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-rw-r--r--src/kernel/mm/vm.cc459
1 files changed, 0 insertions, 459 deletions
diff --git a/src/kernel/mm/vm.cc b/src/kernel/mm/vm.cc
deleted file mode 100644
index be2f2f2..0000000
--- a/src/kernel/mm/vm.cc
+++ /dev/null
@@ -1,459 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * Copyright (C) 2026 Richard QIn
- */
-#include "kernel/mm.h"
-#include "kernel/pmm.h"
-#include "kernel/riscv.h"
-#include "common/types.h"
-#include "lib/string.h"
-#include "drivers/uart.h"
-#include "kernel/fdt.h"
-
-extern "C"
-{
- extern char kernel_end[];
- extern char trampoline[];
-}
-
-namespace VM
-{
-
- uint64 *kernel_pagetable;
-
- static void page_ref_inc(uint64 pa)
- {
- struct Page *p = PMM::pa_to_page(pa);
- if (p)
- {
- __atomic_add_fetch(&p->refcnt, 1, __ATOMIC_RELAXED);
- }
- }
-
- static bool page_ref_dec(uint64 pa)
- {
- struct Page *p = PMM::pa_to_page(pa);
- if (p)
- {
- if (__atomic_sub_fetch(&p->refcnt, 1, __ATOMIC_RELEASE) == 0)
- {
- return true;
- }
- }
- return false;
- }
-
- static uint64 *walk(uint64 *pagetable, uint64 va, int alloc)
- {
- if (va >= MAXVA)
- return nullptr;
-
- for (int level = 2; level > 0; level--)
- {
- uint64 *pte = &pagetable[PX(level, va)];
- if (*pte & PTE_V)
- {
- pagetable = (uint64 *)PTE2PA(*pte);
- }
- else
- {
- if (!alloc || (pagetable = (uint64 *)PMM::alloc_page()) == nullptr)
- return nullptr;
-
- memset(pagetable, 0, PGSIZE);
- *pte = PA2PTE(pagetable) | PTE_V;
- }
- }
- return &pagetable[PX(0, va)];
- }
-
- int mappages(uint64 *pagetable, uint64 va, uint64 size, uint64 pa, int perm)
- {
- uint64 a, last;
- uint64 *pte;
-
- if (size == 0)
- return -1;
-
- a = PGROUNDDOWN(va);
- last = PGROUNDDOWN(va + size - 1);
-
- for (;;)
- {
- if ((pte = walk(pagetable, a, 1)) == nullptr)
- return -1;
-
- if (*pte & PTE_V)
- {
- return -1;
- }
-
- *pte = PA2PTE(pa) | perm | PTE_V;
-
- if (a == last)
- break;
- a += PGSIZE;
- pa += PGSIZE;
- }
- return 0;
- }
-
- uint64 *uvmcreate()
- {
- uint64 *pagetable = (uint64 *)PMM::alloc_page();
- if (pagetable)
- {
- memset(pagetable, 0, PGSIZE);
-
- if (mappages(pagetable, TRAMPOLINE, PGSIZE, (uint64)trampoline, PTE_R | PTE_X) < 0)
- {
- PMM::free_page(pagetable);
- return nullptr;
- }
- }
- return pagetable;
- }
-
- void uvminit(uint64 *pagetable, uchar *src, uint64 sz)
- {
- char *mem;
-
- if (sz >= PGSIZE)
- {
- Drivers::uart_puts("uvminit: initcode too big!\n");
- return;
- }
-
- mem = (char *)PMM::alloc_page();
- memset(mem, 0, PGSIZE);
-
- mappages(pagetable, 0, PGSIZE, (uint64)mem, PTE_W | PTE_R | PTE_X | PTE_U);
- memmove(mem, src, sz);
- }
-
- uint64 uvmalloc(uint64 *pagetable, uint64 oldsz, uint64 newsz, int xperm)
- {
- char *mem;
- uint64 a;
-
- if (newsz < oldsz)
- return oldsz;
-
- oldsz = PGROUNDUP(oldsz);
- for (a = oldsz; a < newsz; a += PGSIZE)
- {
- mem = (char *)PMM::alloc_page();
- if (mem == nullptr)
- {
