[PATCH v2 18/31] EDAC/amd64: Define function to get number of interleaved channels

[Yazen Ghannam]

Move number of interleaved channel calculation to a separate helper
function. Drop unused cases.

Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
---
Link:
https://lkml.kernel.org/r/20210507190140.18854-15-Yazen.Ghannam@xxxxxxx

v1->v2:
* Moved from arch/x86 to EDAC.

 drivers/edac/amd64_edac.c | 42 +++++++++++++++++++++------------------
 1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 02dc34c13d65..80192a05bb93 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -1097,6 +1097,7 @@ struct addr_ctx {
 	u8 inst_id;
 	u8 map_num;
 	u8 intlv_addr_bit;
+	u8 intlv_num_chan;
 	u8 cs_id;
 	int (*dehash_addr)(struct addr_ctx *ctx);
 };
@@ -1226,12 +1227,29 @@ static int get_intlv_addr_bit(struct addr_ctx *ctx)
 	return 0;
 }
 
+static void get_intlv_num_chan(struct addr_ctx *ctx)
+{
+	/* Save the log2(# of channels). */
+	switch (ctx->intlv_mode) {
+	case NONE:
+		ctx->intlv_num_chan = 0;
+		break;
+	case NOHASH_2CH:
+	case DF2_HASH_2CH:
+		ctx->intlv_num_chan = 1;
+		break;
+	default:
+		/* Valid interleaving modes where checked earlier. */
+		break;
+	}
+}
+
 static int denormalize_addr(struct addr_ctx *ctx)
 {
 	u32 tmp;
 
 	u8 die_id_shift, die_id_mask, socket_id_shift, socket_id_mask;
-	u8 intlv_num_dies, intlv_num_chan, intlv_num_sockets;
+	u8 intlv_num_dies, intlv_num_sockets;
 	u8 num_intlv_bits, cs_mask = 0;
 
 	/* Return early if no interleaving. */
@@ -1244,23 +1262,9 @@ static int denormalize_addr(struct addr_ctx *ctx)
 	intlv_num_sockets = (ctx->reg_limit_addr >> 8) & 0x1;
 	intlv_num_dies	  = (ctx->reg_limit_addr >> 10) & 0x3;
 
-	/* Re-use intlv_num_chan by setting it equal to log2(#channels) */
-	switch (intlv_num_chan) {
-	case 0:	intlv_num_chan = 0; break;
-	case 1: intlv_num_chan = 1; break;
-	case 3: intlv_num_chan = 2; break;
-	case 5:	intlv_num_chan = 3; break;
-	case 7:	intlv_num_chan = 4; break;
-
-	case 8: intlv_num_chan = 1;
-		break;
-	default:
-		pr_err("%s: Invalid number of interleaved channels %d.\n",
-			__func__, intlv_num_chan);
-		return -EINVAL;
-	}
+	get_intlv_num_chan(ctx);
 
-	num_intlv_bits = intlv_num_chan;
+	num_intlv_bits = ctx->intlv_num_chan;
 
 	if (intlv_num_dies > 2) {
 		pr_err("%s: Invalid number of interleaved nodes/dies %d.\n",
@@ -1298,8 +1302,8 @@ static int denormalize_addr(struct addr_ctx *ctx)
 		die_id_bit   = 0;
 
 		/* If interleaved over more than 1 channel: */
-		if (intlv_num_chan) {
-			die_id_bit = intlv_num_chan;
+		if (ctx->intlv_num_chan) {
+			die_id_bit = ctx->intlv_num_chan;
 			cs_mask	   = (1 << die_id_bit) - 1;
 			ctx->cs_id = cs_fabric_id & cs_mask;
 		}
-- 
2.25.1