[PATCH 01/26] cxl/mbox: Flag support for Dynamic Capacity Devices (DCD)

[ira . weiny]

From: Navneet Singh <navneet.singh@xxxxxxxxx>

Per the CXL 3.1 specification software must check the Command Effects
Log (CEL) to know if a device supports dynamic capacity (DC).  If the
device does support DC the specifics of the DC Regions (0-7) are read
through the mailbox.

Flag DC Device (DCD) commands in a device if they are supported.
Subsequent patches will key off these bits to configure DCD.

Signed-off-by: Navneet Singh <navneet.singh@xxxxxxxxx>
Co-developed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
---
Changes for v1
[iweiny: update to latest master]
[iweiny: update commit message]
[iweiny: Based on the fix:
	https://lore.kernel.org/all/20230903-cxl-cel-fix-v1-1-e260c9467be3@xxxxxxxxx/
[jonathan: remove unneeded format change]
[jonathan: don't split security code in mbox.c]
---
 drivers/cxl/core/mbox.c | 33 +++++++++++++++++++++++++++++++++
 drivers/cxl/cxlmem.h    | 15 +++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 9adda4795eb7..ed4131c6f50b 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -161,6 +161,34 @@ static void cxl_set_security_cmd_enabled(struct cxl_security_state *security,
 	}
 }
 
+static bool cxl_is_dcd_command(u16 opcode)
+{
+#define CXL_MBOX_OP_DCD_CMDS 0x48
+
+	return (opcode >> 8) == CXL_MBOX_OP_DCD_CMDS;
+}
+
+static void cxl_set_dcd_cmd_enabled(struct cxl_memdev_state *mds,
+					u16 opcode)
+{
+	switch (opcode) {
+	case CXL_MBOX_OP_GET_DC_CONFIG:
+		set_bit(CXL_DCD_ENABLED_GET_CONFIG, mds->dcd_cmds);
+		break;
+	case CXL_MBOX_OP_GET_DC_EXTENT_LIST:
+		set_bit(CXL_DCD_ENABLED_GET_EXTENT_LIST, mds->dcd_cmds);
+		break;
+	case CXL_MBOX_OP_ADD_DC_RESPONSE:
+		set_bit(CXL_DCD_ENABLED_ADD_RESPONSE, mds->dcd_cmds);
+		break;
+	case CXL_MBOX_OP_RELEASE_DC:
+		set_bit(CXL_DCD_ENABLED_RELEASE, mds->dcd_cmds);
+		break;
+	default:
+		break;
+	}
+}
+
 static bool cxl_is_poison_command(u16 opcode)
 {
 #define CXL_MBOX_OP_POISON_CMDS 0x43
@@ -733,6 +761,11 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
 			enabled++;
 		}
 
+		if (cxl_is_dcd_command(opcode)) {
+			cxl_set_dcd_cmd_enabled(mds, opcode);
+			enabled++;
+		}
+
 		dev_dbg(dev, "Opcode 0x%04x %s\n", opcode,
 			enabled ? "enabled" : "unsupported by driver");
 	}
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 20fb3b35e89e..79a67cff9143 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -238,6 +238,15 @@ struct cxl_event_state {
 	struct mutex log_lock;
 };
 
+/* Device enabled DCD commands */
+enum dcd_cmd_enabled_bits {
+	CXL_DCD_ENABLED_GET_CONFIG,
+	CXL_DCD_ENABLED_GET_EXTENT_LIST,
+	CXL_DCD_ENABLED_ADD_RESPONSE,
+	CXL_DCD_ENABLED_RELEASE,
+	CXL_DCD_ENABLED_MAX
+};
+
 /* Device enabled poison commands */
 enum poison_cmd_enabled_bits {
 	CXL_POISON_ENABLED_LIST,
@@ -454,6 +463,7 @@ struct cxl_dev_state {
  *                (CXL 2.0 8.2.9.5.1.1 Identify Memory Device)
  * @mbox_mutex: Mutex to synchronize mailbox access.
  * @firmware_version: Firmware version for the memory device.
+ * @dcd_cmds: List of DCD commands implemented by memory device
  * @enabled_cmds: Hardware commands found enabled in CEL.
  * @exclusive_cmds: Commands that are kernel-internal only
  * @total_bytes: sum of all possible capacities
@@ -481,6 +491,7 @@ struct cxl_memdev_state {
 	size_t lsa_size;
 	struct mutex mbox_mutex; /* Protects device mailbox and firmware */
 	char firmware_version[0x10];
+	DECLARE_BITMAP(dcd_cmds, CXL_DCD_ENABLED_MAX);
 	DECLARE_BITMAP(enabled_cmds, CXL_MEM_COMMAND_ID_MAX);
 	DECLARE_BITMAP(exclusive_cmds, CXL_MEM_COMMAND_ID_MAX);
 	u64 total_bytes;
@@ -551,6 +562,10 @@ enum cxl_opcode {
 	CXL_MBOX_OP_UNLOCK		= 0x4503,
 	CXL_MBOX_OP_FREEZE_SECURITY	= 0x4504,
 	CXL_MBOX_OP_PASSPHRASE_SECURE_ERASE	= 0x4505,
+	CXL_MBOX_OP_GET_DC_CONFIG	= 0x4800,
+	CXL_MBOX_OP_GET_DC_EXTENT_LIST	= 0x4801,
+	CXL_MBOX_OP_ADD_DC_RESPONSE	= 0x4802,
+	CXL_MBOX_OP_RELEASE_DC		= 0x4803,
 	CXL_MBOX_OP_MAX			= 0x10000
 };
 

-- 
2.44.0