Changeset 74df77d in mainline

Timestamp:

2005-06-10T16:18:43Z (20 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

87cd61f

Parents:

18e0a6c

Message:

Add map_structure() to automate mapping of memory structures that can span multiple pages and/or cross page boundaries.
Change ACPI map_sdt() to use map_structure().

Small changes in MPS code.
The extra frame allocation for accessing frame 0 is unnecessary as it is possible to access frame 0 from kernel address space.
Zero TSS descriptor in the newly prepared GDT.

Files:

• arch/ia32/include/atomic.h (modified) (2 diffs)
• arch/ia32/src/acpi/acpi.c (modified) (1 diff)
• arch/ia32/src/mm/page.c (modified) (1 diff)
• arch/ia32/src/smp/mps.c (modified) (3 diffs)
• include/mm/page.h (modified) (2 diffs)
• src/mm/page.c (modified) (2 diffs)

arch/ia32/include/atomic.h

@@ -48 +48 @@
 }
 
-static inline int test_and_set(int *val) {
+static inline int test_and_set(volatile int *val) {
         int v;
         
@@ -62 +62 @@
 
 
-extern void spinlock_arch(int *val);
+extern void spinlock_arch(volatile int *val);
 
 #endif

arch/ia32/src/acpi/acpi.c

@@ -79 +79 @@
 void map_sdt(struct acpi_sdt_header *sdt)
 {
-        int i, cnt, length;
-
         map_page_to_frame((__address) sdt, (__address) sdt, PAGE_NOT_CACHEABLE, 0);
-        
-        length = sdt->length + ((__address) sdt) - ((__address) sdt)&0xfffff000;
-        cnt = length/PAGE_SIZE + (length%PAGE_SIZE>0);
-        
-        for (i = 1; i < cnt; i++)
-                map_page_to_frame(((__address) sdt) + i*PAGE_SIZE, ((__address) sdt) + i*PAGE_SIZE, PAGE_NOT_CACHEABLE, 0);
+        map_structure((__address) sdt, sdt->length);
 }
 

arch/ia32/src/mm/page.c

@@ -61 +61 @@
 
                 /*
-                 * Identity mapping for all but 0th page.
-                 * PA2KA(identity) mapping for all but 0th page.
+                 * Identity mapping for all frames.
+                 * PA2KA(identity) mapping for all frames.
                  */
-                for (i = 1; i < frames; i++) {
+                for (i = 0; i < frames; i++) {
                         map_page_to_frame(i * PAGE_SIZE, i * PAGE_SIZE, PAGE_CACHEABLE, KA2PA(dba));
                         map_page_to_frame(PA2KA(i * PAGE_SIZE), i * PAGE_SIZE, PAGE_CACHEABLE, KA2PA(dba));

arch/ia32/src/smp/mps.c

@@ -405 +405 @@
         struct __processor_entry *pr;
         __address src, dst;
-        __address frame;
         int i;
 
@@ -417 +416 @@
         /*
          * We need to access data in frame 0.
-         */
-        frame = frame_alloc(0);
-        map_page_to_frame(frame,0,PAGE_CACHEABLE,0);
+         * We boldly make use of kernel address space mapping.
+         */
 
         /*
          * Set the warm-reset vector to the real-mode address of 4K-aligned ap_boot()
          */
-        *((__u16 *) (frame + 0x467+0)) =  ((__address) ap_boot) >> 4;   /* segment */
-        *((__u16 *) (frame + 0x467+2)) =  0;                            /* offset */
-        
-        /*
-         * Give back and unmap the borrowed frame.
-         */
-        map_page_to_frame(frame,0,PAGE_NOT_PRESENT,0);
-        frame_free(frame);
-
+        *((__u16 *) (PA2KA(0x467+0))) =  ((__address) ap_boot) >> 4;    /* segment */
+        *((__u16 *) (PA2KA(0x467+2))) =  0;                             /* offset */
+        
         /*
          * Save 0xa to address 0xf of the CMOS RAM.
@@ -472 +464 @@
 
                 memcopy(gdt, gdt_new, GDT_ITEMS*sizeof(struct descriptor));
+                memsetb(&gdt_new[TSS_DES], sizeof(struct descriptor), 0);
                 gdtr.base = KA2PA((__address) gdt_new);
 

include/mm/page.h

@@ -32 +32 @@
 #include <arch/types.h>
 #include <arch/mm/page.h>
+#include <typedefs.h>
 
 #define PAGE_NOT_CACHEABLE      (0<<0)
@@ -48 +49 @@
 extern void page_init(void);
 extern void map_page_to_frame(__address page, __address frame, int flags, __address root);
+extern void map_structure(__address s, size_t size);
 
 #endif

src/mm/page.c

@@ -29 +29 @@
 #include <mm/page.h>
 #include <arch/mm/page.h>
+#include <arch/types.h>
+#include <typedefs.h>
 
 void page_init(void)
@@ -35 +37 @@
         map_page_to_frame(0x0, 0x0, PAGE_NOT_PRESENT, 0);
 }
+
+/** Map memory structure
+ *
+ * Identity-map memory structure
+ * considering possible crossings
+ * of page boundaries.
+ *
+ * @param s Address of the structure.
+ * @param size Size of the structure.
+ */
+void map_structure(__address s, size_t size)
+{
+        int i, cnt, length;
+
+        /* TODO: implement portable way of computing page address from address */
+        length = size + (s - (s & 0xfffff000));
+        cnt = length/PAGE_SIZE + (length%PAGE_SIZE>0);
+
+        for (i = 0; i < cnt; i++)
+                map_page_to_frame(s + i*PAGE_SIZE, s + i*PAGE_SIZE, PAGE_NOT_CACHEABLE, 0);
+
+}