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Subject[PATCH v3 2/9] NTB: Add indexed ports NTB API
Date
There is some NTB hardware, which can combine more than just two domains
over NTB. For instance, some IDT PCIe-switches can have NTB-functions
activated on more than two-ports. The different domains are distinguished
by ports they are connected to. So the new port-related methods are added to
the NTB API:
ntb_port_number() - return local port
ntb_peer_port_count() - return number of peers local port can connect to
ntb_peer_port_number(pdix) - return port number by it index
ntb_peer_port_idx(port) - return port index by it number

Current test-drivers aren't changed much. They still support two-ports devices
for the time being while multi-ports hardware drivers aren't added.

By default port-related API is declared for two-ports hardware.
So corresponding hardware drivers won't need to implement it.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
---
drivers/ntb/ntb.c | 54 ++++++++++++++
drivers/ntb/ntb_transport.c | 6 ++
drivers/ntb/test/ntb_perf.c | 4 ++
drivers/ntb/test/ntb_pingpong.c | 6 ++
drivers/ntb/test/ntb_tool.c | 5 ++
include/linux/ntb.h | 156 ++++++++++++++++++++++++++++++++++++++++
6 files changed, 231 insertions(+)

diff --git a/drivers/ntb/ntb.c b/drivers/ntb/ntb.c
index 2e25307..1e92e52 100644
--- a/drivers/ntb/ntb.c
+++ b/drivers/ntb/ntb.c
@@ -191,6 +191,60 @@ void ntb_db_event(struct ntb_dev *ntb, int vector)
}
EXPORT_SYMBOL(ntb_db_event);

+int ntb_default_port_number(struct ntb_dev *ntb)
+{
+ switch (ntb->topo) {
+ case NTB_TOPO_PRI:
+ case NTB_TOPO_B2B_USD:
+ return NTB_PORT_PRI_USD;
+ case NTB_TOPO_SEC:
+ case NTB_TOPO_B2B_DSD:
+ return NTB_PORT_SEC_DSD;
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(ntb_default_port_number);
+
+int ntb_default_peer_port_count(struct ntb_dev *ntb)
+{
+ return NTB_DEF_PEER_CNT;
+}
+EXPORT_SYMBOL(ntb_default_peer_port_count);
+
+int ntb_default_peer_port_number(struct ntb_dev *ntb, int pidx)
+{
+ if (pidx != NTB_DEF_PEER_IDX)
+ return -EINVAL;
+
+ switch (ntb->topo) {
+ case NTB_TOPO_PRI:
+ case NTB_TOPO_B2B_USD:
+ return NTB_PORT_SEC_DSD;
+ case NTB_TOPO_SEC:
+ case NTB_TOPO_B2B_DSD:
+ return NTB_PORT_PRI_USD;
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(ntb_default_peer_port_number);
+
+int ntb_default_peer_port_idx(struct ntb_dev *ntb, int port)
+{
+ int peer_port = ntb_default_peer_port_number(ntb, NTB_DEF_PEER_IDX);
+
+ if (peer_port == -EINVAL || port != peer_port)
+ return -EINVAL;
+
+ return 0;
+}
+EXPORT_SYMBOL(ntb_default_peer_port_idx);
+
static int ntb_probe(struct device *dev)
{
struct ntb_dev *ntb;
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 4eb8adb..10518b7 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -94,6 +94,9 @@ MODULE_PARM_DESC(use_dma, "Use DMA engine to perform large data copy");

static struct dentry *nt_debugfs_dir;

+/* Only two-ports NTB devices are supported */
+#define PIDX NTB_DEF_PEER_IDX
+
struct ntb_queue_entry {
/* ntb_queue list reference */
struct list_head entry;
@@ -1083,6 +1086,9 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
dev_dbg(&ndev->dev,
"scratchpad is unsafe, proceed anyway...\n");

+ if (ntb_peer_port_count(ndev) != NTB_DEF_PEER_CNT)
+ dev_warn(&ndev->dev, "Multi-port NTB devices unsupported\n");
+
node = dev_to_node(&ndev->dev);

nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
diff --git a/drivers/ntb/test/ntb_perf.c b/drivers/ntb/test/ntb_perf.c
index e75d4fd..c908b3a 100644
--- a/drivers/ntb/test/ntb_perf.c
+++ b/drivers/ntb/test/ntb_perf.c
@@ -76,6 +76,7 @@
#define DMA_RETRIES 20
#define SZ_4G (1ULL << 32)
#define MAX_SEG_ORDER 20 /* no larger than 1M for kmalloc buffer */
+#define PIDX NTB_DEF_PEER_IDX

MODULE_LICENSE(DRIVER_LICENSE);
MODULE_VERSION(DRIVER_VERSION);
@@ -764,6 +765,9 @@ static int perf_probe(struct ntb_client *client, struct ntb_dev *ntb)
return -EIO;
}

