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1 // Copyright 2020 Espressif Systems (Shanghai) PTE LTD
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 
7 //     http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #pragma once
16 
17 #define RSR(reg, at)         asm volatile ("rsr %0, %1" : "=r" (at) : "i" (reg))
18 #define WSR(reg, at)         asm volatile ("wsr %0, %1" : : "r" (at), "i" (reg))
19 #define XSR(reg, at)         asm volatile ("xsr %0, %1" : "+r" (at) : "i" (reg))
20 
21 #define RER(reg, at)         asm volatile ("rer %0, %1" : "=r" (at) : "r" (reg))
22 
23 #define WITLB(at, as)        asm volatile ("witlb  %0, %1; \n isync \n " : : "r" (at), "r" (as))
24 #define WDTLB(at, as)        asm volatile ("wdtlb  %0, %1; \n dsync \n " : : "r" (at), "r" (as))
25 
26 /* The SET_STACK implements a setting a new stack pointer (sp or a1).
27  * to do this the need reset PS_WOE, reset WINDOWSTART, update SP, and return PS_WOE.
28  *
29  * Note: It has 2 implementations one for using in assembler files (*.S) and one for using in C.
30  *
31  * C code prototype for SET_STACK:
32  *   uint32_t ps_reg;
33  *   uint32_t w_base;
34  *   RSR(PS, ps_reg);
35  *   ps_reg &= ~(PS_WOE_MASK | PS_OWB_MASK | PS_CALLINC_MASK);
36  *   WSR(PS, ps_reg);
37  *
38  *   RSR(WINDOWBASE, w_base);
39  *   WSR(WINDOWSTART, (1 << w_base));
40  *
41  *   asm volatile ( "movi sp, "XTSTR( (SOC_DRAM_LOW + (SOC_DRAM_HIGH - SOC_DRAM_LOW) / 2) )"");
42  *
43  *   RSR(PS, ps_reg);
44  *   ps_reg |= (PS_WOE_MASK);
45  *   WSR(PS, ps_reg);
46 */
47 #ifdef __ASSEMBLER__
48     .macro SET_STACK  new_sp tmp1 tmp2
49     rsr.ps \tmp1
50     movi \tmp2, ~(PS_WOE_MASK | PS_OWB_MASK | PS_CALLINC_MASK)
51     and \tmp1, \tmp1, \tmp2
52     wsr.ps \tmp1
53     rsync
54 
55     rsr.windowbase \tmp1
56     ssl	\tmp1
57     movi \tmp1, 1
58     sll	\tmp1, \tmp1
59     wsr.windowstart \tmp1
60     rsync
61 
62     mov sp, \new_sp
63 
64     rsr.ps \tmp1
65     movi \tmp2, (PS_WOE)
66     or \tmp1, \tmp1, \tmp2
67     wsr.ps \tmp1
68     rsync
69     .endm
70 #else
71 #define SET_STACK(new_sp) \
72     do { \
73         uint32_t tmp1 = 0, tmp2 = 0; \
74         asm volatile ( \
75           "rsr.ps %1 \n"\
76           "movi %2, ~" XTSTR( PS_WOE_MASK | PS_OWB_MASK | PS_CALLINC_MASK ) " \n"\
77           "and %1, %1, %2 \n"\
78           "wsr.ps %1 \n"\
79           "rsync \n"\
80           " \n"\
81           "rsr.windowbase %1 \n"\
82           "ssl	%1 \n"\
83           "movi %1, 1 \n"\
84           "sll	%1, %1 \n"\
85           "wsr.windowstart %1 \n"\
86           "rsync \n"\
87           " \n"\
88           "mov sp, %0 \n"\
89           "rsr.ps %1 \n"\
90           " \n"\
91           "movi %2, " XTSTR( PS_WOE_MASK ) "\n"\
92           " \n"\
93           "or %1, %1, %2 \n"\
94           "wsr.ps %1 \n"\
95           "rsync \n"\
96           : "+r"(new_sp), "+r"(tmp1), "+r"(tmp2)); \
97     } while (0);
98 #endif // __ASSEMBLER__
99