From 517234446c1ad1d6bb0d9f5b94a71b24f80edaae Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 13 Feb 2024 22:04:56 +0100
Subject: x86/apic: Get rid of get_physical_broadcast()

There is no point for this function. The only case where this is used is
when there is no XAPIC available, which means the broadcast address is 0xF.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240212154639.057209154@linutronix.de
---
 arch/x86/kernel/apic/apic.c | 10 ----------
 1 file changed, 10 deletions(-)

(limited to 'arch/x86/kernel/apic/apic.c')

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 4667bc4b00ab..814e15c8b8cd 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -261,16 +261,6 @@ u64 native_apic_icr_read(void)
 	return icr1 | ((u64)icr2 << 32);
 }
 
-#ifdef CONFIG_X86_32
-/**
- * get_physical_broadcast - Get number of physical broadcast IDs
- */
-int get_physical_broadcast(void)
-{
-	return modern_apic() ? 0xff : 0xf;
-}
-#endif
-
 /**
  * lapic_get_maxlvt - get the maximum number of local vector table entries
  */
-- 
cgit v1.2.3


From 350b5e2730d1e15337a10bd913694ee4527c02f0 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 13 Feb 2024 22:05:17 +0100
Subject: x86/mpparse: Remove the physid_t bitmap wrapper

physid_t is a wrapper around bitmap. Just remove the onion layer and use
bitmap functionality directly.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240212154639.994904510@linutronix.de
---
 arch/x86/include/asm/mpspec.h      | 32 +++++++++-----------------------
 arch/x86/kernel/apic/apic.c        | 11 +++++------
 arch/x86/kernel/apic/apic_common.c | 12 +-----------
 arch/x86/kernel/apic/io_apic.c     | 24 ++++++++++++------------
 arch/x86/kernel/apic/local.h       |  1 -
 arch/x86/kernel/smpboot.c          |  8 +++-----
 6 files changed, 30 insertions(+), 58 deletions(-)

(limited to 'arch/x86/kernel/apic/apic.c')

diff --git a/arch/x86/include/asm/mpspec.h b/arch/x86/include/asm/mpspec.h
index b423d11e002d..1b79d0ee95df 100644
--- a/arch/x86/include/asm/mpspec.h
+++ b/arch/x86/include/asm/mpspec.h
@@ -2,6 +2,7 @@
 #ifndef _ASM_X86_MPSPEC_H
 #define _ASM_X86_MPSPEC_H
 
+#include <linux/types.h>
 
 #include <asm/mpspec_def.h>
 #include <asm/x86_init.h>
@@ -62,32 +63,17 @@ static inline void e820__memblock_alloc_reserved_mpc_new(void) { }
 
 int generic_processor_info(int apicid);
 
-#define PHYSID_ARRAY_SIZE	BITS_TO_LONGS(MAX_LOCAL_APIC)
+extern DECLARE_BITMAP(phys_cpu_present_map, MAX_LOCAL_APIC);
 
-struct physid_mask {
-	unsigned long mask[PHYSID_ARRAY_SIZE];
-};
-
-typedef struct physid_mask physid_mask_t;
-
-#define physid_set(physid, map)			set_bit(physid, (map).mask)
-#define physid_isset(physid, map)		test_bit(physid, (map).mask)
-
-#define physids_clear(map)					\
-	bitmap_zero((map).mask, MAX_LOCAL_APIC)
-
-#define physids_empty(map)					\
-	bitmap_empty((map).mask, MAX_LOCAL_APIC)
-
-static inline void physid_set_mask_of_physid(int physid, physid_mask_t *map)
+static inline void reset_phys_cpu_present_map(u32 apicid)
 {
-	physids_clear(*map);
-	physid_set(physid, *map);
+	bitmap_zero(phys_cpu_present_map, MAX_LOCAL_APIC);
+	set_bit(apicid, phys_cpu_present_map);
 }
 
-#define PHYSID_MASK_ALL		{ {[0 ... PHYSID_ARRAY_SIZE-1] = ~0UL} }
-#define PHYSID_MASK_NONE	{ {[0 ... PHYSID_ARRAY_SIZE-1] = 0UL} }
-
-extern physid_mask_t phys_cpu_present_map;
+static inline void copy_phys_cpu_present_map(unsigned long *dst)
+{
+	bitmap_copy(dst, phys_cpu_present_map, MAX_LOCAL_APIC);
+}
 
 #endif /* _ASM_X86_MPSPEC_H */
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 814e15c8b8cd..ce6d31bfc6e3 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -19,6 +19,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/mc146818rtc.h>
 #include <linux/acpi_pmtmr.h>
+#include <linux/bitmap.h>
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
 #include <linux/memblock.h>
@@ -77,10 +78,8 @@ EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
 
 u8 boot_cpu_apic_version __ro_after_init;
 
-/*
- * Bitmask of physically existing CPUs:
- */
-physid_mask_t phys_cpu_present_map;
+/* Bitmap of physically present CPUs. */
+DECLARE_BITMAP(phys_cpu_present_map, MAX_LOCAL_APIC);
 
 /*
  * Processor to be disabled specified by kernel parameter
@@ -2387,7 +2386,7 @@ static void cpu_update_apic(int cpu, u32 apicid)
 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
 #endif
 	set_cpu_possible(cpu, true);
-	physid_set(apicid, phys_cpu_present_map);
+	set_bit(apicid, phys_cpu_present_map);
 	set_cpu_present(cpu, true);
 	num_processors++;
 
@@ -2489,7 +2488,7 @@ static void __init apic_bsp_up_setup(void)
 #ifdef CONFIG_X86_64
 	apic_write(APIC_ID, apic->set_apic_id(boot_cpu_physical_apicid));
 #endif
-	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
+	reset_phys_cpu_present_map(boot_cpu_physical_apicid);
 }
 
 /**
diff --git a/arch/x86/kernel/apic/apic_common.c b/arch/x86/kernel/apic/apic_common.c
index 8a00141073ea..d4dfa437081a 100644
--- a/arch/x86/kernel/apic/apic_common.c
+++ b/arch/x86/kernel/apic/apic_common.c
@@ -18,16 +18,6 @@ u32 apic_flat_calc_apicid(unsigned int cpu)
 	return 1U << cpu;
 }
 
