[PATCH net-next v6 01/15] ibmveth: Add MQ RX hypercall wrappers and call definitions

[Mingming Cao <mmc@linux.ibm.com>]

Single-queue ibmveth only needs h_register_logical_lan() plus legacy
buffer add/free calls. MQ RX uses per-queue handles, so the driver must
also be able to register/deregister subordinate queues and post
buffers against a specific queue handle.

Add the PHYP call IDs for:

  H_REG_LOGICAL_LAN_QUEUE (0x49C)
  H_ADD_LOGICAL_LAN_BUFFERS_QUEUE (0x4A0)
  H_FREE_LOGICAL_LAN_QUEUE (0x4A8)

as defined in PAPR 11.20.00. The gaps at 0x498 (reserved) and 0x4A4
(reserved for H_FREE_LOGICAL_LAN_BUFFER_QUEUE) are intentional; this
series tears queues down with H_FREE_LOGICAL_LAN_QUEUE and does not add
the buffer-queue free hcall.

Raising MAX_HCALL_OPCODE for these IDs also widens KVM's
kvm_arch.enabled_hcalls bitmap and the range KVM_CAP_PPC_ENABLE_HCALL
accepts. Neither is user-visible: KVM implements none of the three, so
the ioctl still rejects them, and the bitmap rounds to the same five
unsigned longs, so struct kvm_arch does not change size.

Add ibmveth.h wrapper helpers (h_register_logical_lan_queue(),
h_add_logical_lan_buffers_queue(), h_free_logical_lan_queue()) with
argument ordering and return semantics matching the existing ibmveth
hcall wrappers. h_free_logical_lan_queue() uses plpar_hcall_norets()
like h_free_logical_lan(). Also add h_register_logical_lan_with_handle()
so queue 0 can capture the PHYP queue handle in MQ mode. Both new
registration wrappers use plpar_hcall() rather than plpar_hcall9(), so
they do not read unwritten stack slots. Both new
registration wrappers use plpar_hcall() rather than plpar_hcall9(), so
they do not read unwritten stack slots.

This patch is intentionally plumbing only: no runtime behavior change
yet. Legacy firmware keeps H_REGISTER_LOGICAL_LAN and the existing
buffer hcalls. The new wrappers are used only when a later commit sets
multi_queue from H_ILLAN_ATTRIBUTES.

Signed-off-by: Mingming Cao <mmc@linux.ibm.com>
Reviewed-by: Dave Marquardt <davemarq@linux.ibm.com>
Tested-by: Shaik Abdulla <shaik.abdulla1@ibm.com>
---

Changes in v6:
- both new registration wrappers use plpar_hcall() instead of
  plpar_hcall9(). They do not need nine args, and plpar_hcall9() was
  reading three unwritten stack slots
- Widen add-buffers-queue and free-queue @queue_handle kdoc: handle may
  come from h_register_logical_lan_queue() or
  h_register_logical_lan_with_handle() (queue 0)
- add-buffers-queue Return: also H_FUNCTION (MQ firmware missing that
  hcall)

Changes in v5:
- Cite PAPR 11.20.00 for MQ hcall IDs 0x49C / 0x4A0 / 0x4A8 (v4 named
  the opcodes only)
- Call out reserved gaps at 0x498 and 0x4A4 (0x4A4 =
  H_FREE_LOGICAL_LAN_BUFFER_QUEUE); decision: do not add that hcall -
  queue teardown uses H_FREE_LOGICAL_LAN_QUEUE
- Note MAX_HCALL_OPCODE raise also widens KVM enabled_hcalls /
  KVM_CAP_PPC_ENABLE_HCALL accepted range (cross-subsystem)
- Rename h_reg_logical_lan_queue() -> h_register_logical_lan_queue() to
  match h_register_logical_lan() / h_free_logical_lan()
- Unify queue_handle out-params as unsigned long * on both
  h_register_logical_lan_queue() and h_register_logical_lan_with_handle()
  (v4 used u64 * on with_handle)
- h_free_logical_lan_queue() uses plpar_hcall_norets() like
  h_free_logical_lan() (v4 used plpar_hcall9 with unused retbuf)

