1 files changed, 77 insertions, 0 deletions
diff --git a/kernel/drivers/pcie.c b/kernel/drivers/pcie.c
new file mode 100644
index 0000000..6003eab
--- /dev/null
+++ b/kernel/drivers/pcie.c
@@ -0,0 +1,77 @@
+#include "drivers/pcie.h"
+#include <drivers/pcie.h>
+#include <main/acpi.h>
+#include <mm/kmalloc.h>
+#include <mm/pagetable.h>
+#include <util/debug.h>
+
+#define MCFG_SIGNATURE (*(uint32_t *)"MCFG")
+static uintptr_t pcie_base_addr;
+
+typedef struct pcie_table
+{
+    pcie_device_t devices[PCI_NUM_BUSES][PCI_NUM_DEVICES_PER_BUS]
+                         [PCI_NUM_FUNCTIONS_PER_DEVICE];
+} pcie_table_t;
+
+static pcie_table_t *pcie_table;
+
+#define PCIE_DEV(bus, device, func) \
+    (&pcie_table->devices[(bus)][(device)][(func)])
+static list_t pcie_wrapper_list;
+
+void pci_init(void)
+{
+    // TODO document; needs -machine type=q35 flag in qemu!
+    void *table = acpi_table(MCFG_SIGNATURE, 0);
+    KASSERT(table);
+    pcie_base_addr = *(uintptr_t *)((uintptr_t)table + 44) + PHYS_OFFSET;
+    pcie_table = (pcie_table_t *)pcie_base_addr;
+    pt_map_range(pt_get(), pcie_base_addr - PHYS_OFFSET, pcie_base_addr,
+                 pcie_base_addr + PAGE_SIZE_1GB, PT_WRITE | PT_PRESENT,
+                 PT_WRITE | PT_PRESENT);
+
+    list_init(&pcie_wrapper_list);
+    for (unsigned bus = 0; bus < PCI_NUM_BUSES; bus++)
+    {
+        for (unsigned device = 0; device < PCI_NUM_DEVICES_PER_BUS; device++)
+        {
+            unsigned int max_functions =
+                (PCIE_DEV(bus, device, 0)->standard.header_type & 0x80)
+                    ? PCI_NUM_DEVICES_PER_BUS
+                    : 1;
+            for (unsigned function = 0; function < max_functions; function++)
+            {
+                pcie_device_t *dev = PCIE_DEV(bus, device, function);
+                if (!dev->standard.vendor_id ||
+                    dev->standard.vendor_id == (uint16_t)-1)
+                    continue;
+                pcie_device_wrapper_t *wrapper =
+                    kmalloc(sizeof(pcie_device_wrapper_t));
+                wrapper->dev = dev;
+                wrapper->class = dev->standard.class;
+                wrapper->subclass = dev->standard.subclass;
+                wrapper->interface = dev->standard.prog_if;
+                list_link_init(&wrapper->link);
+                list_insert_tail(&pcie_wrapper_list, &wrapper->link);
+            }
+        }
+    }
+}
+
+pcie_device_t *pcie_lookup(uint8_t class, uint8_t subclass, uint8_t interface)
+{
+    list_iterate(&pcie_wrapper_list, wrapper, pcie_device_wrapper_t, link)
+    {
+        /* verify the class subclass and interface are correct */
+        if (((class == PCI_LOOKUP_WILDCARD) || (wrapper->class == class)) &&
+            ((subclass == PCI_LOOKUP_WILDCARD) ||
+             (wrapper->subclass == subclass)) &&
+            ((interface == PCI_LOOKUP_WILDCARD) ||
+             (wrapper->interface == interface)))
+        {
+            return wrapper->dev;
+        }
+    }
+    return NULL;
+}