From: Adam Young <admiyo@amperecomputing.com>

Implementation of DMTF DSP:0292
Management Control Transport Protocol(MCTP) over
Platform Communication Channel(PCC) network driver.

MCTP devices are specified by entries in DSDT/SDST and
reference channels specified in the PCCT.

Communication with other devices use the PCC based
doorbell mechanism.

Signed-off-by: Adam Young <admiyo@os.amperecomputing.com>
---
 drivers/net/mctp/Kconfig    |  13 ++
 drivers/net/mctp/Makefile   |   1 +
 drivers/net/mctp/mctp-pcc.c | 373 ++++++++++++++++++++++++++++++++++++
 3 files changed, 387 insertions(+)
 create mode 100644 drivers/net/mctp/mctp-pcc.c

diff --git a/drivers/net/mctp/Kconfig b/drivers/net/mctp/Kconfig
index ce9d2d2ccf3b..ff4effd8e99c 100644
--- a/drivers/net/mctp/Kconfig
+++ b/drivers/net/mctp/Kconfig
@@ -42,6 +42,19 @@ config MCTP_TRANSPORT_I3C
 	  A MCTP protocol network device is created for each I3C bus
 	  having a "mctp-controller" devicetree property.
 
+config MCTP_TRANSPORT_PCC
+	tristate "MCTP  PCC transport"
+	select ACPI
+	help
+	  Provides a driver to access MCTP devices over PCC transport,
+	  A MCTP protocol network device is created via ACPI for each
+	  entry in the DST/SDST that matches the identifier. The Platform
+	  commuinucation channels are selected from the corresponding
+	  entries in the PCCT.
+
+	  Say y here if you need to connect to MCTP endpoints over PCC. To
+	  compile as a module, use m; the module will be called mctp-pcc.
+
 endmenu
 
