1 files changed, 125 insertions, 0 deletions
diff --git a/include/asm-x86/pda.h b/include/asm-x86/pda.h
new file mode 100644
index 000000000000..5642634843c4
--- /dev/null
+++ b/include/asm-x86/pda.h
@@ -0,0 +1,125 @@
+#ifndef X86_64_PDA_H
+#define X86_64_PDA_H
+
+#ifndef __ASSEMBLY__
+#include <linux/stddef.h>
+#include <linux/types.h>
+#include <linux/cache.h>
+#include <asm/page.h>
+
+/* Per processor datastructure. %gs points to it while the kernel runs */ 
+struct x8664_pda {
+	struct task_struct *pcurrent;	/* 0  Current process */
+	unsigned long data_offset;	/* 8 Per cpu data offset from linker
+					   address */
+	unsigned long kernelstack;  /* 16 top of kernel stack for current */
+	unsigned long oldrsp; 	    /* 24 user rsp for system call */
+        int irqcount;		    /* 32 Irq nesting counter. Starts with -1 */
+	int cpunumber;		    /* 36 Logical CPU number */
+#ifdef CONFIG_CC_STACKPROTECTOR
+	unsigned long stack_canary;	/* 40 stack canary value */
+					/* gcc-ABI: this canary MUST be at
+					   offset 40!!! */
+#endif
+	char *irqstackptr;
+	int nodenumber;		    /* number of current node */
+	unsigned int __softirq_pending;
+	unsigned int __nmi_count;	/* number of NMI on this CPUs */
+	short mmu_state;
+	short isidle;
+	struct mm_struct *active_mm;
+	unsigned apic_timer_irqs;
+} ____cacheline_aligned_in_smp;
+
+extern struct x8664_pda *_cpu_pda[];
+extern struct x8664_pda boot_cpu_pda[];
+
+#define cpu_pda(i) (_cpu_pda[i])
+
+/* 
+ * 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.
+ */ 
+extern void __bad_pda_field(void) __attribute__((noreturn));
+
+/*
+ * proxy_pda doesn't actually exist, but tell gcc it is accessed for
+ * all PDA accesses so it gets read/write dependencies right.
+ */
+extern struct x8664_pda _proxy_pda;
+
+#define pda_offset(field) offsetof(struct x8664_pda, field)
+
+#define pda_to_op(op,field,val) do {		\
+	typedef typeof(_proxy_pda.field) T__;	\
+	if (0) { T__ tmp__; tmp__ = (val); }	/* type checking */ \
+	switch (sizeof(_proxy_pda.field)) {	\
+	case 2:					\
+		asm(op "w %1,%%gs:%c2" : 	\
+		    "+m" (_proxy_pda.field) :	\
+		    "ri" ((T__)val),		\
+		    "i"(pda_offset(field))); 	\
+ 		break;				\
+	case 4:					\
+		asm(op "l %1,%%gs:%c2" : 	\
+		    "+m" (_proxy_pda.field) :	\
+		    "ri" ((T__)val),		\
+		    "i" (pda_offset(field))); 	\
+		break;				\
+	case 8:					\
+		asm(op "q %1,%%gs:%c2": 	\
+		    "+m" (_proxy_pda.field) :	\
+		    "ri" ((T__)val),		\
+		    "i"(pda_offset(field))); 	\
+		break;				\
+       default: 				\
+		__bad_pda_field();		\
+       }					\
+       } while (0)
+
+#define pda_from_op(op,field) ({		\
+	typeof(_proxy_pda.field) ret__;		\
+	switch (sizeof(_proxy_pda.field)) {	\
+       	case 2:					\
+		asm(op "w %%gs:%c1,%0" : 	\
+		    "=r" (ret__) :		\
+		    "i" (pda_offset(field)), 	\
+		    "m" (_proxy_pda.field)); 	\
+		 break;				\
+	case 4:					\
+		asm(op "l %%gs:%c1,%0":		\
+		    "=r" (ret__):		\
+		    "i" (pda_offset(field)), 	\
+		    "m" (_proxy_pda.field)); 	\
+		 break;				\
+       case 8:					\
+		asm(op "q %%gs:%c1,%0":		\
+		    "=r" (ret__) :		\
+		    "i" (pda_offset(field)), 	\
+		    "m" (_proxy_pda.field)); 	\
+		 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)
+#define or_pda(field,val) pda_to_op("or",field,val)
+
+/* This is not atomic against other CPUs -- CPU preemption needs to be off */
+#define test_and_clear_bit_pda(bit,field) ({		\
+	int old__;						\
+	asm volatile("btr %2,%%gs:%c3\n\tsbbl %0,%0"		\
+	    : "=r" (old__), "+m" (_proxy_pda.field) 		\
+	    : "dIr" (bit), "i" (pda_offset(field)) : "memory");	\
+	old__;							\
+})
+
+#endif
+
+#define PDA_STACKOFFSET (5*8)
+
+#endif