From 04dd17822334871b23ea2862f7798fb0e0007777 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Sat, 11 May 2024 08:53:19 +0000
Subject: [PATCH] change otg to host mode

---
 kernel/include/linux/ntb.h |  216 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 207 insertions(+), 9 deletions(-)

diff --git a/kernel/include/linux/ntb.h b/kernel/include/linux/ntb.h
index 181d166..191b524 100644
--- a/kernel/include/linux/ntb.h
+++ b/kernel/include/linux/ntb.h
@@ -58,9 +58,11 @@
 
 #include <linux/completion.h>
 #include <linux/device.h>
+#include <linux/interrupt.h>
 
 struct ntb_client;
 struct ntb_dev;
+struct ntb_msi;
 struct pci_dev;
 
 /**
@@ -205,7 +207,7 @@
 }
 
 /**
- * struct ntb_ctx_ops - ntb device operations
+ * struct ntb_dev_ops - ntb device operations
  * @port_number:	See ntb_port_number().
  * @peer_port_count:	See ntb_peer_port_count().
  * @peer_port_number:	See ntb_peer_port_number().
@@ -296,7 +298,8 @@
 	int (*db_clear_mask)(struct ntb_dev *ntb, u64 db_bits);
 
 	int (*peer_db_addr)(struct ntb_dev *ntb,
-			    phys_addr_t *db_addr, resource_size_t *db_size);
+			    phys_addr_t *db_addr, resource_size_t *db_size,
+				u64 *db_data, int db_bit);
 	u64 (*peer_db_read)(struct ntb_dev *ntb);
 	int (*peer_db_set)(struct ntb_dev *ntb, u64 db_bits);
 	int (*peer_db_clear)(struct ntb_dev *ntb, u64 db_bits);
@@ -403,7 +406,7 @@
 #define drv_ntb_client(__drv) container_of((__drv), struct ntb_client, drv)
 
 /**
- * struct ntb_device - ntb device
+ * struct ntb_dev - ntb device
  * @dev:		Linux device object.
  * @pdev:		PCI device entry of the ntb.
  * @topo:		Detected topology of the ntb.
@@ -425,6 +428,10 @@
 	spinlock_t			ctx_lock;
 	/* block unregister until device is fully released */
 	struct completion		released;
+
+#ifdef CONFIG_NTB_MSI
+	struct ntb_msi *msi;
+#endif
 };
 #define dev_ntb(__dev) container_of((__dev), struct ntb_dev, dev)
 
@@ -471,7 +478,7 @@
 int ntb_register_device(struct ntb_dev *ntb);
 
 /**
- * ntb_register_device() - unregister a ntb device
+ * ntb_unregister_device() - unregister a ntb device
  * @ntb:	NTB device context.
  *
  * The device will be removed from the list of ntb devices.  If the ntb device
@@ -615,7 +622,6 @@
 
 	return ntb->ops->port_number(ntb);
 }
-
 /**
  * ntb_peer_port_count() - get the number of peer device ports
  * @ntb:	NTB device context.
@@ -650,6 +656,58 @@
 		return ntb_default_peer_port_number(ntb, pidx);
 
 	return ntb->ops->peer_port_number(ntb, pidx);
+}
+
+/**
+ * ntb_logical_port_number() - get the logical port number of the local port
+ * @ntb:	NTB device context.
+ *
+ * The Logical Port Number is defined to be a unique number for each
+ * port starting from zero through to the number of ports minus one.
+ * This is in contrast to the Port Number where each port can be assigned
+ * any unique physical number by the hardware.
+ *
+ * The logical port number is useful for calculating the resource indexes
+ * used by peers.
+ *
+ * Return: the logical port number or negative value indicating an error
+ */
+static inline int ntb_logical_port_number(struct ntb_dev *ntb)
+{
+	int lport = ntb_port_number(ntb);
+	int pidx;
+
+	if (lport < 0)
+		return lport;
+
+	for (pidx = 0; pidx < ntb_peer_port_count(ntb); pidx++)
+		if (lport <= ntb_peer_port_number(ntb, pidx))
+			return pidx;
+
+	return pidx;
+}
+
+/**
+ * ntb_peer_logical_port_number() - get the logical peer port by given index
+ * @ntb:	NTB device context.
+ * @pidx:	Peer port index.
+ *
+ * The Logical Port Number is defined to be a unique number for each
+ * port starting from zero through to the number of ports minus one.
+ * This is in contrast to the Port Number where each port can be assigned
+ * any unique physical number by the hardware.
+ *
+ * The logical port number is useful for calculating the resource indexes
+ * used by peers.
+ *
+ * Return: the peer's logical port number or negative value indicating an error
+ */
+static inline int ntb_peer_logical_port_number(struct ntb_dev *ntb, int pidx)
+{
+	if (ntb_peer_port_number(ntb, pidx) < ntb_port_number(ntb))
+		return pidx;
+	else
+		return pidx + 1;
 }
 