-bool default_check_apicid_used(physid_mask_t *map, u32 apicid)
-{
-	return physid_isset(apicid, *map);
-}
-
-void default_ioapic_phys_id_map(physid_mask_t *phys_map, physid_mask_t *retmap)
-{
-	*retmap = *phys_map;
-}
-
 u32 default_cpu_present_to_apicid(int mps_cpu)
 {
 	if (mps_cpu < nr_cpu_ids && cpu_present(mps_cpu))
@@ -39,7 +29,7 @@ EXPORT_SYMBOL_GPL(default_cpu_present_to_apicid);
 
 bool default_apic_id_registered(void)
 {
-	return physid_isset(read_apic_id(), phys_cpu_present_map);
+	return test_bit(read_apic_id(), phys_cpu_present_map);
 }
 
 /*
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 6285d880a64c..9f4fb3f2ddc4 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1460,7 +1460,7 @@ void restore_boot_irq_mode(void)
  */
 static void __init setup_ioapic_ids_from_mpc_nocheck(void)
 {
-	physid_mask_t phys_id_present_map;
+	DECLARE_BITMAP(phys_id_present_map, MAX_LOCAL_APIC);
 	const u32 broadcast_id = 0xF;
 	union IO_APIC_reg_00 reg_00;
 	unsigned char old_id;
@@ -1471,7 +1471,7 @@ static void __init setup_ioapic_ids_from_mpc_nocheck(void)
 	 * This is broken; anything with a real cpu count has to
 	 * circumvent this idiocy regardless.
 	 */
-	phys_id_present_map = phys_cpu_present_map;
+	copy_phys_cpu_present_map(phys_id_present_map);
 
 	/*
 	 * Set the IOAPIC ID to the value stored in the MPC table.
@@ -1496,21 +1496,21 @@ static void __init setup_ioapic_ids_from_mpc_nocheck(void)
 		 * system must have a unique ID or we get lots of nice
 		 * 'stuck on smp_invalidate_needed IPI wait' messages.
 		 */
-		if (physid_isset(mpc_ioapic_id(ioapic_idx), phys_id_present_map)) {
+		if (test_bit(mpc_ioapic_id(ioapic_idx), phys_id_present_map)) {
 			pr_err(FW_BUG "IO-APIC#%d ID %d is already used!...\n",
 			       ioapic_idx, mpc_ioapic_id(ioapic_idx));
 			for (i = 0; i < broadcast_id; i++)
-				if (!physid_isset(i, phys_id_present_map))
+				if (!test_bit(i, phys_id_present_map))
 					break;
 			if (i >= broadcast_id)
 				panic("Max APIC ID exceeded!\n");
 			pr_err("... fixing up to %d. (tell your hw vendor)\n", i);
-			physid_set(i, phys_id_present_map);
+			set_bit(i, phys_id_present_map);
 			ioapics[ioapic_idx].mp_config.apicid = i;
 		} else {
 			apic_printk(APIC_VERBOSE, "Setting %d in the phys_id_present_map\n",
 				    mpc_ioapic_id(ioapic_idx));
-			physid_set(mpc_ioapic_id(ioapic_idx), phys_id_present_map);
+			set_bit(mpc_ioapic_id(ioapic_idx), phys_id_present_map);
 		}
 
 		/*
@@ -2491,15 +2491,15 @@ unsigned int arch_dynirq_lower_bound(unsigned int from)
 #ifdef CONFIG_X86_32
 static int io_apic_get_unique_id(int ioapic, int apic_id)
 {
-	static physid_mask_t apic_id_map = PHYSID_MASK_NONE;
+	static DECLARE_BITMAP(apic_id_map, MAX_LOCAL_APIC);
 	const u32 broadcast_id = 0xF;
 	union IO_APIC_reg_00 reg_00;
 	unsigned long flags;
 	int i = 0;
 
 	/* Initialize the ID map */
-	if (physids_empty(apic_id_map))
-		apic_id_map = phys_cpu_present_map;
+	if (bitmap_empty(apic_id_map, MAX_LOCAL_APIC))
+		copy_phys_cpu_present_map(apic_id_map);
 
 	raw_spin_lock_irqsave(&ioapic_lock, flags);
 	reg_00.raw = io_apic_read(ioapic, 0);
@@ -2512,9 +2512,9 @@ static int io_apic_get_unique_id(int ioapic, int apic_id)
 	}
 
 	/* Every APIC in a system must have a unique ID */
-	if (physid_isset(apic_id, apic_id_map)) {
+	if (test_bit(apic_id, apic_id_map)) {
 		for (i = 0; i < broadcast_id; i++) {
-			if (!physid_isset(i, apic_id_map))
+			if (!test_bit(i, apic_id_map))
 				break;
 		}
 
@@ -2525,7 +2525,7 @@ static int io_apic_get_unique_id(int ioapic, int apic_id)
 		apic_id = i;
 	}
 
-	physid_set(apic_id, apic_id_map);
+	set_bit(apic_id, apic_id_map);
 
 	if (reg_00.bits.ID != apic_id) {
 		reg_00.bits.ID = apic_id;
diff --git a/arch/x86/kernel/apic/local.h b/arch/x86/kernel/apic/local.h
index 8fd37c9d1b34..a77c23e62459 100644
--- a/arch/x86/kernel/apic/local.h
+++ b/arch/x86/kernel/apic/local.h
@@ -63,7 +63,6 @@ void default_send_IPI_all(int vector);
 void default_send_IPI_self(int vector);
 
 bool default_apic_id_registered(void);
-bool default_check_apicid_used(physid_mask_t *map, u32 apicid);
 
 #ifdef CONFIG_X86_32
 void default_send_IPI_mask_sequence_logical(const struct cpumask *mask, int vector);
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 9cdb056c37b5..000b856db8ce 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1072,7 +1072,7 @@ int native_kick_ap(unsigned int cpu, struct task_struct *tidle)
 
 	pr_debug("++++++++++++++++++++=_---CPU UP  %u\n", cpu);
 
-	if (apicid == BAD_APICID || !physid_isset(apicid, phys_cpu_present_map) ||
+	if (apicid == BAD_APICID || !test_bit(apicid, phys_cpu_present_map) ||
 	    !apic_id_valid(apicid)) {
 		pr_err("%s: bad cpu %d\n", __func__, cpu);
 		return -EINVAL;
@@ -1147,10 +1147,8 @@ static __init void disable_smp(void)
 	init_cpu_present(cpumask_of(0));
 	init_cpu_possible(cpumask_of(0));
 
-	if (smp_found_config)
-		physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
-	else
-		physid_set_mask_of_physid(0, &phys_cpu_present_map);
+	reset_phys_cpu_present_map(smp_found_config ? boot_cpu_physical_apicid : 0);
+
 	cpumask_set_cpu(0, topology_sibling_cpumask(0));
 	cpumask_set_cpu(0, topology_core_cpumask(0));
 	cpumask_set_cpu(0, topology_die_cpumask(0));
-- 
cgit v1.2.3


From 58d16928358f91d48421838a7484321b3149130d Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 13 Feb 2024 22:05:19 +0100
Subject: x86/apic: Remove the pointless writeback of boot_cpu_physical_apicid

There is absolutely no point to write the APIC ID which was read from the
local APIC earlier, back into the local APIC for the 64-bit UP case.

