******************** CPU err device********************************/
+static u32 cpc925_cpu_getmask(void)
+{
+	struct device_node *cpus;
+	struct device_node *cpunode;
+	static u32 mask = 0;
+
+	if (mask != 0)
+		return mask;
+
+	mask = APIMASK_ADI0 | APIMASK_ADI1;
+
+	cpus = of_find_node_by_path("/cpus");
+	if (cpus == NULL) {
+		cpc925_printk(KERN_DEBUG, "No /cpus node !\n");
+		return 0;
+	}
+
+	/* Get first CPU node */
+	for (cpunode = NULL;
+	     (cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
+		const u32 *reg = of_get_property(cpunode, "reg", NULL);
+
+		if (!strcmp(cpunode->type, "cpu") && reg != NULL)
+			mask &= ~APIMASK_ADI(*reg);
+	}
+
+	if (mask != APIMASK_ADI0 | APIMASK_ADI1) {
+		/* We assume that each CPU sits on it's own PI and that
+		 * for present CPUs the reg property equals to the PI
+		 * interface id */
+		cpc925_printk(KERN_WARNING,
+				"Assuming PI id is equal to CPU MPIC id!\n");
+	}
+
+	of_node_put(cpunode);
+	of_node_put(cpus);
+
+	return mask;
+}
+
 /* Enable CPU Errors detection */
 static void cpc925_cpu_init(struct cpc925_dev_info *dev_info)
 {
 	u32 apimask;
+	u32 cpumask;
 
 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
 	if ((apimask & CPU_MASK_ENABLE) == 0) {
 		apimask |= CPU_MASK_ENABLE;
 		__raw_writel(apimask, dev_info->vbase + REG_APIMASK_OFFSET);
 	}
+
+	cpumask = cpc925_cpu_getmask();
+	if (apimask & cpumask) {
+		cpc925_printk(KERN_WARNING, "CPU(s) not present, "
+				"but enabled in APIMASK, disabling\n");
+		apimask &= ~cpumask;
+	}
 }
 
 /* Disable CPU Errors detection */
@@ -622,6 +671,9 @@  static void cpc925_cpu_check(struct edac_device_ctl_info *edac_dev)
 	if ((apiexcp & CPU_EXCP_DETECTED) == 0)
 		return;
 
+	if ((apiexcp & ~cpc925_cpu_getmask()) == 0)
+		return;
+
 	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
 	cpc925_printk(KERN_INFO, "Processor Interface Fault\n"
 				 "Processor Interface register dump:\n");