[PATCH v2 6/8] x86/MCE/AMD: Drop tmp variable in translation code

[Yazen Ghannam <Yazen.Ghannam@amd.com>]

From: Yazen Ghannam <yazen.ghannam@amd.com>

Remove the "tmp" variable used to save register values. Save the values
in existing variables, if possible.

The register values are 32 bits. Use separate "reg_" variables to hold
the register values if the existing variable sizes doesn't match, or if
no bitfields in a register share the same name as the register.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
---
Link:
https://lkml.kernel.org/r/20200814191449.183998-3-Yazen.Ghannam@amd.com

v1 -> v2:
* New patch based on comments for v1 Patch 2.

 arch/x86/kernel/cpu/mce/amd.c | 56 +++++++++++++++++++----------------
 1 file changed, 30 insertions(+), 26 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 90c3ad61ae19..5a18937ff7cd 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -688,11 +688,14 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
 
 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;
+	u64 dram_base_addr, dram_limit_addr;
+	u32 dram_hole_base;
+
+	u32 reg_dram_base_addr, reg_dram_limit_addr;
+	u32 reg_dram_offset;
 
 	u8 die_id_shift, die_id_mask, socket_id_shift, socket_id_mask;
 	u8 intlv_num_dies, intlv_num_chan, intlv_num_sockets;
@@ -702,12 +705,12 @@ int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr)
 	u8 cs_mask, cs_id = 0;
 	bool hash_enabled = false;
 
-	if (amd_df_indirect_read(nid, 0, DF_F0_DRAMOFFSET, umc, &tmp))
+	if (amd_df_indirect_read(nid, 0, DF_F0_DRAMOFFSET, umc, &reg_dram_offset))
 		goto out_err;
 
 	/* Remove HiAddrOffset from normalized address, if enabled: */
-	if (tmp & BIT(0)) {
-		u64 hi_addr_offset = get_bits(tmp, 31, 20) << 28;
+	if (reg_dram_offset & BIT(0)) {
+		u64 hi_addr_offset = get_bits(reg_dram_offset, 31, 20) << 28;
 
 		/* Check if base 1 is used. */
 		if (norm_addr >= hi_addr_offset) {
@@ -716,20 +719,20 @@ int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr)
 		}
 	}
 
-	if (amd_df_indirect_read(nid, 0, DF_F0_DRAMBASEADDR + (8 * base), umc, &tmp))
+	if (amd_df_indirect_read(nid, 0, DF_F0_DRAMBASEADDR + (8 * base), umc, &reg_dram_base_addr))
 		goto out_err;
 
 	/* Check if address range is valid. */
-	if (!(tmp & BIT(0))) {
+	if (!(reg_dram_base_addr & BIT(0))) {
 		pr_err("%s: Invalid DramBaseAddress range: 0x%x.\n",
-			__func__, tmp);
+			__func__, reg_dram_base_addr);
 		goto out_err;
 	}
 
-	lgcy_mmio_hole_en = get_bit(tmp, 1);
-	intlv_num_chan	  = get_bits(tmp, 7, 4);
-	intlv_addr_sel	  = get_bits(tmp, 10, 8);
-	dram_base_addr	  = get_bits(tmp, 31, 12) << 28;
+	lgcy_mmio_hole_en = get_bit(reg_dram_base_addr, 1);
+	intlv_num_chan	  = get_bits(reg_dram_base_addr, 7, 4);
+	intlv_addr_sel	  = get_bits(reg_dram_base_addr, 10, 8);
+	dram_base_addr	  = get_bits(reg_dram_base_addr, 31, 12) << 28;
 
 	/* {0, 1, 2, 3} map to address bits {8, 9, 10, 11} respectively */
 	if (intlv_addr_sel > 3) {
@@ -738,12 +741,12 @@ int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr)
 		goto out_err;
 	}
 
