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From:   Diana Craciun <diana.craciun@oss.nxp.com>
To:     linux-kernel@vger.kernel.org, laurentiu.tudor@nxp.com
Cc:     stuyoder@gmail.com, leoyang.li@nxp.com, gregkh@linuxfoundation.org,
        linux-arm-kernel@lists.infradead.org, bharatb.linux@gmail.com,
        Diana Craciun <diana.craciun@oss.nxp.com>
Subject: [PATCH v4 13/13] bus/fsl-mc: Add a new version for dprc_get_obj_region command
Date:   Wed, 26 Aug 2020 12:25:27 +0300
Message-Id: <20200826092527.4992-14-diana.craciun@oss.nxp.com>
In-Reply-To: <20200826092527.4992-1-diana.craciun@oss.nxp.com>
References: <20200826092527.4992-1-diana.craciun@oss.nxp.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The region size reported by the firmware for mc and software
portals was less than allocated by the hardware. This may be
problematic when mmapping the region in user space because the
region size is less than page size. However the size as reserved
by the hardware is 64K.

Signed-off-by: Diana Craciun <diana.craciun@oss.nxp.com>
---
 drivers/bus/fsl-mc/dprc.c           | 38 ++++++++++++++++++-----------
 drivers/bus/fsl-mc/fsl-mc-private.h |  3 +++
 2 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/drivers/bus/fsl-mc/dprc.c b/drivers/bus/fsl-mc/dprc.c
index 650808799a29..57b097caf255 100644
--- a/drivers/bus/fsl-mc/dprc.c
+++ b/drivers/bus/fsl-mc/dprc.c
@@ -536,20 +536,30 @@ int dprc_get_obj_region(struct fsl_mc_io *mc_io,
 			return err;
 	}
 
-	/**
-	 * MC API version 6.3 introduced a new field to the region
-	 * descriptor: base_address. If the older API is in use then the base
-	 * address is set to zero to indicate it needs to be obtained elsewhere
-	 * (typically the device tree).
-	 */
-	if (dprc_major_ver > 6 || (dprc_major_ver == 6 && dprc_minor_ver >= 3))
-		cmd.header =
-			mc_encode_cmd_header(DPRC_CMDID_GET_OBJ_REG_V2,
-					     cmd_flags, token);
-	else
-		cmd.header =
-			mc_encode_cmd_header(DPRC_CMDID_GET_OBJ_REG,
-					     cmd_flags, token);
+	if (dprc_major_ver > 6 || (dprc_major_ver == 6 && dprc_minor_ver >= 6)) {
+		/*
+		 * MC API version 6.6 changed the size of the MC portals and software
+		 * portals to 64K (as implemented by hardware). If older API is in use the
+		 * size reported is less (64 bytes for mc portals and 4K for software
+		 * portals).
+		 */
+
+		cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_OBJ_REG_V3,
+						  cmd_flags, token);
+
+	} else if (dprc_major_ver == 6 && dprc_minor_ver >= 3) {
+		/*
+		 * MC API version 6.3 introduced a new field to the region
+		 * descriptor: base_address. If the older API is in use then the base
+		 * address is set to zero to indicate it needs to be obtained elsewhere
+		 * (typically the device tree).
+		 */
+		cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_OBJ_REG_V2,
+						  cmd_flags, token);
+	} else {
+		cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_OBJ_REG,
+						  cmd_flags, token);
+	}
 
 	cmd_params = (struct dprc_cmd_get_obj_region *)cmd.params;
 	cmd_params->obj_id = cpu_to_le32(obj_id);
diff --git a/drivers/bus/fsl-mc/fsl-mc-private.h b/drivers/bus/fsl-mc/fsl-mc-private.h
index 3e9f9c778631..85ca5fdee581 100644
--- a/drivers/bus/fsl-mc/fsl-mc-private.h
+++ b/drivers/bus/fsl-mc/fsl-mc-private.h
@@ -80,10 +80,12 @@ int dpmcp_reset(struct fsl_mc_io *mc_io,
 /* DPRC command versioning */
 #define DPRC_CMD_BASE_VERSION			1
 #define DPRC_CMD_2ND_VERSION			2
+#define DPRC_CMD_3RD_VERSION			3
 #define DPRC_CMD_ID_OFFSET			4
 
 #define DPRC_CMD(id)	(((id) << DPRC_CMD_ID_OFFSET) | DPRC_CMD_BASE_VERSION)
 #define DPRC_CMD_V2(id)	(((id) << DPRC_CMD_ID_OFFSET) | DPRC_CMD_2ND_VERSION)
+#define DPRC_CMD_V3(id)	(((id) << DPRC_CMD_ID_OFFSET) | DPRC_CMD_3RD_VERSION)
 
 /* DPRC command IDs */
 #define DPRC_CMDID_CLOSE                        DPRC_CMD(0x800)
@@ -105,6 +107,7 @@ int dpmcp_reset(struct fsl_mc_io *mc_io,
 #define DPRC_CMDID_GET_OBJ                      DPRC_CMD(0x15A)
 #define DPRC_CMDID_GET_OBJ_REG                  DPRC_CMD(0x15E)
 #define DPRC_CMDID_GET_OBJ_REG_V2               DPRC_CMD_V2(0x15E)
+#define DPRC_CMDID_GET_OBJ_REG_V3               DPRC_CMD_V3(0x15E)
 #define DPRC_CMDID_SET_OBJ_IRQ                  DPRC_CMD(0x15F)
 
 #define DPRC_CMDID_GET_CONNECTION               DPRC_CMD(0x16C)
-- 
2.17.1