cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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match.c (2719B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <asm/cpu_device_id.h>
      3#include <asm/cpufeature.h>
      4#include <linux/cpu.h>
      5#include <linux/export.h>
      6#include <linux/slab.h>
      7
      8/**
      9 * x86_match_cpu - match current CPU again an array of x86_cpu_ids
     10 * @match: Pointer to array of x86_cpu_ids. Last entry terminated with
     11 *         {}.
     12 *
     13 * Return the entry if the current CPU matches the entries in the
     14 * passed x86_cpu_id match table. Otherwise NULL.  The match table
     15 * contains vendor (X86_VENDOR_*), family, model and feature bits or
     16 * respective wildcard entries.
     17 *
     18 * A typical table entry would be to match a specific CPU
     19 *
     20 * X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6, INTEL_FAM6_BROADWELL,
     21 *				      X86_FEATURE_ANY, NULL);
     22 *
     23 * Fields can be wildcarded with %X86_VENDOR_ANY, %X86_FAMILY_ANY,
     24 * %X86_MODEL_ANY, %X86_FEATURE_ANY (except for vendor)
     25 *
     26 * asm/cpu_device_id.h contains a set of useful macros which are shortcuts
     27 * for various common selections. The above can be shortened to:
     28 *
     29 * X86_MATCH_INTEL_FAM6_MODEL(BROADWELL, NULL);
     30 *
     31 * Arrays used to match for this should also be declared using
     32 * MODULE_DEVICE_TABLE(x86cpu, ...)
     33 *
     34 * This always matches against the boot cpu, assuming models and features are
     35 * consistent over all CPUs.
     36 */
     37const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match)
     38{
     39	const struct x86_cpu_id *m;
     40	struct cpuinfo_x86 *c = &boot_cpu_data;
     41
     42	for (m = match;
     43	     m->vendor | m->family | m->model | m->steppings | m->feature;
     44	     m++) {
     45		if (m->vendor != X86_VENDOR_ANY && c->x86_vendor != m->vendor)
     46			continue;
     47		if (m->family != X86_FAMILY_ANY && c->x86 != m->family)
     48			continue;
     49		if (m->model != X86_MODEL_ANY && c->x86_model != m->model)
     50			continue;
     51		if (m->steppings != X86_STEPPING_ANY &&
     52		    !(BIT(c->x86_stepping) & m->steppings))
     53			continue;
     54		if (m->feature != X86_FEATURE_ANY && !cpu_has(c, m->feature))
     55			continue;
     56		return m;
     57	}
     58	return NULL;
     59}
     60EXPORT_SYMBOL(x86_match_cpu);
     61
     62static const struct x86_cpu_desc *
     63x86_match_cpu_with_stepping(const struct x86_cpu_desc *match)
     64{
     65	struct cpuinfo_x86 *c = &boot_cpu_data;
     66	const struct x86_cpu_desc *m;
     67
     68	for (m = match; m->x86_family | m->x86_model; m++) {
     69		if (c->x86_vendor != m->x86_vendor)
     70			continue;
     71		if (c->x86 != m->x86_family)
     72			continue;
     73		if (c->x86_model != m->x86_model)
     74			continue;
     75		if (c->x86_stepping != m->x86_stepping)
     76			continue;
     77		return m;
     78	}
     79	return NULL;
     80}
     81
     82bool x86_cpu_has_min_microcode_rev(const struct x86_cpu_desc *table)
     83{
     84	const struct x86_cpu_desc *res = x86_match_cpu_with_stepping(table);
     85
     86	if (!res || res->x86_microcode_rev > boot_cpu_data.microcode)
     87		return false;
     88
     89	return true;
     90}
     91EXPORT_SYMBOL_GPL(x86_cpu_has_min_microcode_rev);