kernel: dev: Add PCI driver

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 223 insertions, 0 deletions

diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c
new file mode 100644
index 0000000..6f27200
--- /dev/null
+++ b/sys/dev/pci/pci.c
@@ -0,0 +1,223 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <dev/pci/pci.h>
+#include <dev/pci/pcivar.h>
+#include <sys/cdefs.h>
+#include <sys/panic.h>
+#include <sys/queue.h>
+#include <sys/syslog.h>
+#include <vm/dynalloc.h>
+#if defined(__x86_64__)
+#include <machine/io.h>
+#endif
+#include <assert.h>
+
+__MODULE_NAME("pci");
+__KERNEL_META("$Hyra$: pci.c, Ian Marco Moffett, "
+              "PCI driver core");
+
+static TAILQ_HEAD(, pci_device) device_list;
+static int access_method = PCI_ACCESS_CAM;
+
+/*
+ * Read device's legacy PCI CAM space
+ *
+ * @dev: Device to read.
+ * @offset: Offset to read at.
+ *
+ * XXX: Do not use directly!
+ */
+static uint32_t
+pci_cam_read(const struct pci_device *dev, uint32_t offset)
+{
+#if defined(__x86_64__)
+    uint32_t address, data;
+
+    address = __BIT(31)         |
+              (offset & ~3)     |
+              (dev->func << 8)  |
+              (dev->slot << 11) |
+              (dev->bus << 16);
+
+    outl(0xCF8, address);
+    data = inl(0xCFC) >> ((offset & 3) * 8);
+    return data;
+#else
+    panic("Invalid arch (%s())\n", __func__);
+#endif
+}
+
+static bool
+pci_device_exists(uint8_t bus, uint8_t slot, uint8_t func)
+{
+    uint16_t vendor_id;
+    struct pci_device dev_tmp = {
+        .bus = bus,
+        .slot = slot,
+        .func = func
+    };
+
+    vendor_id = pci_cam_read(&dev_tmp, 0x0) & 0xFFFF;
+
+    if (vendor_id == 0xFFFF) {
+        return false;
+    }
+
+    return true;
+}
+
+/*
+ * Sets other device information e.g., device id, vendor id, etc
+ *
+ * @dev: Device descriptor to set up.
+ *
+ * XXX: Expects device bus, slot and func to be set.
+ */
+static void
+pci_set_device_info(struct pci_device *dev)
+{
+    dev->vendor_id = pci_readl(dev, 0x0) & 0xFFFF;
+    dev->device_id = pci_readl(dev, 0x0) >> 16;
+    dev->pci_class = pci_readl(dev, 0x8) >> 24;
+
+    dev->pci_subclass = (pci_readl(dev, 0x8) >> 16) & 0xFF;
+    dev->prog_if = (pci_readl(dev, 0x8) >> 8) & 0xFF;
+
+    dev->bar[0] = pci_readl(dev, 0x10);
+    dev->bar[1] = pci_readl(dev, 0x14);
+    dev->bar[2] = pci_readl(dev, 0x18);
+    dev->bar[3] = pci_readl(dev, 0x1C);
+    dev->bar[4] = pci_readl(dev, 0x20);
+    dev->bar[6] = pci_readl(dev, 0x24);
+
+    dev->irq_line = pci_readl(dev, 0x3C) & 0xFF;
+}
+
+static void
+pci_register_device(uint8_t bus, uint8_t slot, uint8_t func)
+{
+    struct pci_device *dev = NULL;
+
+    if (!pci_device_exists(bus, slot, func)) {
+        return;
+    }
+
+    dev = dynalloc(sizeof(struct pci_device));
+    __assert(dev != NULL);
+
+    dev->bus = bus;
+    dev->slot = slot;
+    dev->func = func;
+
+    pci_set_device_info(dev);
+    TAILQ_INSERT_TAIL(&device_list, dev, link);
+}
+
+static void
+pci_scan_bus(uint8_t bus)
+{
+    for (int slot = 0; slot < 32; ++slot) {
+        for (int func = 0; func < 8; ++func) {
+            pci_register_device(bus, slot, func);
+        }
+    }
+}
+
+/*
+ * Read PCI(e) configuration space.
+ *
+ * @dev: Device to read from.
+ * @offset: Offset to read at.
+ */
+uint32_t
+pci_readl(struct pci_device *dev, uint32_t offset)
+{
+    if (access_method == PCI_ACCESS_CAM) {
+        return pci_cam_read(dev, offset);
+    }
+
+    panic("Invalid access method (%s())\n", __func__);
+    __builtin_unreachable();
+}
+
+struct pci_device *
+pci_get_device(struct pci_lookup lookup, uint16_t lookup_type)
+{
+    struct pci_device *dev;
+    uint16_t lookup_matches = 0;
+
+    TAILQ_FOREACH(dev, &device_list, link) {
+        if (__TEST(lookup_type, PCI_DEVICE_ID)) {
+            /* Check device ID */
+            if (lookup.device_id == dev->device_id)
+                lookup_matches |= PCI_DEVICE_ID;
+        }
+
+        if (__TEST(lookup_type, PCI_VENDOR_ID)) {
+            /* Check vendor ID */
+            if (lookup.vendor_id == dev->vendor_id)
+                lookup_matches |= PCI_VENDOR_ID;
+        }
+
+        if (__TEST(lookup_type, PCI_CLASS)) {
+            /* Check PCI class */
+            if (lookup.pci_class == dev->pci_class)
+                lookup_matches |= PCI_CLASS;
+        }
+
+        if (__TEST(lookup_type, PCI_SUBCLASS)) {
+            /* Check PCI class */
+            if (lookup.pci_subclass == dev->pci_subclass)
+                lookup_matches |= PCI_SUBCLASS;
+        }
+
+        if (lookup_type == lookup_matches) {
+            /* We found the device! */
+            return dev;
+        }
+        lookup_matches = 0;
+    }
+
+    return NULL;
+}
+
+int
+pci_init(void)
+{
+    TAILQ_INIT(&device_list);
+
+    KINFO("Scanning each bus...\n");
+
+    for (uint16_t i = 0; i < 256; ++i) {
+        pci_scan_bus(i);
+    }
+
+    return 0;
+}