[PATCH v3 03/33] EDAC/amd64: Allow for DF Indirect Broadcast reads

[Yazen Ghannam]

The DF Indirect Access method allows for "Broadcast" accesses in which
case no specific instance is targeted. Add support using a reserved
instance ID of 0xFF to indicate a broadcast access. Set the FICAA
register appropriately.

Define helpers functions for instance and broadcast reads and use them
where appropriate.

Drop the "amd_" prefix since these functions are all static.

Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
---
Link:
https://lkml.kernel.org/r/20210623192002.3671647-5-yazen.ghannam@xxxxxxx

v2->v3:
* Was patch 4 in v2.
* Define wrapper functions for instance/broadcast access.
* Drop "amd_" prefix.
* Dropped "df_regs" use.

v1->v2:
* New in v2.

 drivers/edac/amd64_edac.c | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 28c96fd06019..bad230745d60 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -998,8 +998,11 @@ static DEFINE_MUTEX(df_indirect_mutex);
  *
  * Fabric Indirect Configuration Access Data (FICAD): There are FICAD LO
  * and FICAD HI registers but so far we only need the LO register.
+ *
+ * Use Instance Id 0xFF to indicate a broadcast read.
  */
-static int amd_df_indirect_read(u16 node, u8 func, u16 reg, u8 instance_id, u32 *lo)
+#define DF_BROADCAST	0xFF
+static int __df_indirect_read(u16 node, u8 func, u16 reg, u8 instance_id, u32 *lo)
 {
 	struct pci_dev *F4;
 	u32 ficaa;
@@ -1012,7 +1015,7 @@ static int amd_df_indirect_read(u16 node, u8 func, u16 reg, u8 instance_id, u32
 	if (!F4)
 		goto out;
 
-	ficaa  = 1;
+	ficaa  = (instance_id == DF_BROADCAST) ? 0 : 1;
 	ficaa |= reg & 0x3FC;
 	ficaa |= (func & 0x7) << 11;
 	ficaa |= instance_id << 16;
@@ -1036,6 +1039,16 @@ static int amd_df_indirect_read(u16 node, u8 func, u16 reg, u8 instance_id, u32
 	return err;
 }
 
+static int df_indirect_read_instance(u16 node, u8 func, u16 reg, u8 instance_id, u32 *lo)
+{
+	return __df_indirect_read(node, func, reg, instance_id, lo);
+}
+
+static int df_indirect_read_broadcast(u16 node, u8 func, u16 reg, u32 *lo)
+{
+	return __df_indirect_read(node, func, reg, DF_BROADCAST, lo);
+}
+
 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;
@@ -1053,7 +1066,7 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 	bool hash_enabled = false;
 
 	/* Read D18F0x1B4 (DramOffset), check if base 1 is used. */
-	if (amd_df_indirect_read(nid, 0, 0x1B4, umc, &tmp))
+	if (df_indirect_read_instance(nid, 0, 0x1B4, umc, &tmp))
 		goto out_err;
 
 	/* Remove HiAddrOffset from normalized address, if enabled: */
@@ -1067,7 +1080,7 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 	}
 
 	/* Read D18F0x110 (DramBaseAddress). */
-	if (amd_df_indirect_read(nid, 0, 0x110 + (8 * base), umc, &tmp))
+	if (df_indirect_read_instance(nid, 0, 0x110 + (8 * base), umc, &tmp))
 		goto out_err;
 
 	/* Check if address range is valid. */
@@ -1090,7 +1103,7 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 	}
 
 	/* Read D18F0x114 (DramLimitAddress). */
-	if (amd_df_indirect_read(nid, 0, 0x114 + (8 * base), umc, &tmp))
+	if (df_indirect_read_instance(nid, 0, 0x114 + (8 * base), umc, &tmp))
 		goto out_err;
 
 	intlv_num_sockets = (tmp >> 8) & 0x1;
@@ -1146,7 +1159,7 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 		 * umc/channel# as instance id of the coherent slave
 		 * for FICAA.
 		 */
-		if (amd_df_indirect_read(nid, 0, 0x50, umc, &tmp))
+		if (df_indirect_read_instance(nid, 0, 0x50, umc, &tmp))
 			goto out_err;
 
 		cs_fabric_id = (tmp >> 8) & 0xFF;
@@ -1163,7 +1176,7 @@ static int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr
 
 		/* Read D18F1x208 (SystemFabricIdMask). */
 		if (intlv_num_dies || intlv_num_sockets)
-			if (amd_df_indirect_read(nid, 1, 0x208, umc, &tmp))
+			if (df_indirect_read_broadcast(nid, 1, 0x208, &tmp))
 				goto out_err;
 
 		/* If interleaved over more than 1 die. */
@@ -1202,7 +1215,7 @@ static 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, 0x104, umc, &tmp))
+		if (df_indirect_read_broadcast(nid, 0, 0x104, &tmp))
 			goto out_err;
 
 		dram_hole_base = tmp & GENMASK(31, 24);
-- 
2.25.1