Subject: [PATCH 5/9] powerpc/64: Retrieve number of L1 cache sets from device-tree

From: Benjamin Herrenschmidt <[email-masked]>
Date: Sun, 8 Jan 2017 17:31:46 -0600

It will be used to calculate the associativity

Signed-off-by: Benjamin Herrenschmidt <[email-masked]>
---
 arch/powerpc/include/asm/cache.h |  2 ++
 arch/powerpc/kernel/setup_64.c   | 27 +++++++++++++++++++++++++--
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/cache.h b/arch/powerpc/include/asm/cache.h
index c74ebc2..ceb1244 100644
--- a/arch/powerpc/include/asm/cache.h
+++ b/arch/powerpc/include/asm/cache.h
@@ -33,11 +33,13 @@ struct ppc64_caches {
 	u32	dblock_size;		/* L1 d-cache block size */
 	u32	log_dblock_size;
 	u32	dblocks_per_page;
+	u32	dsets;
 	u32	isize;			/* L1 i-cache size */
 	u32	iline_size;		/* L1 d-cache line size	*/
 	u32	iblock_size;		/* L1 i-cache block size */
 	u32	log_iblock_size;
 	u32	iblocks_per_page;
+	u32	isets;
 };
 
 extern struct ppc64_caches ppc64_caches;
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index e7e5c1b..d36b6f4 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -404,14 +404,18 @@ void __init initialize_cache_info(void)
 		 * d-cache and i-cache sizes... -Peter
 		 */
 		if (num_cpus == 1) {
-			const __be32 *sizep, *lsizep, *bsizep;
-			u32 size, lsize, bsize;
+			const __be32 *sizep, *lsizep, *bsizep, *setsp;
+			u32 size, lsize, bsize, sets;
 
 			size = 0;
+			sets = -1u;
 			lsize = bsize = cur_cpu_spec->dcache_bsize;
 			sizep = of_get_property(np, "d-cache-size", NULL);
 			if (sizep != NULL)
 				size = be32_to_cpu(*sizep);
+			setsp = of_get_property(np, "d-cache-sets", NULL);
+			if (setsp != NULL)
+				sets = be32_to_cpu(*setsp);
 			bsizep = of_get_property(np, "d-cache-block-size",
 						 NULL);
 			lsizep = of_get_property(np, "d-cache-line-size",
@@ -427,17 +431,31 @@ void __init initialize_cache_info(void)
 				    "sizep: %p, bsizep: %p, lsizep: %p\n",
 				    sizep, bsizep, lsizep);
 
+			/* OF is weird .. it represents fully associative caches
+			 * as "1 way" which doesn't make much sense and doesn't
+			 * leave room for direct mapped. We'll assume that 0
+			 * in OF means direct mapped for that reason.
+			 */
+			if (sets == 1)
+				sets = 0;
+			else if (sets == 0)
+				sets = 1;
 			ppc64_caches.dsize = size;
+			ppc64_caches.dsets = sets;
 			ppc64_caches.dline_size = lsize;
 			ppc64_caches.dblock_size = bsize;
 			ppc64_caches.log_dblock_size = __ilog2(bsize);
 			ppc64_caches.dblocks_per_page = PAGE_SIZE / bsize;
 
 			size = 0;
+			sets = -1u;
 			lsize = bsize = cur_cpu_spec->icache_bsize;
 			sizep = of_get_property(np, "i-cache-size", NULL);
 			if (sizep != NULL)
 				size = be32_to_cpu(*sizep);
+			setsp = of_get_property(np, "i-cache-sets", NULL);
+			if (setsp != NULL)
+				sets = be32_to_cpu(*setsp);
 			bsizep = of_get_property(np, "i-cache-block-size",
 						 NULL);
 			lsizep = of_get_property(np, "i-cache-line-size",
@@ -453,7 +471,12 @@ void __init initialize_cache_info(void)
 				    "sizep: %p, bsizep: %p, lsizep: %p\n",
 				    sizep, bsizep, lsizep);
 
+			if (sets == 1)
+				sets = 0;
+			else if (sets == 0)
+				sets = 1;
 			ppc64_caches.isize = size;
+			ppc64_caches.isets = sets;
 			ppc64_caches.iline_size = lsize;
 			ppc64_caches.iblock_size = bsize;
 			ppc64_caches.log_iblock_size = __ilog2(bsize);
-- 
2.9.3