1 files changed, 251 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c
new file mode 100644
index 000000000..7862b152a
--- /dev/null
+++ b/arch/x86/kernel/apic/apic_flat_64.c
@@ -0,0 +1,251 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2004 James Cleverdon, IBM.
+ *
+ * Flat APIC subarch code.
+ *
+ * Hacked for x86-64 by James Cleverdon from i386 architecture code by
+ * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
+ * James Cleverdon.
+ */
+#include <linux/cpumask.h>
+#include <linux/export.h>
+#include <linux/acpi.h>
+
+#include <asm/jailhouse_para.h>
+#include <asm/apic.h>
+
+#include "local.h"
+
+static struct apic apic_physflat;
+static struct apic apic_flat;
+
+struct apic *apic __ro_after_init = &apic_flat;
+EXPORT_SYMBOL_GPL(apic);
+
+static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+{
+	return 1;
+}
+
+/*
+ * Set up the logical destination ID.
+ *
+ * Intel recommends to set DFR, LDR and TPR before enabling
+ * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
+ * document number 292116).  So here it goes...
+ */
+void flat_init_apic_ldr(void)
+{
+	unsigned long val;
+	unsigned long num, id;
+
+	num = smp_processor_id();
+	id = 1UL << num;
+	apic_write(APIC_DFR, APIC_DFR_FLAT);
+	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
+	val |= SET_APIC_LOGICAL_ID(id);
+	apic_write(APIC_LDR, val);
+}
+
+static void _flat_send_IPI_mask(unsigned long mask, int vector)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__default_send_IPI_dest_field(mask, vector, apic->dest_logical);
+	local_irq_restore(flags);
+}
+
+static void flat_send_IPI_mask(const struct cpumask *cpumask, int vector)
+{
+	unsigned long mask = cpumask_bits(cpumask)[0];
+
+	_flat_send_IPI_mask(mask, vector);
+}
+
+static void
+flat_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector)
+{
+	unsigned long mask = cpumask_bits(cpumask)[0];
+	int cpu = smp_processor_id();
+
+	if (cpu < BITS_PER_LONG)
+		__clear_bit(cpu, &mask);
+
+	_flat_send_IPI_mask(mask, vector);
+}
+
+static unsigned int flat_get_apic_id(unsigned long x)
+{
+	return (x >> 24) & 0xFF;
+}
+
+static u32 set_apic_id(unsigned int id)
+{
+	return (id & 0xFF) << 24;
+}
+
+static unsigned int read_xapic_id(void)
+{
+	return flat_get_apic_id(apic_read(APIC_ID));
+}
+
+static int flat_apic_id_registered(void)
+{
+	return physid_isset(read_xapic_id(), phys_cpu_present_map);
+}
+
+static int flat_phys_pkg_id(int initial_apic_id, int index_msb)
+{
+	return initial_apic_id >> index_msb;
+}
+
+static int flat_probe(void)
+{
+	return 1;
+}
+
+static struct apic apic_flat __ro_after_init = {
+	.name				= "flat",
+	.probe				= flat_probe,
+	.acpi_madt_oem_check		= flat_acpi_madt_oem_check,
+	.apic_id_valid			= default_apic_id_valid,
+	.apic_id_registered		= flat_apic_id_registered,
+
+	.irq_delivery_mode		= dest_Fixed,
+	.irq_dest_mode			= 1, /* logical */
+
+	.disable_esr			= 0,
+	.dest_logical			= APIC_DEST_LOGICAL,
+	.check_apicid_used		= NULL,
+
+	.init_apic_ldr			= flat_init_apic_ldr,
+
+	.ioapic_phys_id_map		= NULL,
+	.setup_apic_routing		= NULL,
+	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
+	.apicid_to_cpu_present		= NULL,
+	.check_phys_apicid_present	= default_check_phys_apicid_present,
+	.phys_pkg_id			= flat_phys_pkg_id,
+
+	.get_apic_id			= flat_get_apic_id,
+	.set_apic_id			= set_apic_id,
+
+	.calc_dest_apicid		= apic_flat_calc_apicid,
+
+	.send_IPI			= default_send_IPI_single,
+	.send_IPI_mask			= flat_send_IPI_mask,
+	.send_IPI_mask_allbutself	= flat_send_IPI_mask_allbutself,
+	.send_IPI_allbutself		= default_send_IPI_allbutself,
+	.send_IPI_all			= default_send_IPI_all,
+	.send_IPI_self			= default_send_IPI_self,
+
+	.inquire_remote_apic		= default_inquire_remote_apic,
+
+	.read				= native_apic_mem_read,
+	.write				= native_apic_mem_write,
+	.eoi_write			= native_apic_mem_write,
+	.icr_read			= native_apic_icr_read,
+	.icr_write			= native_apic_icr_write,
+	.wait_icr_idle			= native_apic_wait_icr_idle,
+	.safe_wait_icr_idle		= native_safe_apic_wait_icr_idle,
+};
+
+/*
+ * Physflat mode is used when there are more than 8 CPUs on a system.
