x86/cpu: Track legacy CPU model data only on 32-bit kernels

struct cpu_dev's c_models is only ever set inside CONFIG_X86_32
conditionals (or code that's being built for 32-bit only), so
there's no use of reserving the (empty) space for the model
names in a 64-bit kernel.

Similarly, c_size_cache is only used in the #else of a
CONFIG_X86_64 conditional, so reserving space for (and in one
case even initializing) that field is pointless for 64-bit
kernels too.

While moving both fields to the end of the structure, I also
noticed that:

 - the c_models array size was one too small, potentially causing
   table_lookup_model() to return garbage on Intel CPUs (intel.c's
   instance was lacking the sentinel with family being zero), so the
   patch bumps that by one,

 - c_models' vendor sub-field was unused (and anyway redundant
   with the base structure's c_x86_vendor field), so the patch deletes it.

Also rename the legacy fields so that their legacy nature stands out
and comment their declarations.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/5265036802000078000FC4DB@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 903a264..3daece7 100644 (file)
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -823,8 +823,8 @@ static const struct cpu_dev amd_cpu_dev = {
        .c_vendor       = "AMD",
        .c_ident        = { "AuthenticAMD" },
 #ifdef CONFIG_X86_32
-       .c_models = {
-               { .vendor = X86_VENDOR_AMD, .family = 4, .model_names =
+       .legacy_models = {
+               { .family = 4, .model_names =
                  {
                          [3] = "486 DX/2",
                          [7] = "486 DX/2-WB",
@@ -835,7 +835,7 @@ static const struct cpu_dev amd_cpu_dev = {
                  }
                },
        },
-       .c_size_cache   = amd_size_cache,
+       .legacy_cache_size = amd_size_cache,
 #endif
        .c_early_init   = early_init_amd,
        .c_detect_tlb   = cpu_detect_tlb_amd,

diff --git a/arch/x86/kernel/cpu/centaur.c b/arch/x86/kernel/cpu/centaur.c
index fbf6c3b..8d5652d 100644 (file)
--- a/arch/x86/kernel/cpu/centaur.c
+++ b/arch/x86/kernel/cpu/centaur.c
@@ -468,10 +468,10 @@ static void init_centaur(struct cpuinfo_x86 *c)
 #endif
 }
 
+#ifdef CONFIG_X86_32
 static unsigned int
 centaur_size_cache(struct cpuinfo_x86 *c, unsigned int size)
 {
-#ifdef CONFIG_X86_32
        /* VIA C3 CPUs (670-68F) need further shifting. */
        if ((c->x86 == 6) && ((c->x86_model == 7) || (c->x86_model == 8)))
                size >>= 8;
@@ -484,16 +484,18 @@ centaur_size_cache(struct cpuinfo_x86 *c, unsigned int size)
        if ((c->x86 == 6) && (c->x86_model == 9) &&
                                (c->x86_mask == 1) && (size == 65))
                size -= 1;
-#endif
        return size;
 }
+#endif
 
 static const struct cpu_dev centaur_cpu_dev = {
        .c_vendor       = "Centaur",
        .c_ident        = { "CentaurHauls" },
        .c_early_init   = early_init_centaur,
        .c_init         = init_centaur,
-       .c_size_cache   = centaur_size_cache,
+#ifdef CONFIG_X86_32
+       .legacy_cache_size = centaur_size_cache,
+#endif
        .c_x86_vendor   = X86_VENDOR_CENTAUR,
 };
 

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 2793d1f..9ada0b3 100644 (file)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -346,7 +346,8 @@ static void filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
 /* Look up CPU names by table lookup. */
 static const char *table_lookup_model(struct cpuinfo_x86 *c)
 {
-       const struct cpu_model_info *info;
+#ifdef CONFIG_X86_32
+       const struct legacy_cpu_model_info *info;
 
        if (c->x86_model >= 16)
                return NULL;    /* Range check */
@@ -354,13 +355,14 @@ static const char *table_lookup_model(struct cpuinfo_x86 *c)
        if (!this_cpu)
                return NULL;
 
-       info = this_cpu->c_models;
+       info = this_cpu->legacy_models;
 
-       while (info && info->family) {
+       while (info->family) {
                if (info->family == c->x86)
                        return info->model_names[c->x86_model];
                info++;
        }
+#endif
        return NULL;            /* Not found */
 }
 