 endif
diff --git a/drivers/net/mctp/Makefile b/drivers/net/mctp/Makefile
index e1cb99ced54a..492a9e47638f 100644
--- a/drivers/net/mctp/Makefile
+++ b/drivers/net/mctp/Makefile
@@ -1,3 +1,4 @@
+obj-$(CONFIG_MCTP_TRANSPORT_PCC) += mctp-pcc.o
 obj-$(CONFIG_MCTP_SERIAL) += mctp-serial.o
 obj-$(CONFIG_MCTP_TRANSPORT_I2C) += mctp-i2c.o
 obj-$(CONFIG_MCTP_TRANSPORT_I3C) += mctp-i3c.o
diff --git a/drivers/net/mctp/mctp-pcc.c b/drivers/net/mctp/mctp-pcc.c
new file mode 100644
index 000000000000..1ce9c58099cb
--- /dev/null
+++ b/drivers/net/mctp/mctp-pcc.c
@@ -0,0 +1,373 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * mctp-pcc.c - Driver for MCTP over PCC.
+ * Copyright (c) 2024, Ampere Computing LLC
+ */
+
+#include <linux/acpi.h>
+#include <linux/if_arp.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/platform_device.h>
+#include <linux/string.h>
+
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+#include <acpi/acrestyp.h>
+#include <acpi/actbl.h>
+#include <net/mctp.h>
+#include <net/mctpdevice.h>
+#include <acpi/pcc.h>
+
+#define SPDM_VERSION_OFFSET	1
+#define SPDM_REQ_RESP_OFFSET	2
+#define MCTP_PAYLOAD_LENGTH	256
+#define MCTP_CMD_LENGTH		4
+#define MCTP_PCC_VERSION	0x1 /* DSP0253 defines a single version: 1 */
+#define MCTP_SIGNATURE		"MCTP"
+#define SIGNATURE_LENGTH	4
+#define MCTP_HEADER_LENGTH	12
+#define MCTP_MIN_MTU		68
+#define PCC_MAGIC		0x50434300
+#define PCC_HEADER_FLAG_REQ_INT	0x1
+#define PCC_HEADER_FLAGS	PCC_HEADER_FLAG_REQ_INT
+#define PCC_DWORD_TYPE		0x0c
+#define PCC_ACK_FLAG_MASK	0x1
+
+struct mctp_pcc_hdr {
+	u32 signature;
+	u32 flags;
+	u32 length;
+	char mctp_signature[4];
+};
+
+struct mctp_pcc_hw_addr {
+	u32 inbox_index;
+	u32 outbox_index;
+};
+
+/* The netdev structure. One of these per PCC adapter. */
+struct mctp_pcc_ndev {
+	struct list_head next;
+	/* spinlock to serialize access to pcc buffer and registers*/
+	spinlock_t lock;
+	struct mctp_dev mdev;
+	struct acpi_device *acpi_device;
+	struct pcc_mbox_chan *in_chan;
+	struct pcc_mbox_chan *out_chan;
+	struct mbox_client outbox_client;
+	struct mbox_client inbox_client;
+	void __iomem *pcc_comm_inbox_addr;
+	void __iomem *pcc_comm_outbox_addr;
+	struct mctp_pcc_hw_addr hw_addr;
+};
+
+static struct list_head mctp_pcc_ndevs;
+
+static void mctp_pcc_client_rx_callback(struct mbox_client *c, void *buffer)
+{
+	struct mctp_pcc_ndev *mctp_pcc_dev;
+	struct mctp_pcc_hdr mctp_pcc_hdr;
+	struct mctp_skb_cb *cb;
+	struct sk_buff *skb;
+	void *skb_buf;
+	u32 data_len;
+	u32 flags;
+
+	mctp_pcc_dev = container_of(c, struct mctp_pcc_ndev, inbox_client);
+	memcpy_fromio(&mctp_pcc_hdr, mctp_pcc_dev->pcc_comm_inbox_addr,
+		      sizeof(struct mctp_pcc_hdr));
+	data_len = mctp_pcc_hdr.length + MCTP_HEADER_LENGTH;
+
+	if (data_len > mctp_pcc_dev->mdev.dev->max_mtu) {
+		mctp_pcc_dev->mdev.dev->stats.rx_dropped++;
+		return;
+	}
+
+	skb = netdev_alloc_skb(mctp_pcc_dev->mdev.dev, data_len);
+	if (!skb) {
+		mctp_pcc_dev->mdev.dev->stats.rx_dropped++;
+		return;
+	}
+	mctp_pcc_dev->mdev.dev->stats.rx_packets++;
+	mctp_pcc_dev->mdev.dev->stats.rx_bytes += data_len;
+	skb->protocol = htons(ETH_P_MCTP);
+	skb_buf = skb_put(skb, data_len);
+	memcpy_fromio(skb_buf, mctp_pcc_dev->pcc_comm_inbox_addr, data_len);
+	skb_reset_mac_header(skb);
+	skb_pull(skb, sizeof(struct mctp_pcc_hdr));
+	skb_reset_network_header(skb);
+	cb = __mctp_cb(skb);
+	cb->halen = 0;
+	netif_rx(skb);
+
+	flags = mctp_pcc_hdr.flags;
+	mctp_pcc_dev->in_chan->ack_rx = (flags & PCC_ACK_FLAG_MASK) > 0;
+}
+
+static netdev_tx_t mctp_pcc_tx(struct sk_buff *skb, struct net_device *ndev)
+{
+	struct mctp_pcc_hdr pcc_header;
+	struct mctp_pcc_ndev *mpnd;
