cndm: Implement mmap and ioctl

Signed-off-by: Alex Forencich <alex@alexforencich.com>

src/cndm/modules/cndm/cndm.h

@@ -45,8 +45,9 @@ struct cndm_dev {
 
 	struct net_device *ndev[32];
 
-	void __iomem *bar;
+	resource_size_t hw_regs_size;
-	resource_size_t bar_len;
+	phys_addr_t hw_regs_phys;
+	void __iomem *hw_addr;
 
 	u32 port_count;
 	u32 port_offset;

src/cndm/modules/cndm/cndm_dev.c

@@ -9,6 +9,7 @@ Authors:
 */
 
 #include "cndm.h"
+#include "cndm_ioctl.h"
 
 #include <linux/uaccess.h>
 
@@ -28,8 +29,108 @@ static int cndm_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
+static int cndm_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct miscdevice *miscdev = file->private_data;
+	struct cndm_dev *cdev = container_of(miscdev, struct cndm_dev, misc_dev);
+	int index;
+	u64 pgoff, req_len, req_start;
+
+	index = vma->vm_pgoff >> (40 - PAGE_SHIFT);
+	req_len = vma->vm_end - vma->vm_start;
+	pgoff = vma->vm_pgoff & ((1U << (40 - PAGE_SHIFT)) - 1);
+	req_start = pgoff << PAGE_SHIFT;
+
+	if (vma->vm_end < vma->vm_start)
+		return -EINVAL;
+
+	if ((vma->vm_flags & VM_SHARED) == 0)
+		return -EINVAL;
+
+	switch (index) {
+	case 0:
+		if (req_start + req_len > cdev->hw_regs_size)
+			return -EINVAL;
+
+		return io_remap_pfn_range(vma, vma->vm_start,
+			(cdev->hw_regs_phys >> PAGE_SHIFT) + pgoff,
+			req_len, pgprot_noncached(vma->vm_page_prot));
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static long cndm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct miscdevice *miscdev = file->private_data;
+	struct cndm_dev *cdev = container_of(miscdev, struct cndm_dev, misc_dev);
+	size_t minsz;
+
+	if (cmd == CNDM_IOCTL_GET_API_VERSION) {
+		// Get API version
+		return CNDM_IOCTL_API_VERSION;
+	} else if (cmd == CNDM_IOCTL_GET_DEVICE_INFO) {
+		// Get device information
+		struct cndm_ioctl_device_info info;
+
+		minsz = offsetofend(struct cndm_ioctl_device_info, num_irqs);
+
+		if (copy_from_user(&info, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (info.argsz < minsz)
+			return -EINVAL;
+
+		info.flags = 0;
+		info.num_regions = 1;
+		info.num_irqs = 0;
+
+		return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0;
+	} else if (cmd == CNDM_IOCTL_GET_REGION_INFO) {
+		// Get region information
+		struct cndm_ioctl_region_info info;
+
+		minsz = offsetofend(struct cndm_ioctl_region_info, name);
+
+		if (copy_from_user(&info, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (info.argsz < minsz)
+			return -EINVAL;
+
+		info.flags = 0;
+		info.type = CNDM_REGION_TYPE_UNIMPLEMENTED;
+		info.next = 0;
+		info.child = 0;
+		info.size = 0;
+		info.offset = ((u64)info.index) << 40;
+		info.name[0] = 0;
+
+		switch (info.index) {
+		case 0:
+			info.type = CNDM_REGION_TYPE_NIC_CTRL;
+			info.next = 0;
+			info.child = 0;
+			info.size = cdev->hw_regs_size;
+			info.offset = ((u64)info.index) << 40;
+			strscpy(info.name, "ctrl", sizeof(info.name));
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0;
+	}
+
+	return -EINVAL;
+}
+
 const struct file_operations cndm_fops = {
 	.owner = THIS_MODULE,
 	.open = cndm_open,
 	.release = cndm_release,
+	.mmap = cndm_mmap,
+	.unlocked_ioctl = cndm_ioctl,
 };