+ if (ntb_peer_port_count(ntb) != NTB_DEF_PEER_CNT)
+ dev_warn(&ntb->dev, "Multi-port NTB devices unsupported\n");
+
node = dev_to_node(&pdev->dev);

perf = kzalloc_node(sizeof(*perf), GFP_KERNEL, node);
diff --git a/drivers/ntb/test/ntb_pingpong.c b/drivers/ntb/test/ntb_pingpong.c
index 4358611..12f8b40 100644
--- a/drivers/ntb/test/ntb_pingpong.c
+++ b/drivers/ntb/test/ntb_pingpong.c
@@ -90,6 +90,9 @@ static unsigned long db_init = 0x7;
module_param(db_init, ulong, 0644);
MODULE_PARM_DESC(db_init, "Initial doorbell bits to ring on the peer");

+/* Only two-ports NTB devices are supported */
+#define PIDX NTB_DEF_PEER_IDX
+
struct pp_ctx {
struct ntb_dev *ntb;
u64 db_bits;
@@ -230,6 +233,9 @@ static int pp_probe(struct ntb_client *client,
}
}

+ if (ntb_peer_port_count(ntb) != NTB_DEF_PEER_CNT)
+ dev_warn(&ntb->dev, "multi-port NTB is unsupported\n");
+
pp = kmalloc(sizeof(*pp), GFP_KERNEL);
if (!pp) {
rc = -ENOMEM;
diff --git a/drivers/ntb/test/ntb_tool.c b/drivers/ntb/test/ntb_tool.c
index 61bf2ef..690862d 100644
--- a/drivers/ntb/test/ntb_tool.c
+++ b/drivers/ntb/test/ntb_tool.c
@@ -120,6 +120,8 @@ MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESCRIPTION);

#define MAX_MWS 16
+/* Only two-ports devices are supported */
+#define PIDX NTB_DEF_PEER_IDX

static struct dentry *tool_dbgfs;

@@ -919,6 +921,9 @@ static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
if (ntb_spad_is_unsafe(ntb))
dev_dbg(&ntb->dev, "scratchpad is unsafe\n");

+ if (ntb_peer_port_count(ntb) != NTB_DEF_PEER_CNT)
+ dev_warn(&ntb->dev, "multi-port NTB is unsupported\n");
+
tc = kzalloc(sizeof(*tc), GFP_KERNEL);
if (!tc) {
rc = -ENOMEM;
diff --git a/include/linux/ntb.h b/include/linux/ntb.h
index 5d1f260..fe175c7 100644
--- a/include/linux/ntb.h
+++ b/include/linux/ntb.h
@@ -140,6 +140,20 @@ enum ntb_width {
};

/**
+ * enum ntb_default_port - NTB default port number
+ * @NTB_PORT_PRI_USD: Default port of the NTB_TOPO_PRI/NTB_TOPO_B2B_USD
+ * topologies
+ * @NTB_PORT_SEC_DSD: Default port of the NTB_TOPO_SEC/NTB_TOPO_B2B_DSD
+ * topologies
+ */
+enum ntb_default_port {
+ NTB_PORT_PRI_USD,
+ NTB_PORT_SEC_DSD
+};
+#define NTB_DEF_PEER_CNT (1)
+#define NTB_DEF_PEER_IDX (0)
+
+/**
* struct ntb_client_ops - ntb client operations
* @probe: Notify client of a new device.
* @remove: Notify client to remove a device.
@@ -179,6 +193,10 @@ static inline int ntb_ctx_ops_is_valid(const struct ntb_ctx_ops *ops)

/**
* struct ntb_ctx_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().
+ * @peer_port_idx: See ntb_peer_port_idx().
* @link_is_up: See ntb_link_is_up().
* @link_enable: See ntb_link_enable().
* @link_disable: See ntb_link_disable().
@@ -212,6 +230,11 @@ static inline int ntb_ctx_ops_is_valid(const struct ntb_ctx_ops *ops)
* @peer_spad_write: See ntb_peer_spad_write().
*/
struct ntb_dev_ops {
+ int (*port_number)(struct ntb_dev *ntb);
+ int (*peer_port_count)(struct ntb_dev *ntb);
+ int (*peer_port_number)(struct ntb_dev *ntb, int pidx);
+ int (*peer_port_idx)(struct ntb_dev *ntb, int port);
+
int (*link_is_up)(struct ntb_dev *ntb,
enum ntb_speed *speed, enum ntb_width *width);
int (*link_enable)(struct ntb_dev *ntb,
@@ -265,6 +288,9 @@ static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops *ops)
{
/* commented callbacks are not required: */
return
+ !ops->peer_port_count == !ops->port_number &&
+ !ops->peer_port_number == !ops->port_number &&
+ !ops->peer_port_idx == !ops->port_number &&
ops->link_is_up &&
ops->link_enable &&
ops->link_disable &&
@@ -442,6 +468,136 @@ void ntb_link_event(struct ntb_dev *ntb);
void ntb_db_event(struct ntb_dev *ntb, int vector);