+	void __iomem *buffer;
+	unsigned long flags;
+	int rc;
+
+	ndev->stats.tx_bytes += skb->len;
+	ndev->stats.tx_packets++;
+	mpnd = netdev_priv(ndev);
+
+	spin_lock_irqsave(&mpnd->lock, flags);
+	buffer = mpnd->pcc_comm_outbox_addr;
+	pcc_header.signature = PCC_MAGIC | mpnd->hw_addr.outbox_index;
+	pcc_header.flags = PCC_HEADER_FLAGS;
+	memcpy(pcc_header.mctp_signature, MCTP_SIGNATURE, SIGNATURE_LENGTH);
+	pcc_header.length = skb->len + SIGNATURE_LENGTH;
+	memcpy_toio(buffer, &pcc_header, sizeof(struct mctp_pcc_hdr));
+	memcpy_toio(buffer + sizeof(struct mctp_pcc_hdr), skb->data, skb->len);
+	mpnd->out_chan->mchan->mbox->ops->send_data(mpnd->out_chan->mchan,
+						    NULL);
+	spin_unlock_irqrestore(&mpnd->lock, flags);
+
+	dev_consume_skb_any(skb);
+	return NETDEV_TX_OK;
+}
+
+static void
+mctp_pcc_net_stats(struct net_device *net_dev,
+		   struct rtnl_link_stats64 *stats)
+{
+	struct mctp_pcc_ndev *mpnd;
+
+	mpnd = (struct mctp_pcc_ndev *)netdev_priv(net_dev);
+	stats->rx_errors = 0;
+	stats->rx_packets = mpnd->mdev.dev->stats.rx_packets;
+	stats->tx_packets = mpnd->mdev.dev->stats.tx_packets;
+	stats->rx_dropped = 0;
+	stats->tx_bytes = mpnd->mdev.dev->stats.tx_bytes;
+	stats->rx_bytes = mpnd->mdev.dev->stats.rx_bytes;
+}
+
+static const struct net_device_ops mctp_pcc_netdev_ops = {
+	.ndo_start_xmit = mctp_pcc_tx,
+	.ndo_get_stats64 = mctp_pcc_net_stats,
+};
+
+static void  mctp_pcc_setup(struct net_device *ndev)
+{
+	ndev->type = ARPHRD_MCTP;
+	ndev->hard_header_len = 0;
+	ndev->addr_len = 0;
+	ndev->tx_queue_len = 0;
+	ndev->flags = IFF_NOARP;
+	ndev->netdev_ops = &mctp_pcc_netdev_ops;
+	ndev->needs_free_netdev = true;
+}
+
+static int create_mctp_pcc_netdev(struct acpi_device *acpi_dev,
+				  struct device *dev, int inbox_index,
+				  int outbox_index)
+{
+	struct mctp_pcc_ndev *mctp_pcc_dev;
+	struct net_device *ndev;
+	int mctp_pcc_mtu;
+	char name[32];
+	int rc;
+
+	snprintf(name, sizeof(name), "mctpipcc%d", inbox_index);
+	ndev = alloc_netdev(sizeof(struct mctp_pcc_ndev), name, NET_NAME_ENUM,
+			    mctp_pcc_setup);
+	if (!ndev)
+		return -ENOMEM;
+	mctp_pcc_dev = (struct mctp_pcc_ndev *)netdev_priv(ndev);
+	INIT_LIST_HEAD(&mctp_pcc_dev->next);
+	spin_lock_init(&mctp_pcc_dev->lock);
+
+	mctp_pcc_dev->hw_addr.inbox_index = inbox_index;
+	mctp_pcc_dev->hw_addr.outbox_index = outbox_index;
+	mctp_pcc_dev->inbox_client.rx_callback = mctp_pcc_client_rx_callback;
+	mctp_pcc_dev->out_chan =
+		pcc_mbox_request_channel(&mctp_pcc_dev->outbox_client,
+					 outbox_index);
+	if (IS_ERR(mctp_pcc_dev->out_chan)) {
+		rc = PTR_ERR(mctp_pcc_dev->out_chan);
+		goto free_netdev;
+	}
+	mctp_pcc_dev->in_chan =
+		pcc_mbox_request_channel(&mctp_pcc_dev->inbox_client,
+					 inbox_index);
+	if (IS_ERR(mctp_pcc_dev->in_chan)) {
+		rc = PTR_ERR(mctp_pcc_dev->in_chan);
+		goto cleanup_out_channel;
+	}
+	mctp_pcc_dev->pcc_comm_inbox_addr =
+		devm_ioremap(dev, mctp_pcc_dev->in_chan->shmem_base_addr,
+			     mctp_pcc_dev->in_chan->shmem_size);
+	if (!mctp_pcc_dev->pcc_comm_inbox_addr) {
+		rc = -EINVAL;
+		goto cleanup_in_channel;
+	}
+	mctp_pcc_dev->pcc_comm_outbox_addr =
+		devm_ioremap(dev, mctp_pcc_dev->out_chan->shmem_base_addr,
+			     mctp_pcc_dev->out_chan->shmem_size);
+	if (!mctp_pcc_dev->pcc_comm_outbox_addr) {
+		rc = -EINVAL;
+		goto cleanup_in_channel;
+	}
+	mctp_pcc_dev->acpi_device = acpi_dev;
+	mctp_pcc_dev->inbox_client.dev = dev;
+	mctp_pcc_dev->outbox_client.dev = dev;
+	mctp_pcc_dev->mdev.dev = ndev;
+	acpi_dev->driver_data = mctp_pcc_dev;
+
+	/* There is no clean way to pass the MTU
+	 * to the callback function used for registration,
+	 * so set the values ahead of time.