Changes in v4:
- Document @queue_handle and @irq in h_reg_logical_lan_queue() kdoc.
- Wrap h_register_logical_lan_with_handle() prototype for readability /
  checkpatch.
- Drop unused H_FREE_LOGICAL_LAN_BUFFER_QUEUE wrapper/opcode (no caller;
  buffer return is local harvest + queue free).

 arch/powerpc/include/asm/hvcall.h  |   6 +-
 drivers/net/ethernet/ibm/ibmveth.h | 139 +++++++++++++++++++++++++++++
 2 files changed, 144 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index dff90a7d7f70..cb0ea53491e6 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -362,7 +362,11 @@
 #define H_GUEST_DELETE		0x488
 #define H_PKS_WRAP_OBJECT	0x490
 #define H_PKS_UNWRAP_OBJECT	0x494
-#define MAX_HCALL_OPCODE	H_PKS_UNWRAP_OBJECT
+/* 0x498 reserved; 0x4A4 = H_FREE_LOGICAL_LAN_BUFFER_QUEUE (unused here) */
+#define H_REG_LOGICAL_LAN_QUEUE 0x49C
+#define H_ADD_LOGICAL_LAN_BUFFERS_QUEUE 0x4A0
+#define H_FREE_LOGICAL_LAN_QUEUE 0x4A8
+#define MAX_HCALL_OPCODE	H_FREE_LOGICAL_LAN_QUEUE
 
 /* Scope args for H_SCM_UNBIND_ALL */
 #define H_UNBIND_SCOPE_ALL (0x1)
diff --git a/drivers/net/ethernet/ibm/ibmveth.h b/drivers/net/ethernet/ibm/ibmveth.h
index d87713668ed3..08504d1cafd5 100644
--- a/drivers/net/ethernet/ibm/ibmveth.h
+++ b/drivers/net/ethernet/ibm/ibmveth.h
@@ -66,6 +66,145 @@ static inline long h_add_logical_lan_buffers(unsigned long unit_address,
 			    desc5, desc6, desc7, desc8);
 }
 
