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-rw-r--r--sys/Makefile1
-rw-r--r--sys/dev/dev_init.c14
-rw-r--r--sys/include/kalloc.h4
-rw-r--r--sys/include/sbi.h6
-rw-r--r--sys/include/vm.h66
-rw-r--r--sys/sys/init.c4
-rw-r--r--sys/sys/vm/vm.c58
7 files changed, 147 insertions, 6 deletions
diff --git a/sys/Makefile b/sys/Makefile
index 970809f..3376c79 100644
--- a/sys/Makefile
+++ b/sys/Makefile
@@ -12,6 +12,7 @@ SRC=\
sys/init.c\
sys/printf.c\
sys/mm/kalloc.c\
+ sys/vm/vm.c\
sys/smp/spinlock.c\
dev/dev_init.c\
diff --git a/sys/dev/dev_init.c b/sys/dev/dev_init.c
index 9933c2a..bacf427 100644
--- a/sys/dev/dev_init.c
+++ b/sys/dev/dev_init.c
@@ -26,6 +26,19 @@ mem_init(struct fdt_header *fdt, struct devicetree *dt)
printf("[mem_init] found %d memory reserve map entries\n", n);
}
+static void
+cpu_init(struct fdt_header *fdt, struct devicetree *dt)
+{
+
+ int cpus = fdt_path_offset(fdt, "/cpus");
+ if (cpus < 0)
+ printf("[dev_init] failed to find cpus node\n");
+
+ int node = 0;
+ fdt_for_each_subnode(node, fdt, cpus) {
+
+ }
+}
struct devicetree
dev_init(struct fdt_header *fdt)
@@ -39,6 +52,7 @@ dev_init(struct fdt_header *fdt)
printf("[dev_init] detecting memory...\n");
mem_init(fdt, &dt);
+ cpu_init(fdt, &dt);
// int offset = fdt_next_node(fdt, offset, 0);
// do {
diff --git a/sys/include/kalloc.h b/sys/include/kalloc.h
index 5553d94..d77eae5 100644
--- a/sys/include/kalloc.h
+++ b/sys/include/kalloc.h
@@ -1,13 +1,15 @@
#ifndef _KALLOC_H
#define _KALLOC_H
+#include <stdint.h>
+
void *kalloc(void);
void *kzalloc(void);
void kfree(void *);
-void kalloc_init(size_t);
+void kalloc_init(uintptr_t end);
void walkfree(void);
diff --git a/sys/include/sbi.h b/sys/include/sbi.h
index 86ca295..7430bc6 100644
--- a/sys/include/sbi.h
+++ b/sys/include/sbi.h
@@ -67,6 +67,12 @@ sbi_debug_console_write_byte(uint8_t byte)
}
static inline void
+sbi_remote_sfence_vma(unsigned long hart_mask, unsigned long hart_mask_base, unsigned long start_addr, unsigned long size)
+{
+ sbi_ecall(0x52464E43, 1, hart_mask, hart_mask_base, start_addr, size, 0, 0);
+}
+
+static inline void
sbi_shutdown(void)
{
sbi_ecall(8, 0, 0, 0, 0, 0, 0, 0);
diff --git a/sys/include/vm.h b/sys/include/vm.h
index 1883ea7..4378552 100644
--- a/sys/include/vm.h
+++ b/sys/include/vm.h
@@ -1,6 +1,70 @@
#ifndef _VM_H
#define _VM_H
-void vminit(void);
+#include <stdint.h>
+
+#define PAGEBITS_VALID (1 << 0)
+#define PAGEBITS_R (1 << 1)
+#define PAGEBITS_W (1 << 2)
+#define PAGEBITS_X (1 << 3)
+#define PAGEBITS_USER (1 << 4)
+#define PAGEBITS_GLOBAL (1 << 5)
+#define PAGEBITS_ACCESSED (1 << 6)
+#define PAGEBITS_DIRTY (1 << 7)
+
+#define PAGEBITS_RO PAGEBITS_R
+#define PAGEBITS_XO PAGEBITS_X
+#define PAGEBITS_RW (PAGEBITS_R | PAGEBITS_W)
+#define PAGEPITS_RX (PAGEBITS_R | PAGEBITS_X)
+#define PAGEBITS_RWX (PAGEBITS_R | PAGEBITS_W | PAGEBITS_X)
+
+#define MODE_SV39 (8L << 60)
+
+typedef uint64_t pt_entry_t;
+typedef struct _pagetable {
+ pt_entry_t entries[512];
+} pagetable_t;
+
+/* allocate kernel pagetable */
+void kptinit(void);
+void kptinithart(void);