@@ -450,8 +452,8 @@ void cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
        c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
 #else
        /* do processor-specific cache resizing */
-       if (this_cpu->c_size_cache)
-               l2size = this_cpu->c_size_cache(c, l2size);
+       if (this_cpu->legacy_cache_size)
+               l2size = this_cpu->legacy_cache_size(c, l2size);
 
        /* Allow user to override all this if necessary. */
        if (cachesize_override != -1)

diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h
index 4041c24..c37dc37 100644 (file)
--- a/arch/x86/kernel/cpu/cpu.h
+++ b/arch/x86/kernel/cpu/cpu.h
@@ -1,12 +1,6 @@
 #ifndef ARCH_X86_CPU_H
 #define ARCH_X86_CPU_H
 
-struct cpu_model_info {
-       int             vendor;
-       int             family;
-       const char      *model_names[16];
-};
-
 /* attempt to consolidate cpu attributes */
 struct cpu_dev {
        const char      *c_vendor;
@@ -14,15 +8,23 @@ struct cpu_dev {
        /* some have two possibilities for cpuid string */
        const char      *c_ident[2];
 
-       struct          cpu_model_info c_models[4];
-
        void            (*c_early_init)(struct cpuinfo_x86 *);
        void            (*c_bsp_init)(struct cpuinfo_x86 *);
        void            (*c_init)(struct cpuinfo_x86 *);
        void            (*c_identify)(struct cpuinfo_x86 *);
        void            (*c_detect_tlb)(struct cpuinfo_x86 *);
-       unsigned int    (*c_size_cache)(struct cpuinfo_x86 *, unsigned int);
        int             c_x86_vendor;
+#ifdef CONFIG_X86_32
+       /* Optional vendor specific routine to obtain the cache size. */
+       unsigned int    (*legacy_cache_size)(struct cpuinfo_x86 *,
+                                            unsigned int);
+
+       /* Family/stepping-based lookup table for model names. */
+       struct legacy_cpu_model_info {
+               int             family;
+               const char      *model_names[16];
+       }               legacy_models[5];
+#endif
 };
 
 struct _tlb_table {

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index ec72995..dc1ec0d 100644 (file)
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -665,8 +665,8 @@ static const struct cpu_dev intel_cpu_dev = {
        .c_vendor       = "Intel",
        .c_ident        = { "GenuineIntel" },
 #ifdef CONFIG_X86_32
-       .c_models = {
-               { .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
+       .legacy_models = {
+               { .family = 4, .model_names =
                  {
                          [0] = "486 DX-25/33",
                          [1] = "486 DX-50",
@@ -679,7 +679,7 @@ static const struct cpu_dev intel_cpu_dev = {
                          [9] = "486 DX/4-WB"
                  }
                },
-               { .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
+               { .family = 5, .model_names =
                  {
                          [0] = "Pentium 60/66 A-step",
                          [1] = "Pentium 60/66",
@@ -690,7 +690,7 @@ static const struct cpu_dev intel_cpu_dev = {
                          [8] = "Mobile Pentium MMX"
                  }
                },
-               { .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
+               { .family = 6, .model_names =
                  {
                          [0] = "Pentium Pro A-step",
                          [1] = "Pentium Pro",
@@ -704,7 +704,7 @@ static const struct cpu_dev intel_cpu_dev = {
                          [11] = "Pentium III (Tualatin)",
                  }
                },
-               { .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
+               { .family = 15, .model_names =
                  {
                          [0] = "Pentium 4 (Unknown)",
                          [1] = "Pentium 4 (Willamette)",
@@ -714,7 +714,7 @@ static const struct cpu_dev intel_cpu_dev = {
                  }
                },
        },
-       .c_size_cache   = intel_size_cache,
+       .legacy_cache_size = intel_size_cache,
 #endif
        .c_detect_tlb   = intel_detect_tlb,
        .c_early_init   = early_init_intel,

diff --git a/arch/x86/kernel/cpu/umc.c b/arch/x86/kernel/cpu/umc.c
index 202759a..75c5ad5 100644 (file)
--- a/arch/x86/kernel/cpu/umc.c
+++ b/arch/x86/kernel/cpu/umc.c
@@ -11,8 +11,8 @@
 static const struct cpu_dev umc_cpu_dev = {
        .c_vendor       = "UMC",
        .c_ident        = { "UMC UMC UMC" },
-       .c_models = {
-               { .vendor = X86_VENDOR_UMC, .family = 4, .model_names =
+       .legacy_models  = {
+               { .family = 4, .model_names =
                  {
                          [1] = "U5D",
                          [2] = "U5S",