patch-2.4.20 linux-2.4.20/include/asm-x86_64/pda.h

• Lines: 75
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/include/asm-x86_64/pda.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/include/asm-x86_64/pda.h linux-2.4.20/include/asm-x86_64/pda.h
@@ -0,0 +1,74 @@
+#ifndef X86_64_PDA_H
+#define X86_64_PDA_H
+
+#include <linux/stddef.h>
+#ifndef ASM_OFFSET_H
+#include <asm/offset.h>
+#endif
+#include <linux/cache.h>
+
+/* Per processor datastructure. %gs points to it while the kernel runs */ 
+/* To use a new field with the *_pda macros it needs to be added to tools/offset.c */
+struct x8664_pda {
+	unsigned long kernelstack;  /* TOS for current process */ 
+	unsigned long oldrsp; 	    /* user rsp for system call */
+	unsigned long irqrsp;	    /* Old rsp for interrupts. */ 
+	struct task_struct *pcurrent;	/* Current process */
+        int irqcount;		    /* Irq nesting counter. Starts with -1 */  	
+	int cpunumber;		    /* Logical CPU number */
+	/* XXX: could be a single list */
+	unsigned long *pgd_quick;
+	unsigned long *pmd_quick;
+	unsigned long *pte_quick;
+	unsigned long pgtable_cache_sz;
+	char *irqstackptr;	/* top of irqstack */
+	unsigned long volatile *level4_pgt; 
+} ____cacheline_aligned;
+
+#define PDA_STACKOFFSET (5*8)
+
+#define IRQSTACK_ORDER 2
+#define IRQSTACKSIZE (PAGE_SIZE << IRQSTACK_ORDER) 
+
+extern struct x8664_pda cpu_pda[];
+
+/* 
+ * There is no fast way to get the base address of the PDA, all the accesses
+ * have to mention %fs/%gs.  So it needs to be done this Torvaldian way.
+ */ 
+#define sizeof_field(type,field)  (sizeof(((type *)0)->field))
+#define typeof_field(type,field)  typeof(((type *)0)->field)
+#ifndef __STR
+#define __STR(x) #x
+#endif
+#define __STR2(x) __STR(x) 
+
+extern void __bad_pda_field(void);
+
+#define pda_to_op(op,field,val) do { \
+       switch (sizeof_field(struct x8664_pda, field)) { 		\
+       case 2: asm volatile(op "w %0,%%gs:" __STR2(pda_ ## field) ::"r" (val):"memory"); break;	\
+       case 4: asm volatile(op "l %0,%%gs:" __STR2(pda_ ## field) ::"r" (val):"memory"); break;	\
+       case 8: asm volatile(op "q %0,%%gs:" __STR2(pda_ ## field) ::"r" (val):"memory"); break;	\
+       default: __bad_pda_field(); 					\
+       } \
+       } while (0)
+
+
+#define pda_from_op(op,field) ({ \
+       typedef typeof_field(struct x8664_pda, field) T__; T__ ret__; \
+       switch (sizeof_field(struct x8664_pda, field)) { 		\
+       case 2: asm volatile(op "w %%gs:" __STR2(pda_ ## field) ",%0":"=r" (ret__)::"memory"); break;	\
+       case 4: asm volatile(op "l %%gs:" __STR2(pda_ ## field) ",%0":"=r" (ret__)::"memory"); break;	\
+       case 8: asm volatile(op "q %%gs:" __STR2(pda_ ## field) ",%0":"=r" (ret__)::"memory"); break;	\
+       default: __bad_pda_field(); 					\
+       } \
+       ret__; })
+
+
+#define read_pda(field) pda_from_op("mov",field)
+#define write_pda(field,val) pda_to_op("mov",field,val)
+#define add_pda(field,val) pda_to_op("add",field,val)
+#define sub_pda(field,val) pda_to_op("sub",field,val)
+
+#endif