148f9bb877
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings. In any case, they are temporary and harmless.
This removes all the arch/x86 uses of the __cpuinit macros from
all C files. x86 only had the one __CPUINIT used in assembly files,
and it wasn't paired off with a .previous or a __FINIT, so we can
delete it directly w/o any corresponding additional change there.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
100 lines
2.5 KiB
C
100 lines
2.5 KiB
C
/*
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* Check for extended topology enumeration cpuid leaf 0xb and if it
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* exists, use it for populating initial_apicid and cpu topology
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* detection.
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*/
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#include <linux/cpu.h>
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#include <asm/apic.h>
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#include <asm/pat.h>
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#include <asm/processor.h>
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/* leaf 0xb SMT level */
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#define SMT_LEVEL 0
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/* leaf 0xb sub-leaf types */
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#define INVALID_TYPE 0
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#define SMT_TYPE 1
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#define CORE_TYPE 2
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#define LEAFB_SUBTYPE(ecx) (((ecx) >> 8) & 0xff)
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#define BITS_SHIFT_NEXT_LEVEL(eax) ((eax) & 0x1f)
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#define LEVEL_MAX_SIBLINGS(ebx) ((ebx) & 0xffff)
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/*
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* Check for extended topology enumeration cpuid leaf 0xb and if it
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* exists, use it for populating initial_apicid and cpu topology
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* detection.
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*/
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void detect_extended_topology(struct cpuinfo_x86 *c)
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{
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#ifdef CONFIG_SMP
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unsigned int eax, ebx, ecx, edx, sub_index;
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unsigned int ht_mask_width, core_plus_mask_width;
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unsigned int core_select_mask, core_level_siblings;
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static bool printed;
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if (c->cpuid_level < 0xb)
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return;
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cpuid_count(0xb, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
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/*
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* check if the cpuid leaf 0xb is actually implemented.
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*/
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if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE))
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return;
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set_cpu_cap(c, X86_FEATURE_XTOPOLOGY);
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/*
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* initial apic id, which also represents 32-bit extended x2apic id.
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*/
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c->initial_apicid = edx;
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/*
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* Populate HT related information from sub-leaf level 0.
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*/
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core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
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core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
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sub_index = 1;
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do {
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cpuid_count(0xb, sub_index, &eax, &ebx, &ecx, &edx);
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/*
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* Check for the Core type in the implemented sub leaves.
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*/
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if (LEAFB_SUBTYPE(ecx) == CORE_TYPE) {
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core_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
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core_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
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break;
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}
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sub_index++;
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} while (LEAFB_SUBTYPE(ecx) != INVALID_TYPE);
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core_select_mask = (~(-1 << core_plus_mask_width)) >> ht_mask_width;
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c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, ht_mask_width)
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& core_select_mask;
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c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, core_plus_mask_width);
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/*
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* Reinit the apicid, now that we have extended initial_apicid.
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*/
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c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
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c->x86_max_cores = (core_level_siblings / smp_num_siblings);
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if (!printed) {
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printk(KERN_INFO "CPU: Physical Processor ID: %d\n",
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c->phys_proc_id);
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if (c->x86_max_cores > 1)
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printk(KERN_INFO "CPU: Processor Core ID: %d\n",
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c->cpu_core_id);
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printed = 1;
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}
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return;
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#endif
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}
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