Remove that along with the apic callback which is solely there for this
pointless exercise.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240212154640.055288922@linutronix.de
---
 arch/x86/include/asm/apic.h           |  1 -
 arch/x86/kernel/apic/apic.c           |  3 ---
 arch/x86/kernel/apic/apic_flat_64.c   |  7 -------
 arch/x86/kernel/apic/apic_numachip.c  | 12 ------------
 arch/x86/kernel/apic/bigsmp_32.c      |  1 -
 arch/x86/kernel/apic/local.h          |  1 -
 arch/x86/kernel/apic/x2apic_cluster.c |  1 -
 arch/x86/kernel/apic/x2apic_phys.c    |  6 ------
 arch/x86/kernel/apic/x2apic_uv_x.c    |  6 ------
 arch/x86/xen/apic.c                   |  7 -------
 10 files changed, 45 deletions(-)

(limited to 'arch/x86/kernel/apic/apic.c')

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 16e5e0071f1c..89eae0c1e552 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -294,7 +294,6 @@ struct apic {
 	u32	(*cpu_present_to_apicid)(int mps_cpu);
 
 	u32	(*get_apic_id)(u32 id);
-	u32	(*set_apic_id)(u32 apicid);
 
 	/* wakeup_secondary_cpu */
 	int	(*wakeup_secondary_cpu)(u32 apicid, unsigned long start_eip);
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index ce6d31bfc6e3..e3cebd45526b 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -2485,9 +2485,6 @@ EXPORT_SYMBOL_GPL(x86_msi_msg_get_destid);
 
 static void __init apic_bsp_up_setup(void)
 {
-#ifdef CONFIG_X86_64
-	apic_write(APIC_ID, apic->set_apic_id(boot_cpu_physical_apicid));
-#endif
 	reset_phys_cpu_present_map(boot_cpu_physical_apicid);
 }
 
diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c
index fe9b728799f2..f6ef12126ba1 100644
--- a/arch/x86/kernel/apic/apic_flat_64.c
+++ b/arch/x86/kernel/apic/apic_flat_64.c
@@ -61,11 +61,6 @@ static u32 flat_get_apic_id(u32 x)
 	return (x >> 24) & 0xFF;
 }
 
-static u32 set_apic_id(u32 id)
-{
-	return (id & 0xFF) << 24;
-}
-
 static int flat_probe(void)
 {
 	return 1;
@@ -86,7 +81,6 @@ static struct apic apic_flat __ro_after_init = {
 
 	.max_apic_id			= 0xFE,
 	.get_apic_id			= flat_get_apic_id,
-	.set_apic_id			= set_apic_id,
 
 	.calc_dest_apicid		= apic_flat_calc_apicid,
 
@@ -155,7 +149,6 @@ static struct apic apic_physflat __ro_after_init = {
 
 	.max_apic_id			= 0xFE,
 	.get_apic_id			= flat_get_apic_id,
-	.set_apic_id			= set_apic_id,
 
 	.calc_dest_apicid		= apic_default_calc_apicid,
 
diff --git a/arch/x86/kernel/apic/apic_numachip.c b/arch/x86/kernel/apic/apic_numachip.c
index f7591dc656d3..16410f087b7a 100644
--- a/arch/x86/kernel/apic/apic_numachip.c
+++ b/arch/x86/kernel/apic/apic_numachip.c
@@ -38,11 +38,6 @@ static u32 numachip1_get_apic_id(u32 x)
 	return id;
 }
 
-static u32 numachip1_set_apic_id(u32 id)
-{
-	return (id & 0xff) << 24;
-}
-
 static u32 numachip2_get_apic_id(u32 x)
 {
 	u64 mcfg;
@@ -51,11 +46,6 @@ static u32 numachip2_get_apic_id(u32 x)
 	return ((mcfg >> (28 - 8)) & 0xfff00) | (x >> 24);
 }
 
-static u32 numachip2_set_apic_id(u32 id)
-{
-	return id << 24;
-}
-
 static void numachip1_apic_icr_write(int apicid, unsigned int val)
 {
 	write_lcsr(CSR_G3_EXT_IRQ_GEN, (apicid << 16) | val);
@@ -225,7 +215,6 @@ static const struct apic apic_numachip1 __refconst = {
 
 	.max_apic_id			= UINT_MAX,
 	.get_apic_id			= numachip1_get_apic_id,
-	.set_apic_id			= numachip1_set_apic_id,
 
 	.calc_dest_apicid		= apic_default_calc_apicid,
 
@@ -260,7 +249,6 @@ static const struct apic apic_numachip2 __refconst = {
 
 	.max_apic_id			= UINT_MAX,
 	.get_apic_id			= numachip2_get_apic_id,
-	.set_apic_id			= numachip2_set_apic_id,
 
 	.calc_dest_apicid		= apic_default_calc_apicid,
 
diff --git a/arch/x86/kernel/apic/bigsmp_32.c b/arch/x86/kernel/apic/bigsmp_32.c
index 29f354a699d5..9285d500d5b4 100644
--- a/arch/x86/kernel/apic/bigsmp_32.c
+++ b/arch/x86/kernel/apic/bigsmp_32.c
@@ -72,7 +72,6 @@ static struct apic apic_bigsmp __ro_after_init = {
 
 	.max_apic_id			= 0xFE,
 	.get_apic_id			= bigsmp_get_apic_id,
-	.set_apic_id			= NULL,
 
 	.calc_dest_apicid		= apic_default_calc_apicid,
 
diff --git a/arch/x86/kernel/apic/local.h b/arch/x86/kernel/apic/local.h
index a77c23e62459..f8a87f9e72e6 100644
--- a/arch/x86/kernel/apic/local.h
+++ b/arch/x86/kernel/apic/local.h
@@ -16,7 +16,6 @@
 /* X2APIC */
 void __x2apic_send_IPI_dest(unsigned int apicid, int vector, unsigned int dest);
 u32 x2apic_get_apic_id(u32 id);
-u32 x2apic_set_apic_id(u32 id);
 
 void x2apic_send_IPI_all(int vector);
 void x2apic_send_IPI_allbutself(int vector);
diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c
index 4926b127b230..567dbd2fe4b6 100644
--- a/arch/x86/kernel/apic/x2apic_cluster.c
+++ b/arch/x86/kernel/apic/x2apic_cluster.c
@@ -237,7 +237,6 @@ static struct apic apic_x2apic_cluster __ro_after_init = {
 	.max_apic_id			= UINT_MAX,
 	.x2apic_set_max_apicid		= true,
 	.get_apic_id			= x2apic_get_apic_id,
-	.set_apic_id			= x2apic_set_apic_id,
 
