[PATCH v3 06/13] bus/fsl-mc: Add dprc-reset-container support

From: Diana Craciun
Date: Mon Jul 06 2020 - 08:43:15 EST


From: Bharat Bhushan <Bharat.Bhushan@xxxxxxx>

DPRC reset is required by VFIO-mc in order to stop a device
to further generate DMA transactions.

Signed-off-by: Bharat Bhushan <Bharat.Bhushan@xxxxxxx>
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>
Signed-off-by: Diana Craciun <diana.craciun@xxxxxxxxxxx>
---
drivers/bus/fsl-mc/dprc.c | 71 +++++++++++++++++++++++++++++
drivers/bus/fsl-mc/fsl-mc-private.h | 7 +++
include/linux/fsl/mc.h | 7 +++
3 files changed, 85 insertions(+)

diff --git a/drivers/bus/fsl-mc/dprc.c b/drivers/bus/fsl-mc/dprc.c
index 01bf41743efc..44bde72bdea7 100644
--- a/drivers/bus/fsl-mc/dprc.c
+++ b/drivers/bus/fsl-mc/dprc.c
@@ -80,6 +80,77 @@ int dprc_close(struct fsl_mc_io *mc_io,
}
EXPORT_SYMBOL_GPL(dprc_close);

+/**
+ * dprc_reset_container - Reset child container.
+ * @mc_io: Pointer to MC portal's I/O object
+ * @cmd_flags: Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token: Token of DPRC object
+ * @child_container_id: ID of the container to reset
+ * @options: 32 bit options:
+ * - 0 (no bits set) - all the objects inside the container are
+ * reset. The child containers are entered recursively and the
+ * objects reset. All the objects (including the child containers)
+ * are closed.
+ * - bit 0 set - all the objects inside the container are reset.
+ * However the child containers are not entered recursively.
+ * This option is supported for API versions >= 6.5
+ * In case a software context crashes or becomes non-responsive, the parent
+ * may wish to reset its resources container before the software context is
+ * restarted.
+ *
+ * This routine informs all objects assigned to the child container that the
+ * container is being reset, so they may perform any cleanup operations that are
+ * needed. All objects handles that were owned by the child container shall be
+ * closed.
+ *
+ * Note that such request may be submitted even if the child software context
+ * has not crashed, but the resulting object cleanup operations will not be
+ * aware of that.
+ *
+ * Return: '0' on Success; Error code otherwise.
+ */
+int dprc_reset_container(struct fsl_mc_io *mc_io,
+ u32 cmd_flags,
+ u16 token,
+ int child_container_id,
+ u32 options)
+{
+ struct fsl_mc_command cmd = { 0 };
+ struct dprc_cmd_reset_container *cmd_params;
+ u32 cmdid = DPRC_CMDID_RESET_CONT;
+ int err;
+
+ /**
+ * If the DPRC object version was not yet cached, cache it now.
+ * Otherwise use the already cached value.
+ */
+ if (!dprc_major_ver && !dprc_minor_ver) {
+ err = dprc_get_api_version(mc_io, 0,
+ &dprc_major_ver,
+ &dprc_minor_ver);
+ if (err)
+ return err;
+ }
+
+ /**
+ * MC API 6.5 introduced a new field in the command used to pass
+ * some flags.
+ * Bit 0 indicates that the child containers are not recursively reset.
+ */
+ if (dprc_major_ver > 6 || (dprc_major_ver == 6 && dprc_minor_ver >= 5))
+ cmdid = DPRC_CMDID_RESET_CONT_V2;
+
+ /* prepare command */
+ cmd.header = mc_encode_cmd_header(cmdid, cmd_flags, token);
+ cmd_params = (struct dprc_cmd_reset_container *)cmd.params;
+ cmd_params->child_container_id = cpu_to_le32(child_container_id);
+ cmd_params->options = cpu_to_le32(options);
+
+ /* send command to mc*/
+ return mc_send_command(mc_io, &cmd);
+}
+EXPORT_SYMBOL_GPL(dprc_reset_container);
+
/**
* dprc_set_irq() - Set IRQ information for the DPRC to trigger an interrupt.
* @mc_io: Pointer to MC portal's I/O object
diff --git a/drivers/bus/fsl-mc/fsl-mc-private.h b/drivers/bus/fsl-mc/fsl-mc-private.h
index c2a688c07ee2..fdd9e9aa6701 100644
--- a/drivers/bus/fsl-mc/fsl-mc-private.h
+++ b/drivers/bus/fsl-mc/fsl-mc-private.h
@@ -91,6 +91,8 @@ int dpmcp_reset(struct fsl_mc_io *mc_io,
#define DPRC_CMDID_GET_API_VERSION DPRC_CMD(0xa05)

#define DPRC_CMDID_GET_ATTR DPRC_CMD(0x004)
+#define DPRC_CMDID_RESET_CONT DPRC_CMD(0x005)
+#define DPRC_CMDID_RESET_CONT_V2 DPRC_CMD_V2(0x005)

#define DPRC_CMDID_SET_IRQ DPRC_CMD(0x010)
#define DPRC_CMDID_SET_IRQ_ENABLE DPRC_CMD(0x012)
@@ -111,6 +113,11 @@ struct dprc_cmd_open {
__le32 container_id;
};

+struct dprc_cmd_reset_container {
+ __le32 child_container_id;
+ __le32 options;
+};
+
struct dprc_cmd_set_irq {
/* cmd word 0 */
__le32 irq_val;
diff --git a/include/linux/fsl/mc.h b/include/linux/fsl/mc.h
index 651ffeff8c13..6339f33c7390 100644
--- a/include/linux/fsl/mc.h
+++ b/include/linux/fsl/mc.h
@@ -494,6 +494,13 @@ static inline bool is_fsl_mc_bus_dpseci(const struct fsl_mc_device *mc_dev)
return mc_dev->dev.type == &fsl_mc_bus_dpseci_type;
}

+#define DPRC_RESET_OPTION_NON_RECURSIVE 0x00000001
+int dprc_reset_container(struct fsl_mc_io *mc_io,
+ u32 cmd_flags,
+ u16 token,
+ int child_container_id,
+ u32 options);
+
/*
* Data Path Buffer Pool (DPBP) API
* Contains initialization APIs and runtime control APIs for DPBP
--
2.17.1