+/**
+ * h_register_logical_lan_queue - Register a subordinate receive queue
+ * @unit_address: Device unit address
+ * @buffer_list: DMA address of 4KB page for tracking registered buffers
+ * @rec_queue: Buffer descriptor of receive queue
+ * @queue_handle: Output queue handle on success (may be NULL)
+ * @irq: Output hypervisor IRQ number on success (may be NULL)
+ *
+ * Registers a subordinate receive queue with the hypervisor.
+ *
+ * Return:
+ *   H_SUCCESS (0) on success
+ *   H_PARAMETER if parameters are invalid
+ *
+ * On success, hypervisor returns:
+ *   R3: H_SUCCESS
+ *   R4: Queue handle
+ *   R5: IRQ number for this queue
+ */
+static inline long
+h_register_logical_lan_queue(unsigned long unit_address,
+			     unsigned long buffer_list,
+			     unsigned long rec_queue,
+			     unsigned long *queue_handle,
+			     unsigned long *irq)
+{
+	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
+	long rc;
+
+	rc = plpar_hcall(H_REG_LOGICAL_LAN_QUEUE,
+			 retbuf, unit_address,
+			 buffer_list, rec_queue);
+
+	if (rc == H_SUCCESS) {
+		if (queue_handle)
+			*queue_handle = retbuf[0];
+		if (irq)
+			*irq = retbuf[1];
+	}
+
+	return rc;
+}
+
+/**
+ * h_add_logical_lan_buffers_queue - Add buffers to subordinate queue
+ * @unit_address: Device unit address
+ * @queue_handle: Queue handle from h_register_logical_lan_queue() or
+ *		  h_register_logical_lan_with_handle() (queue 0)
+ * @buffersznum: Buffer size (upper 32 bits) | count (lower 32 bits)
+ * @ioba12: Buffer addresses 1 and 2 packed ((addr1 << 32) | addr2)
+ * @ioba34: Buffer addresses 3 and 4 packed
+ * @ioba56: Buffer addresses 5 and 6 packed
+ * @ioba78: Buffer addresses 7 and 8 packed
+ * @ioba910: Buffer addresses 9 and 10 packed
+ * @ioba1112: Buffer addresses 11 and 12 packed
+ *
+ * Return:
+ *   H_SUCCESS - All buffers added successfully
+ *   H_PARAMETER - Invalid parameters
+ *   H_HARDWARE - Hardware error
+ *   H_FUNCTION - Firmware does not support this hcall
+ */
+static inline long h_add_logical_lan_buffers_queue(unsigned long unit_address,
+						   unsigned long queue_handle,
+						   unsigned long buffersznum,
+						   unsigned long ioba12,
+						   unsigned long ioba34,
+						   unsigned long ioba56,
+						   unsigned long ioba78,
+						   unsigned long ioba910,
+						   unsigned long ioba1112)
+{
+	unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
+
+	return plpar_hcall9(H_ADD_LOGICAL_LAN_BUFFERS_QUEUE,
+			    retbuf, unit_address,
+			    queue_handle, buffersznum,
+			    ioba12, ioba34, ioba56,
+			    ioba78, ioba910, ioba1112);
+}
+
+/**
+ * h_free_logical_lan_queue - Deregister subordinate receive queue
+ * @unit_address: Device unit address
+ * @queue_handle: Queue handle from h_register_logical_lan_queue() or
+ *		  h_register_logical_lan_with_handle() (queue 0)
+ *
+ * Deregisters and frees all structures associated with the subordinate queue.
+ *
+ * Return:
+ *   H_SUCCESS - Queue freed successfully
+ *   H_PARAMETER - Invalid parameters
+ *   H_HARDWARE - Hardware error
+ *   H_STATE - VIOA not in valid state
+ *   H_BUSY / H_LONG_BUSY_* - Resource busy, retry
+ */
+static inline long h_free_logical_lan_queue(unsigned long unit_address,
+					    unsigned long queue_handle)
+{
+	return plpar_hcall_norets(H_FREE_LOGICAL_LAN_QUEUE,
+				  unit_address, queue_handle);
+}
+
+/**
+ * h_register_logical_lan_with_handle - Register primary queue and get handle
+ * @unit_address: Device unit address
+ * @buffer_list: DMA address of buffer list
+ * @rec_queue: Buffer descriptor of receive queue
+ * @filter_list: DMA address of filter list
+ * @mac_address: MAC address
+ * @queue_handle: Output parameter for queue handle (may be NULL)
+ *
+ * Registers the primary receive queue (queue 0) with the hypervisor and
+ * returns the queue handle. This is needed in multi-queue mode to use
+ * h_add_logical_lan_buffers_queue() for all queues including queue 0.
+ *
+ * Return: H_SUCCESS (0) on success, error code otherwise
+ */
+static inline long
+h_register_logical_lan_with_handle(unsigned long unit_address,
+				   unsigned long buffer_list,
+				   unsigned long rec_queue,
+				   unsigned long filter_list,
+				   unsigned long mac_address,
+				   unsigned long *queue_handle)
+{
+	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
+	long rc;
+
+	rc = plpar_hcall(H_REGISTER_LOGICAL_LAN, retbuf,
+			 unit_address, buffer_list, rec_queue,
+			 filter_list, mac_address);
+
+	if (rc == H_SUCCESS && queue_handle)
+		*queue_handle = retbuf[0];
+
+	return rc;
+}
+
 /* FW allows us to send 6 descriptors but we only use one so mark
  * the other 5 as unused (0)
  */
-- 
2.50.1 (Apple Git-155)