[PATCH] i386/x86-64: Emulate CPUID4 on AMD

Intel systems report the cache level data from CPUID 4 in sysfs.
Add a CPUID 4 emulation for AMD CPUs to report the same
information for them. This allows programs to read this
information in a uniform way.

The AMD way to report this is less flexible so some assumptions
are hardcoded (e.g. no L3)

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/i386/kernel/cpu/amd.c b/arch/i386/kernel/cpu/amd.c
index b9c93d9..fd0457c 100644 (file)
--- a/arch/i386/kernel/cpu/amd.c
+++ b/arch/i386/kernel/cpu/amd.c
@@ -242,6 +242,8 @@ static void __init init_amd(struct cpuinfo_x86 *c)
        }
 #endif
 
+       if (cpuid_eax(0x80000000) >= 0x80000006)
+               num_cache_leaves = 3;
 }
 
 static unsigned int amd_size_cache(struct cpuinfo_x86 * c, unsigned int size)

diff --git a/arch/i386/kernel/cpu/intel_cacheinfo.c b/arch/i386/kernel/cpu/intel_cacheinfo.c
index c8547a6..6c37b4f 100644 (file)
--- a/arch/i386/kernel/cpu/intel_cacheinfo.c
+++ b/arch/i386/kernel/cpu/intel_cacheinfo.c
@@ -4,6 +4,7 @@
  *      Changes:
  *      Venkatesh Pallipadi    : Adding cache identification through cpuid(4)
  *             Ashok Raj <ashok.raj@intel.com>: Work with CPU hotplug infrastructure.
+ *     Andi Kleen              : CPUID4 emulation on AMD.
  */
 
 #include <linux/init.h>
@@ -130,25 +131,111 @@ struct _cpuid4_info {
        cpumask_t shared_cpu_map;
 };
 
-static unsigned short                  num_cache_leaves;
+unsigned short                 num_cache_leaves;
+
+/* AMD doesn't have CPUID4. Emulate it here to report the same
+   information to the user.  This makes some assumptions about the machine:
+   No L3, L2 not shared, no SMT etc. that is currently true on AMD CPUs.
+
+   In theory the TLBs could be reported as fake type (they are in "dummy").
+   Maybe later */
+union l1_cache {
+       struct {
+               unsigned line_size : 8;
+               unsigned lines_per_tag : 8;
+               unsigned assoc : 8;
+               unsigned size_in_kb : 8;
+       };
+       unsigned val;
+};
+
+union l2_cache {
+       struct {
+               unsigned line_size : 8;
+               unsigned lines_per_tag : 4;
+               unsigned assoc : 4;
+               unsigned size_in_kb : 16;
+       };
+       unsigned val;
+};
+
+static unsigned short assocs[] = {
+       [1] = 1, [2] = 2, [4] = 4, [6] = 8,
+       [8] = 16,
+       [0xf] = 0xffff // ??
+       };
+static unsigned char levels[] = { 1, 1, 2 };
+static unsigned char types[] = { 1, 2, 3 };
+
+static void __cpuinit amd_cpuid4(int leaf, union _cpuid4_leaf_eax *eax,
+                      union _cpuid4_leaf_ebx *ebx,
+                      union _cpuid4_leaf_ecx *ecx)
+{
+       unsigned dummy;
+       unsigned line_size, lines_per_tag, assoc, size_in_kb;
+       union l1_cache l1i, l1d;
+       union l2_cache l2;
+
+       eax->full = 0;
+       ebx->full = 0;
+       ecx->full = 0;
+
+       cpuid(0x80000005, &dummy, &dummy, &l1d.val, &l1i.val);
+       cpuid(0x80000006, &dummy, &dummy, &l2.val, &dummy);
+
+       if (leaf > 2 || !l1d.val || !l1i.val || !l2.val)
+               return;
+
+       eax->split.is_self_initializing = 1;
+       eax->split.type = types[leaf];
+       eax->split.level = levels[leaf];
+       eax->split.num_threads_sharing = 0;
+       eax->split.num_cores_on_die = current_cpu_data.x86_max_cores - 1;
+
+       if (leaf <= 1) {
+               union l1_cache *l1 = leaf == 0 ? &l1d : &l1i;
+               assoc = l1->assoc;
+               line_size = l1->line_size;
+               lines_per_tag = l1->lines_per_tag;
+               size_in_kb = l1->size_in_kb;
+       } else {
+               assoc = l2.assoc;
+               line_size = l2.line_size;
+               lines_per_tag = l2.lines_per_tag;
+               /* cpu_data has errata corrections for K7 applied */
+               size_in_kb = current_cpu_data.x86_cache_size;
+       }
+
+       if (assoc == 0xf)
+               eax->split.is_fully_associative = 1;
+       ebx->split.coherency_line_size = line_size - 1;
+       ebx->split.ways_of_associativity = assocs[assoc] - 1;
+       ebx->split.physical_line_partition = lines_per_tag - 1;
+       ecx->split.number_of_sets = (size_in_kb * 1024) / line_size /
+               (ebx->split.ways_of_associativity + 1) - 1;
+}
 
