Revision 8339f0008c47cdd921c73f6d53d5588b5484f93c authored by Eric W. Biederman on 29 January 2007, 20:19:05 UTC, committed by Linus Torvalds on 30 January 2007, 16:29:58 UTC
When the world was a simple and static place setting up irqs was easy.
It sufficed to allocate a linux irq number and a find a free cpu
vector we could receive that linux irq on.  In those days it was
a safe assumption that any allocated vector was actually in use
so after one global pass through all of the vectors we would have
none left.

These days things are much more dynamic with interrupt controllers
(in the form of MSI or MSI-X) appearing on plug in cards and linux
irqs appearing and disappearing.  As these irqs come and go vectors
are allocated and freed,  invalidating the ancient assumption that all
allocated vectors stayed in use forever.

So this patch modifies the vector allocator to walk through every
possible vector before giving up, and to check to see if a vector
is in use before assigning it.  With these changes we stop leaking
freed vectors and it becomes possible to allocate and free irq vectors
all day long.

This changed was modeled after the vector allocator on x86_64 where
this limitation has already been removed.  In essence we don't update
the static variables that hold the position of the last vector we
allocated until have successfully allocated another vector.  This
allows us to detect if we have completed one complete scan through
all of the possible vectors.

Acked-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent c9cc8e7
Raw File
cpufeature.h
/*
 * cpufeature.h
 *
 * Defines x86 CPU feature bits
 */

#ifndef __ASM_X8664_CPUFEATURE_H
#define __ASM_X8664_CPUFEATURE_H

#define NCAPINTS	7	/* N 32-bit words worth of info */

/* Intel-defined CPU features, CPUID level 0x00000001, word 0 */
#define X86_FEATURE_FPU		(0*32+ 0) /* Onboard FPU */
#define X86_FEATURE_VME		(0*32+ 1) /* Virtual Mode Extensions */
#define X86_FEATURE_DE		(0*32+ 2) /* Debugging Extensions */
#define X86_FEATURE_PSE 	(0*32+ 3) /* Page Size Extensions */
#define X86_FEATURE_TSC		(0*32+ 4) /* Time Stamp Counter */
#define X86_FEATURE_MSR		(0*32+ 5) /* Model-Specific Registers, RDMSR, WRMSR */
#define X86_FEATURE_PAE		(0*32+ 6) /* Physical Address Extensions */
#define X86_FEATURE_MCE		(0*32+ 7) /* Machine Check Architecture */
#define X86_FEATURE_CX8		(0*32+ 8) /* CMPXCHG8 instruction */
#define X86_FEATURE_APIC	(0*32+ 9) /* Onboard APIC */
#define X86_FEATURE_SEP		(0*32+11) /* SYSENTER/SYSEXIT */
#define X86_FEATURE_MTRR	(0*32+12) /* Memory Type Range Registers */
#define X86_FEATURE_PGE		(0*32+13) /* Page Global Enable */
#define X86_FEATURE_MCA		(0*32+14) /* Machine Check Architecture */
#define X86_FEATURE_CMOV	(0*32+15) /* CMOV instruction (FCMOVCC and FCOMI too if FPU present) */
#define X86_FEATURE_PAT		(0*32+16) /* Page Attribute Table */
#define X86_FEATURE_PSE36	(0*32+17) /* 36-bit PSEs */
#define X86_FEATURE_PN		(0*32+18) /* Processor serial number */
#define X86_FEATURE_CLFLSH	(0*32+19) /* Supports the CLFLUSH instruction */
#define X86_FEATURE_DS		(0*32+21) /* Debug Store */
#define X86_FEATURE_ACPI	(0*32+22) /* ACPI via MSR */
#define X86_FEATURE_MMX		(0*32+23) /* Multimedia Extensions */
#define X86_FEATURE_FXSR	(0*32+24) /* FXSAVE and FXRSTOR instructions (fast save and restore */
				          /* of FPU context), and CR4.OSFXSR available */
#define X86_FEATURE_XMM		(0*32+25) /* Streaming SIMD Extensions */
#define X86_FEATURE_XMM2	(0*32+26) /* Streaming SIMD Extensions-2 */
#define X86_FEATURE_SELFSNOOP	(0*32+27) /* CPU self snoop */
#define X86_FEATURE_HT		(0*32+28) /* Hyper-Threading */
#define X86_FEATURE_ACC		(0*32+29) /* Automatic clock control */
#define X86_FEATURE_IA64	(0*32+30) /* IA-64 processor */

/* AMD-defined CPU features, CPUID level 0x80000001, word 1 */
/* Don't duplicate feature flags which are redundant with Intel! */
#define X86_FEATURE_SYSCALL	(1*32+11) /* SYSCALL/SYSRET */
#define X86_FEATURE_MMXEXT	(1*32+22) /* AMD MMX extensions */
#define X86_FEATURE_FXSR_OPT	(1*32+25) /* FXSR optimizations */
#define X86_FEATURE_RDTSCP	(1*32+27) /* RDTSCP */
#define X86_FEATURE_LM		(1*32+29) /* Long Mode (x86-64) */
#define X86_FEATURE_3DNOWEXT	(1*32+30) /* AMD 3DNow! extensions */
#define X86_FEATURE_3DNOW	(1*32+31) /* 3DNow! */

