x86/apic: Get rid of apic_version[] array

commit cff9ab2b291e64259d97add48fe073c081afe4e2 upstream.

The array has a size of MAX_LOCAL_APIC, which can be as large as 32k, so it
can consume up to 128k.

The array has been there forever and was never used for anything useful
other than a version mismatch check which was introduced in 2009.

There is no reason to store the version in an array. The kernel is not
prepared to handle different APIC versions anyway, so the real important
part is to detect a version mismatch and warn about it, which can be done
with a single variable as well.

[ tglx: Massaged changelog ]

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Borislav Petkov <bp@alien8.de>
CC: Brian Gerst <brgerst@gmail.com>
CC: Mike Travis <travis@sgi.com>
Link: http://lkml.kernel.org/r/20160913181232.30815-1-dvlasenk@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/mpspec.h b/arch/x86/include/asm/mpspec.h
index b07233b64578721668b6d5d06903c5b148bd169d..c2f94dcc92ce8eb110c05040d78ff806beb3824a 100644 (file)
--- a/arch/x86/include/asm/mpspec.h
+++ b/arch/x86/include/asm/mpspec.h
@@ -6,7 +6,6 @@
 #include <asm/x86_init.h>
 #include <asm/apicdef.h>
 
-extern int apic_version[];
 extern int pic_mode;
 
 #ifdef CONFIG_X86_32
@@ -40,6 +39,7 @@ extern int mp_bus_id_to_type[MAX_MP_BUSSES];
 extern DECLARE_BITMAP(mp_bus_not_pci, MAX_MP_BUSSES);
 
 extern unsigned int boot_cpu_physical_apicid;
+extern u8 boot_cpu_apic_version;
 extern unsigned long mp_lapic_addr;
 
 #ifdef CONFIG_X86_LOCAL_APIC

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 90d84c3eee53a323a775ebd8ab4055f777b81c1d..fbd19444403f8b0f2b9666086169fd5ac60820b8 100644 (file)
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -182,7 +182,7 @@ static int acpi_register_lapic(int id, u32 acpiid, u8 enabled)
        }
 
        if (boot_cpu_physical_apicid != -1U)
-               ver = apic_version[boot_cpu_physical_apicid];
+               ver = boot_cpu_apic_version;
 
        cpu = generic_processor_info(id, ver);
        if (cpu >= 0)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index f3e9b2df4b165d9d1a31322960778a2e9ef68bf3..076c315cdf18bf340335ea9bfcd25ec05246d54a 100644 (file)
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -64,6 +64,8 @@ unsigned disabled_cpus;
 unsigned int boot_cpu_physical_apicid = -1U;
 EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
 
+u8 boot_cpu_apic_version;
+
 /*
  * The highest APIC ID seen during enumeration.
  */
@@ -1816,8 +1818,7 @@ void __init init_apic_mappings(void)
                 * since smp_sanity_check is prepared for such a case
                 * and disable smp mode
                 */
-               apic_version[new_apicid] =
-                        GET_APIC_VERSION(apic_read(APIC_LVR));
+               boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
        }
 }
 
@@ -1832,13 +1833,10 @@ void __init register_lapic_address(unsigned long address)
        }
        if (boot_cpu_physical_apicid == -1U) {
                boot_cpu_physical_apicid  = read_apic_id();
-               apic_version[boot_cpu_physical_apicid] =
-                        GET_APIC_VERSION(apic_read(APIC_LVR));
+               boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
        }
 }
 
-int apic_version[MAX_LOCAL_APIC];
-
 /*
  * Local APIC interrupts
  */
@@ -2130,11 +2128,10 @@ int generic_processor_info(int apicid, int version)
                           cpu, apicid);
                version = 0x10;
        }
-       apic_version[apicid] = version;
 