 /**
@@ -1078,6 +1136,8 @@
  * @ntb:	NTB device context.
  * @db_addr:	OUT - The address of the peer doorbell register.
  * @db_size:	OUT - The number of bytes to write the peer doorbell register.
+ * @db_data:	OUT - The data of peer doorbell register
+ * @db_bit:		door bell bit number
  *
  * Return the address of the peer doorbell register.  This may be used, for
  * example, by drivers that offload memory copy operations to a dma engine.
@@ -1091,12 +1151,13 @@
  */
 static inline int ntb_peer_db_addr(struct ntb_dev *ntb,
 				   phys_addr_t *db_addr,
-				   resource_size_t *db_size)
+				   resource_size_t *db_size,
+				   u64 *db_data, int db_bit)
 {
 	if (!ntb->ops->peer_db_addr)
 		return -EINVAL;
 
-	return ntb->ops->peer_db_addr(ntb, db_addr, db_size);
+	return ntb->ops->peer_db_addr(ntb, db_addr, db_size, db_data, db_bit);
 }
 
 /**
@@ -1290,7 +1351,7 @@
  * @sidx:	Scratchpad index.
  * @spad_addr:	OUT - The address of the peer scratchpad register.
  *
- * Return the address of the peer doorbell register.  This may be used, for
+ * Return the address of the peer scratchpad register.  This may be used, for
  * example, by drivers that offload memory copy operations to a dma engine.
  *
  * Return: Zero on success, otherwise an error number.
@@ -1312,7 +1373,7 @@
  *
  * Read the peer scratchpad register, and return the value.
  *
- * Return: The value of the local scratchpad register.
+ * Return: The value of the peer scratchpad register.
  */
 static inline u32 ntb_peer_spad_read(struct ntb_dev *ntb, int pidx, int sidx)
 {
@@ -1502,4 +1563,141 @@
 	return ntb->ops->peer_msg_write(ntb, pidx, midx, msg);
 }
 
