xref: /openbmc/linux/arch/arm64/include/asm/assembler.h (revision 15b7cc78)
1 /*
2  * Based on arch/arm/include/asm/assembler.h, arch/arm/mm/proc-macros.S
3  *
4  * Copyright (C) 1996-2000 Russell King
5  * Copyright (C) 2012 ARM Ltd.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 #ifndef __ASSEMBLY__
20 #error "Only include this from assembly code"
21 #endif
22 
23 #ifndef __ASM_ASSEMBLER_H
24 #define __ASM_ASSEMBLER_H
25 
26 #include <asm/asm-offsets.h>
27 #include <asm/page.h>
28 #include <asm/pgtable-hwdef.h>
29 #include <asm/ptrace.h>
30 #include <asm/thread_info.h>
31 
32 /*
33  * Enable and disable interrupts.
34  */
35 	.macro	disable_irq
36 	msr	daifset, #2
37 	.endm
38 
39 	.macro	enable_irq
40 	msr	daifclr, #2
41 	.endm
42 
43 /*
44  * Enable and disable debug exceptions.
45  */
46 	.macro	disable_dbg
47 	msr	daifset, #8
48 	.endm
49 
50 	.macro	enable_dbg
51 	msr	daifclr, #8
52 	.endm
53 
54 	.macro	disable_step_tsk, flgs, tmp
55 	tbz	\flgs, #TIF_SINGLESTEP, 9990f
56 	mrs	\tmp, mdscr_el1
57 	bic	\tmp, \tmp, #1
58 	msr	mdscr_el1, \tmp
59 	isb	// Synchronise with enable_dbg
60 9990:
61 	.endm
62 
63 	.macro	enable_step_tsk, flgs, tmp
64 	tbz	\flgs, #TIF_SINGLESTEP, 9990f
65 	disable_dbg
66 	mrs	\tmp, mdscr_el1
67 	orr	\tmp, \tmp, #1
68 	msr	mdscr_el1, \tmp
69 9990:
70 	.endm
71 
72 /*
73  * Enable both debug exceptions and interrupts. This is likely to be
74  * faster than two daifclr operations, since writes to this register
75  * are self-synchronising.
76  */
77 	.macro	enable_dbg_and_irq
78 	msr	daifclr, #(8 | 2)
79 	.endm
80 
81 /*
82  * SMP data memory barrier
83  */
84 	.macro	smp_dmb, opt
85 	dmb	\opt
86 	.endm
87 
88 /*
89  * Emit an entry into the exception table
90  */
91 	.macro		_asm_extable, from, to
92 	.pushsection	__ex_table, "a"
93 	.align		3
94 	.long		(\from - .), (\to - .)
95 	.popsection
96 	.endm
97 
98 #define USER(l, x...)				\
99 9999:	x;					\
100 	_asm_extable	9999b, l
101 
102 /*
103  * Register aliases.
104  */
105 lr	.req	x30		// link register
106 
107 /*
108  * Vector entry
109  */
110 	 .macro	ventry	label
111 	.align	7
112 	b	\label
113 	.endm
114 
115 /*
116  * Select code when configured for BE.
117  */
118 #ifdef CONFIG_CPU_BIG_ENDIAN
119 #define CPU_BE(code...) code
120 #else
121 #define CPU_BE(code...)
122 #endif
123 
124 /*
125  * Select code when configured for LE.
126  */
127 #ifdef CONFIG_CPU_BIG_ENDIAN
128 #define CPU_LE(code...)
129 #else
130 #define CPU_LE(code...) code
131 #endif
132 
133 /*
134  * Define a macro that constructs a 64-bit value by concatenating two
135  * 32-bit registers. Note that on big endian systems the order of the
136  * registers is swapped.
137  */
138 #ifndef CONFIG_CPU_BIG_ENDIAN
139 	.macro	regs_to_64, rd, lbits, hbits
140 #else
141 	.macro	regs_to_64, rd, hbits, lbits
142 #endif
143 	orr	\rd, \lbits, \hbits, lsl #32
144 	.endm
145 
146 /*
147  * Pseudo-ops for PC-relative adr/ldr/str <reg>, <symbol> where
148  * <symbol> is within the range +/- 4 GB of the PC.