 	.calc_dest_apicid		= x2apic_calc_apicid,
 
diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c
index 8f1c39fa8121..12d4c35547a6 100644
--- a/arch/x86/kernel/apic/x2apic_phys.c
+++ b/arch/x86/kernel/apic/x2apic_phys.c
@@ -129,11 +129,6 @@ u32 x2apic_get_apic_id(u32 id)
 	return id;
 }
 
-u32 x2apic_set_apic_id(u32 id)
-{
-	return id;
-}
-
 static struct apic apic_x2apic_phys __ro_after_init = {
 
 	.name				= "physical x2apic",
@@ -149,7 +144,6 @@ static struct apic apic_x2apic_phys __ro_after_init = {
 	.max_apic_id			= UINT_MAX,
 	.x2apic_set_max_apicid		= true,
 	.get_apic_id			= x2apic_get_apic_id,
-	.set_apic_id			= x2apic_set_apic_id,
 
 	.calc_dest_apicid		= apic_default_calc_apicid,
 
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 3ae696f072bb..7fef504ca508 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -745,11 +745,6 @@ static void uv_send_IPI_all(int vector)
 	uv_send_IPI_mask(cpu_online_mask, vector);
 }
 
-static u32 set_apic_id(u32 id)
-{
-	return id;
-}
-
 static int uv_probe(void)
 {
 	return apic == &apic_x2apic_uv_x;
@@ -769,7 +764,6 @@ static struct apic apic_x2apic_uv_x __ro_after_init = {
 
 	.max_apic_id			= UINT_MAX,
 	.get_apic_id			= x2apic_get_apic_id,
-	.set_apic_id			= set_apic_id,
 
 	.calc_dest_apicid		= apic_default_calc_apicid,
 
diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
index d4752382b600..8835d1cc961d 100644
--- a/arch/x86/xen/apic.c
+++ b/arch/x86/xen/apic.c
@@ -33,12 +33,6 @@ static unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
 	return 0xfd;
 }
 
-static u32 xen_set_apic_id(u32 x)
-{
-	WARN_ON(1);
-	return x;
-}
-
 static u32 xen_get_apic_id(u32 x)
 {
 	return ((x)>>24) & 0xFFu;
@@ -131,7 +125,6 @@ static struct apic xen_pv_apic __ro_after_init = {
 
 	.max_apic_id			= UINT_MAX,
 	.get_apic_id			= xen_get_apic_id,
-	.set_apic_id			= xen_set_apic_id,
 
 	.calc_dest_apicid		= apic_flat_calc_apicid,
 
-- 
cgit v1.2.3


From 4a5f72a4a39f5d5dcf9b9dc1acc57ecbbb8d4caa Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 13 Feb 2024 22:05:20 +0100
Subject: x86/apic: Remove yet another dubious callback

Paranoia is not wrong, but having an APIC callback which is in most
implementations a complete NOOP and in one actually looking whether the
APICID of an upcoming CPU has been registered. The same APICID which was
used to bring the CPU out of wait for startup.

That's paranoia for the paranoia sake. Remove the voodoo.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240212154640.116510935@linutronix.de
---
 arch/x86/include/asm/apic.h         | 1 -
 arch/x86/kernel/apic/apic.c         | 3 ---
 arch/x86/kernel/apic/apic_common.c  | 5 -----
 arch/x86/kernel/apic/apic_flat_64.c | 2 --
 arch/x86/kernel/apic/local.h        | 2 --
 arch/x86/kernel/apic/probe_32.c     | 1 -
 6 files changed, 14 deletions(-)

(limited to 'arch/x86/kernel/apic/apic.c')

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 89eae0c1e552..ba219d6c851e 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -288,7 +288,6 @@ struct apic {
 	/* Probe, setup and smpboot functions */
 	int	(*probe)(void);
 	int	(*acpi_madt_oem_check)(char *oem_id, char *oem_table_id);
-	bool	(*apic_id_registered)(void);
 
 	void	(*init_apic_ldr)(void);
 	u32	(*cpu_present_to_apicid)(int mps_cpu);
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index e3cebd45526b..68767a9dd3d1 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1538,9 +1538,6 @@ static void setup_local_APIC(void)
 		apic_write(APIC_ESR, 0);
 	}
 #endif
-	/* Validate that the APIC is registered if required */
-	BUG_ON(apic->apic_id_registered && !apic->apic_id_registered());
-
 	/*
 	 * Intel recommends to set DFR, LDR and TPR before enabling
 	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
diff --git a/arch/x86/kernel/apic/apic_common.c b/arch/x86/kernel/apic/apic_common.c
index d4dfa437081a..9ef3be866832 100644
--- a/arch/x86/kernel/apic/apic_common.c
+++ b/arch/x86/kernel/apic/apic_common.c
@@ -27,11 +27,6 @@ u32 default_cpu_present_to_apicid(int mps_cpu)
 }
 EXPORT_SYMBOL_GPL(default_cpu_present_to_apicid);
 
-bool default_apic_id_registered(void)
-{
-	return test_bit(read_apic_id(), phys_cpu_present_map);
-}
-
 /*
  * Set up the logical destination ID when the APIC operates in logical
  * destination mode.
diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c
index f6ef12126ba1..f37ad3392fec 100644
--- a/arch/x86/kernel/apic/apic_flat_64.c
+++ b/arch/x86/kernel/apic/apic_flat_64.c
@@ -70,7 +70,6 @@ static struct apic apic_flat __ro_after_init = {
 	.name				= "flat",
 	.probe				= flat_probe,
 	.acpi_madt_oem_check		= flat_acpi_madt_oem_check,
-	.apic_id_registered		= default_apic_id_registered,
 
 	.dest_mode_logical		= true,
 
@@ -139,7 +138,6 @@ static struct apic apic_physflat __ro_after_init = {
 	.name				= "physical flat",
 	.probe				= physflat_probe,
 	.acpi_madt_oem_check		= physflat_acpi_madt_oem_check,
-	.apic_id_registered		= default_apic_id_registered,
 
