[PATCH] i386/x86-64: Use new official CPUID to get APICID/core split on AMD platforms

[mirror_ubuntu-artful-kernel.git] / arch / x86_64 / kernel / setup.c

diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index 655b9192eeb3727d85a8921d10cdd4049c2a5232..1cb3e21c571ac46dd629222cd7f94b3dad520903 100644 (file)
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -728,7 +728,7 @@ void __init setup_arch(char **cmdline_p)
 #endif
 #ifdef CONFIG_KEXEC
        if (crashk_res.start != crashk_res.end) {
-               reserve_bootmem(crashk_res.start,
+               reserve_bootmem_generic(crashk_res.start,
                        crashk_res.end - crashk_res.start + 1);
        }
 #endif
@@ -873,10 +873,18 @@ static void __init amd_detect_cmp(struct cpuinfo_x86 *c)
        int node = 0;
        unsigned apicid = hard_smp_processor_id();
 #endif
+       unsigned ecx = cpuid_ecx(0x80000008);
 
-       bits = 0;
-       while ((1 << bits) < c->x86_max_cores)
-               bits++;
+       c->x86_max_cores = (ecx & 0xff) + 1;
+
+       /* CPU telling us the core id bits shift? */
+       bits = (ecx >> 12) & 0xF;
+
+       /* Otherwise recompute */
+       if (bits == 0) {
+               while ((1 << bits) < c->x86_max_cores)
+                       bits++;
+       }
 
        /* Low order bits define the core id (index of core in socket) */
        cpu_core_id[cpu] = phys_proc_id[cpu] & ((1 << bits)-1);
@@ -964,11 +972,9 @@ static int __init init_amd(struct cpuinfo_x86 *c)
        if (c->x86_power & (1<<8))
                set_bit(X86_FEATURE_CONSTANT_TSC, &c->x86_capability);
 
-       if (c->extended_cpuid_level >= 0x80000008) {
-               c->x86_max_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
-
+       /* Multi core CPU? */
+       if (c->extended_cpuid_level >= 0x80000008)
                amd_detect_cmp(c);
-       }
 
        return r;
 }