+	 */
+	mctp_pcc_mtu = mctp_pcc_dev->out_chan->shmem_size -
+		sizeof(struct mctp_pcc_hdr);
+	ndev->mtu = MCTP_MIN_MTU;
+	ndev->max_mtu = mctp_pcc_mtu;
+	ndev->min_mtu = MCTP_MIN_MTU;
+
+	rc = register_netdev(ndev);
+	if (rc)
+		goto cleanup_in_channel;
+	list_add_tail(&mctp_pcc_dev->next, &mctp_pcc_ndevs);
+	return 0;
+
+cleanup_in_channel:
+	pcc_mbox_free_channel(mctp_pcc_dev->in_chan);
+cleanup_out_channel:
+	pcc_mbox_free_channel(mctp_pcc_dev->out_chan);
+free_netdev:
+	unregister_netdev(ndev);
+	free_netdev(ndev);
+	return rc;
+}
+
+struct lookup_context {
+	int index;
+	u32 inbox_index;
+	u32 outbox_index;
+};
+
+static acpi_status lookup_pcct_indices(struct acpi_resource *ares,
+				       void *context)
+{
+	struct acpi_resource_address32 *addr;
+	struct lookup_context *luc = context;
+
+	switch (ares->type) {
+	case PCC_DWORD_TYPE:
+		break;
+	default:
+		return AE_OK;
+	}
+
+	addr = ACPI_CAST_PTR(struct acpi_resource_address32, &ares->data);
+	switch (luc->index) {
+	case 0:
+		luc->outbox_index = addr[0].address.minimum;
+		break;
+	case 1:
+		luc->inbox_index = addr[0].address.minimum;
+		break;
+	}
+	luc->index++;
+	return AE_OK;
+}
+
+static int mctp_pcc_driver_add(struct acpi_device *adev)
+{
+	int outbox_index;
+	int inbox_index;
+	acpi_handle dev_handle;
+	acpi_status status;
+	struct lookup_context context = {0, 0, 0};
+
+	dev_dbg(&adev->dev, "Adding mctp_pcc device for HID  %s\n",
+		acpi_device_hid(adev));
+	dev_handle = acpi_device_handle(adev);
+	status = acpi_walk_resources(dev_handle, "_CRS", lookup_pcct_indices,
+				     &context);
+	if (!ACPI_SUCCESS(status)) {
+		dev_err(&adev->dev, "FAILURE to lookup PCC indexes from CRS");
+		return -EINVAL;
+	}
+	inbox_index = context.inbox_index;
+	outbox_index = context.outbox_index;
+	return create_mctp_pcc_netdev(adev, &adev->dev, inbox_index,
+				      outbox_index);
+}
+
+/* pass in adev=NULL to remove all devices
+ */
+static void mctp_pcc_driver_remove(struct acpi_device *adev)
+{
+	struct mctp_pcc_ndev *mctp_pcc_dev = NULL;
+	struct list_head *ptr;
+	struct list_head *tmp;
+
+	list_for_each_safe(ptr, tmp, &mctp_pcc_ndevs) {
+		struct net_device *ndev;
+
+		mctp_pcc_dev = list_entry(ptr, struct mctp_pcc_ndev, next);
+		if (adev && mctp_pcc_dev->acpi_device != adev)
+			continue;
+		pcc_mbox_free_channel(mctp_pcc_dev->out_chan);
+		pcc_mbox_free_channel(mctp_pcc_dev->in_chan);
+		ndev = mctp_pcc_dev->mdev.dev;
+		if (ndev)
+			mctp_unregister_netdev(ndev);
+		list_del(ptr);
+		if (adev)
+			break;
+	}
+}
+
+static const struct acpi_device_id mctp_pcc_device_ids[] = {
+	{ "DMT0001", 0},
+	{ "", 0},
+};
+
+static struct acpi_driver mctp_pcc_driver = {
+	.name = "mctp_pcc",
+	.class = "Unknown",
+	.ids = mctp_pcc_device_ids,
+	.ops = {
+		.add = mctp_pcc_driver_add,
+		.remove = mctp_pcc_driver_remove,
+	},
+	.owner = THIS_MODULE,
+};
+
+static int __init mctp_pcc_mod_init(void)
+{
+	int rc;
+
+	pr_debug("Initializing MCTP over PCC transport driver\n");
+	INIT_LIST_HEAD(&mctp_pcc_ndevs);
+	rc = acpi_bus_register_driver(&mctp_pcc_driver);
+	if (rc < 0)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error registering driver\n"));
+	return rc;
+}
+
+static __exit void mctp_pcc_mod_exit(void)
+{
+	pr_debug("Removing MCTP over PCC transport driver\n");
+	mctp_pcc_driver_remove(NULL);
+	acpi_bus_unregister_driver(&mctp_pcc_driver);
+}
+
+module_init(mctp_pcc_mod_init);
+module_exit(mctp_pcc_mod_exit);
+
+MODULE_DEVICE_TABLE(acpi, mctp_pcc_device_ids);
+
+MODULE_DESCRIPTION("MCTP PCC device");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Adam Young <admiyo@os.amperecomputing.com>");
-- 
2.34.1

Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on rafael-pm/linux-next]
[also build test WARNING on rafael-pm/bleeding-edge linus/master v6.10-rc4 next-20240619]
[cannot apply to horms-ipvs/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/admiyo-os-amperecomputing-com/mctp-pcc-Check-before-sending-MCTP-PCC-response-ACK/20240620-040816
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
patch link:    https://lore.kernel.org/r/20240619200552.119080-4-admiyo%40os.amperecomputing.com
patch subject: [PATCH v2 3/3] mctp pcc: Implement MCTP over PCC Transport
config: arm64-kismet-CONFIG_ACPI-CONFIG_MCTP_TRANSPORT_PCC-0-0 (https://download.01.org/0day-ci/archive/20240620/202406202206.9e7oGmfh-lkp@intel.com/config)
reproduce: (https://download.01.org/0day-ci/archive/20240620/202406202206.9e7oGmfh-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202406202206.9e7oGmfh-lkp@intel.com/

kismet warnings: (new ones prefixed by >>)
>> kismet: WARNING: unmet direct dependencies detected for ACPI when selected by MCTP_TRANSPORT_PCC
   WARNING: unmet direct dependencies detected for ACPI
     Depends on [n]: ARCH_SUPPORTS_ACPI [=n]
     Selected by [y]:
     - MCTP_TRANSPORT_PCC [=y] && NETDEVICES [=y] && MCTP [=y]