- uvmdealloc(pagetable, a, oldsz);
- return 0;
- }
- memset(mem, 0, PGSIZE);
- if (mappages(pagetable, a, PGSIZE, (uint64)mem, PTE_R | PTE_U | xperm) != 0)
- {
- PMM::free_page(mem);
- uvmdealloc(pagetable, a, oldsz);
- return 0;
- }
- }
- return newsz;
- }
-
- uint64 uvmdealloc(uint64 *pagetable, uint64 oldsz, uint64 newsz)
- {
- if (newsz >= oldsz)
- return oldsz;
-
- if (PGROUNDUP(newsz) < PGROUNDUP(oldsz))
- {
- int npages = (PGROUNDUP(oldsz) - PGROUNDUP(newsz)) / PGSIZE;
- uvmunmap(pagetable, PGROUNDUP(newsz), npages, 1);
- }
-
- return newsz;
- }
-
- void uvmunmap(uint64 *pagetable, uint64 va, uint64 npages, int do_free)
- {
- uint64 a;
- uint64 *pte;
-
- if ((va % PGSIZE) != 0)
- return;
-
- for (a = va; a < va + npages * PGSIZE; a += PGSIZE)
- {
- if ((pte = walk(pagetable, a, 0)) == nullptr)
- continue;
-
- if ((*pte & PTE_V) == 0)
- continue;
-
- if ((PTE_FLAGS(*pte) & (PTE_R | PTE_W | PTE_X)) == 0)
- {
- continue;
- }
-
- if (do_free)
- {
- uint64 pa = PTE2PA(*pte);
- if (page_ref_dec(pa))
- {
- PMM::free_page((void *)pa);
- }
- }
- *pte = 0;
- }
- }
-
- static void freewalk(uint64 *pagetable)
- {
- for (int i = 0; i < 512; i++)
- {
- uint64 pte = pagetable[i];
- if ((pte & PTE_V) && (pte & (PTE_R | PTE_W | PTE_X)) == 0)
- {
- uint64 *child = (uint64 *)PTE2PA(pte);
- freewalk(child);
- pagetable[i] = 0;
- }
- }
- PMM::free_page(pagetable);
- }
-
- void uvmfree(uint64 *pagetable, uint64 sz)
- {
- if (sz > 0)
- uvmunmap(pagetable, 0, PGROUNDUP(sz) / PGSIZE, 1);
- freewalk(pagetable);
- }
-
- int uvmcopy(uint64 *oldpt, uint64 *newpt, uint64 sz)
- {
- uint64 *pte;
- uint64 pa, i;
- uint flags;
-
- for (i = 0; i < sz; i += PGSIZE)
- {
- if ((pte = walk(oldpt, i, 0)) == nullptr)
- continue;
- if ((*pte & PTE_V) == 0)
- continue;
-
- pa = PTE2PA(*pte);
- flags = PTE_FLAGS(*pte);
-
- if (flags & PTE_W)
- {
- flags &= ~PTE_W;
- flags |= PTE_COW;
- *pte = PA2PTE(pa) | flags;
- }
-
- if (mappages(newpt, i, PGSIZE, pa, flags) != 0)
- {
- return -1;
- }
-
- page_ref_inc(pa);
- }
-
- sfence_vma();
- return 0;
- }
-
- int handle_cow_fault(uint64 *pagetable, uint64 va);
-
- int copyout(uint64 *pagetable, uint64 dstva, char *src, uint64 len)
- {
- uint64 n, va0, pa0;
- uint64 *pte;
-
- while (len > 0)
- {
- va0 = PGROUNDDOWN(dstva);
- pte = walk(pagetable, va0, 0);
- if (pte == nullptr || (*pte & PTE_V) == 0 || (*pte & PTE_U) == 0)
- return -1;
-
- // Note: Maybe a bug
- if (*pte & PTE_COW)
- {
- if (handle_cow_fault(pagetable, va0) < 0)
- return -1;
- // Re-walk because handle_cow_fault replaced the page mapping
- pte = walk(pagetable, va0, 0);
- if (pte == nullptr || (*pte & PTE_V) == 0 || (*pte & PTE_U) == 0)
- return -1;
- }
-
- pa0 = PTE2PA(*pte);
- n = PGSIZE - (dstva - va0);
- if (n > len)
- n = len;
-
- memmove((void *)(pa0 + (dstva - va0)), src, n);
-
- len -= n;
- src += n;
- dstva = va0 + PGSIZE;
- }
- return 0;
- }
-
- int copyin(uint64 *pagetable, char *dst, uint64 srcva, uint64 len)
