Re: [RFC, 6/8] powerpc/prom: Simplify the logic while fetching SLB size

On 07/21/2015 03:51 PM, Michael Ellerman wrote:

On Tue, 2015-21-07 at 06:58:44 UTC, Anshuman Khandual wrote:

quoted

quoted

From: "khandual@linux.vnet.ibm.com" <redacted>

This patch just simplifies the existing code logic while fetching
the SLB size property from the device tree.

Signed-off-by: Anshuman Khandual <redacted>
---
 arch/powerpc/kernel/prom.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 8b888b1..f6168e2 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c

@@ -223,14 +223,12 @@ static void __init check_cpu_slb_size(unsigned long node)
 	const __be32 *slb_size_ptr;
 
 	slb_size_ptr = of_get_flat_dt_prop(node, "slb-size", NULL);
-	if (slb_size_ptr != NULL) {
-		mmu_slb_size = be32_to_cpup(slb_size_ptr);
-		return;
-	}
-	slb_size_ptr = of_get_flat_dt_prop(node, "ibm,slb-size", NULL);
-	if (slb_size_ptr != NULL) {
-		mmu_slb_size = be32_to_cpup(slb_size_ptr);
+	if (!slb_size_ptr) {
+		slb_size_ptr = of_get_flat_dt_prop(node, "ibm,slb-size", NULL);
+		if (!slb_size_ptr)
+			return;
 	}
+	mmu_slb_size = be32_to_cpup(slb_size_ptr);
 }

It's still ugly. Why not go the whole way:


	p = of_get_flat_dt_prop(node, "slb-size", NULL) ? :
	    of_get_flat_dt_prop(node, "ibm,slb-size", NULL);

	if (p)
		mmu_slb_size = be32_to_cpup(p);

Yeah this is better.

And while you're at it, rename the function, it doesn't check anything. It
initialises mmu_slb_size, so call it init_mmu_slb_size()?

Sure, will do.