61c4628b53
Split the FPU save area from the task struct. This allows easy migration of FPU context, and it's generally cleaner. It also allows the following two optimizations: 1) only allocate when the application actually uses FPU, so in the first lazy FPU trap. This could save memory for non-fpu using apps. Next patch does this lazy allocation. 2) allocate the right size for the actual cpu rather than 512 bytes always. Patches enabling xsave/xrstor support (coming shortly) will take advantage of this. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
90 lines
3.7 KiB
C
90 lines
3.7 KiB
C
/*---------------------------------------------------------------------------+
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| fpu_system.h |
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| Copyright (C) 1992,1994,1997 |
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| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
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| Australia. E-mail billm@suburbia.net |
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+---------------------------------------------------------------------------*/
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#ifndef _FPU_SYSTEM_H
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#define _FPU_SYSTEM_H
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/* system dependent definitions */
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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/* This sets the pointer FPU_info to point to the argument part
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of the stack frame of math_emulate() */
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#define SETUP_DATA_AREA(arg) FPU_info = (struct info *) &arg
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/* s is always from a cpu register, and the cpu does bounds checking
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* during register load --> no further bounds checks needed */
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#define LDT_DESCRIPTOR(s) (((struct desc_struct *)current->mm->context.ldt)[(s) >> 3])
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#define SEG_D_SIZE(x) ((x).b & (3 << 21))
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#define SEG_G_BIT(x) ((x).b & (1 << 23))
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#define SEG_GRANULARITY(x) (((x).b & (1 << 23)) ? 4096 : 1)
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#define SEG_286_MODE(x) ((x).b & ( 0xff000000 | 0xf0000 | (1 << 23)))
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#define SEG_BASE_ADDR(s) (((s).b & 0xff000000) \
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| (((s).b & 0xff) << 16) | ((s).a >> 16))
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#define SEG_LIMIT(s) (((s).b & 0xff0000) | ((s).a & 0xffff))
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#define SEG_EXECUTE_ONLY(s) (((s).b & ((1 << 11) | (1 << 9))) == (1 << 11))
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#define SEG_WRITE_PERM(s) (((s).b & ((1 << 11) | (1 << 9))) == (1 << 9))
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#define SEG_EXPAND_DOWN(s) (((s).b & ((1 << 11) | (1 << 10))) \
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== (1 << 10))
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#define I387 (current->thread.xstate)
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#define FPU_info (I387->soft.info)
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#define FPU_CS (*(unsigned short *) &(FPU_info->___cs))
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#define FPU_SS (*(unsigned short *) &(FPU_info->___ss))
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#define FPU_DS (*(unsigned short *) &(FPU_info->___ds))
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#define FPU_EAX (FPU_info->___eax)
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#define FPU_EFLAGS (FPU_info->___eflags)
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#define FPU_EIP (FPU_info->___eip)
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#define FPU_ORIG_EIP (FPU_info->___orig_eip)
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#define FPU_lookahead (I387->soft.lookahead)
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/* nz if ip_offset and cs_selector are not to be set for the current
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instruction. */
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#define no_ip_update (*(u_char *)&(I387->soft.no_update))
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#define FPU_rm (*(u_char *)&(I387->soft.rm))
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/* Number of bytes of data which can be legally accessed by the current
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instruction. This only needs to hold a number <= 108, so a byte will do. */
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#define access_limit (*(u_char *)&(I387->soft.alimit))
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#define partial_status (I387->soft.swd)
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#define control_word (I387->soft.cwd)
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#define fpu_tag_word (I387->soft.twd)
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#define registers (I387->soft.st_space)
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#define top (I387->soft.ftop)
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#define instruction_address (*(struct address *)&I387->soft.fip)
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#define operand_address (*(struct address *)&I387->soft.foo)
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#define FPU_access_ok(x,y,z) if ( !access_ok(x,y,z) ) \
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math_abort(FPU_info,SIGSEGV)
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#define FPU_abort math_abort(FPU_info, SIGSEGV)
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#undef FPU_IGNORE_CODE_SEGV
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#ifdef FPU_IGNORE_CODE_SEGV
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/* access_ok() is very expensive, and causes the emulator to run
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about 20% slower if applied to the code. Anyway, errors due to bad
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code addresses should be much rarer than errors due to bad data
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addresses. */
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#define FPU_code_access_ok(z)
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#else
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/* A simpler test than access_ok() can probably be done for
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FPU_code_access_ok() because the only possible error is to step
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past the upper boundary of a legal code area. */
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#define FPU_code_access_ok(z) FPU_access_ok(VERIFY_READ,(void __user *)FPU_EIP,z)
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#endif
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#define FPU_get_user(x,y) get_user((x),(y))
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#define FPU_put_user(x,y) put_user((x),(y))
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#endif
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