x86/microcode: Decrease CPUID use

Get CPUID(1).EAX value once per CPU and propagate value into the callers
instead of conveniently calling it every time.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-9-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 9d5f4f3..9fb398e 100644 (file)
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -47,6 +47,7 @@ static struct equiv_cpu_entry *equiv_cpu_table;
  */
 static struct cont_desc {
        struct microcode_amd *mc;
+       u32                  cpuid_1_eax;
        u32                  psize;
        u16                  eq_id;
        u8                   *data;
@@ -86,7 +87,6 @@ static ssize_t parse_container(u8 *ucode, ssize_t size, struct cont_desc *desc)
        struct equiv_cpu_entry *eq;
        ssize_t orig_size = size;
        u32 *hdr = (u32 *)ucode;
-       u32 eax, ebx, ecx, edx;
        u16 eq_id;
        u8 *buf;
 
@@ -102,12 +102,8 @@ static ssize_t parse_container(u8 *ucode, ssize_t size, struct cont_desc *desc)
 
        eq = (struct equiv_cpu_entry *)(buf + CONTAINER_HDR_SZ);
 
-       eax = 1;
-       ecx = 0;
-       native_cpuid(&eax, &ebx, &ecx, &edx);
-
        /* Find the equivalence ID of our CPU in this table: */
-       eq_id = find_equiv_id(eq, eax);
+       eq_id = find_equiv_id(eq, desc->cpuid_1_eax);
 
        buf  += hdr[2] + CONTAINER_HDR_SZ;
        size -= hdr[2] + CONTAINER_HDR_SZ;
@@ -205,8 +201,9 @@ static int __apply_microcode_amd(struct microcode_amd *mc)
  *
  * Returns true if container found (sets @desc), false otherwise.
  */
-static bool apply_microcode_early_amd(void *ucode, size_t size, bool save_patch,
-                                     struct cont_desc *ret_desc)
+static bool
+apply_microcode_early_amd(u32 cpuid_1_eax, void *ucode, size_t size,
+                         bool save_patch, struct cont_desc *ret_desc)
 {
        struct cont_desc desc = { 0 };
        u8 (*patch)[PATCH_MAX_SIZE];
@@ -225,6 +222,8 @@ static bool apply_microcode_early_amd(void *ucode, size_t size, bool save_patch,
        if (check_current_patch_level(&rev, true))
                return false;
 
+       desc.cpuid_1_eax = cpuid_1_eax;
+
        scan_containers(ucode, size, &desc);
        if (!desc.eq_id)
                return ret;
@@ -267,10 +266,9 @@ static bool get_builtin_microcode(struct cpio_data *cp, unsigned int family)
 #endif
 }
 
-void __init load_ucode_amd_bsp(unsigned int family)
+void __init load_ucode_amd_bsp(unsigned int cpuid_1_eax)
 {
        struct ucode_cpu_info *uci;
-       u32 eax, ebx, ecx, edx;
        struct cpio_data cp;
        const char *path;
        bool use_pa;
@@ -285,19 +283,16 @@ void __init load_ucode_amd_bsp(unsigned int family)
                use_pa  = false;
        }
 
-       if (!get_builtin_microcode(&cp, family))
+       if (!get_builtin_microcode(&cp, x86_family(cpuid_1_eax)))
                cp = find_microcode_in_initrd(path, use_pa);
 
        if (!(cp.data && cp.size))
                return;
 
-       /* Get BSP's CPUID.EAX(1), needed in load_microcode_amd() */
-       eax = 1;
-       ecx = 0;
-       native_cpuid(&eax, &ebx, &ecx, &edx);
-       uci->cpu_sig.sig = eax;
+       /* Needed in load_microcode_amd() */
+       uci->cpu_sig.sig = cpuid_1_eax;
 
-       apply_microcode_early_amd(cp.data, cp.size, true, NULL);
+       apply_microcode_early_amd(cpuid_1_eax, cp.data, cp.size, true, NULL);
 }
 