+//void kptinitharts(uintptr_t mask);
+
+/* maps virtual address to physical address for @pt. */
+void vmap(pagetable_t *root, uintptr_t vaddr, uintptr_t paddr, int bits, int level);
+
+/* returns address of page table entry for @vaddr. if @alloc, next level page tables will be allocated */
+pt_entry_t *walkpt(pagetable_t *root, uintptr_t vaddr, int alloc);
+
+/* helper functions */
+static inline void write_satp(uintptr_t mode, uintptr_t ppn);
+static inline int pte_is_branch(pt_entry_t);
+static inline int pte_is_valid(pt_entry_t);
+
+#define PA2PTE(pa) ((uintptr_t)pa >> 2)
+#define PTE2PA(pa) ((uintptr_t)pa << 2)
+#define FLUSH_TLB() asm volatile("sfence.vma zero, zero")
+
+static inline void
+write_satp(uintptr_t mode, uintptr_t ppn)
+{
+ FLUSH_TLB();
+ asm volatile("csrw satp, %0" : : "r"((ppn >> 12) | mode));
+ FLUSH_TLB();
+}
+
+static inline int
+pte_is_branch(pt_entry_t e)
+{
+ return ((e & PAGEBITS_RWX) == 0);
+}
+#define pte_is_leaf(e) (!pte_is_branch(e))
+
+static inline int
+pte_is_valid(pt_entry_t e)
+{
+ return (e & PAGEBITS_VALID);
+}
+
#endif /* _VM_H */
diff --git a/sys/sys/init.c b/sys/sys/init.c
index 05e8d49..a2a2543 100644
--- a/sys/sys/init.c
+++ b/sys/sys/init.c
@@ -7,6 +7,7 @@
#include <printf.h>
#include <sbi.h>
#include <stdint.h>
+#include <vm.h>
extern uint64_t HEAP_START;
@@ -29,6 +30,9 @@ init(unsigned long hartid, struct fdt_header *fdt)
kalloc_init(dt.memory.origin + dt.memory.size);
printf("done!\n");
+ printf("allocating kernel pagetable...\n");
+ kptinit();
+
// walkfree();
printf("bringing up other harts...\n");
diff --git a/sys/sys/vm/vm.c b/sys/sys/vm/vm.c
index a9173be..25c4142 100644
--- a/sys/sys/vm/vm.c
+++ b/sys/sys/vm/vm.c
@@ -1,10 +1,60 @@
#include <vm.h>
+#include <stddef.h>
+#include <kalloc.h>
+#include <stdio.h>
#include <asm.h>
-#define SV39 (8L << 60)
+pagetable_t *kpt;
-void
-vminit(void)
+#define VPN(vaddr, level) \
+ (((uintptr_t)vaddr >> (12 + (9 * level))) & 0x1ff)
+
+#define PPN(paddr, level) \
+ (((uintptr_t)paddr >> (12 + (9 * level))) & \
+ ((level == 2) ? 0x3ffffff : 0x1ff))
+
+void
+kptinit(void)
{
- csrw_satp(SATP, (uint64_t)pt >> 12);
+ kpt = kzalloc();
+}
+
+void
+kptinithart(void)
+{
+ FLUSH_TLB();
+ write_satp(MODE_SV39, (uintptr_t)kpt);
+ FLUSH_TLB();
+}
+
+void
+vmap(pagetable_t *root, uintptr_t vaddr, uintptr_t paddr, int bits, int level)
+{
+ if (pte_is_branch(bits))
+ printf("error: pte_is_branch\n"); return;
+
+ pt_entry_t *e = walkpt(root, vaddr, 1);
+ if (pte_is_valid(*e))
+ printf("warning: mapping already exists for this address\n");
+
+ *e = PA2PTE(paddr) | PAGEBITS_VALID | bits;
+}
+
+pt_entry_t *
+walkpt(pagetable_t *root, uintptr_t vaddr, int alloc) {
+ pt_entry_t *pt = root->entries;
+ for (int level = 2; level > 0; level--) {
+ pt_entry_t *e = &pt[VPN(vaddr, level)];
+ if (!pte_is_valid(*e)) {
+ if (!alloc)
+ return NULL;
+ pt = kzalloc();
+ *e = PA2PTE(pt) | PAGEBITS_VALID;
+ continue;
+ }
+ pt = (pt_entry_t *)PTE2PA(*e);
+
+ }
+ /* now we should be at level 0, and e should point to our entry */
+ return &pt[VPN(vaddr, 0)];
}