/**
+ * ntb_default_port_number() - get the default local port number
+ * @ntb: NTB device context.
+ *
+ * If hardware driver doesn't specify port_number() callback method, the NTB
+ * is considered with just two ports. So this method returns default local
+ * port number in compliance with topology.
+ *
+ * NOTE Don't call this method directly. The ntb_port_number() function should
+ * be used instead.
+ *
+ * Return: the default local port number
+ */
+int ntb_default_port_number(struct ntb_dev *ntb);
+
+/**
+ * ntb_default_port_count() - get the default number of peer device ports
+ * @ntb: NTB device context.
+ *
+ * By default hardware driver supports just one peer device.
+ *
+ * NOTE Don't call this method directly. The ntb_peer_port_count() function
+ * should be used instead.
+ *
+ * Return: the default number of peer ports
+ */
+int ntb_default_peer_port_count(struct ntb_dev *ntb);
+
+/**
+ * ntb_default_peer_port_number() - get the default peer port by given index
+ * @ntb: NTB device context.
+ * @idx: Peer port index (should not differ from zero).
+ *
+ * By default hardware driver supports just one peer device, so this method
+ * shall return the corresponding value from enum ntb_default_port.
+ *
+ * NOTE Don't call this method directly. The ntb_peer_port_number() function
+ * should be used instead.
+ *
+ * Return: the peer device port or negative value indicating an error
+ */
+int ntb_default_peer_port_number(struct ntb_dev *ntb, int pidx);
+
+/**
+ * ntb_default_peer_port_idx() - get the default peer device port index by
+ * given port number
+ * @ntb: NTB device context.
+ * @port: Peer port number (should be one of enum ntb_default_port).
+ *
+ * By default hardware driver supports just one peer device, so while
+ * specified port-argument indicates peer port from enum ntb_default_port,
+ * the return value shall be zero.
+ *
+ * NOTE Don't call this method directly. The ntb_peer_port_idx() function
+ * should be used instead.
+ *
+ * Return: the peer port index or negative value indicating an error
+ */
+int ntb_default_peer_port_idx(struct ntb_dev *ntb, int port);
+
+/**
+ * ntb_port_number() - get the local port number
+ * @ntb: NTB device context.
+ *
+ * Hardware must support at least simple two-ports ntb connection
+ *
+ * Return: the local port number
+ */
+static inline int ntb_port_number(struct ntb_dev *ntb)
+{
+ if (!ntb->ops->port_number)
+ return ntb_default_port_number(ntb);
+
+ return ntb->ops->port_number(ntb);
+}
+
+/**
+ * ntb_peer_port_count() - get the number of peer device ports
+ * @ntb: NTB device context.
+ *
+ * Hardware may support an access to memory of several remote domains
+ * over multi-port NTB devices. This method returns the number of peers,
+ * local device can have shared memory with.
+ *
+ * Return: the number of peer ports
+ */
+static inline int ntb_peer_port_count(struct ntb_dev *ntb)
+{
+ if (!ntb->ops->peer_port_count)
+ return ntb_default_peer_port_count(ntb);
+
+ return ntb->ops->peer_port_count(ntb);
+}
+
+/**
+ * ntb_peer_port_number() - get the peer port by given index
+ * @ntb: NTB device context.
+ * @pidx: Peer port index.
+ *
+ * Peer ports are continuously enumerated by NTB API logic, so this method
+ * lets to retrieve port real number by its index.
+ *
+ * Return: the peer device port or negative value indicating an error
+ */
+static inline int ntb_peer_port_number(struct ntb_dev *ntb, int pidx)
+{
+ if (!ntb->ops->peer_port_number)
+ return ntb_default_peer_port_number(ntb, pidx);
+
+ return ntb->ops->peer_port_number(ntb, pidx);
+}
+
+/**
+ * ntb_peer_port_idx() - get the peer device port index by given port number
+ * @ntb: NTB device context.
+ * @port: Peer port number.
+ *
+ * Inverse operation of ntb_peer_port_number(), so one can get port index
+ * by specified port number.
+ *
+ * Return: the peer port index or negative value indicating an error
+ */
+static inline int ntb_peer_port_idx(struct ntb_dev *ntb, int port)
+{
+ if (!ntb->ops->peer_port_idx)
+ return ntb_default_peer_port_idx(ntb, port);
+
+ return ntb->ops->peer_port_idx(ntb, port);
+}
+
+/**
* ntb_link_is_up() - get the current ntb link state
* @ntb: NTB device context.
* @speed: OUT - The link speed expressed as PCIe generation number.
--
2.6.6
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