+/**
+ * ntb_peer_resource_idx() - get a resource index for a given peer idx
+ * @ntb:	NTB device context.
+ * @pidx:	Peer port index.
+ *
+ * When constructing a graph of peers, each remote peer must use a different
+ * resource index (mw, doorbell, etc) to communicate with each other
+ * peer.
+ *
+ * In a two peer system, this function should always return 0 such that
+ * resource 0 points to the remote peer on both ports.
+ *
+ * In a 5 peer system, this function will return the following matrix
+ *
+ * pidx \ port    0    1    2    3    4
+ * 0              0    0    1    2    3
+ * 1              0    1    1    2    3
+ * 2              0    1    2    2    3
+ * 3              0    1    2    3    3
+ *
+ * For example, if this function is used to program peer's memory
+ * windows, port 0 will program MW 0 on all it's peers to point to itself.
+ * port 1 will program MW 0 in port 0 to point to itself and MW 1 on all
+ * other ports. etc.
+ *
+ * For the legacy two host case, ntb_port_number() and ntb_peer_port_number()
+ * both return zero and therefore this function will always return zero.
+ * So MW 0 on each host would be programmed to point to the other host.
+ *
+ * Return: the resource index to use for that peer.
+ */
+static inline int ntb_peer_resource_idx(struct ntb_dev *ntb, int pidx)
+{
+	int local_port, peer_port;
+
+	if (pidx >= ntb_peer_port_count(ntb))
+		return -EINVAL;
+
+	local_port = ntb_logical_port_number(ntb);
+	peer_port = ntb_peer_logical_port_number(ntb, pidx);
+
+	if (peer_port < local_port)
+		return local_port - 1;
+	else
+		return local_port;
+}
+
+/**
+ * ntb_peer_highest_mw_idx() - get a memory window index for a given peer idx
+ *	using the highest index memory windows first
+ *
+ * @ntb:	NTB device context.
+ * @pidx:	Peer port index.
+ *
+ * Like ntb_peer_resource_idx(), except it returns indexes starting with
+ * last memory window index.
+ *
+ * Return: the resource index to use for that peer.
+ */
+static inline int ntb_peer_highest_mw_idx(struct ntb_dev *ntb, int pidx)
+{
+	int ret;
+
+	ret = ntb_peer_resource_idx(ntb, pidx);
+	if (ret < 0)
+		return ret;
+
+	return ntb_mw_count(ntb, pidx) - ret - 1;
+}
+
+struct ntb_msi_desc {
+	u32 addr_offset;
+	u32 data;
+};
+
+#ifdef CONFIG_NTB_MSI
+
+int ntb_msi_init(struct ntb_dev *ntb, void (*desc_changed)(void *ctx));
+int ntb_msi_setup_mws(struct ntb_dev *ntb);
+void ntb_msi_clear_mws(struct ntb_dev *ntb);
+int ntbm_msi_request_threaded_irq(struct ntb_dev *ntb, irq_handler_t handler,
+				  irq_handler_t thread_fn,
+				  const char *name, void *dev_id,
+				  struct ntb_msi_desc *msi_desc);
+void ntbm_msi_free_irq(struct ntb_dev *ntb, unsigned int irq, void *dev_id);
+int ntb_msi_peer_trigger(struct ntb_dev *ntb, int peer,
+			 struct ntb_msi_desc *desc);
+int ntb_msi_peer_addr(struct ntb_dev *ntb, int peer,
+		      struct ntb_msi_desc *desc,
+		      phys_addr_t *msi_addr);
+
+#else /* not CONFIG_NTB_MSI */
+
+static inline int ntb_msi_init(struct ntb_dev *ntb,
+			       void (*desc_changed)(void *ctx))
+{
+	return -EOPNOTSUPP;
+}
+static inline int ntb_msi_setup_mws(struct ntb_dev *ntb)
+{
+	return -EOPNOTSUPP;
+}
+static inline void ntb_msi_clear_mws(struct ntb_dev *ntb) {}
+static inline int ntbm_msi_request_threaded_irq(struct ntb_dev *ntb,
+						irq_handler_t handler,
+						irq_handler_t thread_fn,
+						const char *name, void *dev_id,
+						struct ntb_msi_desc *msi_desc)
+{
+	return -EOPNOTSUPP;
+}
+static inline void ntbm_msi_free_irq(struct ntb_dev *ntb, unsigned int irq,
+				     void *dev_id) {}
+static inline int ntb_msi_peer_trigger(struct ntb_dev *ntb, int peer,
+				       struct ntb_msi_desc *desc)
+{
+	return -EOPNOTSUPP;
+}
+static inline int ntb_msi_peer_addr(struct ntb_dev *ntb, int peer,
+				    struct ntb_msi_desc *desc,
+				    phys_addr_t *msi_addr)
+{
+	return -EOPNOTSUPP;
+
+}
+
+#endif /* CONFIG_NTB_MSI */
+
+static inline int ntbm_msi_request_irq(struct ntb_dev *ntb,
+				       irq_handler_t handler,
+				       const char *name, void *dev_id,
+				       struct ntb_msi_desc *msi_desc)
+{
+	return ntbm_msi_request_threaded_irq(ntb, handler, NULL, name,
+					     dev_id, msi_desc);
+}
+
 #endif

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