 	.dest_mode_logical		= false,
 
diff --git a/arch/x86/kernel/apic/local.h b/arch/x86/kernel/apic/local.h
index f8a87f9e72e6..842fe28496be 100644
--- a/arch/x86/kernel/apic/local.h
+++ b/arch/x86/kernel/apic/local.h
@@ -61,8 +61,6 @@ void default_send_IPI_allbutself(int vector);
 void default_send_IPI_all(int vector);
 void default_send_IPI_self(int vector);
 
-bool default_apic_id_registered(void);
-
 #ifdef CONFIG_X86_32
 void default_send_IPI_mask_sequence_logical(const struct cpumask *mask, int vector);
 void default_send_IPI_mask_allbutself_logical(const struct cpumask *mask, int vector);
diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
index cdf4047d88e1..f75ee345c02d 100644
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -38,7 +38,6 @@ static struct apic apic_default __ro_after_init = {
 
 	.name				= "default",
 	.probe				= probe_default,
-	.apic_id_registered		= default_apic_id_registered,
 
 	.dest_mode_logical		= true,
 
-- 
cgit v1.2.3


From 1a5d0f62d10d5da44c2b6a97b6600dea8a7519fb Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 13 Feb 2024 22:05:21 +0100
Subject: x86/apic: Use a proper define for invalid ACPI CPU ID

The ACPI ID for CPUs is preset with U32_MAX which is completely non
obvious. Use a proper define for it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240212154640.177504138@linutronix.de
---
 arch/x86/include/asm/apic.h  | 3 +++
 arch/x86/kernel/apic/apic.c  | 2 +-
 arch/x86/xen/enlighten_hvm.c | 2 +-
 3 files changed, 5 insertions(+), 2 deletions(-)

(limited to 'arch/x86/kernel/apic/apic.c')

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index ba219d6c851e..109f9808e0bd 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -48,7 +48,10 @@ static inline void x86_32_probe_apic(void) { }
 
 extern u32 cpuid_to_apicid[];
 
+#define CPU_ACPIID_INVALID	U32_MAX
+
 #ifdef CONFIG_X86_LOCAL_APIC
+
 extern int apic_verbosity;
 extern int local_apic_timer_c2_ok;
 
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 68767a9dd3d1..fa11e2585e20 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -111,7 +111,7 @@ static inline bool apic_accessible(void)
  * Map cpu index to physical APIC ID
  */
 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_apicid, BAD_APICID);
-DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, U32_MAX);
+DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, CPU_ACPIID_INVALID);
 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
 
diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
index 3f8c34707c50..99a68fa71dbe 100644
--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -168,7 +168,7 @@ static int xen_cpu_up_prepare_hvm(unsigned int cpu)
 	 */
 	xen_uninit_lock_cpu(cpu);
 
-	if (cpu_acpi_id(cpu) != U32_MAX)
+	if (cpu_acpi_id(cpu) != CPU_ACPIID_INVALID)
 		per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
 	else
 		per_cpu(xen_vcpu_id, cpu) = cpu;
-- 
cgit v1.2.3


From c0a66c2847908e41c771ca2355fba935a82a9f62 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 13 Feb 2024 22:05:35 +0100
Subject: x86/cpu/topology: Move registration out of APIC code

The APIC/CPU registration sits in the middle of the APIC code. In fact this
is a topology evaluation function and has nothing to do with the inner
workings of the local APIC.

Move it out into a file which reflects what this is about.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210251.543948812@linutronix.de
---
 arch/x86/include/asm/apic.h    |   2 +
 arch/x86/kernel/apic/apic.c    | 185 +----------------------------------------
 arch/x86/kernel/cpu/Makefile   |  12 +--
 arch/x86/kernel/cpu/topology.c | 184 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 195 insertions(+), 188 deletions(-)
 create mode 100644 arch/x86/kernel/cpu/topology.c

(limited to 'arch/x86/kernel/apic/apic.c')

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 109f9808e0bd..11938d5206f4 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -171,6 +171,8 @@ extern bool apic_needs_pit(void);
 
 extern void apic_send_IPI_allbutself(unsigned int vector);
 
+extern void topology_register_boot_apic(u32 apic_id);
+
 #else /* !CONFIG_X86_LOCAL_APIC */
 static inline void lapic_shutdown(void) { }
 #define local_apic_timer_c2_ok		1
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index fa11e2585e20..5814b8014197 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -68,26 +68,12 @@
 
 #include "local.h"
 
-unsigned int num_processors;
-
-unsigned disabled_cpus;
-
 /* Processor that is doing the boot up */
 u32 boot_cpu_physical_apicid __ro_after_init = BAD_APICID;
 EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
 
 u8 boot_cpu_apic_version __ro_after_init;
 
-/* Bitmap of physically present CPUs. */
-DECLARE_BITMAP(phys_cpu_present_map, MAX_LOCAL_APIC);
-
-/*
- * Processor to be disabled specified by kernel parameter
- * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
- * avoid undefined behaviour caused by sending INIT from AP to BSP.
- */
-static u32 disabled_cpu_apicid __ro_after_init = BAD_APICID;
-
 /*
  * This variable controls which CPUs receive external NMIs.  By default,
  * external NMIs are delivered only to the BSP.
@@ -107,14 +93,6 @@ static inline bool apic_accessible(void)
 	return x2apic_mode || apic_mmio_base;
 }
 
-/*
- * Map cpu index to physical APIC ID
- */
-DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_apicid, BAD_APICID);
-DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, CPU_ACPIID_INVALID);
-EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
-EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
-
 #ifdef CONFIG_X86_32
 /* Local APIC was disabled by the BIOS and enabled by the kernel */
 static int enabled_via_apicbase __ro_after_init;
@@ -1676,8 +1654,6 @@ void apic_ap_setup(void)
 	end_local_APIC_setup();
 }
 
-static __init void cpu_set_boot_apic(void);
-
 static __init void apic_read_boot_cpu_id(bool x2apic)
 {
 	/*
@@ -1692,7 +1668,8 @@ static __init void apic_read_boot_cpu_id(bool x2apic)
 		boot_cpu_physical_apicid = read_apic_id();
 		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
 	}
-	cpu_set_boot_apic();
+	topology_register_boot_apic(boot_cpu_physical_apicid);
+	x86_32_probe_bigsmp_early();
 }
 
 #ifdef CONFIG_X86_X2APIC
@@ -2291,155 +2268,6 @@ void disconnect_bsp_APIC(int virt_wire_setup)
 	apic_write(APIC_LVT1, value);
 }
 
