[PATCH v2 23/31] EDAC/amd64: Define function to calculate CS ID

[Yazen Ghannam]

Move code used to calculate the CS ID into a separate helper function.

Drop redundant code comment about reading DF register.

The "num_intlv_bits" variable is left uninitialized as it will be removed
in a later patch.

Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
---
Link:
https://lkml.kernel.org/r/20210507190140.18854-20-Yazen.Ghannam@xxxxxxx

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

 drivers/edac/amd64_edac.c | 98 +++++++++++++++++++--------------------
 1 file changed, 48 insertions(+), 50 deletions(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index b497af7c3561..0270bf4f1f90 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -1286,12 +1286,54 @@ static void get_intlv_num_chan(struct addr_ctx *ctx)
 	}
 }
 
-static int denormalize_addr(struct addr_ctx *ctx)
+static int calculate_cs_id(struct addr_ctx *ctx)
 {
+	u8 die_id_shift, die_id_mask, socket_id_shift, socket_id_mask;
+	u8 die_id_bit, sock_id_bit, cs_fabric_id, cs_mask = 0;
 	u32 tmp;
 
-	u8 die_id_shift, die_id_mask, socket_id_shift, socket_id_mask;
-	u8 num_intlv_bits, cs_mask = 0;
+	if (amd_df_indirect_read(ctx->nid, df_regs[FAB_BLK_INST_INFO_3], ctx->inst_id, &tmp))
+		return -EINVAL;
+
+	cs_fabric_id = (tmp >> 8) & 0xFF;
+	die_id_bit   = 0;
+
+	/* If interleaved over more than 1 channel: */
+	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;
+	}
+
+	sock_id_bit = die_id_bit;
+
+	if (ctx->intlv_num_dies || ctx->intlv_num_sockets)
+		if (amd_df_indirect_read(ctx->nid, df_regs[SYS_FAB_ID_MASK], ctx->inst_id, &tmp))
+			return -EINVAL;
+
+	/* If interleaved over more than 1 die: */
+	if (ctx->intlv_num_dies) {
+		sock_id_bit  = die_id_bit + ctx->intlv_num_dies;
+		die_id_shift = (tmp >> 24) & 0xF;
+		die_id_mask  = (tmp >> 8) & 0xFF;
+
+		ctx->cs_id |= ((cs_fabric_id & die_id_mask) >> die_id_shift) << die_id_bit;
+	}
+
+	/* If interleaved over more than 1 socket: */
+	if (ctx->intlv_num_sockets) {
+		socket_id_shift	= (tmp >> 28) & 0xF;
+		socket_id_mask	= (tmp >> 16) & 0xFF;
+
+		ctx->cs_id |= ((cs_fabric_id & socket_id_mask) >> socket_id_shift) << sock_id_bit;
+	}
+
+	return 0;
+}
+
+static int denormalize_addr(struct addr_ctx *ctx)
+{
+	u8 num_intlv_bits;
 
 	/* Return early if no interleaving. */
 	if (ctx->intlv_mode == NONE)
@@ -1306,56 +1348,12 @@ static int denormalize_addr(struct addr_ctx *ctx)
 
 	ctx->make_space_for_cs_id(ctx);
 
+	if (calculate_cs_id(ctx))
+		return -EINVAL;
+
 	if (num_intlv_bits > 0) {
-		u8 die_id_bit, sock_id_bit, cs_fabric_id;
 		u64 temp_addr_i;
 
-		/*
-		 * Read FabricBlockInstanceInformation3_CS[BlockFabricID].
-		 * This is the fabric id for this coherent slave. Use
-		 * umc/channel# as instance id of the coherent slave
-		 * for FICAA.
-		 */
-		if (amd_df_indirect_read(ctx->nid, df_regs[FAB_BLK_INST_INFO_3],
-					 ctx->inst_id, &tmp))
-			return -EINVAL;
-
-		cs_fabric_id = (tmp >> 8) & 0xFF;
-		die_id_bit   = 0;
-
-		/* If interleaved over more than 1 channel: */
-		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;
-		}
-
-		sock_id_bit = die_id_bit;
-
-		if (ctx->intlv_num_dies || ctx->intlv_num_sockets)
-			if (amd_df_indirect_read(ctx->nid, df_regs[SYS_FAB_ID_MASK],
-						 ctx->inst_id, &tmp))
-				return -EINVAL;
-
-		/* If interleaved over more than 1 die. */
-		if (ctx->intlv_num_dies) {
-			sock_id_bit  = die_id_bit + ctx->intlv_num_dies;
-			die_id_shift = (tmp >> 24) & 0xF;
-			die_id_mask  = (tmp >> 8) & 0xFF;
-
-			ctx->cs_id |= ((cs_fabric_id & die_id_mask)
-					>> die_id_shift) << die_id_bit;
-		}
-
-		/* If interleaved over more than 1 socket. */
-		if (ctx->intlv_num_sockets) {
-			socket_id_shift	= (tmp >> 28) & 0xF;
-			socket_id_mask	= (tmp >> 16) & 0xFF;
-
-			ctx->cs_id |= ((cs_fabric_id & socket_id_mask)
-					>> socket_id_shift) << sock_id_bit;
-		}
-
 		/*
 		 * The pre-interleaved address consists of XXXXXXIIIYYYYY
 		 * where III is the ID for this CS, and XXXXXXYYYYY are the
-- 
2.25.1