 #ifdef CONFIG_X86_32
@@ -308,7 +303,7 @@ void __init load_ucode_amd_bsp(unsigned int family)
  * In save_microcode_in_initrd_amd() BSP's patch is copied to amd_ucode_patch,
  * which is used upon resume from suspend.
  */
-void load_ucode_amd_ap(unsigned int family)
+void load_ucode_amd_ap(unsigned int cpuid_1_eax)
 {
        struct microcode_amd *mc;
        struct cpio_data cp;
@@ -319,7 +314,7 @@ void load_ucode_amd_ap(unsigned int family)
                return;
        }
 
-       if (!get_builtin_microcode(&cp, family))
+       if (!get_builtin_microcode(&cp, x86_family(cpuid_1_eax)))
                cp = find_microcode_in_initrd((const char *)__pa_nodebug(ucode_path), true);
 
        if (!(cp.data && cp.size))
@@ -329,14 +324,14 @@ void load_ucode_amd_ap(unsigned int family)
         * This would set amd_ucode_patch above so that the following APs can
         * use it directly instead of going down this path again.
         */
-       apply_microcode_early_amd(cp.data, cp.size, true, NULL);
+       apply_microcode_early_amd(cpuid_1_eax, cp.data, cp.size, true, NULL);
 }
 #else
-void load_ucode_amd_ap(unsigned int family)
+void load_ucode_amd_ap(unsigned int cpuid_1_eax)
 {
        struct equiv_cpu_entry *eq;
        struct microcode_amd *mc;
-       u32 rev, eax;
+       u32 rev;
        u16 eq_id;
 
        /* 64-bit runs with paging enabled, thus early==false. */
@@ -351,7 +346,7 @@ void load_ucode_amd_ap(unsigned int family)
                        return;
 
 reget:
-               if (!get_builtin_microcode(&cp, family)) {
+               if (!get_builtin_microcode(&cp, x86_family(cpuid_1_eax))) {
 #ifdef CONFIG_BLK_DEV_INITRD
                        cp = find_cpio_data(ucode_path, (void *)initrd_start,
                                            initrd_end - initrd_start, NULL);
@@ -367,17 +362,16 @@ reget:
                        }
                }
 
-               if (!apply_microcode_early_amd(cp.data, cp.size, false, &cont)) {
+               if (!apply_microcode_early_amd(cpuid_1_eax, cp.data, cp.size, false, &cont)) {
                        cont.data = NULL;
                        cont.size = -1;
                        return;
                }
        }
 
-       eax = cpuid_eax(0x00000001);
        eq  = (struct equiv_cpu_entry *)(cont.data + CONTAINER_HDR_SZ);
 
-       eq_id = find_equiv_id(eq, eax);
+       eq_id = find_equiv_id(eq, cpuid_1_eax);
        if (!eq_id)
                return;
 
@@ -403,7 +397,7 @@ reget:
 static enum ucode_state
 load_microcode_amd(int cpu, u8 family, const u8 *data, size_t size);
 
-int __init save_microcode_in_initrd_amd(unsigned int fam)
+int __init save_microcode_in_initrd_amd(unsigned int cpuid_1_eax)
 {
        enum ucode_state ret;
        int retval = 0;
@@ -422,6 +416,8 @@ int __init save_microcode_in_initrd_amd(unsigned int fam)
                                return -EINVAL;
                        }
 
+                       cont.cpuid_1_eax = cpuid_1_eax;
+
                        scan_containers(cp.data, cp.size, &cont);
                        if (!cont.eq_id) {
                                cont.size = -1;
@@ -432,7 +428,7 @@ int __init save_microcode_in_initrd_amd(unsigned int fam)
                        return -EINVAL;
        }
 
