1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * NOOP APIC driver. |
4 | * |
5 | * Does almost nothing and should be substituted by a real apic driver via |
6 | * probe routine. |
7 | * |
8 | * Though in case if apic is disabled (for some reason) we try |
9 | * to not uglify the caller's code and allow to call (some) apic routines |
10 | * like self-ipi, etc... |
11 | * |
12 | * FIXME: Remove this gunk. The above argument which was intentionally left |
13 | * in place is silly to begin with because none of the callbacks except for |
14 | * APIC::read/write() have a WARN_ON_ONCE() in them. Sigh... |
15 | */ |
16 | #include <linux/cpumask.h> |
17 | #include <linux/thread_info.h> |
18 | |
19 | #include <asm/apic.h> |
20 | |
21 | #include "local.h" |
22 | |
23 | static void noop_send_IPI(int cpu, int vector) { } |
24 | static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { } |
25 | static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { } |
26 | static void noop_send_IPI_allbutself(int vector) { } |
27 | static void noop_send_IPI_all(int vector) { } |
28 | static void noop_send_IPI_self(int vector) { } |
29 | static void noop_apic_icr_write(u32 low, u32 id) { } |
30 | static int noop_wakeup_secondary_cpu(u32 apicid, unsigned long start_eip) { return -1; } |
31 | static u64 noop_apic_icr_read(void) { return 0; } |
32 | static u32 noop_get_apic_id(u32 apicid) { return 0; } |
33 | static void noop_apic_eoi(void) { } |
34 | |
35 | static u32 noop_apic_read(u32 reg) |
36 | { |
37 | WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !apic_is_disabled); |
38 | return 0; |
39 | } |
40 | |
41 | static void noop_apic_write(u32 reg, u32 val) |
42 | { |
43 | WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !apic_is_disabled); |
44 | } |
45 | |
46 | struct apic apic_noop __ro_after_init = { |
47 | .name = "noop" , |
48 | |
49 | .dest_mode_logical = true, |
50 | |
51 | .disable_esr = 0, |
52 | |
53 | .cpu_present_to_apicid = default_cpu_present_to_apicid, |
54 | |
55 | .max_apic_id = 0xFE, |
56 | .get_apic_id = noop_get_apic_id, |
57 | |
58 | .calc_dest_apicid = apic_flat_calc_apicid, |
59 | |
60 | .send_IPI = noop_send_IPI, |
61 | .send_IPI_mask = noop_send_IPI_mask, |
62 | .send_IPI_mask_allbutself = noop_send_IPI_mask_allbutself, |
63 | .send_IPI_allbutself = noop_send_IPI_allbutself, |
64 | .send_IPI_all = noop_send_IPI_all, |
65 | .send_IPI_self = noop_send_IPI_self, |
66 | |
67 | .wakeup_secondary_cpu = noop_wakeup_secondary_cpu, |
68 | |
69 | .read = noop_apic_read, |
70 | .write = noop_apic_write, |
71 | .eoi = noop_apic_eoi, |
72 | .icr_read = noop_apic_icr_read, |
73 | .icr_write = noop_apic_icr_write, |
74 | }; |
75 | |