Hack to provide kernel with space for page table.

diff --git a/servers/pm/alloc.c b/servers/pm/alloc.c
index 391e1f823b70be165a329a7c9962b2005712f8f5..edb8e8fcf49a2f27e79fe636c8b16ea7c67880d8 100644 (file)
--- a/servers/pm/alloc.c
+++ b/servers/pm/alloc.c
@@ -227,6 +227,8 @@ phys_clicks *free;          /* memory size summaries */
   *free = 0;
   for (i=NR_MEMS-1; i>=0; i--) {
        if (chunks[i].size > 0) {
+               printf("mem_init: adding (clicks) 0x%x @ 0x%x\n",
+                       chunks[i].size, chunks[i].base);
                free_mem(chunks[i].base, chunks[i].size);
                *free += chunks[i].size;
 #if ENABLE_SWAP

diff --git a/servers/pm/main.c b/servers/pm/main.c
index 0225c1211079ec3d1246f01ba673dd1429054f47..04e98843ba94e89043a51063cab37c3604373632 100644 (file)
--- a/servers/pm/main.c
+++ b/servers/pm/main.c
@@ -32,6 +32,7 @@ FORWARD _PROTOTYPE( int get_nice_value, (int queue)                   );
 FORWARD _PROTOTYPE( void get_mem_chunks, (struct memory *mem_chunks)   );
 FORWARD _PROTOTYPE( void patch_mem_chunks, (struct memory *mem_chunks, 
        struct mem_map *map_ptr)        );
+FORWARD _PROTOTYPE( void do_x86_vm, (struct memory mem_chunks[NR_MEMS])        );
 
 #define click_to_round_k(n) \
        ((unsigned) ((((unsigned long) (n) << CLICK_SHIFT) + 512) / 1024))
@@ -259,6 +260,9 @@ PRIVATE void pm_init()
   }
 #endif /* ENABLE_BOOTDEV */
 
+  /* Withhold some memory from x86 VM */
+  do_x86_vm(mem_chunks);
+
   /* Initialize tables to all physical memory and print memory information. */
   printf("Physical memory:");
   mem_init(mem_chunks, &free_clicks);
@@ -380,3 +384,58 @@ struct mem_map *map_ptr;                   /* memory to remove */
   }
 }
 
+#define PAGE_SIZE      4096
+#define PAGE_TABLE_COVER (1024*PAGE_SIZE)
+/*=========================================================================*
+ *                             do_x86_vm                                  *
+ *=========================================================================*/
+PRIVATE void do_x86_vm(mem_chunks)
+struct memory mem_chunks[NR_MEMS];
+{
+       phys_bytes high, bytes;
+       phys_clicks clicks, base_click;
+       unsigned pages;
+       int i, r;
+
+       /* Compute the highest memory location */
+       high= 0;
+       for (i= 0; i<NR_MEMS; i++)
+       {
+               if (mem_chunks[i].size == 0)
+                       continue;
+               if (mem_chunks[i].base + mem_chunks[i].size > high)
+                       high= mem_chunks[i].base + mem_chunks[i].size;
+       }
+
+       high <<= CLICK_SHIFT;
+       printf("do_x86_vm: found high 0x%x\n", high);
+
+       /* The number of pages we need is one for the page directory, enough
+        * page tables to cover the memory, and one page for alignement.
+        */
+       pages= 1 + (high + PAGE_TABLE_COVER-1)/PAGE_TABLE_COVER + 1;
+       bytes= pages*PAGE_SIZE;
+       clicks= (bytes + CLICK_SIZE-1) >> CLICK_SHIFT;
+
+       printf("do_x86_vm: need %d pages\n", pages);
+       printf("do_x86_vm: need %d bytes\n", bytes);
+       printf("do_x86_vm: need %d clicks\n", clicks);
+
+       for (i= 0; i<NR_MEMS; i++)
+       {
+               if (mem_chunks[i].size <= clicks)
+                       continue;
+               break;
+       }
+       if (i >= NR_MEMS)
+               panic("PM", "not enough memory for VM page tables?", NO_NUM);
+       base_click= mem_chunks[i].base;
+       mem_chunks[i].base += clicks;
+       mem_chunks[i].size -= clicks;
+
+       printf("do_x86_vm: using 0x%x clicks @ 0x%x\n", clicks, base_click);
+       r= sys_vm_setbuf(base_click << CLICK_SHIFT, clicks << CLICK_SHIFT,
+               high);
+       if (r != 0)
+               printf("do_x86_vm: sys_vm_setbuf failed: %d\n", r);
+}