1  // SPDX-License-Identifier: GPL-2.0
2  #include <linux/init.h>
3  #include <linux/thread_info.h>
4  
5  #include <asm/x86_init.h>
6  #include <asm/apic.h>
7  #include <asm/io_apic.h>
8  #include <asm/xen/hypercall.h>
9  
10  #include <xen/xen.h>
11  #include <xen/interface/physdev.h>
12  #include "xen-ops.h"
13  #include "pmu.h"
14  #include "smp.h"
15  
xen_io_apic_read(unsigned apic,unsigned reg)16  static unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
17  {
18  	struct physdev_apic apic_op;
19  	int ret;
20  
21  	apic_op.apic_physbase = mpc_ioapic_addr(apic);
22  	apic_op.reg = reg;
23  	ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
24  	if (!ret)
25  		return apic_op.value;
26  
27  	/* fallback to return an emulated IO_APIC values */
28  	if (reg == 0x1)
29  		return 0x00170020;
30  	else if (reg == 0x0)
31  		return apic << 24;
32  
33  	return 0xfd;
34  }
35  
xen_set_apic_id(unsigned int x)36  static u32 xen_set_apic_id(unsigned int x)
37  {
38  	WARN_ON(1);
39  	return x;
40  }
41  
xen_get_apic_id(unsigned long x)42  static unsigned int xen_get_apic_id(unsigned long x)
43  {
44  	return ((x)>>24) & 0xFFu;
45  }
46  
xen_apic_read(u32 reg)47  static u32 xen_apic_read(u32 reg)
48  {
49  	struct xen_platform_op op = {
50  		.cmd = XENPF_get_cpuinfo,
51  		.interface_version = XENPF_INTERFACE_VERSION,
52  		.u.pcpu_info.xen_cpuid = 0,
53  	};
54  	int ret;
55  
56  	/* Shouldn't need this as APIC is turned off for PV, and we only
57  	 * get called on the bootup processor. But just in case. */
58  	if (!xen_initial_domain() || smp_processor_id())
59  		return 0;
60  
61  	if (reg == APIC_LVR)
62  		return 0x14;
63  	if (reg != APIC_ID)
64  		return 0;
65  
66  	ret = HYPERVISOR_platform_op(&op);
67  	if (ret)
68  		op.u.pcpu_info.apic_id = BAD_APICID;
69  
70  	return op.u.pcpu_info.apic_id << 24;
71  }
72  
xen_apic_write(u32 reg,u32 val)73  static void xen_apic_write(u32 reg, u32 val)
74  {
75  	if (reg == APIC_LVTPC) {
76  		(void)pmu_apic_update(reg);
77  		return;
78  	}
79  
80  	/* Warn to see if there's any stray references */
81  	WARN(1,"register: %x, value: %x\n", reg, val);
82  }
83  
xen_apic_icr_read(void)84  static u64 xen_apic_icr_read(void)
85  {
86  	return 0;
87  }
88  
xen_apic_icr_write(u32 low,u32 id)89  static void xen_apic_icr_write(u32 low, u32 id)
90  {
91  	/* Warn to see if there's any stray references */
92  	WARN_ON(1);
93  }
94  
xen_safe_apic_wait_icr_idle(void)95  static u32 xen_safe_apic_wait_icr_idle(void)
96  {
97          return 0;
98  }
99  
xen_apic_probe_pv(void)100  static int xen_apic_probe_pv(void)
101  {
102  	if (xen_pv_domain())
103  		return 1;
104  
105  	return 0;
106  }
107  
xen_madt_oem_check(char * oem_id,char * oem_table_id)108  static int xen_madt_oem_check(char *oem_id, char *oem_table_id)
109  {
110  	return xen_pv_domain();
111  }
112  
xen_id_always_valid(u32 apicid)113  static int xen_id_always_valid(u32 apicid)
114  {
115  	return 1;
116  }
117  
xen_id_always_registered(void)118  static int xen_id_always_registered(void)
