rename common to src

+ I keep starting to type src and wondering why autocomplete won't work,
  I guess src is just uncounciously a better name

1 files changed, 154 insertions, 0 deletions

diff --git a/src/dmem.c b/src/dmem.c
new file mode 100644
index 0000000..bbabe09
--- /dev/null
+++ b/src/dmem.c
@@ -0,0 +1,154 @@
+/* SPDX-License-Identifier: copyleft-next-0.3.1 */
+/* Copyright 2021 - 2022, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */
+
+/**
+ * @file dmem.c
+ * Handle device memory, i.e. anything outside the physical RAM.
+ *
+ * \todo Handle NUMA.
+ */
+
+#include <kmi/assert.h>
+#include <kmi/dmem.h>
+
+/** Region before RAM. */
+static struct mem_region_root pre_ram = { 0 };
+
+/** Region after RAM. */
+static struct mem_region_root post_ram = { 0 };
+
+pm_t __pre_base = 0;
+pm_t __pre_top = 0;
+pm_t __post_base = 0;
+pm_t __post_top = 0;
+
+stat_t init_devmem(pm_t ram_base, pm_t ram_top)
+{
+	pm_t mem_top = (pm_t)-1;
+
+	__pre_base = 0;
+	__pre_top = ram_base - 1;
+
+	__post_base = ram_top;
+	__post_top = mem_top;
+
+	size_t pre_pages = __pages(__pre_top);
+	size_t post_pages = __pages(__post_top) - __pages(__post_base);
+
+	init_region(&pre_ram, __pre_base, pre_pages);
+	init_region(&post_ram, __post_base, post_pages);
+
+	return OK;
+}
+
+/**
+ * Device virtual memory worker callback for \ref map_fill_region().
+ *
+ * @param b Virtual memory to work in.
+ * @param offset Hint for \ref alloc_page().
+ * @param vaddr Current virtual address.
+ * @param flags Flags of region.
+ * @param order Suggested page order.
+ * @param data Pointer to \ref stat_t.
+ * @return \see alloc_uvmem_wrapper().
+ *
+ * \see alloc_uvmem_wrapper().
+ */
+static stat_t dev_alloc_wrapper(struct vmem *b, pm_t *offset, vm_t vaddr,
+                                vmflags_t flags, enum mm_order order,
+                                void *data)
+{
+	stat_t *status = (stat_t *)data;
+	/** \todo remember to do something with this status info */
+	*status = map_vpage(b, *offset, vaddr, flags, order);
+	*offset += order_size(order);
+	return OK;
+}
+
+/**
+ * Device virtual memory freeing worker callback for \ref map_fill_region().
+ *
+ * @param b Virtual memory to work in.
+ * @param offset Hint for \ref alloc_page().
+ * @param vaddr Current virtual address.
+ * @param flags Flags of region.
+ * @param order Suggested page order.
+ * @param data Pointer to \ref stat_t.
+ * @return \see alloc_uvmem_wrapper().
+ *
+ * \see alloc_uvmem_wrapper().
+ */
+static stat_t dev_free_wrapper(struct vmem *b, pm_t *offset, vm_t vaddr,
+                               vmflags_t flags, enum mm_order order, void *data)
+{
+	UNUSED(offset);
+	UNUSED(flags);
+	pm_t paddr = 0;
+	enum mm_order v_order = 0;
+	stat_vpage(b, vaddr, &paddr, &v_order, 0);
+	if (order != v_order)
+		return INFO_TRGN;
+
+	stat_t *status = (stat_t *)data;
+	*status = unmap_vpage(b, vaddr);
+	return OK;
+}
+
+vm_t alloc_devmem(struct tcb *t, pm_t dev_start, size_t bytes, vmflags_t flags)
+{
+	hard_assert(t && is_proc(t), ERR_INVAL);
+
+	vm_t region = 0;
+	if (dev_start < __pre_top)
+		region = alloc_region(&pre_ram, bytes, 0, flags);
+
+	if (dev_start > __post_base)
+		region = alloc_region(&post_ram, bytes, 0, flags);
+
+	if (!region)
+		return NULL;
+
+	stat_t status = OK;
+	const vm_t w = map_fill_region(t->proc.vmem, &dev_alloc_wrapper,
+	                               dev_start, region,
+	                               bytes, flags, &status);
+
+	if (status)
+		return NULL;
+
+	return w;
+}
+
+stat_t free_devmem(struct tcb *t, vm_t dev_start)
+{
+	hard_assert(t && is_proc(t), ERR_INVAL);
+
+	pm_t dev_paddr = 0;
+	stat_vpage(t->proc.vmem, dev_start, &dev_paddr, 0, 0);
+
+	if (dev_paddr >= __pre_top && dev_paddr <= __post_base)
+		return ERR_ADDR;
+
+	struct mem_region *m = 0;
+	if (dev_paddr < __pre_top)
+		m = find_used_region(&pre_ram, dev_paddr);
+
+	if (dev_paddr > __post_base)
+		m = find_used_region(&post_ram, dev_paddr);
+
+	if (!m)
+		return ERR_NF;
+
+	size_t region_size = __addr(m->end - m->start);
+	stat_t status = OK;
+	map_fill_region(t->proc.vmem, &dev_free_wrapper, dev_paddr, dev_start,
+	                region_size, 0, &status);
+
+	if (dev_paddr < __pre_top)
+		free_region(&pre_ram, dev_paddr);
+
+	if (dev_paddr > __post_base)
+		free_region(&post_ram, dev_paddr);
+
+	return status;
+}