linux-kernel - [PATCH 08/25] x86/MCE/AMD: Define function to dehash address

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Message-Id: <20210507190140.18854-9-Yazen.Ghannam@amd.com>
Date:   Fri,  7 May 2021 15:01:23 -0400
From:   Yazen Ghannam <Yazen.Ghannam@....com>
To:     linux-edac@...r.kernel.org
Cc:     Yazen Ghannam <Yazen.Ghannam@....com>,
        linux-kernel@...r.kernel.org, tony.luck@...el.com, x86@...nel.org,
        Smita.KoralahalliChannabasappa@....com
Subject: [PATCH 08/25] x86/MCE/AMD: Define function to dehash address

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

Move the dehashing code into a separate helper function. Define a
DF2-specific function for the current code. Specific helper functions
will be added for future DF versions.

Signed-off-by: Yazen Ghannam <yazen.ghannam@....com>
---
 arch/x86/kernel/cpu/mce/amd.c | 41 ++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index d1a6405bb990..e341737e03d4 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -961,12 +961,34 @@ static int add_base_and_hole(struct addr_ctx *ctx)
 	return 0;
 }
 
+static int dehash_addr_df2(struct addr_ctx *ctx)
+{
+	u8 hashed_bit =	(ctx->ret_addr >> 12) ^
+			(ctx->ret_addr >> 18) ^
+			(ctx->ret_addr >> 21) ^
+			(ctx->ret_addr >> 30) ^
+			ctx->cs_id;
+
+	hashed_bit &= BIT(0);
+
+	if (hashed_bit != ((ctx->ret_addr >> ctx->intlv_addr_bit) & BIT(0)))
+		ctx->ret_addr ^= BIT(ctx->intlv_addr_bit);
+
+	return 0;
+}
+
+static int dehash_addr(struct addr_ctx *ctx)
+{
+	if (!ctx->hash_enabled)
+		return 0;
+
+	return dehash_addr_df2(ctx);
+}
+
 int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr)
 {
 	u64 dram_limit_addr;
 
-	u8 hashed_bit;
-
 	struct addr_ctx ctx;
 
 	memset(&ctx, 0, sizeof(ctx));
@@ -996,19 +1018,8 @@ int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr)
 	if (add_base_and_hole(&ctx))
 		goto out_err;
 
-	if (ctx.hash_enabled) {
-		/* Save some parentheses and grab ls-bit at the end. */
-		hashed_bit =	(ctx.ret_addr >> 12) ^
-				(ctx.ret_addr >> 18) ^
-				(ctx.ret_addr >> 21) ^
-				(ctx.ret_addr >> 30) ^
-				ctx.cs_id;
-
-		hashed_bit &= BIT(0);
-
-		if (hashed_bit != ((ctx.ret_addr >> ctx.intlv_addr_bit) & BIT(0)))
-			ctx.ret_addr ^= BIT(ctx.intlv_addr_bit);
-	}
+	if (dehash_addr(&ctx))
+		goto out_err;
 
 	/* Is calculated system address is above DRAM limit address? */
 	if (ctx.ret_addr > dram_limit_addr)
-- 
2.25.1