149  */
150 	/*
151 	 * @dst: destination register (64 bit wide)
152 	 * @sym: name of the symbol
153 	 * @tmp: optional scratch register to be used if <dst> == sp, which
154 	 *       is not allowed in an adrp instruction
155 	 */
156 	.macro	adr_l, dst, sym, tmp=
157 	.ifb	\tmp
158 	adrp	\dst, \sym
159 	add	\dst, \dst, :lo12:\sym
160 	.else
161 	adrp	\tmp, \sym
162 	add	\dst, \tmp, :lo12:\sym
163 	.endif
164 	.endm
165 
166 	/*
167 	 * @dst: destination register (32 or 64 bit wide)
168 	 * @sym: name of the symbol
169 	 * @tmp: optional 64-bit scratch register to be used if <dst> is a
170 	 *       32-bit wide register, in which case it cannot be used to hold
171 	 *       the address
172 	 */
173 	.macro	ldr_l, dst, sym, tmp=
174 	.ifb	\tmp
175 	adrp	\dst, \sym
176 	ldr	\dst, [\dst, :lo12:\sym]
177 	.else
178 	adrp	\tmp, \sym
179 	ldr	\dst, [\tmp, :lo12:\sym]
180 	.endif
181 	.endm
182 
183 	/*
184 	 * @src: source register (32 or 64 bit wide)
185 	 * @sym: name of the symbol
186 	 * @tmp: mandatory 64-bit scratch register to calculate the address
187 	 *       while <src> needs to be preserved.
188 	 */
189 	.macro	str_l, src, sym, tmp
190 	adrp	\tmp, \sym
191 	str	\src, [\tmp, :lo12:\sym]
192 	.endm
193 
194 	/*
195 	 * @sym: The name of the per-cpu variable
196 	 * @reg: Result of per_cpu(sym, smp_processor_id())
197 	 * @tmp: scratch register
198 	 */
199 	.macro this_cpu_ptr, sym, reg, tmp
200 	adr_l	\reg, \sym
201 	mrs	\tmp, tpidr_el1
202 	add	\reg, \reg, \tmp
203 	.endm
204 
205 /*
206  * vma_vm_mm - get mm pointer from vma pointer (vma->vm_mm)
207  */
208 	.macro	vma_vm_mm, rd, rn
209 	ldr	\rd, [\rn, #VMA_VM_MM]
210 	.endm
211 
212 /*
213  * mmid - get context id from mm pointer (mm->context.id)
214  */
215 	.macro	mmid, rd, rn
216 	ldr	\rd, [\rn, #MM_CONTEXT_ID]
217 	.endm
218 
219 /*
220  * dcache_line_size - get the minimum D-cache line size from the CTR register.
221  */
222 	.macro	dcache_line_size, reg, tmp
223 	mrs	\tmp, ctr_el0			// read CTR
224 	ubfm	\tmp, \tmp, #16, #19		// cache line size encoding
225 	mov	\reg, #4			// bytes per word
226 	lsl	\reg, \reg, \tmp		// actual cache line size
227 	.endm
228 
229 /*
230  * icache_line_size - get the minimum I-cache line size from the CTR register.