src/cndm/modules/cndm/cndm_ioctl.h

@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL */
+/*
+
+Copyright (c) 2025 FPGA Ninja, LLC
+
+Authors:
+- Alex Forencich
+
+*/
+
+#ifndef CNDM_IOCTL_H
+#define CNDM_IOCTL_H
+
+#include <linux/types.h>
+
+#define CNDM_IOCTL_API_VERSION 0
+
+#define CNDM_IOCTL_TYPE 0x63
+#define CNDM_IOCTL_BASE 0xC0
+
+enum {
+	CNDM_REGION_TYPE_UNIMPLEMENTED = 0x00000000,
+	CNDM_REGION_TYPE_CTRL = 0x00001000,
+	CNDM_REGION_TYPE_NIC_CTRL = 0x00001001,
+	CNDM_REGION_TYPE_APP_CTRL = 0x00001002,
+};
+
+// get API version
+#define CNDM_IOCTL_GET_API_VERSION _IO(CNDM_IOCTL_TYPE, CNDM_IOCTL_BASE + 0)
+
+// get device information
+struct cndm_ioctl_device_info {
+	__u32 argsz;
+	__u32 flags;
+	__u32 fw_id;
+	__u32 fw_ver;
+	__u32 board_id;
+	__u32 board_ver;
+	__u32 build_date;
+	__u32 git_hash;
+	__u32 rel_info;
+	__u32 num_regions;
+	__u32 num_irqs;
+};
+
+#define CNDM_IOCTL_GET_DEVICE_INFO _IO(CNDM_IOCTL_TYPE, CNDM_IOCTL_BASE + 1)
+
+// get region information
+struct cndm_ioctl_region_info {
+	__u32 argsz;
+	__u32 flags;
+	__u32 index;
+	__u32 type;
+	__u32 next;
+	__u32 child;
+	__u32 size;
+	__u64 offset;
+	__u8 name[32];
+};
+
+#define CNDM_IOCTL_GET_REGION_INFO _IO(CNDM_IOCTL_TYPE, CNDM_IOCTL_BASE + 2)
+
+#endif

src/cndm/modules/cndm/cndm_main.c

@@ -52,9 +52,9 @@ static int cndm_common_probe(struct cndm_dev *cdev)
 	devlink_register(devlink, dev);
 #endif
 
-	cdev->port_count = ioread32(cdev->bar + 0x0100);
+	cdev->port_count = ioread32(cdev->hw_addr + 0x0100);
-	cdev->port_offset = ioread32(cdev->bar + 0x0104);
+	cdev->port_offset = ioread32(cdev->hw_addr + 0x0104);
-	cdev->port_stride = ioread32(cdev->bar + 0x0108);
+	cdev->port_stride = ioread32(cdev->hw_addr + 0x0108);
 
 	dev_info(dev, "Port count: %d", cdev->port_count);
 	dev_info(dev, "Port offset: 0x%x", cdev->port_offset);
@@ -63,7 +63,7 @@ static int cndm_common_probe(struct cndm_dev *cdev)
 	for (k = 0; k < cdev->port_count; k++) {
 		struct net_device *ndev;
 
-		ndev = cndm_create_netdev(cdev, k, cdev->bar + cdev->port_offset + (cdev->port_stride*k));
+		ndev = cndm_create_netdev(cdev, k, cdev->hw_addr + cdev->port_offset + (cdev->port_stride*k));
 		if (IS_ERR_OR_NULL(ndev)) {
 			ret = PTR_ERR(ndev);
 			goto fail_netdev;
@@ -155,17 +155,18 @@ static int cndm_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto fail_regions;
 	}
 
-	cdev->bar_len = pci_resource_len(pdev, 0);
+	cdev->hw_regs_size = pci_resource_len(pdev, 0);
+	cdev->hw_regs_phys = pci_resource_start(pdev, 0);
 
-	dev_info(dev, "BAR size: %llu", cdev->bar_len);
+	dev_info(dev, "Control BAR size: %llu", cdev->hw_regs_size);
-	cdev->bar = pci_ioremap_bar(pdev, 0);
+	cdev->hw_addr = pci_ioremap_bar(pdev, 0);
-	if (!cdev->bar) {
+	if (!cdev->hw_addr) {
 		ret = -ENOMEM;
-		dev_err(dev, "Failed to map BAR 0");
+		dev_err(dev, "Failed to map control BAR");
 		goto fail_map_bars;
 	}
 
-	if (ioread32(cdev->bar + 0x0000) == 0xffffffff) {
+	if (ioread32(cdev->hw_addr + 0x0000) == 0xffffffff) {
 		ret = -EIO;
 		dev_err(dev, "Device needs to be reset");
 		goto fail_map_bars;
@@ -187,8 +188,8 @@ fail_common:
 	cndm_irq_deinit_pcie(cdev);
 fail_init_irq:
 fail_map_bars:
-	if (cdev->bar)
+	if (cdev->hw_addr)
-		pci_iounmap(pdev, cdev->bar);
+		pci_iounmap(pdev, cdev->hw_addr);
 	pci_release_regions(pdev);
 fail_regions:
 	pci_clear_master(pdev);
@@ -211,8 +212,8 @@ static void cndm_pci_remove(struct pci_dev *pdev)
 	cndm_common_remove(cdev);
 
 	cndm_irq_deinit_pcie(cdev);
-	if (cdev->bar)
+	if (cdev->hw_addr)
-		pci_iounmap(pdev, cdev->bar);
+		pci_iounmap(pdev, cdev->hw_addr);
 	pci_release_regions(pdev);
 	pci_clear_master(pdev);
 	pci_disable_device(pdev);