-       ret = load_microcode_amd(smp_processor_id(), fam, cont.data, cont.size);
+       ret = load_microcode_amd(smp_processor_id(), x86_family(cpuid_1_eax), cont.data, cont.size);
        if (ret != UCODE_OK)
                retval = -EINVAL;
 

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index 2af69d2..437996c 100644 (file)
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -64,10 +64,6 @@ static DEFINE_MUTEX(microcode_mutex);
 
 struct ucode_cpu_info          ucode_cpu_info[NR_CPUS];
 
-/*
- * Operations that are run on a target cpu:
- */
-
 struct cpu_info_ctx {
        struct cpu_signature    *cpu_sig;
        int                     err;
@@ -76,7 +72,6 @@ struct cpu_info_ctx {
 static bool __init check_loader_disabled_bsp(void)
 {
        static const char *__dis_opt_str = "dis_ucode_ldr";
-       u32 a, b, c, d;
 
 #ifdef CONFIG_X86_32
        const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
@@ -92,16 +87,12 @@ static bool __init check_loader_disabled_bsp(void)
        if (!have_cpuid_p())
                return *res;
 
-       a = 1;
-       c = 0;
-       native_cpuid(&a, &b, &c, &d);
-
        /*
         * CPUID(1).ECX[31]: reserved for hypervisor use. This is still not
         * completely accurate as xen pv guests don't see that CPUID bit set but
         * that's good enough as they don't land on the BSP path anyway.
         */
-       if (c & BIT(31))
+       if (native_cpuid_ecx(1) & BIT(31))
                return *res;
 
        if (cmdline_find_option_bool(cmdline, option) <= 0)
@@ -131,23 +122,22 @@ bool get_builtin_firmware(struct cpio_data *cd, const char *name)
 
 void __init load_ucode_bsp(void)
 {
-       int vendor;
-       unsigned int family;
+       unsigned int vendor, cpuid_1_eax;
 
        if (check_loader_disabled_bsp())
                return;
 
-       vendor = x86_cpuid_vendor();
-       family = x86_cpuid_family();
+       vendor      = x86_cpuid_vendor();
+       cpuid_1_eax = native_cpuid_eax(1);
 
        switch (vendor) {
        case X86_VENDOR_INTEL:
-               if (family >= 6)
+               if (x86_family(cpuid_1_eax) >= 6)
                        load_ucode_intel_bsp();
                break;
        case X86_VENDOR_AMD:
-               if (family >= 0x10)
-                       load_ucode_amd_bsp(family);
+               if (x86_family(cpuid_1_eax) >= 0x10)
+                       load_ucode_amd_bsp(cpuid_1_eax);
                break;
        default:
                break;
@@ -165,22 +155,22 @@ static bool check_loader_disabled_ap(void)
 
 void load_ucode_ap(void)
 {
-       int vendor, family;
+       unsigned int vendor, cpuid_1_eax;
 
        if (check_loader_disabled_ap())
                return;
 
-       vendor = x86_cpuid_vendor();
-       family = x86_cpuid_family();
+       vendor      = x86_cpuid_vendor();
+       cpuid_1_eax = native_cpuid_eax(1);
 
        switch (vendor) {
        case X86_VENDOR_INTEL:
-               if (family >= 6)
+               if (x86_family(cpuid_1_eax) >= 6)
                        load_ucode_intel_ap();
                break;
        case X86_VENDOR_AMD:
-               if (family >= 0x10)
-                       load_ucode_amd_ap(family);
+               if (x86_family(cpuid_1_eax) >= 0x10)
+                       load_ucode_amd_ap(cpuid_1_eax);
                break;
        default:
                break;
@@ -198,7 +188,7 @@ static int __init save_microcode_in_initrd(void)
                break;
        case X86_VENDOR_AMD:
                if (c->x86 >= 0x10)
-                       return save_microcode_in_initrd_amd(c->x86);
+                       return save_microcode_in_initrd_amd(cpuid_eax(1));
                break;
        default:
                break;