- {
- uint64 n, va0, pa0;
- uint64 *pte;
-
- while (len > 0)
- {
- va0 = PGROUNDDOWN(srcva);
- pte = walk(pagetable, va0, 0);
- if (pte == nullptr || (*pte & PTE_V) == 0 || (*pte & PTE_U) == 0)
- return -1;
-
- pa0 = PTE2PA(*pte);
- n = PGSIZE - (srcva - va0);
- if (n > len)
- n = len;
-
- memmove(dst, (void *)(pa0 + (srcva - va0)), n);
-
- len -= n;
- dst += n;
- srcva = va0 + PGSIZE;
- }
- return 0;
- }
-
- int copyinstr(uint64 *pagetable, char *dst, uint64 srcva, uint64 max)
- {
- uint64 n, va0, pa0;
- uint64 *pte;
- int got_null = 0;
- uint64 len = 0;
-
- while (len < max)
- {
- va0 = PGROUNDDOWN(srcva);
- pte = walk(pagetable, va0, 0);
-
- if (pte == nullptr || (*pte & PTE_V) == 0 || (*pte & PTE_U) == 0)
- return -1;
-
- pa0 = PTE2PA(*pte);
-
- n = PGSIZE - (srcva - va0);
- if (n > max - len)
- n = max - len;
-
- char *p = (char *)(pa0 + (srcva - va0));
- while (n > 0)
- {
- if (*p == '\0')
- {
- *dst = '\0';
- got_null = 1;
- break;
- }
- *dst = *p;
- n--;
- srcva++;
- dst++;
- p++;
- len++;
- }
- if (got_null)
- break;
- }
-
- if (got_null)
- return 0;
-
- return -1;
- }
-
- int handle_cow_fault(uint64 *pagetable, uint64 va)
- {
- if (va >= MAXVA)
- return -1;
-
- uint64 *pte = walk(pagetable, va, 0);
- if (pte == nullptr || (*pte & PTE_V) == 0 || (*pte & PTE_U) == 0)
- return -1;
-
- if ((*pte & PTE_COW) == 0)
- return -1;
-
- uint64 pa = PTE2PA(*pte);
- uint64 flags = PTE_FLAGS(*pte);
-
- char *mem = (char *)PMM::alloc_page();
- if (mem == nullptr)
- return -1;
-
- memmove(mem, (char *)pa, PGSIZE);
-
- uint64 new_flags = (flags | PTE_W) & ~PTE_COW;
- *pte = PA2PTE((uint64)mem) | new_flags | PTE_V;
-
- if (page_ref_dec(pa))
- {
- PMM::free_page((void *)pa);
- }
-
- sfence_vma();
- return 0;
- }
-
- static void kvmmap(uint64 va, uint64 pa, uint64 sz, int perm)
- {
- if (mappages(kernel_pagetable, va, sz, pa, perm) != 0)
- {
- Drivers::uart_puts("kvmmap: failed\n");
- while (1)
- ;
- }
- }
-
- void kvminit()
- {
- kernel_pagetable = uvmcreate();
-
- // 1. Map all device MMIO regions discovered by FDT
- for (int i = 0; i < g_devices.mmio_count; i++)
- {
- uint64 base = g_devices.mmio_regions[i].base;
- uint64 size = g_devices.mmio_regions[i].size;
- kvmmap(base, base, size, PTE_R | PTE_W);
- }
-
- // 2. Map Kernel Memory (PHYSTOP is now dynamic based on FDT)
- kvmmap(KERNBASE, KERNBASE, PHYSTOP - KERNBASE, PTE_R | PTE_W | PTE_X);
- }
-
- void kvminithart()
- {
- w_satp(MAKE_SATP(kernel_pagetable));
- sfence_vma();
- Drivers::uart_puts("[Boot] MMU ENABLED! Using virtual addresses.\n");
- }
-
- uint64 walkaddr(uint64 *pagetable, uint64 va)
- {
- uint64 *pte;
- uint64 pa;
-
- if (va >= MAXVA)
- return 0;
-
- pte = walk(pagetable, va, 0);
- if (pte == 0 || (*pte & PTE_V) == 0 || (*pte & PTE_U) == 0)
- return 0;
-
- pa = PTE2PA(*pte);
- return pa;
- }
-} \ No newline at end of file
generated by cgit v1.2.3 (git 2.46.0) at 2026-10-29 09:42:02 +0000