[PATCH v2 2/9] NTB: Add indexed ports NTB API

From: Serge Semin
Date: Mon Dec 12 2016 - 16:09:21 EST

There are 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.

Signed-off-by: Serge Semin <fancer.lancer@xxxxxxxxx>

---
drivers/ntb/hw/amd/ntb_hw_amd.c | 47 ++++++++++++++++++++++++
drivers/ntb/hw/amd/ntb_hw_amd.h | 9 +++++
drivers/ntb/hw/intel/ntb_hw_intel.c | 52 ++++++++++++++++++++++++++-
drivers/ntb/hw/intel/ntb_hw_intel.h | 9 +++++
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 | 71 +++++++++++++++++++++++++++++++++++++
9 files changed, 208 insertions(+), 1 deletion(-)

diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.c b/drivers/ntb/hw/amd/ntb_hw_amd.c
index 6704327..0b767ef 100644
--- a/drivers/ntb/hw/amd/ntb_hw_amd.c
+++ b/drivers/ntb/hw/amd/ntb_hw_amd.c
@@ -71,6 +71,49 @@ MODULE_AUTHOR("AMD Inc.");
static const struct file_operations amd_ntb_debugfs_info;
static struct dentry *debugfs_dir;

+static int amd_ntb_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;
+}
+
+static int amd_ntb_peer_port_count(struct ntb_dev *ntb)
+{
+ return NTB_PEER_CNT;
+}
+
+static int amd_ntb_peer_port_number(struct ntb_dev *ntb, int pidx)
+{
+ int local_port = amd_ntb_port_number(ntb);
+
+ if (pidx > NTB_PIDX_MAX)
+ return -EINVAL;
+
+ return (local_port == NTB_PORT_PRI_USD ?
+ NTB_PORT_SEC_DSD : NTB_PORT_PRI_USD);
+}
+
+static int amd_ntb_peer_port_idx(struct ntb_dev *ntb, int port)
+{
+ int local_port = amd_ntb_port_number(ntb);
+
+ if ((local_port == NTB_PORT_PRI_USD && port != NTB_PORT_SEC_DSD) ||
+ (local_port == NTB_PORT_SEC_DSD && port != NTB_PORT_PRI_USD))
+ return -EINVAL;
+
+ return 0;
+}
+
static int amd_link_is_up(struct amd_ntb_dev *ndev)
{
if (!ndev->peer_sta)
@@ -431,6 +474,10 @@ static int amd_ntb_peer_spad_write(struct ntb_dev *ntb,
}

static const struct ntb_dev_ops amd_ntb_ops = {
+ .port_number = amd_ntb_port_number,
+ .peer_port_count = amd_ntb_peer_port_count,
+ .peer_port_number = amd_ntb_peer_port_number,
+ .peer_port_idx = amd_ntb_peer_port_idx,
.link_is_up = amd_ntb_link_is_up,
.link_enable = amd_ntb_link_enable,
.link_disable = amd_ntb_link_disable,
diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.h b/drivers/ntb/hw/amd/ntb_hw_amd.h
index 2eac3cd..1aeb08f 100644
--- a/drivers/ntb/hw/amd/ntb_hw_amd.h
+++ b/drivers/ntb/hw/amd/ntb_hw_amd.h
@@ -62,6 +62,10 @@
#define NTB_LNK_STA_SPEED(x) (((x) & NTB_LNK_STA_SPEED_MASK) >> 16)
#define NTB_LNK_STA_WIDTH(x) (((x) & NTB_LNK_STA_WIDTH_MASK) >> 20)

+/* port related constants */
+#define NTB_PEER_CNT (1)
+#define NTB_PIDX_MAX (0)
+
#ifndef read64
#ifdef readq
#define read64 readq
@@ -91,6 +95,11 @@ static inline void _write64(u64 val, void __iomem *mmio)
#endif
#endif

+enum amd_ntb_port {
+ NTB_PORT_PRI_USD,
+ NTB_PORT_SEC_DSD
+};
+
enum {
/* AMD NTB Capability */
AMD_MW_CNT = 3,
diff --git a/drivers/ntb/hw/intel/ntb_hw_intel.c b/drivers/ntb/hw/intel/ntb_hw_intel.c
index 68d9908..7e44dc3 100644
--- a/drivers/ntb/hw/intel/ntb_hw_intel.c
+++ b/drivers/ntb/hw/intel/ntb_hw_intel.c
@@ -1035,6 +1035,49 @@ static void ndev_deinit_debugfs(struct intel_ntb_dev *ndev)
debugfs_remove_recursive(ndev->debugfs_dir);
}

