kern: pci: Add bus framework and PCI BAR mapper

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

1 files changed, 73 insertions, 0 deletions

diff --git a/src/sys/include/os/bus.h b/src/sys/include/os/bus.h
new file mode 100644
index 0000000..86b1a75
--- /dev/null
+++ b/src/sys/include/os/bus.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and L5 engineers
+ * 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 the project 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.
+ */
+
+#ifndef _OS_BUS_H_
+#define _OS_BUS_H_
+
+#include <sys/types.h>
+
+typedef enum {
+    BUS_PCI_NONE,
+    BUS_PCI_PCI,
+} bus_type_t;
+
+/*
+ * Represents a physical or virtual MMIO address that
+ * allows tranmission and reception on the bus.
+ */
+typedef uintptr_t bus_addr_t;
+
+/*
+ * Represents a bus space that can be used with certain
+ * bus interfaces
+ *
+ * @va_base: Virtual address base
+ * @length: Length at buffer
+ * @type: Type of the space space (see BUS_*)
+ */
+struct bus_space {
+    void *va_base;
+    size_t length;
+    bus_type_t type;
+};
+
+/*
+ * Initialize a bus space descriptor and map a physical
+ * bus address.
+ *
+ * @bp: Bus space descriptor to use
+ * @pa: Physical bus address to map.
+ * @len: Length of mapping to use
+ *
+ * Returns zero on success, otherwise a less than zero
+ * value.
+ */
+int bus_space_map(struct bus_space *bp, bus_addr_t pa, size_t len);
+
+#endif  /* !_OS_BUS_H_ */