1 /**
2  * \file
3  * \brief   UTCB definitions for MIPS.
4  * \ingroup l4_utcb_api
5  */
6 #pragma once
7 
8 #include <l4/sys/types.h>
9 
10 /**
11  * \defgroup l4_utcb_api_mips MIPS Virtual Registers (UTCB)
12  * \ingroup  l4_utcb_api
13  */
14 
15 /**
16  * \brief UTCB structure for exceptions.
17  * \ingroup l4_utcb_api_mips
18  *
19  * l4_exc_regs_t matches l4_vcpu_regs_t and corresponds to
20  * fiasco/src/kern/mips32/trap_state.cpp: Trap_state_regs and
21  * entry_frame-mips32.cpp: Syscall_frame and Return_frame
22  */
23 typedef struct l4_exc_regs_t
24 {
25   l4_umword_t bad_instr_p;
26   l4_umword_t bad_instr;
27   union
28   {
29     l4_umword_t r[32];   /**< registers */
30     struct
31     {
32       l4_umword_t zero;
33       l4_umword_t at;
34       l4_umword_t v0, v1;
35       l4_umword_t a0, a1, a2, a3;
36       l4_umword_t t0, t1, t2, t3, t4, t5, t6, t7;
37       l4_umword_t s0, s1, s2, s3, s4, s5, s6, s7;
38       l4_umword_t t8, t9;
39       l4_umword_t k0, k1;
40       l4_umword_t gp;
41       l4_umword_t sp;
42       l4_umword_t s8;
43       l4_umword_t ra;
44     };
45   };
46   l4_umword_t hi, lo;
47   union
48   {
49     l4_umword_t pfa;
50     l4_umword_t bad_v_addr;
51   };
52   l4_umword_t cause;
53   l4_umword_t status;
54   union
55   {
56     l4_umword_t epc;
57     l4_umword_t ip;
58   };
59   l4_umword_t ulr;
60 } l4_exc_regs_t;
61 
62 /**
63  * \brief UTCB constants for MIPS
64  * \ingroup l4_utcb_api_mips
65  * \hideinitializer
66  */
67 enum L4_utcb_consts_mips
68 {
69   L4_UTCB_EXCEPTION_REGS_SIZE    = sizeof(l4_exc_regs_t) / sizeof(l4_umword_t),
70   L4_UTCB_GENERIC_DATA_SIZE      = 63,
71   L4_UTCB_GENERIC_BUFFERS_SIZE   = 58,
72 
73   L4_UTCB_MSG_REGS_OFFSET        = 0,
74   L4_UTCB_BUF_REGS_OFFSET        = 64 * sizeof(l4_umword_t),
75   L4_UTCB_THREAD_REGS_OFFSET     = 123 * sizeof(l4_umword_t),
76 
77   L4_UTCB_INHERIT_FPU            = 1UL << 24,
78 
79   L4_UTCB_OFFSET                 = 128 * sizeof(l4_umword_t),
80 };
81 
82 #include_next <l4/sys/utcb.h>
83 
84 /*
85  * ==================================================================
86  * Implementations.
87  */
88 
l4_utcb_direct(void)89 L4_INLINE l4_utcb_t *l4_utcb_direct(void) L4_NOTHROW
90 {
91   /* We store the UTCB pointer at offset -0x700c from the ULR value.  This is
92    * compatible with MIPS TLS used by L4Re. We provide a slot in the TCB for
93    * the UTCB pointer and the TCB is stored at this offset per TLS convention.
94    * The kernel also initially sets the ULR to point 0x700c behind the UTCB
95    * pointer in the UTCB itself.
96    */
97   char const *utcb;
98   __asm__ ("rdhwr %0, $29" : "=r" (utcb));
99   return *(l4_utcb_t * const*)(utcb - 0x7000 - (3 * sizeof(void*)));
100 }
101 
l4_utcb_exc_pc(l4_exc_regs_t const * u)102 L4_INLINE l4_umword_t l4_utcb_exc_pc(l4_exc_regs_t const *u) L4_NOTHROW
103 {
104   return u->epc;
105 }
106 
l4_utcb_exc_pc_set(l4_exc_regs_t * u,l4_addr_t pc)107 L4_INLINE void l4_utcb_exc_pc_set(l4_exc_regs_t *u, l4_addr_t pc) L4_NOTHROW
108 {
109   u->epc = pc;
110 }
111 
l4_utcb_exc_typeval(l4_exc_regs_t const * u)112 L4_INLINE l4_umword_t l4_utcb_exc_typeval(l4_exc_regs_t const *u) L4_NOTHROW
113 {
114   return u->cause & 0x1ff;
115 }
116 
l4_utcb_exc_is_pf(l4_exc_regs_t const * u)117 L4_INLINE int l4_utcb_exc_is_pf(l4_exc_regs_t const *u) L4_NOTHROW
118 {
119   unsigned c = (u->cause >> 2) & 0x1f;
120   return ((1 <= c) && (c <= 7)) || ((19 <= c) && (c <= 20));
121 }
122 
l4_utcb_exc_pfa(l4_exc_regs_t const * u)123 L4_INLINE l4_addr_t l4_utcb_exc_pfa(l4_exc_regs_t const *u) L4_NOTHROW
124 {
125   return (u->bad_v_addr & ~7) | ((u->cause >> 1) & 2);
126 }
127 
l4_utcb_exc_is_ex_regs_exception(l4_exc_regs_t const * u)128 L4_INLINE int l4_utcb_exc_is_ex_regs_exception(l4_exc_regs_t const *u) L4_NOTHROW
129 {
130   return l4_utcb_exc_typeval(u) == 0x101;
131 }
132