x86/xen/apic.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <linux/init.h>
0003 #include <linux/thread_info.h>
0004
0005 #include <asm/x86_init.h>
0006 #include <asm/apic.h>
0007 #include <asm/io_apic.h>
0008 #include <asm/xen/hypercall.h>
0009
0010 #include <xen/xen.h>
0011 #include <xen/interface/physdev.h>
0012 #include "xen-ops.h"
0013 #include "pmu.h"
0014 #include "smp.h"
0015
0016 static unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
0017 {
0018     struct physdev_apic apic_op;
0019     int ret;
0020
0021     apic_op.apic_physbase = mpc_ioapic_addr(apic);
0022     apic_op.reg = reg;
0023     ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
0024     if (!ret)
0025         return apic_op.value;
0026
0027     /* fallback to return an emulated IO_APIC values */
0028     if (reg == 0x1)
0029         return 0x00170020;
0030     else if (reg == 0x0)
0031         return apic << 24;
0032
0033     return 0xfd;
0034 }
0035
0036 static u32 xen_set_apic_id(unsigned int x)
0037 {
0038     WARN_ON(1);
0039     return x;
0040 }
0041
0042 static unsigned int xen_get_apic_id(unsigned long x)
0043 {
0044     return ((x)>>24) & 0xFFu;
0045 }
0046
0047 static u32 xen_apic_read(u32 reg)
0048 {
0049     struct xen_platform_op op = {
0050         .cmd = XENPF_get_cpuinfo,
0051         .interface_version = XENPF_INTERFACE_VERSION,
0052         .u.pcpu_info.xen_cpuid = 0,
0053     };
0054     int ret;
0055
0056     /* Shouldn't need this as APIC is turned off for PV, and we only
0057      * get called on the bootup processor. But just in case. */
0058     if (!xen_initial_domain() || smp_processor_id())
0059         return 0;
0060
0061     if (reg == APIC_LVR)
0062         return 0x14;
0063     if (reg != APIC_ID)
0064         return 0;
0065
0066     ret = HYPERVISOR_platform_op(&op);
0067     if (ret)
0068         op.u.pcpu_info.apic_id = BAD_APICID;
0069
0070     return op.u.pcpu_info.apic_id << 24;
0071 }
0072
0073 static void xen_apic_write(u32 reg, u32 val)
0074 {
0075     if (reg == APIC_LVTPC) {
0076         (void)pmu_apic_update(reg);
0077         return;
0078     }
0079
0080     /* Warn to see if there's any stray references */
0081     WARN(1,"register: %x, value: %x\n", reg, val);
0082 }
0083
0084 static u64 xen_apic_icr_read(void)
0085 {
0086     return 0;
0087 }
0088
0089 static void xen_apic_icr_write(u32 low, u32 id)
0090 {
0091     /* Warn to see if there's any stray references */
0092     WARN_ON(1);
0093 }
0094
0095 static u32 xen_safe_apic_wait_icr_idle(void)
0096 {
0097         return 0;
0098 }
0099
0100 static int xen_apic_probe_pv(void)
0101 {
0102     if (xen_pv_domain())
0103         return 1;
0104
0105     return 0;
0106 }
0107
0108 static int xen_madt_oem_check(char *oem_id, char *oem_table_id)
0109 {
0110     return xen_pv_domain();
0111 }
0112
0113 static int xen_id_always_valid(u32 apicid)
0114 {
0115     return 1;
0116 }
0117
0118 static int xen_id_always_registered(void)
0119 {
0120     return 1;
0121 }
0122
0123 static int xen_phys_pkg_id(int initial_apic_id, int index_msb)
0124 {
0125     return initial_apic_id >> index_msb;
0126 }
0127
0128 static void xen_noop(void)
0129 {
0130 }
0131
0132 static void xen_silent_inquire(int apicid)
0133 {
0134 }
0135
0136 static int xen_cpu_present_to_apicid(int cpu)
0137 {
0138     if (cpu_present(cpu))
0139         return cpu_data(cpu).apicid;
0140     else
0141         return BAD_APICID;
0142 }
0143
0144 static struct apic xen_pv_apic = {
0145     .name               = "Xen PV",
0146     .probe              = xen_apic_probe_pv,
0147     .acpi_madt_oem_check        = xen_madt_oem_check,
0148     .apic_id_valid          = xen_id_always_valid,
0149     .apic_id_registered         = xen_id_always_registered,
0150
0151     /* .delivery_mode and .dest_mode_logical not used by XENPV */
0152
0153     .disable_esr            = 0,
0154
0155     .check_apicid_used      = default_check_apicid_used, /* Used on 32-bit */
0156     .init_apic_ldr          = xen_noop, /* setup_local_APIC calls it */
0157     .ioapic_phys_id_map     = default_ioapic_phys_id_map, /* Used on 32-bit */
0158     .setup_apic_routing     = NULL,
0159     .cpu_present_to_apicid      = xen_cpu_present_to_apicid,
0160     .apicid_to_cpu_present      = physid_set_mask_of_physid, /* Used on 32-bit */
0161     .check_phys_apicid_present  = default_check_phys_apicid_present, /* smp_sanity_check needs it */
0162     .phys_pkg_id            = xen_phys_pkg_id, /* detect_ht */
0163
0164     .get_apic_id            = xen_get_apic_id,
0165     .set_apic_id            = xen_set_apic_id, /* Can be NULL on 32-bit. */
0166
0167     .calc_dest_apicid       = apic_flat_calc_apicid,
0168
0169 #ifdef CONFIG_SMP
0170     .send_IPI_mask          = xen_send_IPI_mask,
0171     .send_IPI_mask_allbutself   = xen_send_IPI_mask_allbutself,
0172     .send_IPI_allbutself        = xen_send_IPI_allbutself,
0173     .send_IPI_all           = xen_send_IPI_all,
0174     .send_IPI_self          = xen_send_IPI_self,
0175 #endif
0176     /* .wait_for_init_deassert- used  by AP bootup - smp_callin which we don't use */
0177     .inquire_remote_apic        = xen_silent_inquire,
0178
0179     .read               = xen_apic_read,
0180     .write              = xen_apic_write,
0181     .eoi_write          = xen_apic_write,
0182
0183     .icr_read           = xen_apic_icr_read,
0184     .icr_write          = xen_apic_icr_write,
0185     .wait_icr_idle          = xen_noop,
0186     .safe_wait_icr_idle         = xen_safe_apic_wait_icr_idle,
0187 };
0188
0189 static void __init xen_apic_check(void)
0190 {
0191     if (apic == &xen_pv_apic)
0192         return;
0193
0194     pr_info("Switched APIC routing from %s to %s.\n", apic->name,
0195         xen_pv_apic.name);
0196     apic = &xen_pv_apic;
0197 }
0198 void __init xen_init_apic(void)
0199 {
0200     x86_apic_ops.io_apic_read = xen_io_apic_read;
0201     /* On PV guests the APIC CPUID bit is disabled so none of the
0202      * routines end up executing. */
0203     if (!xen_initial_domain())
0204         apic = &xen_pv_apic;
0205
0206     x86_platform.apic_post_init = xen_apic_check;
0207 }
0208 apic_driver(xen_pv_apic);