linux-kernel - [PATCH v4 1/4] RAS/AMD/ATL: Read DRAM hole base early

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Message-ID: <20240506154605.71814-2-john.allen@amd.com>
Date: Mon, 6 May 2024 15:46:02 +0000
From: John Allen <john.allen@....com>
To: <bp@...en8.de>, <linux-edac@...r.kernel.org>, <tony.luck@...el.com>,
	<yazen.ghannam@....com>
CC: <linux-kernel@...r.kernel.org>, <avadhut.naik@....com>,
	<muralidhara.mk@....com>, John Allen <john.allen@....com>
Subject: [PATCH v4 1/4] RAS/AMD/ATL: Read DRAM hole base early

Read DRAM hole base when constructing the address map as the value will
not change during run time.

Reviewed-by: Yazen Ghannam <yazen.ghannam@....com>
Signed-off-by: John Allen <john.allen@....com>
---
v2:
  - Fix compilation error. ctx->addr should read ctx->ret_addr.
  - Improve commit description.
v3:
  - Include "0x" prefix for dram_hole_base print
---
 drivers/ras/amd/atl/core.c     | 15 ++-------------
 drivers/ras/amd/atl/internal.h |  2 ++
 drivers/ras/amd/atl/system.c   | 21 +++++++++++++++++++++
 3 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/drivers/ras/amd/atl/core.c b/drivers/ras/amd/atl/core.c
index 6dc4e06305f7..63513d972c07 100644
--- a/drivers/ras/amd/atl/core.c
+++ b/drivers/ras/amd/atl/core.c
@@ -51,22 +51,11 @@ static bool legacy_hole_en(struct addr_ctx *ctx)
 
 static int add_legacy_hole(struct addr_ctx *ctx)
 {
-	u32 dram_hole_base;
-	u8 func = 0;
-
 	if (!legacy_hole_en(ctx))
 		return 0;
 
-	if (df_cfg.rev >= DF4)
-		func = 7;
-
-	if (df_indirect_read_broadcast(ctx->node_id, func, 0x104, &dram_hole_base))
-		return -EINVAL;
-
-	dram_hole_base &= DF_DRAM_HOLE_BASE_MASK;
-
-	if (ctx->ret_addr >= dram_hole_base)
-		ctx->ret_addr += (BIT_ULL(32) - dram_hole_base);
+	if (ctx->ret_addr >= df_cfg.dram_hole_base)
+		ctx->ret_addr += (BIT_ULL(32) - df_cfg.dram_hole_base);
 
 	return 0;
 }
diff --git a/drivers/ras/amd/atl/internal.h b/drivers/ras/amd/atl/internal.h
index 5de69e0bb0f9..1413c8ddc6c5 100644
--- a/drivers/ras/amd/atl/internal.h
+++ b/drivers/ras/amd/atl/internal.h
@@ -132,6 +132,8 @@ struct df_config {
 	/* Number of DRAM Address maps visible in a Coherent Station. */
 	u8 num_coh_st_maps;
 
+	u32 dram_hole_base;
+
 	/* Global flags to handle special cases. */
 	struct df_flags flags;
 };
diff --git a/drivers/ras/amd/atl/system.c b/drivers/ras/amd/atl/system.c
index 701349e84942..a4314f5073ab 100644
--- a/drivers/ras/amd/atl/system.c
+++ b/drivers/ras/amd/atl/system.c
@@ -223,6 +223,21 @@ static int determine_df_rev(void)
 	return -EINVAL;
 }
 
+static int get_dram_hole_base(void)
+{
+	u8 func = 0;
+
+	if (df_cfg.rev >= DF4)
+		func = 7;
+
+	if (df_indirect_read_broadcast(0, func, 0x104, &df_cfg.dram_hole_base))
+		return -EINVAL;
+
+	df_cfg.dram_hole_base &= DF_DRAM_HOLE_BASE_MASK;
+
+	return 0;
+}
+
 static void get_num_maps(void)
 {
 	switch (df_cfg.rev) {
@@ -266,6 +281,7 @@ static void dump_df_cfg(void)
 
 	pr_debug("num_coh_st_maps=%u",			df_cfg.num_coh_st_maps);
 
+	pr_debug("dram_hole_base=0x%x",			df_cfg.dram_hole_base);
 	pr_debug("flags.legacy_ficaa=%u",		df_cfg.flags.legacy_ficaa);
 	pr_debug("flags.socket_id_shift_quirk=%u",	df_cfg.flags.socket_id_shift_quirk);
 }
@@ -282,6 +298,11 @@ int get_df_system_info(void)
 
 	get_num_maps();
 
+	if (get_dram_hole_base()) {
+		pr_warn("amd_atl: Failed to read DRAM hole base");
+		return -EINVAL;
+	}
+
 	dump_df_cfg();
 
 	return 0;
-- 
2.34.1