1 2 #include <libcflat.h> 3 #include "smp.h" 4 #include "apic.h" 5 #include "fwcfg.h" 6 #include "desc.h" 7 8 #define IPI_VECTOR 0x20 9 10 typedef void (*ipi_function_type)(void *data); 11 12 static struct spinlock ipi_lock; 13 static volatile ipi_function_type ipi_function; 14 static void *volatile ipi_data; 15 static volatile int ipi_done; 16 static volatile bool ipi_wait; 17 static int _cpu_count; 18 19 static __attribute__((used)) void ipi() 20 { 21 void (*function)(void *data) = ipi_function; 22 void *data = ipi_data; 23 bool wait = ipi_wait; 24 25 if (!wait) { 26 ipi_done = 1; 27 apic_write(APIC_EOI, 0); 28 } 29 function(data); 30 if (wait) { 31 ipi_done = 1; 32 apic_write(APIC_EOI, 0); 33 } 34 } 35 36 asm ( 37 "ipi_entry: \n" 38 " call ipi \n" 39 #ifndef __x86_64__ 40 " iret" 41 #else 42 " iretq" 43 #endif 44 ); 45 46 int cpu_count(void) 47 { 48 return _cpu_count; 49 } 50 51 int smp_id(void) 52 { 53 unsigned id; 54 55 asm ("mov %%gs:0, %0" : "=r"(id)); 56 return id; 57 } 58 59 static void setup_smp_id(void *data) 60 { 61 asm ("mov %0, %%gs:0" : : "r"(apic_id()) : "memory"); 62 } 63 64 static void __on_cpu(int cpu, void (*function)(void *data), void *data, 65 int wait) 66 { 67 spin_lock(&ipi_lock); 68 if (cpu == smp_id()) 69 function(data); 70 else { 71 ipi_done = 0; 72 ipi_function = function; 73 ipi_data = data; 74 ipi_wait = wait; 75 apic_icr_write(APIC_INT_ASSERT | APIC_DEST_PHYSICAL | APIC_DM_FIXED 76 | IPI_VECTOR, 77 cpu); 78 while (!ipi_done) 79 ; 80 } 81 spin_unlock(&ipi_lock); 82 } 83 84 void on_cpu(int cpu, void (*function)(void *data), void *data) 85 { 86 __on_cpu(cpu, function, data, 1); 87 } 88 89 void on_cpu_async(int cpu, void (*function)(void *data), void *data) 90 { 91 __on_cpu(cpu, function, data, 0); 92 } 93 94 95 void smp_init(void) 96 { 97 int i; 98 void ipi_entry(void); 99 100 _cpu_count = fwcfg_get_nb_cpus(); 101 102 setup_idt(); 103 set_idt_entry(IPI_VECTOR, ipi_entry, 0); 104 105 setup_smp_id(0); 106 for (i = 1; i < cpu_count(); ++i) 107 on_cpu(i, setup_smp_id, 0); 108 109 } 110