2 * Based on arch/arm/mm/proc.S
4 * Copyright (C) 2001 Deep Blue Solutions Ltd.
5 * Copyright (C) 2012 ARM Ltd.
6 * Author: Catalin Marinas <catalin.marinas@arm.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #include <linux/init.h>
22 #include <linux/linkage.h>
23 #include <asm/assembler.h>
24 #include <asm/asm-offsets.h>
25 #include <asm/hwcap.h>
26 #include <asm/pgtable.h>
27 #include <asm/pgtable-hwdef.h>
28 #include <asm/cpufeature.h>
29 #include <asm/alternative.h>
31 #ifdef CONFIG_ARM64_64K_PAGES
32 #define TCR_TG_FLAGS TCR_TG0_64K | TCR_TG1_64K
33 #elif defined(CONFIG_ARM64_16K_PAGES)
34 #define TCR_TG_FLAGS TCR_TG0_16K | TCR_TG1_16K
35 #else /* CONFIG_ARM64_4K_PAGES */
36 #define TCR_TG_FLAGS TCR_TG0_4K | TCR_TG1_4K
39 #define TCR_SMP_FLAGS TCR_SHARED
41 /* PTWs cacheable, inner/outer WBWA */
42 #define TCR_CACHE_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA
44 #define MAIR(attr, mt) ((attr) << ((mt) * 8))
49 * Idle the processor (wait for interrupt).
52 dsb sy // WFI may enter a low-power mode
59 * cpu_do_suspend - save CPU registers context
61 * x0: virtual address of context pointer
66 mrs x4, contextidr_el1
73 alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
80 stp x4, xzr, [x0, #16]
83 stp x9, x10, [x0, #64]
84 stp x11, x12, [x0, #80]
86 ENDPROC(cpu_do_suspend)
89 * cpu_do_resume - restore CPU register context
91 * x0: Address of context pointer
93 .pushsection ".idmap.text", "ax"
98 ldp x9, x10, [x0, #48]
99 ldp x11, x12, [x0, #64]
100 ldp x13, x14, [x0, #80]
103 msr contextidr_el1, x4
106 /* Don't change t0sz here, mask those bits when restoring */
108 bfi x8, x5, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH
114 * __cpu_setup() cleared MDSCR_EL1.MDE and friends, before unmasking
115 * debug exceptions. By restoring MDSCR_EL1 here, we may take a debug
116 * exception. Mask them until local_daif_restore() in cpu_suspend()
123 alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
130 * Restore oslsr_el1 by writing oslar_el1
132 ubfx x11, x11, #1, #1
134 reset_pmuserenr_el0 x0 // Disable PMU access from EL0
136 alternative_if ARM64_HAS_RAS_EXTN
137 msr_s SYS_DISR_EL1, xzr
138 alternative_else_nop_endif
142 ENDPROC(cpu_do_resume)
147 * cpu_do_switch_mm(pgd_phys, tsk)
149 * Set the translation table base pointer to be pgd_phys.
151 * - pgd_phys - physical address of new TTB
153 ENTRY(cpu_do_switch_mm)
155 mmid x1, x1 // get mm->context.id
157 #ifdef CONFIG_ARM64_SW_TTBR0_PAN
158 bfi x3, x1, #48, #16 // set the ASID field in TTBR0
160 bfi x2, x1, #48, #16 // set the ASID
161 msr ttbr1_el1, x2 // in TTBR1 (since TCR.A1 is set)
163 msr ttbr0_el1, x3 // now update TTBR0
165 b post_ttbr_update_workaround // Back to C code...
166 ENDPROC(cpu_do_switch_mm)
168 .pushsection ".idmap.text", "ax"
170 * void idmap_cpu_replace_ttbr1(phys_addr_t new_pgd)
172 * This is the low-level counterpart to cpu_replace_ttbr1, and should not be
173 * called by anything else. It can only be executed from a TTBR0 mapping.
175 ENTRY(idmap_cpu_replace_ttbr1)
176 save_and_disable_daif flags=x2
178 adrp x1, empty_zero_page
194 ENDPROC(idmap_cpu_replace_ttbr1)
200 * Initialise the processor for turning the MMU on. Return in x0 the
201 * value of the SCTLR_EL1 register.
203 .pushsection ".idmap.text", "ax"
205 tlbi vmalle1 // Invalidate local TLB
209 msr cpacr_el1, x0 // Enable FP/ASIMD
210 mov x0, #1 << 12 // Reset mdscr_el1 and disable
211 msr mdscr_el1, x0 // access to the DCC from EL0
212 isb // Unmask debug exceptions now,
213 enable_dbg // since this is per-cpu
214 reset_pmuserenr_el0 x0 // Disable PMU access from EL0
216 * Memory region attributes for LPAE:
220 * DEVICE_nGnRnE 000 00000000
221 * DEVICE_nGnRE 001 00000100
222 * DEVICE_GRE 010 00001100
223 * NORMAL_NC 011 01000100
224 * NORMAL 100 11111111
225 * NORMAL_WT 101 10111011
227 ldr x5, =MAIR(0x00, MT_DEVICE_nGnRnE) | \
228 MAIR(0x04, MT_DEVICE_nGnRE) | \
229 MAIR(0x0c, MT_DEVICE_GRE) | \
230 MAIR(0x44, MT_NORMAL_NC) | \
231 MAIR(0xff, MT_NORMAL) | \
232 MAIR(0xbb, MT_NORMAL_WT)
237 mov_q x0, SCTLR_EL1_SET
239 * Set/prepare TCR and TTBR. We use 512GB (39-bit) address range for
240 * both user and kernel.
242 ldr x10, =TCR_TxSZ(VA_BITS) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \
243 TCR_TG_FLAGS | TCR_ASID16 | TCR_TBI0 | TCR_A1
244 tcr_set_idmap_t0sz x10, x9
247 * Set the IPS bits in TCR_EL1.
249 tcr_compute_pa_size x10, #TCR_IPS_SHIFT, x5, x6
250 #ifdef CONFIG_ARM64_HW_AFDBM
252 * Hardware update of the Access and Dirty bits.
254 mrs x9, ID_AA64MMFR1_EL1
259 orr x10, x10, #TCR_HD // hardware Dirty flag update
260 1: orr x10, x10, #TCR_HA // hardware Access flag update
262 #endif /* CONFIG_ARM64_HW_AFDBM */
264 ret // return to head.S