pretty massive virtual memory rewrite

+ The system is now a bit simpler and hopefully easier to understand, while also
  extending the shared memory to be 1:N, where there is one owner who
  may become a zombie while waiting for the N to die.

2 files changed, 59 insertions, 27 deletions

diff --git a/arch/riscv64/include/uapi.h b/arch/riscv64/include/uapi.h
new file mode 100644
index 0000000..a8c236b
--- /dev/null
+++ b/arch/riscv64/include/uapi.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: copyleft-next-0.3.1 */
+/* Copyright 2024, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */
+
+#ifndef KMI_RISCV_UAPI_H
+#define KMI_RISCV_UAPI_H
+
+/**
+ * @file uapi.h
+ *
+ * RISCV-specific stuff that should be visible to userspace, currently mainly
+ * VM_R/VM_W/VM_X flags.
+ */
+
+/** Page is active. */
+#define VM_V (1 << 0)
+
+/** Page is readable. */
+#define VM_R (1 << 1)
+
+/** Page is writable. */
+#define VM_W (1 << 2)
+
+/** Page is executable. */
+#define VM_X (1 << 3)
+
+/** Page is user-accessible. */
+#define VM_U (1 << 4)
+
+/** Page is global. */
+#define VM_G (1 << 5)
+
+/** Page has been accessed. */
+#define VM_A (1 << 6)
+
+/** Page is dirty. */
+#define VM_D (1 << 7)
+
+#endif /* KMI_RISCV_UAPI_H */
diff --git a/arch/riscv64/include/vmem.h b/arch/riscv64/include/vmem.h
index ed99843..704858b 100644
--- a/arch/riscv64/include/vmem.h
+++ b/arch/riscv64/include/vmem.h
@@ -4,6 +4,8 @@
 #ifndef KMI_RISCV_VMAP_H
 #define KMI_RISCV_VMAP_H
 
+#include "uapi.h"
+
 /**
  * @file vmem.h
  * riscv64 definitions of arch-specific virtual memory data types and macros.
@@ -11,9 +13,6 @@
  * architecture-nonspecific, but works for now.
  */
 
-#include <kmi/types.h>
-#include <kmi/attrs.h>
-
 /**
  * Number of entries in one page table, depends on if we're running riscv32 or
  * riscv64.
@@ -26,30 +25,6 @@
 #define RISCV_NUM_LEAVES 1024
 #endif
 
-/** Page is active. */
-#define VM_V (1 << 0)
-
-/** Page is readable. */
-#define VM_R (1 << 1)
-
-/** Page is writable. */
-#define VM_W (1 << 2)
-
-/** Page is executable. */
-#define VM_X (1 << 3)
-
-/** Page is user-accessible. */
-#define VM_U (1 << 4)
-
-/** Page is global. */
-#define VM_G (1 << 5)
-
-/** Page has been accessed. */
-#define VM_A (1 << 6)
-
-/** Page is dirty. */
-#define VM_D (1 << 7)
-
 /** Memory mode of cpu. Currently only Sv39 is supported. */
 enum mm_mode {
 	/** 48bit effective addresses on 64bit systems. */
@@ -71,4 +46,23 @@ struct vmem {
 	struct vmem *leaf[RISCV_NUM_LEAVES];
 };
 
+/**
+ * Extract virtual memory flags (MR_XXX).
+ *
+ * @param x Flags to extract virtual memory region flags from.
+ * @return Virtual memory region flags.
+ */
+#define vm_flags(x) ((x) & ~0xff)
+
+/**
+ * Extract physical memory page flags (VM_XXX).
+ *
+ * @param x Flags to extract physical memory page flags from.
+ * @return Physical memory page flags.
+ */
+#define vp_flags(x) ((x) & 0xff)
+
+/** How many VM_XXX flags architecture has. MR_XXX are applied after them. */
+#define ARCH_VP_FLAGS 8
+
 #endif /* KMI_RISCV_VMAP_H */