119  {
120  	return 1;
121  }
122  
xen_phys_pkg_id(int initial_apic_id,int index_msb)123  static int xen_phys_pkg_id(int initial_apic_id, int index_msb)
124  {
125  	return initial_apic_id >> index_msb;
126  }
127  
xen_noop(void)128  static void xen_noop(void)
129  {
130  }
131  
xen_silent_inquire(int apicid)132  static void xen_silent_inquire(int apicid)
133  {
134  }
135  
xen_cpu_present_to_apicid(int cpu)136  static int xen_cpu_present_to_apicid(int cpu)
137  {
138  	if (cpu_present(cpu))
139  		return cpu_data(cpu).apicid;
140  	else
141  		return BAD_APICID;
142  }
143  
144  static struct apic xen_pv_apic = {
145  	.name 				= "Xen PV",
146  	.probe 				= xen_apic_probe_pv,
147  	.acpi_madt_oem_check		= xen_madt_oem_check,
148  	.apic_id_valid 			= xen_id_always_valid,
149  	.apic_id_registered 		= xen_id_always_registered,
150  
151  	/* .delivery_mode and .dest_mode_logical not used by XENPV */
152  
153  	.disable_esr			= 0,
154  
155  	.check_apicid_used		= default_check_apicid_used, /* Used on 32-bit */
156  	.init_apic_ldr			= xen_noop, /* setup_local_APIC calls it */
157  	.ioapic_phys_id_map		= default_ioapic_phys_id_map, /* Used on 32-bit */
158  	.setup_apic_routing		= NULL,
159  	.cpu_present_to_apicid		= xen_cpu_present_to_apicid,
160  	.apicid_to_cpu_present		= physid_set_mask_of_physid, /* Used on 32-bit */
161  	.check_phys_apicid_present	= default_check_phys_apicid_present, /* smp_sanity_check needs it */
162  	.phys_pkg_id			= xen_phys_pkg_id, /* detect_ht */
163  
164  	.get_apic_id 			= xen_get_apic_id,
165  	.set_apic_id 			= xen_set_apic_id, /* Can be NULL on 32-bit. */
166  
167  	.calc_dest_apicid		= apic_flat_calc_apicid,
168  
169  #ifdef CONFIG_SMP
170  	.send_IPI_mask 			= xen_send_IPI_mask,
171  	.send_IPI_mask_allbutself 	= xen_send_IPI_mask_allbutself,
172  	.send_IPI_allbutself 		= xen_send_IPI_allbutself,
173  	.send_IPI_all 			= xen_send_IPI_all,
174  	.send_IPI_self 			= xen_send_IPI_self,
175  #endif
176  	/* .wait_for_init_deassert- used  by AP bootup - smp_callin which we don't use */
177  	.inquire_remote_apic		= xen_silent_inquire,
178  
179  	.read				= xen_apic_read,
180  	.write				= xen_apic_write,
181  	.eoi_write			= xen_apic_write,
182  
183  	.icr_read 			= xen_apic_icr_read,
184  	.icr_write 			= xen_apic_icr_write,
185  	.wait_icr_idle 			= xen_noop,
186  	.safe_wait_icr_idle 		= xen_safe_apic_wait_icr_idle,
187  };
188  
xen_apic_check(void)189  static void __init xen_apic_check(void)
190  {
191  	if (apic == &xen_pv_apic)
192  		return;
193  
194  	pr_info("Switched APIC routing from %s to %s.\n", apic->name,
195  		xen_pv_apic.name);
196  	apic = &xen_pv_apic;
197  }
xen_init_apic(void)198  void __init xen_init_apic(void)
199  {
200  	x86_apic_ops.io_apic_read = xen_io_apic_read;
201  	/* On PV guests the APIC CPUID bit is disabled so none of the
202  	 * routines end up executing. */
203  	if (!xen_initial_domain())
204  		apic = &xen_pv_apic;
205  
206  	x86_platform.apic_post_init = xen_apic_check;
207  }
208  apic_driver(xen_pv_apic);
209