-	if (amd_df_indirect_read(nid, 0, DF_F0_DRAMLIMITADDR + (8 * base), umc, &tmp))
+	if (amd_df_indirect_read(nid, 0, DF_F0_DRAMLIMITADDR + (8 * base), umc, &reg_dram_limit_addr))
 		goto out_err;
 
-	intlv_num_sockets = get_bit(tmp, 8);
-	intlv_num_dies	  = get_bits(tmp, 11, 10);
-	dram_limit_addr	  = (get_bits(tmp, 31, 12) << 28) | GENMASK_ULL(27, 0);
+	intlv_num_sockets = get_bit(reg_dram_limit_addr, 8);
+	intlv_num_dies	  = get_bits(reg_dram_limit_addr, 11, 10);
+	dram_limit_addr	  = (get_bits(reg_dram_limit_addr, 31, 12) << 28) | GENMASK_ULL(27, 0);
 
 	intlv_addr_bit = intlv_addr_sel + 8;
 
@@ -786,17 +789,18 @@ int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr)
 
 	if (num_intlv_bits > 0) {
 		u64 temp_addr_x, temp_addr_i, temp_addr_y;
-		u8 die_id_bit, sock_id_bit, cs_fabric_id;
+		u32 reg_sys_fabric_id, cs_fabric_id;
+		u8 die_id_bit, sock_id_bit;
 
 		/*
 		 * 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(nid, 0, DF_F0_FABRICINSTINFO3, umc, &tmp))
+		if (amd_df_indirect_read(nid, 0, DF_F0_FABRICINSTINFO3, umc, &cs_fabric_id))
 			goto out_err;
 
-		cs_fabric_id = get_bits(tmp, 15, 8);
+		cs_fabric_id = get_bits(cs_fabric_id, 15, 8);
 		die_id_bit   = 0;
 
 		/* If interleaved over more than 1 channel: */
@@ -809,22 +813,22 @@ int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr)
 		sock_id_bit = die_id_bit;
 
 		if (intlv_num_dies || intlv_num_sockets)
-			if (amd_df_indirect_read(nid, 1, DF_F1_SYSFABRICID, umc, &tmp))
+			if (amd_df_indirect_read(nid, 1, DF_F1_SYSFABRICID, umc, &reg_sys_fabric_id))
 				goto out_err;
 
 		/* If interleaved over more than 1 die. */
 		if (intlv_num_dies) {
 			sock_id_bit  = die_id_bit + intlv_num_dies;
-			die_id_shift = get_bits(tmp, 27, 24);
-			die_id_mask  = get_bits(tmp, 15, 8);
+			die_id_shift = get_bits(reg_sys_fabric_id, 27, 24);
+			die_id_mask  = get_bits(reg_sys_fabric_id, 15, 8);
 
 			cs_id |= ((cs_fabric_id & die_id_mask) >> die_id_shift) << die_id_bit;
 		}
 
 		/* If interleaved over more than 1 socket. */
 		if (intlv_num_sockets) {
-			socket_id_shift	= get_bits(tmp, 31, 28);
-			socket_id_mask	= get_bits(tmp, 23, 16);
+			socket_id_shift	= get_bits(reg_sys_fabric_id, 31, 28);
+			socket_id_mask	= get_bits(reg_sys_fabric_id, 23, 16);
 
 			cs_id |= ((cs_fabric_id & socket_id_mask) >> socket_id_shift) << sock_id_bit;
 		}
@@ -848,10 +852,10 @@ int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr)
 
 	/* If legacy MMIO hole enabled */
 	if (lgcy_mmio_hole_en) {
-		if (amd_df_indirect_read(nid, 0, DF_F0_MMIOHOLE, umc, &tmp))
+		if (amd_df_indirect_read(nid, 0, DF_F0_MMIOHOLE, umc, &dram_hole_base))
 			goto out_err;
 
-		dram_hole_base = tmp & GENMASK(31, 24);
+		dram_hole_base &= GENMASK(31, 24);
 		if (ret_addr >= dram_hole_base)
 			ret_addr += (BIT_ULL(32) - dram_hole_base);
 	}
-- 
2.25.1