/* Transmeta-defined CPU features, CPUID level 0x80860001, word 2 */
#define X86_FEATURE_RECOVERY	(2*32+ 0) /* CPU in recovery mode */
#define X86_FEATURE_LONGRUN	(2*32+ 1) /* Longrun power control */
#define X86_FEATURE_LRTI	(2*32+ 3) /* LongRun table interface */

/* Other features, Linux-defined mapping, word 3 */
/* This range is used for feature bits which conflict or are synthesized */
#define X86_FEATURE_CXMMX	(3*32+ 0) /* Cyrix MMX extensions */
#define X86_FEATURE_K6_MTRR	(3*32+ 1) /* AMD K6 nonstandard MTRRs */
#define X86_FEATURE_CYRIX_ARR	(3*32+ 2) /* Cyrix ARRs (= MTRRs) */
#define X86_FEATURE_CENTAUR_MCR	(3*32+ 3) /* Centaur MCRs (= MTRRs) */
#define X86_FEATURE_REP_GOOD	(3*32+ 4) /* rep microcode works well on this CPU */
#define X86_FEATURE_CONSTANT_TSC (3*32+5) /* TSC runs at constant rate */
#define X86_FEATURE_SYNC_RDTSC  (3*32+6)  /* RDTSC syncs CPU core */
#define X86_FEATURE_FXSAVE_LEAK (3*32+7)  /* FIP/FOP/FDP leaks through FXSAVE */
#define X86_FEATURE_UP		(3*32+8) /* SMP kernel running on UP */
#define X86_FEATURE_ARCH_PERFMON (3*32+9) /* Intel Architectural PerfMon */
#define X86_FEATURE_PEBS	(3*32+10) /* Precise-Event Based Sampling */
#define X86_FEATURE_BTS		(3*32+11) /* Branch Trace Store */

/* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
#define X86_FEATURE_XMM3	(4*32+ 0) /* Streaming SIMD Extensions-3 */
#define X86_FEATURE_MWAIT	(4*32+ 3) /* Monitor/Mwait support */
#define X86_FEATURE_DSCPL	(4*32+ 4) /* CPL Qualified Debug Store */
#define X86_FEATURE_EST		(4*32+ 7) /* Enhanced SpeedStep */
#define X86_FEATURE_TM2		(4*32+ 8) /* Thermal Monitor 2 */
#define X86_FEATURE_CID		(4*32+10) /* Context ID */
#define X86_FEATURE_CX16	(4*32+13) /* CMPXCHG16B */
#define X86_FEATURE_XTPR	(4*32+14) /* Send Task Priority Messages */

/* VIA/Cyrix/Centaur-defined CPU features, CPUID level 0xC0000001, word 5 */
#define X86_FEATURE_XSTORE	(5*32+ 2) /* on-CPU RNG present (xstore insn) */
#define X86_FEATURE_XSTORE_EN	(5*32+ 3) /* on-CPU RNG enabled */
#define X86_FEATURE_XCRYPT	(5*32+ 6) /* on-CPU crypto (xcrypt insn) */
#define X86_FEATURE_XCRYPT_EN	(5*32+ 7) /* on-CPU crypto enabled */

/* More extended AMD flags: CPUID level 0x80000001, ecx, word 6 */
#define X86_FEATURE_LAHF_LM	(6*32+ 0) /* LAHF/SAHF in long mode */
#define X86_FEATURE_CMP_LEGACY	(6*32+ 1) /* If yes HyperThreading not valid */

#define cpu_has(c, bit)                test_bit(bit, (c)->x86_capability)
#define boot_cpu_has(bit)      test_bit(bit, boot_cpu_data.x86_capability)

#define cpu_has_fpu            1
#define cpu_has_vme            0
#define cpu_has_de             1
#define cpu_has_pse            1
#define cpu_has_tsc            1
#define cpu_has_pae            ___BUG___
#define cpu_has_pge            1
#define cpu_has_apic           boot_cpu_has(X86_FEATURE_APIC)
#define cpu_has_mtrr           1
#define cpu_has_mmx            1
#define cpu_has_fxsr           1
#define cpu_has_xmm            1
#define cpu_has_xmm2           1
#define cpu_has_xmm3           boot_cpu_has(X86_FEATURE_XMM3)
#define cpu_has_ht             boot_cpu_has(X86_FEATURE_HT)
#define cpu_has_mp             1 /* XXX */
#define cpu_has_k6_mtrr        0
#define cpu_has_cyrix_arr      0
#define cpu_has_centaur_mcr    0
#define cpu_has_clflush	       boot_cpu_has(X86_FEATURE_CLFLSH)
#define cpu_has_ds 	       boot_cpu_has(X86_FEATURE_DS)
#define cpu_has_pebs 	       boot_cpu_has(X86_FEATURE_PEBS)
#define cpu_has_bts 	       boot_cpu_has(X86_FEATURE_BTS)

#endif /* __ASM_X8664_CPUFEATURE_H */
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