+ * We cannot use logical delivery in this case because the mask
+ * overflows, so use physical mode.
+ */
+static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+{
+#ifdef CONFIG_ACPI
+	/*
+	 * Quirk: some x86_64 machines can only use physical APIC mode
+	 * regardless of how many processors are present (x86_64 ES7000
+	 * is an example).
+	 */
+	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
+		(acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) {
+		printk(KERN_DEBUG "system APIC only can use physical flat");
+		return 1;
+	}
+
+	if (!strncmp(oem_id, "IBM", 3) && !strncmp(oem_table_id, "EXA", 3)) {
+		printk(KERN_DEBUG "IBM Summit detected, will use apic physical");
+		return 1;
+	}
+#endif
+
+	return 0;
+}
+
+static void physflat_init_apic_ldr(void)
+{
+	/*
+	 * LDR and DFR are not involved in physflat mode, rather:
+	 * "In physical destination mode, the destination processor is
+	 * specified by its local APIC ID [...]." (Intel SDM, 10.6.2.1)
+	 */
+}
+
+static int physflat_probe(void)
+{
+	if (apic == &apic_physflat || num_possible_cpus() > 8 ||
+	    jailhouse_paravirt())
+		return 1;
+
+	return 0;
+}
+
+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_valid			= default_apic_id_valid,
+	.apic_id_registered		= flat_apic_id_registered,
+
+	.irq_delivery_mode		= dest_Fixed,
+	.irq_dest_mode			= 0, /* physical */
+
+	.disable_esr			= 0,
+	.dest_logical			= 0,
+	.check_apicid_used		= NULL,
+
+	.init_apic_ldr			= physflat_init_apic_ldr,
+
+	.ioapic_phys_id_map		= NULL,
+	.setup_apic_routing		= NULL,
+	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
+	.apicid_to_cpu_present		= NULL,
+	.check_phys_apicid_present	= default_check_phys_apicid_present,
+	.phys_pkg_id			= flat_phys_pkg_id,
+
+	.get_apic_id			= flat_get_apic_id,
+	.set_apic_id			= set_apic_id,
+
+	.calc_dest_apicid		= apic_default_calc_apicid,
+
+	.send_IPI			= default_send_IPI_single_phys,
+	.send_IPI_mask			= default_send_IPI_mask_sequence_phys,
+	.send_IPI_mask_allbutself	= default_send_IPI_mask_allbutself_phys,
+	.send_IPI_allbutself		= default_send_IPI_allbutself,
+	.send_IPI_all			= default_send_IPI_all,
+	.send_IPI_self			= default_send_IPI_self,
+
+	.inquire_remote_apic		= default_inquire_remote_apic,
+
+	.read				= native_apic_mem_read,
+	.write				= native_apic_mem_write,
+	.eoi_write			= native_apic_mem_write,
+	.icr_read			= native_apic_icr_read,
+	.icr_write			= native_apic_icr_write,
+	.wait_icr_idle			= native_apic_wait_icr_idle,
+	.safe_wait_icr_idle		= native_safe_apic_wait_icr_idle,
+};
+
+/*
+ * We need to check for physflat first, so this order is important.
+ */
+apic_drivers(apic_physflat, apic_flat);