[PATCH v2 09/31] EDAC/amd64: Define function to find interleaving mode

[Yazen Ghannam]

Define a helper function to find the interleaving mode. Define a
DF2-specific function now. Future DF versions will have their own
functions.

Use an enumeration for the interleaving modes to give a human-readable
value. Save the interleaving mode in the context struct, since this will
be used in multiple functions.

Multiple interleaving modes support hashing, so save a boolean in the
context struct to check if hashing is enabled.

Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
---
Link:
https://lkml.kernel.org/r/20210507190140.18854-6-Yazen.Ghannam@xxxxxxx

v1->v2:
* Moved from arch/x86 to EDAC.
* Add new function to data_fabric_ops.

 drivers/edac/amd64_edac.c | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 867ab32caab2..93a4ce9eb735 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -1079,8 +1079,16 @@ static struct df_reg df_regs[] = {
 	[SYS_FAB_ID_MASK]	=	{1, 0x208},
 };
 
+/* These are mapped 1:1 to the hardware values. Special cases are set at > 0x20. */
+enum intlv_modes {
+	NONE		= 0x00,
+	NOHASH_2CH	= 0x01,
+	DF2_HASH_2CH	= 0x21,
+};
+
 /* Use "reg_" prefix for raw register values. */
 struct addr_ctx {
+	enum intlv_modes intlv_mode;
 	u64 ret_addr;
 	u32 reg_dram_offset;
 	u32 reg_base_addr;
@@ -1088,10 +1096,12 @@ struct addr_ctx {
 	u16 nid;
 	u8 inst_id;
 	u8 map_num;
+	bool hash_enabled;
 };
 
 struct data_fabric_ops {
 	u64 (*get_hi_addr_offset)(struct addr_ctx *ctx);
+	int (*get_intlv_mode)(struct addr_ctx *ctx);
 };
 
 static u64 get_hi_addr_offset_df2(struct addr_ctx *ctx)
@@ -1099,8 +1109,26 @@ static u64 get_hi_addr_offset_df2(struct addr_ctx *ctx)
 	return (ctx->reg_dram_offset & GENMASK_ULL(31, 20)) << 8;
 }
 
+static int get_intlv_mode_df2(struct addr_ctx *ctx)
+{
+	ctx->intlv_mode = (ctx->reg_base_addr >> 4) & 0xF;
+
+	if (ctx->intlv_mode == 8) {
+		ctx->intlv_mode = DF2_HASH_2CH;
+		ctx->hash_enabled = true;
+	}
+
+	if (ctx->intlv_mode != NONE &&
+	    ctx->intlv_mode != NOHASH_2CH &&
+	    ctx->intlv_mode != DF2_HASH_2CH)
+		return -EINVAL;
+
+	return 0;
+}
+
 struct data_fabric_ops df2_ops = {
 	.get_hi_addr_offset		=	&get_hi_addr_offset_df2,
+	.get_intlv_mode			=	&get_intlv_mode_df2,
 };
 
 struct data_fabric_ops *df_ops;
@@ -1176,7 +1204,6 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 	u8 num_intlv_bits, hashed_bit;
 	u8 lgcy_mmio_hole_en;
 	u8 cs_mask, cs_id = 0;
-	bool hash_enabled = false;
 
 	struct addr_ctx ctx;
 
@@ -1197,6 +1224,9 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 	if (get_dram_addr_map(&ctx))
 		goto out_err;
 
+	if (df_ops->get_intlv_mode(&ctx))
+		goto out_err;
+
 	lgcy_mmio_hole_en = ctx.reg_base_addr & BIT(1);
 	intlv_num_chan	  = (ctx.reg_base_addr >> 4) & 0xF;
 	intlv_addr_sel	  = (ctx.reg_base_addr >> 8) & 0x7;
@@ -1224,7 +1254,6 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 	case 7:	intlv_num_chan = 4; break;
 
 	case 8: intlv_num_chan = 1;
-		hash_enabled = true;
 		break;
 	default:
 		pr_err("%s: Invalid number of interleaved channels %d.\n",
@@ -1325,7 +1354,7 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 			ctx.ret_addr += (BIT_ULL(32) - dram_hole_base);
 	}
 
-	if (hash_enabled) {
+	if (ctx.hash_enabled) {
 		/* Save some parentheses and grab ls-bit at the end. */
 		hashed_bit =	(ctx.ret_addr >> 12) ^
 				(ctx.ret_addr >> 18) ^
-- 
2.25.1