From: Thomas Gleixner Date: Tue, 8 Aug 2023 22:03:53 +0000 (-0700) Subject: x86/apic/32: Sanitize logical APIC ID handling X-Git-Tag: v6.6-rc1~141^2~39 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e120e58ec2932d3dee05da71168c7ba841bf4cf4;p=thirdparty%2Flinux.git x86/apic/32: Sanitize logical APIC ID handling apic::x86_32_early_logical_apicid() is yet another historical joke. It is used to preset the x86_cpu_to_logical_apicid per CPU variable during APIC enumeration with: - 1 shifted left by the CPU number - the physical APIC ID in case of bigsmp The latter is hillarious because bigsmp uses physical destination mode which never can use the logical APIC ID. It gets even worse. As bigsmp can be enforced late in the boot process the probe function overwrites the per CPU variable which is never used for this APIC type once again. Remove that gunk and store 1 << cpunr unconditionally if and only if the CPU number is less than 8, because the default logical destination mode only allows up to 8 CPUs. This is just an intermediate step before removing the per CPU insanity completely. Stay tuned. Signed-off-by: Thomas Gleixner Signed-off-by: Dave Hansen Acked-by: Peter Zijlstra (Intel) Tested-by: Michael Kelley Tested-by: Sohil Mehta Tested-by: Juergen Gross # Xen PV (dom0 and unpriv. guest) --- diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 098d193f93fb9..daef6812141f0 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -315,19 +315,6 @@ struct apic { /* wakeup secondary CPU using 64-bit wakeup point */ int (*wakeup_secondary_cpu_64)(int apicid, unsigned long start_eip); -#ifdef CONFIG_X86_32 - /* - * Called very early during boot from get_smp_config(). It should - * return the logical apicid. x86_[bios]_cpu_to_apicid is - * initialized before this function is called. - * - * If logical apicid can't be determined that early, the function - * may return BAD_APICID. Logical apicid will be configured after - * init_apic_ldr() while bringing up CPUs. Note that NUMA affinity - * won't be applied properly during early boot in this case. - */ - int (*x86_32_early_logical_apicid)(int cpu); -#endif char *name; }; diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 6eee777ca73cb..89f2a7e5a9f57 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -2435,8 +2435,8 @@ static void cpu_update_apic(int cpu, int apicid) early_per_cpu(x86_cpu_to_apicid, cpu) = apicid; #endif #ifdef CONFIG_X86_32 - early_per_cpu(x86_cpu_to_logical_apicid, cpu) = - apic->x86_32_early_logical_apicid(cpu); + if (cpu < 8) + early_per_cpu(x86_cpu_to_logical_apicid, cpu) = 1U << cpu; #endif set_cpu_possible(cpu, true); physid_set(apicid, phys_cpu_present_map); diff --git a/arch/x86/kernel/apic/apic_noop.c b/arch/x86/kernel/apic/apic_noop.c index c0c3b6bf79b5d..ccd74e8016fc7 100644 --- a/arch/x86/kernel/apic/apic_noop.c +++ b/arch/x86/kernel/apic/apic_noop.c @@ -80,13 +80,6 @@ static void noop_apic_write(u32 reg, u32 val) WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !apic_is_disabled); } -#ifdef CONFIG_X86_32 -static int noop_x86_32_early_logical_apicid(int cpu) -{ - return BAD_APICID; -} -#endif - struct apic apic_noop __ro_after_init = { .name = "noop", .probe = noop_probe, @@ -130,8 +123,4 @@ struct apic apic_noop __ro_after_init = { .icr_write = noop_apic_icr_write, .wait_icr_idle = noop_apic_wait_icr_idle, .safe_wait_icr_idle = noop_safe_apic_wait_icr_idle, - -#ifdef CONFIG_X86_32 - .x86_32_early_logical_apicid = noop_x86_32_early_logical_apicid, -#endif }; diff --git a/arch/x86/kernel/apic/bigsmp_32.c b/arch/x86/kernel/apic/bigsmp_32.c index 6f4bd71e97ec4..b649048c20198 100644 --- a/arch/x86/kernel/apic/bigsmp_32.c +++ b/arch/x86/kernel/apic/bigsmp_32.c @@ -28,12 +28,6 @@ static bool bigsmp_check_apicid_used(physid_mask_t *map, int apicid) return false; } -static int bigsmp_early_logical_apicid(int cpu) -{ - /* on bigsmp, logical apicid is the same as physical */ - return early_per_cpu(x86_cpu_to_apicid, cpu); -} - /* * bigsmp enables physical destination mode * and doesn't use LDR and DFR @@ -154,27 +148,15 @@ static struct apic apic_bigsmp __ro_after_init = { .icr_write = native_apic_icr_write, .wait_icr_idle = native_apic_wait_icr_idle, .safe_wait_icr_idle = native_safe_apic_wait_icr_idle, - - .x86_32_early_logical_apicid = bigsmp_early_logical_apicid, }; void __init generic_bigsmp_probe(void) { - unsigned int cpu; - if (!probe_bigsmp()) return; apic = &apic_bigsmp; - for_each_possible_cpu(cpu) { - if (early_per_cpu(x86_cpu_to_logical_apicid, - cpu) == BAD_APICID) - continue; - early_per_cpu(x86_cpu_to_logical_apicid, cpu) = - bigsmp_early_logical_apicid(cpu); - } - pr_info("Overriding APIC driver with %s\n", apic_bigsmp.name); } diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c index baa8b141eba14..3ee0211b0c291 100644 --- a/arch/x86/kernel/apic/probe_32.c +++ b/arch/x86/kernel/apic/probe_32.c @@ -16,11 +16,6 @@ #include "local.h" -static int default_x86_32_early_logical_apicid(int cpu) -{ - return 1 << cpu; -} - static void setup_apic_flat_routing(void) { #ifdef CONFIG_X86_IO_APIC @@ -101,8 +96,6 @@ static struct apic apic_default __ro_after_init = { .icr_write = native_apic_icr_write, .wait_icr_idle = native_apic_wait_icr_idle, .safe_wait_icr_idle = native_safe_apic_wait_icr_idle, - - .x86_32_early_logical_apicid = default_x86_32_early_logical_apicid, }; apic_driver(apic_default);