-       if (version != apic_version[boot_cpu_physical_apicid]) {
+       if (version != boot_cpu_apic_version) {
                pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
-                       apic_version[boot_cpu_physical_apicid], cpu, version);
+                       boot_cpu_apic_version, cpu, version);
        }
 
        physid_set(apicid, phys_cpu_present_map);
@@ -2277,7 +2274,7 @@ int __init APIC_init_uniprocessor(void)
         * Complain if the BIOS pretends there is one.
         */
        if (!boot_cpu_has(X86_FEATURE_APIC) &&
-           APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
+           APIC_INTEGRATED(boot_cpu_apic_version)) {
                pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
                        boot_cpu_physical_apicid);
                return -1;

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 7491f417a8e4bc255c78f37b0f1f11d0fe6c91ad..48e6d84f173e2325a40a50e5de29a386a2c9277b 100644 (file)
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1593,7 +1593,7 @@ void __init setup_ioapic_ids_from_mpc(void)
         * no meaning without the serial APIC bus.
         */
        if (!(boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
-               || APIC_XAPIC(apic_version[boot_cpu_physical_apicid]))
+               || APIC_XAPIC(boot_cpu_apic_version))
                return;
        setup_ioapic_ids_from_mpc_nocheck();
 }
@@ -2423,7 +2423,7 @@ static int io_apic_get_unique_id(int ioapic, int apic_id)
 static u8 io_apic_unique_id(int idx, u8 id)
 {
        if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
-           !APIC_XAPIC(apic_version[boot_cpu_physical_apicid]))
+           !APIC_XAPIC(boot_cpu_apic_version))
                return io_apic_get_unique_id(idx, id);
        else
                return id;

diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
index 7c43e716c158de0799760a5537ec05a5bd272a9f..563096267ca20ac702e8f0f36ef41b9ae484f582 100644 (file)
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -152,7 +152,7 @@ early_param("apic", parse_apic);
 
 void __init default_setup_apic_routing(void)
 {
-       int version = apic_version[boot_cpu_physical_apicid];
+       int version = boot_cpu_apic_version;
 
        if (num_possible_cpus() > 8) {
                switch (boot_cpu_data.x86_vendor) {

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 4296beb8fdd3b2d91a9644c9843d66dd2132c2ad..75a045424be73de5f908903f8c5bf56580a9198d 100644 (file)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -690,7 +690,7 @@ wakeup_secondary_cpu_via_nmi(int apicid, unsigned long start_eip)
         * Give the other CPU some time to accept the IPI.
         */
        udelay(200);
-       if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
+       if (APIC_INTEGRATED(boot_cpu_apic_version)) {
                maxlvt = lapic_get_maxlvt();
                if (maxlvt > 3)                 /* Due to the Pentium erratum 3AP.  */
                        apic_write(APIC_ESR, 0);
@@ -717,7 +717,7 @@ wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
        /*
         * Be paranoid about clearing APIC errors.
         */
-       if (APIC_INTEGRATED(apic_version[phys_apicid])) {
+       if (APIC_INTEGRATED(boot_cpu_apic_version)) {
                if (maxlvt > 3)         /* Due to the Pentium erratum 3AP.  */
                        apic_write(APIC_ESR, 0);
                apic_read(APIC_ESR);
@@ -756,7 +756,7 @@ wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
         * Determine this based on the APIC version.
         * If we don't have an integrated APIC, don't send the STARTUP IPIs.
         */
-       if (APIC_INTEGRATED(apic_version[phys_apicid]))
+       if (APIC_INTEGRATED(boot_cpu_apic_version))
                num_starts = 2;
        else
                num_starts = 0;
@@ -994,7 +994,7 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
                /*
                 * Be paranoid about clearing APIC errors.
                */
-               if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
+               if (APIC_INTEGRATED(boot_cpu_apic_version)) {
                        apic_write(APIC_ESR, 0);
                        apic_read(APIC_ESR);
                }
@@ -1249,7 +1249,7 @@ static int __init smp_sanity_check(unsigned max_cpus)
        /*
         * If we couldn't find a local APIC, then get out of here now!
         */
-       if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) &&
+       if (APIC_INTEGRATED(boot_cpu_apic_version) &&
            !boot_cpu_has(X86_FEATURE_APIC)) {
                if (!disable_apic) {
                        pr_err("BIOS bug, local APIC #%d not detected!...\n",