aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/pda.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/include/asm/pda.h')
-rw-r--r--arch/x86/include/asm/pda.h137
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pda.h b/arch/x86/include/asm/pda.h
new file mode 100644
index 00000000000..80860afffbd
--- /dev/null
+++ b/arch/x86/include/asm/pda.h
@@ -0,0 +1,137 @@
+#ifndef ASM_X86__PDA_H
+#define ASM_X86__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 -1 */
+ unsigned 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;
+ short nodenumber; /* number of current node (32k max) */
+ short in_bootmem; /* pda lives in bootmem */
+ 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;
+ unsigned irq0_irqs;
+ unsigned irq_resched_count;
+ unsigned irq_call_count;
+ unsigned irq_tlb_count;
+ unsigned irq_thermal_count;
+ unsigned irq_threshold_count;
+ unsigned irq_spurious_count;
+} ____cacheline_aligned_in_smp;
+
+extern struct x8664_pda **_cpu_pda;
+extern void pda_init(int);
+
+#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 /* ASM_X86__PDA_H */