-/*
- * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
- * contiguously, it equals to current allocated max logical CPU ID plus 1.
- * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
- * so the maximum of nr_logical_cpuids is nr_cpu_ids.
- *
- * NOTE: Reserve 0 for BSP.
- */
-static int nr_logical_cpuids = 1;
-
-/*
- * Used to store mapping between logical CPU IDs and APIC IDs.
- */
-u32 cpuid_to_apicid[] = { [0 ... NR_CPUS - 1] = BAD_APICID, };
-
-bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
-{
-	return phys_id == (u64)cpuid_to_apicid[cpu];
-}
-
-#ifdef CONFIG_SMP
-static void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid)
-{
-	/* Isolate the SMT bit(s) in the APICID and check for 0 */
-	u32 mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
-
-	if (smp_num_siblings == 1 || !(apicid & mask))
-		cpumask_set_cpu(cpu, &__cpu_primary_thread_mask);
-}
-
-/*
- * Due to the utter mess of CPUID evaluation smp_num_siblings is not valid
- * during early boot. Initialize the primary thread mask before SMP
- * bringup.
- */
-static int __init smp_init_primary_thread_mask(void)
-{
-	unsigned int cpu;
-
-	/*
-	 * XEN/PV provides either none or useless topology information.
-	 * Pretend that all vCPUs are primary threads.
-	 */
-	if (xen_pv_domain()) {
-		cpumask_copy(&__cpu_primary_thread_mask, cpu_possible_mask);
-		return 0;
-	}
-
-	for (cpu = 0; cpu < nr_logical_cpuids; cpu++)
-		cpu_mark_primary_thread(cpu, cpuid_to_apicid[cpu]);
-	return 0;
-}
-early_initcall(smp_init_primary_thread_mask);
-#else
-static inline void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid) { }
-#endif
-
-/*
- * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
- * and cpuid_to_apicid[] synchronized.
- */
-static int allocate_logical_cpuid(int apicid)
-{
-	int i;
-
-	/*
-	 * cpuid <-> apicid mapping is persistent, so when a cpu is up,
-	 * check if the kernel has allocated a cpuid for it.
-	 */
-	for (i = 0; i < nr_logical_cpuids; i++) {
-		if (cpuid_to_apicid[i] == apicid)
-			return i;
-	}
-
-	/* Allocate a new cpuid. */
-	if (nr_logical_cpuids >= nr_cpu_ids) {
-		WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
-			     "Processor %d/0x%x and the rest are ignored.\n",
-			     nr_cpu_ids, nr_logical_cpuids, apicid);
-		return -EINVAL;
-	}
-
-	cpuid_to_apicid[nr_logical_cpuids] = apicid;
-	return nr_logical_cpuids++;
-}
-
-static void cpu_update_apic(int cpu, u32 apicid)
-{
-#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
-	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
-#endif
-	set_cpu_possible(cpu, true);
-	set_bit(apicid, phys_cpu_present_map);
-	set_cpu_present(cpu, true);
-	num_processors++;
-
-	if (system_state != SYSTEM_BOOTING)
-		cpu_mark_primary_thread(cpu, apicid);
-}
-
-static __init void cpu_set_boot_apic(void)
-{
-	cpuid_to_apicid[0] = boot_cpu_physical_apicid;
-	cpu_update_apic(0, boot_cpu_physical_apicid);
-	x86_32_probe_bigsmp_early();
-}
-
-int generic_processor_info(int apicid)
-{
-	int cpu, max = nr_cpu_ids;
-
-	/* The boot CPU must be set before MADT/MPTABLE parsing happens */
-	if (cpuid_to_apicid[0] == BAD_APICID)
-		panic("Boot CPU APIC not registered yet\n");
-
-	if (apicid == boot_cpu_physical_apicid)
-		return 0;
-
-	if (disabled_cpu_apicid == apicid) {
-		int thiscpu = num_processors + disabled_cpus;
-
-		pr_warn("APIC: Disabling requested cpu. Processor %d/0x%x ignored.\n",
-			thiscpu, apicid);
-
-		disabled_cpus++;
-		return -ENODEV;
-	}
-
-	if (num_processors >= nr_cpu_ids) {
-		int thiscpu = max + disabled_cpus;
-
-		pr_warn("APIC: NR_CPUS/possible_cpus limit of %i reached. "
-			"Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
-
-		disabled_cpus++;
-		return -EINVAL;
-	}
-
-	cpu = allocate_logical_cpuid(apicid);
-	if (cpu < 0) {
-		disabled_cpus++;
-		return -EINVAL;
-	}
-
-	cpu_update_apic(cpu, apicid);
-	return cpu;
-}
-
-
 void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg,
 			   bool dmar)
 {
@@ -2828,15 +2656,6 @@ static int __init lapic_insert_resource(void)
  */
 late_initcall(lapic_insert_resource);
 
-static int __init apic_set_disabled_cpu_apicid(char *arg)
-{
-	if (!arg || !get_option(&arg, &disabled_cpu_apicid))
-		return -EINVAL;
-
-	return 0;
-}
-early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
-
 static int __init apic_set_extnmi(char *arg)
 {
 	if (!arg)
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 9e0a1c119a91..eb4dbcdf41f1 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -26,14 +26,16 @@ obj-y			+= bugs.o
 obj-y			+= aperfmperf.o
 obj-y			+= cpuid-deps.o
 obj-y			+= umwait.o
+obj-y 			+= capflags.o powerflags.o
 
-obj-$(CONFIG_PROC_FS)	+= proc.o
-obj-y += capflags.o powerflags.o
+obj-$(CONFIG_X86_LOCAL_APIC)		+= topology.o
 