+static int intel_ntb_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;
+}
+
+static int intel_ntb_peer_port_count(struct ntb_dev *ntb)
+{
+ return NTB_PEER_CNT;
+}
+
+static int intel_ntb_peer_port_number(struct ntb_dev *ntb, int pidx)
+{
+ int local_port = intel_ntb_port_number(ntb);
+
+ if (pidx > NTB_PIDX_MAX)
+ return -EINVAL;
+
+ return (local_port == NTB_PORT_PRI_USD ?
+ NTB_PORT_SEC_DSD : NTB_PORT_PRI_USD);
+}
+
+static int intel_ntb_peer_port_idx(struct ntb_dev *ntb, int port)
+{
+ int local_port = intel_ntb_port_number(ntb);
+
+ if ((local_port == NTB_PORT_PRI_USD && port != NTB_PORT_SEC_DSD) ||
+ (local_port == NTB_PORT_SEC_DSD && port != NTB_PORT_PRI_USD))
+ return -EINVAL;
+
+ return 0;
+}
+
static int intel_ntb_link_is_up(struct ntb_dev *ntb,
enum ntb_speed *speed,
enum ntb_width *width)
@@ -1775,7 +1818,6 @@ static int skx_init_ntb(struct intel_ntb_dev *ndev)
{
int rc;

-
ndev->mw_count = XEON_MW_COUNT;
ndev->spad_count = SKX_SPAD_COUNT;
ndev->db_count = SKX_DB_COUNT;
@@ -2883,6 +2925,10 @@ static const struct intel_ntb_xlat_reg skx_sec_xlat = {

/* operations for primary side of local ntb */
static const struct ntb_dev_ops intel_ntb_ops = {
+ .port_number = intel_ntb_port_number,
+ .peer_port_count = intel_ntb_peer_port_count,
+ .peer_port_number = intel_ntb_peer_port_number,
+ .peer_port_idx = intel_ntb_peer_port_idx,
.link_is_up = intel_ntb_link_is_up,
.link_enable = intel_ntb_link_enable,
.link_disable = intel_ntb_link_disable,
@@ -2909,6 +2955,10 @@ static const struct ntb_dev_ops intel_ntb_ops = {
};

static const struct ntb_dev_ops intel_ntb3_ops = {
+ .port_number = intel_ntb_port_number,
+ .peer_port_count = intel_ntb_peer_port_count,
+ .peer_port_number = intel_ntb_peer_port_number,
+ .peer_port_idx = intel_ntb_peer_port_idx,
.link_is_up = intel_ntb_link_is_up,
.link_enable = intel_ntb3_link_enable,
.link_disable = intel_ntb_link_disable,
diff --git a/drivers/ntb/hw/intel/ntb_hw_intel.h b/drivers/ntb/hw/intel/ntb_hw_intel.h
index 6e8c182..f12c960 100644
--- a/drivers/ntb/hw/intel/ntb_hw_intel.h
+++ b/drivers/ntb/hw/intel/ntb_hw_intel.h
@@ -295,6 +295,15 @@
#define NTB_BAR_MASK_64 ~(0xfull)
#define NTB_BAR_MASK_32 ~(0xfu)

+/* port related constants */
+#define NTB_PEER_CNT (1)
+#define NTB_PIDX_MAX (0)
+
+enum intel_ntb_port {
+ NTB_PORT_PRI_USD,
+ NTB_PORT_SEC_DSD
+};
+
struct intel_ntb_dev;

struct intel_ntb_reg {
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 4eb8adb..37d428d 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 0
+
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) != 1)
+ 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..481827a 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 0

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) != 1)
+ 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..6dd7582 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 0
+
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) != 1)
+ 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..85b6417 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 0

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) != 1)
+ 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..3216689 100644
--- a/include/linux/ntb.h
+++ b/include/linux/ntb.h
@@ -179,6 +179,10 @@ 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 +216,11 @@ 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 +274,10 @@ static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops *ops)
{
/* commented callbacks are not required: */
return
+ ops->port_number &&
+ ops->peer_port_count &&
+ ops->peer_port_number &&
+ ops->peer_port_idx &&
ops->link_is_up &&
ops->link_enable &&
ops->link_disable &&
@@ -442,6 +455,64 @@ void ntb_link_event(struct ntb_dev *ntb);
void ntb_db_event(struct ntb_dev *ntb, int vector);

/**
+ * 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)
+{
+ 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)
+{
+ 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 methods
+ * 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)
+{
+ 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)
+{
+ 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