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on rafael-pm/linux-next]
[also build test WARNING on rafael-pm/bleeding-edge linus/master v6.10-rc4 next-20240619]
[cannot apply to horms-ipvs/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/admiyo-os-amperecomputing-com/mctp-pcc-Check-before-sending-MCTP-PCC-response-ACK/20240620-040816
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
patch link:    https://lore.kernel.org/r/20240619200552.119080-4-admiyo%40os.amperecomputing.com
patch subject: [PATCH v2 3/3] mctp pcc: Implement MCTP over PCC Transport
config: arc-allyesconfig (https://download.01.org/0day-ci/archive/20240620/202406201832.4oSZmptU-lkp@intel.com/config)
compiler: arceb-elf-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240620/202406201832.4oSZmptU-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202406201832.4oSZmptU-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/net/mctp/mctp-pcc.c:17:
   include/acpi/acpi_drivers.h:72:43: warning: 'struct acpi_pci_root' declared inside parameter list will not be visible outside of this definition or declaration
      72 | struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root);
         |                                           ^~~~~~~~~~~~~
   drivers/net/mctp/mctp-pcc.c: In function 'mctp_pcc_tx':
>> drivers/net/mctp/mctp-pcc.c:116:13: warning: unused variable 'rc' [-Wunused-variable]
     116 |         int rc;
         |             ^~
   drivers/net/mctp/mctp-pcc.c: In function 'create_mctp_pcc_netdev':
   drivers/net/mctp/mctp-pcc.c:223:17: error: invalid use of undefined type 'struct acpi_device'
     223 |         acpi_dev->driver_data = mctp_pcc_dev;
         |                 ^~
   In file included from include/linux/printk.h:573,
                    from include/asm-generic/bug.h:22,
                    from arch/arc/include/asm/bug.h:30,
                    from include/linux/bug.h:5,
                    from include/linux/thread_info.h:13,
                    from include/asm-generic/preempt.h:5,
                    from ./arch/arc/include/generated/asm/preempt.h:1,
                    from include/linux/preempt.h:79,
                    from include/linux/spinlock.h:56,
                    from include/linux/mmzone.h:8,
                    from include/linux/gfp.h:7,
                    from include/linux/slab.h:16,
                    from include/linux/resource_ext.h:11,
                    from include/linux/acpi.h:13,
                    from drivers/net/mctp/mctp-pcc.c:7:
   drivers/net/mctp/mctp-pcc.c: In function 'mctp_pcc_driver_add':
   drivers/net/mctp/mctp-pcc.c:291:22: error: invalid use of undefined type 'struct acpi_device'
     291 |         dev_dbg(&adev->dev, "Adding mctp_pcc device for HID  %s\n",
         |                      ^~
   include/linux/dynamic_debug.h:224:29: note: in definition of macro '__dynamic_func_call_cls'
     224 |                 func(&id, ##__VA_ARGS__);                       \
         |                             ^~~~~~~~~~~
   include/linux/dynamic_debug.h:250:9: note: in expansion of macro '_dynamic_func_call_cls'
     250 |         _dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__)
         |         ^~~~~~~~~~~~~~~~~~~~~~
   include/linux/dynamic_debug.h:273:9: note: in expansion of macro '_dynamic_func_call'
     273 |         _dynamic_func_call(fmt, __dynamic_dev_dbg,              \
         |         ^~~~~~~~~~~~~~~~~~
   include/linux/dev_printk.h:165:9: note: in expansion of macro 'dynamic_dev_dbg'
     165 |         dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
         |         ^~~~~~~~~~~~~~~
   drivers/net/mctp/mctp-pcc.c:291:9: note: in expansion of macro 'dev_dbg'
     291 |         dev_dbg(&adev->dev, "Adding mctp_pcc device for HID  %s\n",
         |         ^~~~~~~
   drivers/net/mctp/mctp-pcc.c:292:17: error: implicit declaration of function 'acpi_device_hid'; did you mean 'acpi_device_dep'? [-Werror=implicit-function-declaration]
     292 |                 acpi_device_hid(adev));
         |                 ^~~~~~~~~~~~~~~
   include/linux/dynamic_debug.h:224:29: note: in definition of macro '__dynamic_func_call_cls'
     224 |                 func(&id, ##__VA_ARGS__);                       \
         |                             ^~~~~~~~~~~
   include/linux/dynamic_debug.h:250:9: note: in expansion of macro '_dynamic_func_call_cls'
     250 |         _dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__)
         |         ^~~~~~~~~~~~~~~~~~~~~~
   include/linux/dynamic_debug.h:273:9: note: in expansion of macro '_dynamic_func_call'
     273 |         _dynamic_func_call(fmt, __dynamic_dev_dbg,              \
         |         ^~~~~~~~~~~~~~~~~~
   include/linux/dev_printk.h:165:9: note: in expansion of macro 'dynamic_dev_dbg'
     165 |         dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
         |         ^~~~~~~~~~~~~~~
   drivers/net/mctp/mctp-pcc.c:291:9: note: in expansion of macro 'dev_dbg'
     291 |         dev_dbg(&adev->dev, "Adding mctp_pcc device for HID  %s\n",
         |         ^~~~~~~
   drivers/net/mctp/mctp-pcc.c:293:22: error: implicit declaration of function 'acpi_device_handle'; did you mean 'acpi_device_dep'? [-Werror=implicit-function-declaration]
     293 |         dev_handle = acpi_device_handle(adev);
         |                      ^~~~~~~~~~~~~~~~~~
         |                      acpi_device_dep
   drivers/net/mctp/mctp-pcc.c:293:20: warning: assignment to 'acpi_handle' {aka 'void *'} from 'int' makes pointer from integer without a cast [-Wint-conversion]
     293 |         dev_handle = acpi_device_handle(adev);
         |                    ^
   In file included from include/linux/device.h:15,
                    from include/linux/acpi.h:14:
   drivers/net/mctp/mctp-pcc.c:297:30: error: invalid use of undefined type 'struct acpi_device'
     297 |                 dev_err(&adev->dev, "FAILURE to lookup PCC indexes from CRS");
         |                              ^~
   include/linux/dev_printk.h:110:25: note: in definition of macro 'dev_printk_index_wrap'
     110 |                 _p_func(dev, fmt, ##__VA_ARGS__);                       \
         |                         ^~~
   drivers/net/mctp/mctp-pcc.c:297:17: note: in expansion of macro 'dev_err'
     297 |                 dev_err(&adev->dev, "FAILURE to lookup PCC indexes from CRS");
         |                 ^~~~~~~
   drivers/net/mctp/mctp-pcc.c:302:50: error: invalid use of undefined type 'struct acpi_device'
     302 |         return create_mctp_pcc_netdev(adev, &adev->dev, inbox_index,
         |                                                  ^~
   drivers/net/mctp/mctp-pcc.c: At top level:
   drivers/net/mctp/mctp-pcc.c:336:15: error: variable 'mctp_pcc_driver' has initializer but incomplete type
     336 | static struct acpi_driver mctp_pcc_driver = {
         |               ^~~~~~~~~~~
   drivers/net/mctp/mctp-pcc.c:337:10: error: 'struct acpi_driver' has no member named 'name'
     337 |         .name = "mctp_pcc",
         |          ^~~~
   drivers/net/mctp/mctp-pcc.c:337:17: warning: excess elements in struct initializer
     337 |         .name = "mctp_pcc",
         |                 ^~~~~~~~~~
   drivers/net/mctp/mctp-pcc.c:337:17: note: (near initialization for 'mctp_pcc_driver')
   drivers/net/mctp/mctp-pcc.c:338:10: error: 'struct acpi_driver' has no member named 'class'
     338 |         .class = "Unknown",
         |          ^~~~~
   drivers/net/mctp/mctp-pcc.c:338:18: warning: excess elements in struct initializer
     338 |         .class = "Unknown",
         |                  ^~~~~~~~~
   drivers/net/mctp/mctp-pcc.c:338:18: note: (near initialization for 'mctp_pcc_driver')
   drivers/net/mctp/mctp-pcc.c:339:10: error: 'struct acpi_driver' has no member named 'ids'
     339 |         .ids = mctp_pcc_device_ids,
         |          ^~~


