kernel/amd64: bus: Add bus resource interface

This commit introduces a bus resource abstraction. A bus resource
encapsulates bus specific information and semantics. Along with
abstracting away bus specific details and providing an overall
smoother interface, this additionally provides flexibility, access
control and security by keeping track of permissions and allowing
things to be turned on or off.

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

1 files changed, 51 insertions, 0 deletions

diff --git a/sys/include/dev/pci/resource.h b/sys/include/dev/pci/resource.h
new file mode 100644
index 0000000..b469e8f
--- /dev/null
+++ b/sys/include/dev/pci/resource.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2023-2025 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.
+ */
+
+#ifndef _PCI_RESOURCE_H_
+#define _PCI_RESOURCE_H_
+
+#include <machine/bus.h>
+
+/* Enable/disable DMA (bus mastering in this case) */
+int pcir_enable_dma(struct bus_resource *brp, void *devp);
+int pcir_disable_dma(struct bus_resource *brp, void *devp);
+
+/* Set/unset bus resource semantics */
+int pcir_set_sem(struct bus_resource *brp, bus_sem_t sem);
+int pcir_clr_sem(struct bus_resource *brp, bus_sem_t sem);
+
+/* DMA buffer helpers (XXX: unused for now) */
+int pcir_dma_alloc(struct bus_resource *brp, void *res);
+int pcir_dma_free(struct bus_resource *brp, void *p);
+
+/* DMA transaction helpers (XXX: unused for now) */
+ssize_t pcir_dma_in(struct bus_resource *brp, void *p);
+ssize_t pcir_dma_out(struct bus_resource *brp, void *p);
+
+#endif  /* !_PCI_RESOURCE_H_ */