231  */
232 	.macro	icache_line_size, reg, tmp
233 	mrs	\tmp, ctr_el0			// read CTR
234 	and	\tmp, \tmp, #0xf		// cache line size encoding
235 	mov	\reg, #4			// bytes per word
236 	lsl	\reg, \reg, \tmp		// actual cache line size
237 	.endm
238 
239 /*
240  * tcr_set_idmap_t0sz - update TCR.T0SZ so that we can load the ID map
241  */
242 	.macro	tcr_set_idmap_t0sz, valreg, tmpreg
243 #ifndef CONFIG_ARM64_VA_BITS_48
244 	ldr_l	\tmpreg, idmap_t0sz
245 	bfi	\valreg, \tmpreg, #TCR_T0SZ_OFFSET, #TCR_TxSZ_WIDTH
246 #endif
247 	.endm
248 
249 /*
250  * Macro to perform a data cache maintenance for the interval
251  * [kaddr, kaddr + size)
252  *
253  * 	op:		operation passed to dc instruction
254  * 	domain:		domain used in dsb instruciton
255  * 	kaddr:		starting virtual address of the region
256  * 	size:		size of the region
257  * 	Corrupts:	kaddr, size, tmp1, tmp2
258  */
259 	.macro dcache_by_line_op op, domain, kaddr, size, tmp1, tmp2
260 	dcache_line_size \tmp1, \tmp2
261 	add	\size, \kaddr, \size
262 	sub	\tmp2, \tmp1, #1
263 	bic	\kaddr, \kaddr, \tmp2
264 9998:	dc	\op, \kaddr
265 	add	\kaddr, \kaddr, \tmp1
266 	cmp	\kaddr, \size
267 	b.lo	9998b
268 	dsb	\domain
269 	.endm
270 
271 /*
272  * reset_pmuserenr_el0 - reset PMUSERENR_EL0 if PMUv3 present
273  */
274 	.macro	reset_pmuserenr_el0, tmpreg
275 	mrs	\tmpreg, id_aa64dfr0_el1	// Check ID_AA64DFR0_EL1 PMUVer
276 	sbfx	\tmpreg, \tmpreg, #8, #4
277 	cmp	\tmpreg, #1			// Skip if no PMU present
278 	b.lt	9000f
279 	msr	pmuserenr_el0, xzr		// Disable PMU access from EL0
280 9000:
281 	.endm
282 
283 /*
284  * copy_page - copy src to dest using temp registers t1-t8
285  */
286 	.macro copy_page dest:req src:req t1:req t2:req t3:req t4:req t5:req t6:req t7:req t8:req
287 9998:	ldp	\t1, \t2, [\src]
288 	ldp	\t3, \t4, [\src, #16]
289 	ldp	\t5, \t6, [\src, #32]
290 	ldp	\t7, \t8, [\src, #48]
291 	add	\src, \src, #64
292 	stnp	\t1, \t2, [\dest]
293 	stnp	\t3, \t4, [\dest, #16]
294 	stnp	\t5, \t6, [\dest, #32]
295 	stnp	\t7, \t8, [\dest, #48]
296 	add	\dest, \dest, #64
297 	tst	\src, #(PAGE_SIZE - 1)
298 	b.ne	9998b
299 	.endm
300 
301 /*
302  * Annotate a function as position independent, i.e., safe to be called before
303  * the kernel virtual mapping is activated.
304  */
305 #define ENDPIPROC(x)			\
306 	.globl	__pi_##x;		\
307 	.type 	__pi_##x, %function;	\
308 	.set	__pi_##x, x;		\
309 	.size	__pi_##x, . - x;	\
310 	ENDPROC(x)
311 
312 	/*
313 	 * Emit a 64-bit absolute little endian symbol reference in a way that
314 	 * ensures that it will be resolved at build time, even when building a
315 	 * PIE binary. This requires cooperation from the linker script, which
316 	 * must emit the lo32/hi32 halves individually.
317 	 */
318 	.macro	le64sym, sym
319 	.long	\sym\()_lo32
320 	.long	\sym\()_hi32
321 	.endm
322 
323 	/*
324 	 * mov_q - move an immediate constant into a 64-bit register using
325 	 *         between 2 and 4 movz/movk instructions (depending on the
326 	 *         magnitude and sign of the operand)
327 	 */
328 	.macro	mov_q, reg, val
329 	.if (((\val) >> 31) == 0 || ((\val) >> 31) == 0x1ffffffff)
330 	movz	\reg, :abs_g1_s:\val
331 	.else
332 	.if (((\val) >> 47) == 0 || ((\val) >> 47) == 0x1ffff)
333 	movz	\reg, :abs_g2_s:\val
334 	.else
335 	movz	\reg, :abs_g3:\val
336 	movk	\reg, :abs_g2_nc:\val
337 	.endif
338 	movk	\reg, :abs_g1_nc:\val
339 	.endif
340 	movk	\reg, :abs_g0_nc:\val
341 	.endm
342 
343 #endif	/* __ASM_ASSEMBLER_H */
344