vim +/rc +116 drivers/net/mctp/mctp-pcc.c

   109	
   110	static netdev_tx_t mctp_pcc_tx(struct sk_buff *skb, struct net_device *ndev)
   111	{
   112		struct mctp_pcc_hdr pcc_header;
   113		struct mctp_pcc_ndev *mpnd;
   114		void __iomem *buffer;
   115		unsigned long flags;
 > 116		int rc;
   117	
   118		ndev->stats.tx_bytes += skb->len;
   119		ndev->stats.tx_packets++;
   120		mpnd = netdev_priv(ndev);
   121	
   122		spin_lock_irqsave(&mpnd->lock, flags);
   123		buffer = mpnd->pcc_comm_outbox_addr;
   124		pcc_header.signature = PCC_MAGIC | mpnd->hw_addr.outbox_index;
   125		pcc_header.flags = PCC_HEADER_FLAGS;
   126		memcpy(pcc_header.mctp_signature, MCTP_SIGNATURE, SIGNATURE_LENGTH);
   127		pcc_header.length = skb->len + SIGNATURE_LENGTH;
   128		memcpy_toio(buffer, &pcc_header, sizeof(struct mctp_pcc_hdr));
   129		memcpy_toio(buffer + sizeof(struct mctp_pcc_hdr), skb->data, skb->len);
   130		mpnd->out_chan->mchan->mbox->ops->send_data(mpnd->out_chan->mchan,
   131							    NULL);
   132		spin_unlock_irqrestore(&mpnd->lock, flags);
   133	
   134		dev_consume_skb_any(skb);
   135		return NETDEV_TX_OK;
   136	}
   137	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

On Wed, 19 Jun 2024 16:05:52 -0400 admiyo@os.amperecomputing.com wrote:
> From: Adam Young <admiyo@amperecomputing.com>
> 
> Implementation of DMTF DSP:0292
> Management Control Transport Protocol(MCTP) over
> Platform Communication Channel(PCC) network driver.
> 
> MCTP devices are specified by entries in DSDT/SDST and
> reference channels specified in the PCCT.
> 
> Communication with other devices use the PCC based
> doorbell mechanism.

