From 9966b49db468de0168c7a455dfb5b4c66c413c4d Mon Sep 17 00:00:00 2001
From: Kimplul <kimi.h.kuparinen@gmail.com>
Date: Sun, 19 Dec 2021 17:10:36 +0200
Subject: Massive changes to jump to userspace

---
 arch/riscv/common/vmem.c | 104 -----------------------------------------------
 1 file changed, 104 deletions(-)
 delete mode 100644 arch/riscv/common/vmem.c

(limited to 'arch/riscv/common/vmem.c')

diff --git a/arch/riscv/common/vmem.c b/arch/riscv/common/vmem.c
deleted file mode 100644
index 6b022e1..0000000
--- a/arch/riscv/common/vmem.c
+++ /dev/null
@@ -1,104 +0,0 @@
-#include <apos/string.h>
-#include <apos/pmem.h>
-#include <apos/vmem.h>
-#include <apos/mem.h>
-#include <apos/debug.h>
-#include <pages.h>
-
-#define pte_ppn(pte) (((pm_t)(pte)) >> 10)
-#define pte_flags(pte) (((pm_t)(pte)) & 0xff)
-#define to_pte(p, f) ((pm_to_pnum(p) << 10) + (f))
-#define pte_addr(pte) (pnum_to_paddr(pte_ppn(pte)))
-#define vm_to_index(a, o) (pm_to_index(a, o))
-
-#if defined(KERNEL)
-
-static vm_t *tmp_pte = 0;
-void arch_init_vmem(struct vm_branch_t *branch, vm_t pte)
-{
-	(void)branch;
-	tmp_pte = (vm_t *)pte;
-}
-
-/* this seems like an awful idea, should probably try to come up with a smarter
- * approach? flushing the cache every time is probably pretty slow and also
- * this code doesn't take into account the cpu ASID, although that's probably
- * not relevant here */
-
-/* what I probably should do is something like Linux, where the kernel has a
- * direct (or linear, I suppose?) so that all direct memory accesses are also
- * accessible from virtual memory. Not entirely sure how I should do that,
- * wouldn't there be situations where the RAM is larger than the allocated
- * memory region?
- *
- * Or maybe some kind of walker, where I maintain a virtual page table that
- * mirrors the physical page table? Not sure yet, but this seems to work for
- * _now_.
- */
-#define QUOTE2(x) #x
-#define QUOTE(x) QUOTE2(x)
-static void *set_vptr(uint8_t flags, pm_t a)
-{
-	*tmp_pte = to_pte(a, flags);
-	__asm__ ("sfence.vma %0, %1"
-			:: "rk" (0), "rK" (TMP_PTE)
-			: "memory");
-
-	return (void *)TMP_PTE;
-}
-
-#else
-struct vm_branch_t *arch_get_tmp_pte(struct vm_branch_t *branch)
-{
-	enum mm_order_t top = __mm_max_order;
-	while(top){
-		size_t idx = vm_to_index(TMP_PTE, top);
-		branch = (struct vm_branch_t *)pte_addr(branch->leaf[idx]);
-		top--;
-	}
-
-	return branch;
-}
-
-#define set_vptr(flags, a) (a)
-#endif
-
-void map_vmem(struct vm_branch_t *branch,
-		pm_t paddr, vm_t vaddr, uint8_t flags, enum mm_order_t order)
-{
-	enum mm_order_t top = __mm_max_order;
-	while (top != order) {
-		size_t idx = vm_to_index(vaddr, top);
-
-		if (!branch->leaf[idx]) {
-			pm_t new_leaf = alloc_page(MM_KPAGE, 0);
-			branch->leaf[idx] =
-				(struct vm_branch_t *)to_pte(new_leaf, VM_V);
-
-			void *leaf_ptr = (void *)set_vptr(VM_R | VM_W | VM_V, new_leaf);
-			memset(leaf_ptr, 0, sizeof(struct vm_branch_t));
-		}
-
-		pm_t pte = (pm_t)branch->leaf[idx];
-		pm_t branch_pptr = (pm_t)pte_addr(pte);
-		branch = (struct vm_branch_t *)set_vptr(VM_R | VM_W | VM_V, branch_pptr);
-		top--;
-	}
-
-	size_t idx = vm_to_index(vaddr, top);
-	branch->leaf[idx] = (struct vm_branch_t *)to_pte(paddr, flags);
-}
-
-void unmap_vmem(struct vm_branch_t *branch, vm_t vaddr, enum mm_order_t order)
-{
-	while (order) {
-		size_t idx = pm_to_index(vaddr, order);
-		branch = (struct vm_branch_t *)pte_addr(branch->leaf[idx]);
-	}
-
-	size_t idx = pm_to_index(vaddr, order);
-	if (branch->leaf[idx])
-		free_page(order, pte_addr(branch->leaf[idx]));
-
-	branch->leaf[idx] = 0;
-}
-- 
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