-obj-$(CONFIG_IA32_FEAT_CTL) += feat_ctl.o
+obj-$(CONFIG_PROC_FS)			+= proc.o
+
+obj-$(CONFIG_IA32_FEAT_CTL)		+= feat_ctl.o
 ifdef CONFIG_CPU_SUP_INTEL
-obj-y			+= intel.o intel_pconfig.o tsx.o
-obj-$(CONFIG_PM)	+= intel_epb.o
+obj-y					+= intel.o intel_pconfig.o tsx.o
+obj-$(CONFIG_PM)			+= intel_epb.o
 endif
 obj-$(CONFIG_CPU_SUP_AMD)		+= amd.o
 obj-$(CONFIG_CPU_SUP_HYGON)		+= hygon.o
diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c
new file mode 100644
index 000000000000..b99cd19b7d12
--- /dev/null
+++ b/arch/x86/kernel/cpu/topology.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/cpu.h>
+
+#include <xen/xen.h>
+
+#include <asm/apic.h>
+#include <asm/mpspec.h>
+#include <asm/smp.h>
+
+/*
+ * Map cpu index to physical APIC ID
+ */
+DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_apicid, BAD_APICID);
+DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, CPU_ACPIID_INVALID);
+EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
+EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
+
+/* Bitmap of physically present CPUs. */
+DECLARE_BITMAP(phys_cpu_present_map, MAX_LOCAL_APIC) __read_mostly;
+
+/* Used for CPU number allocation and parallel CPU bringup */
+u32 cpuid_to_apicid[] __read_mostly = { [0 ... NR_CPUS - 1] = BAD_APICID, };
+
+/*
+ * Processor to be disabled specified by kernel parameter
+ * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
+ * avoid undefined behaviour caused by sending INIT from AP to BSP.
+ */
+static u32 disabled_cpu_apicid __ro_after_init = BAD_APICID;
+
+unsigned int num_processors;
+unsigned disabled_cpus;
+
+/*
+ * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
+ * contiguously, it equals to current allocated max logical CPU ID plus 1.
+ * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
+ * so the maximum of nr_logical_cpuids is nr_cpu_ids.
+ *
+ * NOTE: Reserve 0 for BSP.
+ */
+static int nr_logical_cpuids = 1;
+
+bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+	return phys_id == (u64)cpuid_to_apicid[cpu];
+}
+
+#ifdef CONFIG_SMP
+static void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid)
+{
+	/* Isolate the SMT bit(s) in the APICID and check for 0 */
+	u32 mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
+
+	if (smp_num_siblings == 1 || !(apicid & mask))
+		cpumask_set_cpu(cpu, &__cpu_primary_thread_mask);
+}
+
+/*
+ * Due to the utter mess of CPUID evaluation smp_num_siblings is not valid
+ * during early boot. Initialize the primary thread mask before SMP
+ * bringup.
+ */
+static int __init smp_init_primary_thread_mask(void)
+{
+	unsigned int cpu;
+
+	/*
+	 * XEN/PV provides either none or useless topology information.
+	 * Pretend that all vCPUs are primary threads.
+	 */
+	if (xen_pv_domain()) {
+		cpumask_copy(&__cpu_primary_thread_mask, cpu_possible_mask);
+		return 0;
+	}
+
+	for (cpu = 0; cpu < nr_logical_cpuids; cpu++)
+		cpu_mark_primary_thread(cpu, cpuid_to_apicid[cpu]);
+	return 0;
+}
+early_initcall(smp_init_primary_thread_mask);
+#else
+static inline void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid) { }
+#endif
+
+/*
+ * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
+ * and cpuid_to_apicid[] synchronized.
+ */
+static int allocate_logical_cpuid(int apicid)
+{
+	int i;
+
+	/*
+	 * cpuid <-> apicid mapping is persistent, so when a cpu is up,
+	 * check if the kernel has allocated a cpuid for it.
+	 */
+	for (i = 0; i < nr_logical_cpuids; i++) {
+		if (cpuid_to_apicid[i] == apicid)
+			return i;
+	}
+
+	/* Allocate a new cpuid. */
+	if (nr_logical_cpuids >= nr_cpu_ids) {
+		WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
+			     "Processor %d/0x%x and the rest are ignored.\n",
+			     nr_cpu_ids, nr_logical_cpuids, apicid);
+		return -EINVAL;
+	}
+
+	cpuid_to_apicid[nr_logical_cpuids] = apicid;
+	return nr_logical_cpuids++;
+}
+
+static void cpu_update_apic(int cpu, u32 apicid)
+{
+#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
+	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
+#endif
+	set_cpu_possible(cpu, true);
+	set_bit(apicid, phys_cpu_present_map);
+	set_cpu_present(cpu, true);
+	num_processors++;
+
+	if (system_state != SYSTEM_BOOTING)
+		cpu_mark_primary_thread(cpu, apicid);
+}
+
+void __init topology_register_boot_apic(u32 apic_id)
+{
+	cpuid_to_apicid[0] = apic_id;
+	cpu_update_apic(0, apic_id);
+}
+
+int generic_processor_info(int apicid)
+{
+	int cpu, max = nr_cpu_ids;
+
+	/* The boot CPU must be set before MADT/MPTABLE parsing happens */
+	if (cpuid_to_apicid[0] == BAD_APICID)
+		panic("Boot CPU APIC not registered yet\n");
+
+	if (apicid == boot_cpu_physical_apicid)
+		return 0;
+
+	if (disabled_cpu_apicid == apicid) {
+		int thiscpu = num_processors + disabled_cpus;
+
+		pr_warn("APIC: Disabling requested cpu. Processor %d/0x%x ignored.\n",
+			thiscpu, apicid);
+
+		disabled_cpus++;
+		return -ENODEV;
+	}
+
+	if (num_processors >= nr_cpu_ids) {
+		int thiscpu = max + disabled_cpus;
+
+		pr_warn("APIC: NR_CPUS/possible_cpus limit of %i reached. "
+			"Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
+
+		disabled_cpus++;
+		return -EINVAL;
+	}
+
+	cpu = allocate_logical_cpuid(apicid);
+	if (cpu < 0) {
+		disabled_cpus++;
+		return -EINVAL;
+	}
+
+	cpu_update_apic(cpu, apicid);
+	return cpu;
+}
+
+static int __init apic_set_disabled_cpu_apicid(char *arg)
+{
+	if (!arg || !get_option(&arg, &disabled_cpu_apicid))
+		return -EINVAL;
+
+	return 0;
+}
+early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
-- 
cgit v1.2.3


From 58aa34abe9954cd5dfbf322fc612146c5f45e52b Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 13 Feb 2024 22:05:46 +0100
Subject: x86/cpu/topology: Confine topology information

Now that all external fiddling with num_processors and disabled_cpus is
gone, move the last user prefill_possible_map() into the topology code too
and remove the global visibility of these variables.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210251.994756960@linutronix.de
---
 arch/x86/include/asm/smp.h     |  3 --
 arch/x86/kernel/apic/apic.c    |  1 -
 arch/x86/kernel/cpu/topology.c | 76 ++++++++++++++++++++++++++++++++++++++++--
 arch/x86/kernel/smpboot.c      | 72 ---------------------------------------
 4 files changed, 74 insertions(+), 78 deletions(-)

(limited to 'arch/x86/kernel/apic/apic.c')

diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 4fab2ed454f3..f1510d6f4e84 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -9,7 +9,6 @@
 #include <asm/thread_info.h>
 
 extern int smp_num_siblings;
-extern unsigned int num_processors;
 
 DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
 DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map);
@@ -174,8 +173,6 @@ static inline struct cpumask *cpu_llc_shared_mask(int cpu)
 }
 #endif /* CONFIG_SMP */
 