This patch breaks allmodconfig build:

drivers/net/mctp/mctp-pcc.c:116:6: warning: unused variable 'rc' [-Wunused-variable]
  116 |         int rc;
      |             ^~
drivers/net/mctp/mctp-pcc.c:344:3: error: field designator 'owner' does not refer to any field in type 'struct acpi_driver'
  344 |         .owner = THIS_MODULE,
      |         ~^~~~~~~~~~~~~~~~~~~

In addition, please make sure you don't add new checkpatch warnings,
use:

  ./scripts/checkpatch.pl --strict --max-line-length=80 $patch

Please wait with the repost until next week, unless you get a review
from Jeremy before that. When reposting start a new thread, don't
repost in reply to previous posting. Instead add a lore link to the
previous version, like this:

https://lore.kernel.org/20240619200552.119080-1-admiyo@os.amperecomputing.com/

See also:
https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#changes-requested
-- 
pw-bot: cr

On 6/19/24 19:26, Jakub Kicinski wrote:
> On Wed, 19 Jun 2024 16:05:52 -0400 admiyo@os.amperecomputing.com wrote:
>> From: Adam Young <admiyo@amperecomputing.com>
>>
>> Implementation of DMTF DSP:0292
>> Management Control Transport Protocol(MCTP) over
>> Platform Communication Channel(PCC) network driver.
>>
>> MCTP devices are specified by entries in DSDT/SDST and
>> reference channels specified in the PCCT.
>>
>> Communication with other devices use the PCC based
>> doorbell mechanism.
> This patch breaks allmodconfig build:
>
> drivers/net/mctp/mctp-pcc.c:116:6: warning: unused variable 'rc' [-Wunused-variable]
>    116 |         int rc;
>        |             ^~

Funny, I see that only when building on x86_64, not on arm64.  I will fix.


> drivers/net/mctp/mctp-pcc.c:344:3: error: field designator 'owner' does not refer to any field in type 'struct acpi_driver'
>    344 |         .owner = THIS_MODULE,
>        |         ~^~~~~~~~~~~~~~~~~~~

Not sure how you are getting that last error.  I do not, and the v6.9.3 
code base has this in include/acpi/acpi_bus.h at line 166


struct acpi_driver {
         char name[80];
         char class[80];
         const struct acpi_device_id *ids; /* Supported Hardware IDs */
         unsigned int flags;
         struct acpi_device_ops ops;
         struct device_driver drv;
         struct module *owner;
};

> In addition, please make sure you don't add new checkpatch warnings,
> use:
>
>    ./scripts/checkpatch.pl --strict --max-line-length=80 $patch
That runs clean.
>
> Please wait with the repost until next week, unless you get a review
> from Jeremy before that. When reposting start a new thread, don't
> repost in reply to previous posting. Instead add a lore link to the
> previous version, like this:
>
> https://lore.kernel.org/20240619200552.119080-1-admiyo@os.amperecomputing.com/
>
> See also:
> https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#changes-requested

On Wed, 19 Jun 2024 23:24:41 -0400 Adam Young wrote:
> > drivers/net/mctp/mctp-pcc.c:344:3: error: field designator 'owner' does not refer to any field in type 'struct acpi_driver'
> >    344 |         .owner = THIS_MODULE,
> >        |         ~^~~~~~~~~~~~~~~~~~~  
> 
> Not sure how you are getting that last error.  I do not, and the v6.9.3 
> code base has this in include/acpi/acpi_bus.h at line 166

v6.9.3 is not a development kernel. Your patches will be merged to net-next.
Read more of the process doc I linked in the previous message.

> That runs clean.

It doesn't on patches 1 and 2, but you're right, I think it's
intentional / because of the "historical" ACPI coding style :(