[PATCH v2 05/31] EDAC/amd64: Add context struct

[Yazen Ghannam]

Define an address translation context struct. This will hold values that
will be passed between multiple functions.

Save return address, Node ID, and the Instance ID number to start.
Currently, we use the UMC number as the Instance ID, but future DF
versions may use another value.

Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
---
Link:
https://lkml.kernel.org/r/20210507190140.18854-3-Yazen.Ghannam@xxxxxxx

v1->v2:
* Moved from arch/x86 to EDAC.
* Changed "umc" variable to "inst_id".
* Drop df_types enum.

 drivers/edac/amd64_edac.c | 49 +++++++++++++++++++++++++--------------
 1 file changed, 31 insertions(+), 18 deletions(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index d67cd8f57b94..62eca188458f 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -1079,12 +1079,15 @@ static struct df_reg df_regs[] = {
 	[SYS_FAB_ID_MASK]	=	{1, 0x208},
 };
 
+struct addr_ctx {
+	u64 ret_addr;
+	u16 nid;
+	u8 inst_id;
+};
+
 static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr)
 {
 	u64 dram_base_addr, dram_limit_addr, dram_hole_base;
-	/* We start from the normalized address */
-	u64 ret_addr = norm_addr;
-
 	u32 tmp;
 
 	u8 die_id_shift, die_id_mask, socket_id_shift, socket_id_mask;
@@ -1097,6 +1100,16 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 
 	struct df_reg reg;
 
+	struct addr_ctx ctx;
+
+	memset(&ctx, 0, sizeof(ctx));
+
+	/* We start from the normalized address */
+	ctx.ret_addr = norm_addr;
+
+	ctx.nid = nid;
+	ctx.inst_id = umc;
+
 	if (amd_df_indirect_read(nid, df_regs[DRAM_OFFSET], umc, &tmp))
 		goto out_err;
 
@@ -1105,7 +1118,7 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 		u64 hi_addr_offset = (tmp & GENMASK_ULL(31, 20)) << 8;
 
 		if (norm_addr >= hi_addr_offset) {
-			ret_addr -= hi_addr_offset;
+			ctx.ret_addr -= hi_addr_offset;
 			base = 1;
 		}
 	}
@@ -1236,14 +1249,14 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 		 * bits there are. "intlv_addr_bit" tells us how many "Y" bits
 		 * there are (where "I" starts).
 		 */
-		temp_addr_y = ret_addr & GENMASK_ULL(intlv_addr_bit-1, 0);
+		temp_addr_y = ctx.ret_addr & GENMASK_ULL(intlv_addr_bit - 1, 0);
 		temp_addr_i = (cs_id << intlv_addr_bit);
-		temp_addr_x = (ret_addr & GENMASK_ULL(63, intlv_addr_bit)) << num_intlv_bits;
-		ret_addr    = temp_addr_x | temp_addr_i | temp_addr_y;
+		temp_addr_x = (ctx.ret_addr & GENMASK_ULL(63, intlv_addr_bit)) << num_intlv_bits;
+		ctx.ret_addr    = temp_addr_x | temp_addr_i | temp_addr_y;
 	}
 
 	/* Add dram base address */
-	ret_addr += dram_base_addr;
+	ctx.ret_addr += dram_base_addr;
 
 	/* If legacy MMIO hole enabled */
 	if (lgcy_mmio_hole_en) {
@@ -1251,29 +1264,29 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 			goto out_err;
 
 		dram_hole_base = tmp & GENMASK(31, 24);
-		if (ret_addr >= dram_hole_base)
-			ret_addr += (BIT_ULL(32) - dram_hole_base);
+		if (ctx.ret_addr >= dram_hole_base)
+			ctx.ret_addr += (BIT_ULL(32) - dram_hole_base);
 	}
 
 	if (hash_enabled) {
 		/* Save some parentheses and grab ls-bit at the end. */
-		hashed_bit =	(ret_addr >> 12) ^
-				(ret_addr >> 18) ^
-				(ret_addr >> 21) ^
-				(ret_addr >> 30) ^
+		hashed_bit =	(ctx.ret_addr >> 12) ^
+				(ctx.ret_addr >> 18) ^
+				(ctx.ret_addr >> 21) ^
+				(ctx.ret_addr >> 30) ^
 				cs_id;
 
 		hashed_bit &= BIT(0);
 
-		if (hashed_bit != ((ret_addr >> intlv_addr_bit) & BIT(0)))
-			ret_addr ^= BIT(intlv_addr_bit);
+		if (hashed_bit != ((ctx.ret_addr >> intlv_addr_bit) & BIT(0)))
+			ctx.ret_addr ^= BIT(intlv_addr_bit);
 	}
 
 	/* Is calculated system address is above DRAM limit address? */
-	if (ret_addr > dram_limit_addr)
+	if (ctx.ret_addr > dram_limit_addr)
 		goto out_err;
 
-	*sys_addr = ret_addr;
+	*sys_addr = ctx.ret_addr;
 	return 0;
 
 out_err:
-- 
2.25.1