-extern unsigned disabled_cpus;
-
 #ifdef CONFIG_DEBUG_NMI_SELFTEST
 extern void nmi_selftest(void);
 #else
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 5814b8014197..a42d8a6f7149 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -2054,7 +2054,6 @@ void __init init_apic_mappings(void)
 			pr_info("APIC: disable apic facility\n");
 			apic_disable();
 		}
-		num_processors = 1;
 	}
 }
 
diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c
index 669e258b9e0b..a6c931434951 100644
--- a/arch/x86/kernel/cpu/topology.c
+++ b/arch/x86/kernel/cpu/topology.c
@@ -29,8 +29,8 @@ u32 cpuid_to_apicid[] __read_mostly = { [0 ... NR_CPUS - 1] = BAD_APICID, };
  */
 static u32 disabled_cpu_apicid __ro_after_init = BAD_APICID;
 
-unsigned int num_processors;
-unsigned disabled_cpus;
+static unsigned int num_processors;
+static unsigned int disabled_cpus;
 
 /*
  * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
@@ -174,6 +174,71 @@ static int generic_processor_info(int apicid)
 	return cpu;
 }
 
+static int __initdata setup_possible_cpus = -1;
+
+/*
+ * cpu_possible_mask should be static, it cannot change as cpu's
+ * are onlined, or offlined. The reason is per-cpu data-structures
+ * are allocated by some modules at init time, and don't expect to
+ * do this dynamically on cpu arrival/departure.
+ * cpu_present_mask on the other hand can change dynamically.
+ * In case when cpu_hotplug is not compiled, then we resort to current
+ * behaviour, which is cpu_possible == cpu_present.
+ * - Ashok Raj
+ *
+ * Three ways to find out the number of additional hotplug CPUs:
+ * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
+ * - The user can overwrite it with possible_cpus=NUM
+ * - Otherwise don't reserve additional CPUs.
+ * We do this because additional CPUs waste a lot of memory.
+ * -AK
+ */
+__init void prefill_possible_map(void)
+{
+	int i, possible;
+
+	i = setup_max_cpus ?: 1;
+	if (setup_possible_cpus == -1) {
+		possible = num_processors;
+#ifdef CONFIG_HOTPLUG_CPU
+		if (setup_max_cpus)
+			possible += disabled_cpus;
+#else
+		if (possible > i)
+			possible = i;
+#endif
+	} else
+		possible = setup_possible_cpus;
+
+	total_cpus = max_t(int, possible, num_processors + disabled_cpus);
+
+	/* nr_cpu_ids could be reduced via nr_cpus= */
+	if (possible > nr_cpu_ids) {
+		pr_warn("%d Processors exceeds NR_CPUS limit of %u\n",
+			possible, nr_cpu_ids);
+		possible = nr_cpu_ids;
+	}
+
+#ifdef CONFIG_HOTPLUG_CPU
+	if (!setup_max_cpus)
+#endif
+	if (possible > i) {
+		pr_warn("%d Processors exceeds max_cpus limit of %u\n",
+			possible, setup_max_cpus);
+		possible = i;
+	}
+
+	set_nr_cpu_ids(possible);
+
+	pr_info("Allowing %d CPUs, %d hotplug CPUs\n",
+		possible, max_t(int, possible - num_processors, 0));
+
+	reset_cpu_possible_mask();
+
+	for (i = 0; i < possible; i++)
+		set_cpu_possible(i, true);
+}
+
 /**
  * topology_register_apic - Register an APIC in early topology maps
  * @apic_id:	The APIC ID to set up
@@ -251,6 +316,13 @@ void topology_hotunplug_apic(unsigned int cpu)
 }
 #endif
 
+static int __init _setup_possible_cpus(char *str)
+{
+	get_option(&str, &setup_possible_cpus);
+	return 0;
+}
+early_param("possible_cpus", _setup_possible_cpus);
+
 static int __init apic_set_disabled_cpu_apicid(char *arg)
 {
 	if (!arg || !get_option(&arg, &disabled_cpu_apicid))
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 000b856db8ce..bfb99b5c5606 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1291,78 +1291,6 @@ void __init native_smp_cpus_done(unsigned int max_cpus)
 	cache_aps_init();
 }
 
-static int __initdata setup_possible_cpus = -1;
-static int __init _setup_possible_cpus(char *str)
-{
-	get_option(&str, &setup_possible_cpus);
-	return 0;
-}
-early_param("possible_cpus", _setup_possible_cpus);
-
-
-/*
- * cpu_possible_mask should be static, it cannot change as cpu's
- * are onlined, or offlined. The reason is per-cpu data-structures
- * are allocated by some modules at init time, and don't expect to
- * do this dynamically on cpu arrival/departure.
- * cpu_present_mask on the other hand can change dynamically.
- * In case when cpu_hotplug is not compiled, then we resort to current
- * behaviour, which is cpu_possible == cpu_present.
- * - Ashok Raj
- *
- * Three ways to find out the number of additional hotplug CPUs:
- * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
- * - The user can overwrite it with possible_cpus=NUM
- * - Otherwise don't reserve additional CPUs.
- * We do this because additional CPUs waste a lot of memory.
- * -AK
- */
-__init void prefill_possible_map(void)
-{
-	int i, possible;
-
-	i = setup_max_cpus ?: 1;
-	if (setup_possible_cpus == -1) {
-		possible = num_processors;
-#ifdef CONFIG_HOTPLUG_CPU
-		if (setup_max_cpus)
-			possible += disabled_cpus;
-#else
-		if (possible > i)
-			possible = i;
-#endif
-	} else
-		possible = setup_possible_cpus;
-
-	total_cpus = max_t(int, possible, num_processors + disabled_cpus);
-
-	/* nr_cpu_ids could be reduced via nr_cpus= */
-	if (possible > nr_cpu_ids) {
-		pr_warn("%d Processors exceeds NR_CPUS limit of %u\n",
-			possible, nr_cpu_ids);
-		possible = nr_cpu_ids;
-	}
-
-#ifdef CONFIG_HOTPLUG_CPU
-	if (!setup_max_cpus)
-#endif
-	if (possible > i) {
-		pr_warn("%d Processors exceeds max_cpus limit of %u\n",
-			possible, setup_max_cpus);
-		possible = i;
-	}
-
-	set_nr_cpu_ids(possible);
-
-	pr_info("Allowing %d CPUs, %d hotplug CPUs\n",
-		possible, max_t(int, possible - num_processors, 0));
-
-	reset_cpu_possible_mask();
-
-	for (i = 0; i < possible; i++)
-		set_cpu_possible(i, true);
-}
-
 /* correctly size the local cpu masks */
 void __init setup_cpu_local_masks(void)
 {
-- 
cgit v1.2.3