 static int __cpuinit cpuid4_cache_lookup(int index, struct _cpuid4_info *this_leaf)
 {
-       unsigned int            eax, ebx, ecx, edx;
-       union _cpuid4_leaf_eax  cache_eax;
+       union _cpuid4_leaf_eax  eax;
+       union _cpuid4_leaf_ebx  ebx;
+       union _cpuid4_leaf_ecx  ecx;
+       unsigned                edx;
 
-       cpuid_count(4, index, &eax, &ebx, &ecx, &edx);
-       cache_eax.full = eax;
-       if (cache_eax.split.type == CACHE_TYPE_NULL)
+       if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+               amd_cpuid4(index, &eax, &ebx, &ecx);
+       else
+               cpuid_count(4, index, &eax.full, &ebx.full, &ecx.full,  &edx);
+       if (eax.split.type == CACHE_TYPE_NULL)
                return -EIO; /* better error ? */
 
-       this_leaf->eax.full = eax;
-       this_leaf->ebx.full = ebx;
-       this_leaf->ecx.full = ecx;
-       this_leaf->size = (this_leaf->ecx.split.number_of_sets + 1) *
-               (this_leaf->ebx.split.coherency_line_size + 1) *
-               (this_leaf->ebx.split.physical_line_partition + 1) *
-               (this_leaf->ebx.split.ways_of_associativity + 1);
+       this_leaf->eax = eax;
+       this_leaf->ebx = ebx;
+       this_leaf->ecx = ecx;
+       this_leaf->size = (ecx.split.number_of_sets + 1) *
+               (ebx.split.coherency_line_size + 1) *
+               (ebx.split.physical_line_partition + 1) *
+               (ebx.split.ways_of_associativity + 1);
        return 0;
 }
 

diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index 1cb3e21..4b7e022 100644 (file)
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -976,6 +976,9 @@ static int __init init_amd(struct cpuinfo_x86 *c)
        if (c->extended_cpuid_level >= 0x80000008)
                amd_detect_cmp(c);
 
+       /* Fix cpuid4 emulation for more */
+       num_cache_leaves = 3;
+
        return r;
 }
 

diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h
index 0c83cf1..b796210 100644 (file)
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -112,6 +112,7 @@ extern char ignore_fpu_irq;
 extern void identify_cpu(struct cpuinfo_x86 *);
 extern void print_cpu_info(struct cpuinfo_x86 *);
 extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
+extern unsigned short num_cache_leaves;
 
 #ifdef CONFIG_X86_HT
 extern void detect_ht(struct cpuinfo_x86 *c);

diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h
index 3061a38..e583f0d 100644 (file)
--- a/include/asm-x86_64/processor.h
+++ b/include/asm-x86_64/processor.h
@@ -96,6 +96,7 @@ extern char ignore_irq13;
 extern void identify_cpu(struct cpuinfo_x86 *);
 extern void print_cpu_info(struct cpuinfo_x86 *);
 extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
+extern unsigned short num_cache_leaves;
 
 /*
  * EFLAGS bits