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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * linux/arch/arm/mm/proc-v6.S
+ *
+ * Copyright (C) 2001 Deep Blue Solutions Ltd.
+ * Modified by Catalin Marinas for noMMU support
+ *
+ * This is the "shell" of the ARMv6 processor support.
+ */
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <linux/pgtable.h>
+#include <asm/assembler.h>
+#include <asm/asm-offsets.h>
+#include <asm/hwcap.h>
+#include <asm/pgtable-hwdef.h>
+
+#include "proc-macros.S"
+
+#define D_CACHE_LINE_SIZE 32
+
+#define TTB_C (1 << 0)
+#define TTB_S (1 << 1)
+#define TTB_IMP (1 << 2)
+#define TTB_RGN_NC (0 << 3)
+#define TTB_RGN_WBWA (1 << 3)
+#define TTB_RGN_WT (2 << 3)
+#define TTB_RGN_WB (3 << 3)
+
+#define TTB_FLAGS_UP TTB_RGN_WBWA
+#define PMD_FLAGS_UP PMD_SECT_WB
+#define TTB_FLAGS_SMP TTB_RGN_WBWA|TTB_S
+#define PMD_FLAGS_SMP PMD_SECT_WBWA|PMD_SECT_S
+
+.arch armv6
+
+ENTRY(cpu_v6_proc_init)
+ ret lr
+
+ENTRY(cpu_v6_proc_fin)
+ mrc p15, 0, r0, c1, c0, 0 @ ctrl register
+ bic r0, r0, #0x1000 @ ...i............
+ bic r0, r0, #0x0006 @ .............ca.
+ mcr p15, 0, r0, c1, c0, 0 @ disable caches
+ ret lr
+
+/*
+ * cpu_v6_reset(loc)
+ *
+ * Perform a soft reset of the system. Put the CPU into the
+ * same state as it would be if it had been reset, and branch
+ * to what would be the reset vector.
+ *
+ * - loc - location to jump to for soft reset
+ */
+ .align 5
+ .pushsection .idmap.text, "ax"
+ENTRY(cpu_v6_reset)
+ mrc p15, 0, r1, c1, c0, 0 @ ctrl register
+ bic r1, r1, #0x1 @ ...............m
+ mcr p15, 0, r1, c1, c0, 0 @ disable MMU
+ mov r1, #0
+ mcr p15, 0, r1, c7, c5, 4 @ ISB
+ ret r0
+ENDPROC(cpu_v6_reset)
+ .popsection
+
+/*
+ * cpu_v6_do_idle()
+ *
+ * Idle the processor (eg, wait for interrupt).
+ *
+ * IRQs are already disabled.
+ */
+ENTRY(cpu_v6_do_idle)
+ mov r1, #0
+ mcr p15, 0, r1, c7, c10, 4 @ DWB - WFI may enter a low-power mode
+ mcr p15, 0, r1, c7, c0, 4 @ wait for interrupt
+ ret lr
+
+ENTRY(cpu_v6_dcache_clean_area)
+1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
+ add r0, r0, #D_CACHE_LINE_SIZE
+ subs r1, r1, #D_CACHE_LINE_SIZE
+ bhi 1b
+ ret lr
+
+/*
+ * cpu_v6_switch_mm(pgd_phys, tsk)
+ *
+ * Set the translation table base pointer to be pgd_phys
+ *
+ * - pgd_phys - physical address of new TTB
+ *
+ * It is assumed that:
+ * - we are not using split page tables
+ */
+ENTRY(cpu_v6_switch_mm)
+#ifdef CONFIG_MMU
+ mov r2, #0
+ mmid r1, r1 @ get mm->context.id
+ ALT_SMP(orr r0, r0, #TTB_FLAGS_SMP)
+ ALT_UP(orr r0, r0, #TTB_FLAGS_UP)
+ mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB
+ mcr p15, 0, r2, c7, c10, 4 @ drain write buffer
+ mcr p15, 0, r0, c2, c0, 0 @ set TTB 0
+#ifdef CONFIG_PID_IN_CONTEXTIDR
+ mrc p15, 0, r2, c13, c0, 1 @ read current context ID
+ bic r2, r2, #0xff @ extract the PID
+ and r1, r1, #0xff
+ orr r1, r1, r2 @ insert into new context ID
+#endif
+ mcr p15, 0, r1, c13, c0, 1 @ set context ID
+#endif
+ ret lr
+
+/*
+ * cpu_v6_set_pte_ext(ptep, pte, ext)
+ *
+ * Set a level 2 translation table entry.
+ *
+ * - ptep - pointer to level 2 translation table entry
+ * (hardware version is stored at -1024 bytes)
+ * - pte - PTE value to store
+ * - ext - value for extended PTE bits
+ */
+ armv6_mt_table cpu_v6
+
+ENTRY(cpu_v6_set_pte_ext)
+#ifdef CONFIG_MMU
+ armv6_set_pte_ext cpu_v6
+#endif
+ ret lr
+
+/* Suspend/resume support: taken from arch/arm/mach-s3c64xx/sleep.S */
+.globl cpu_v6_suspend_size
+.equ cpu_v6_suspend_size, 4 * 6
+#ifdef CONFIG_ARM_CPU_SUSPEND
+ENTRY(cpu_v6_do_suspend)
+ stmfd sp!, {r4 - r9, lr}
+ mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
+#ifdef CONFIG_MMU
+ mrc p15, 0, r5, c3, c0, 0 @ Domain ID
+ mrc p15, 0, r6, c2, c0, 1 @ Translation table base 1
+#endif
+ mrc p15, 0, r7, c1, c0, 1 @ auxiliary control register
+ mrc p15, 0, r8, c1, c0, 2 @ co-processor access control
+ mrc p15, 0, r9, c1, c0, 0 @ control register
+ stmia r0, {r4 - r9}
+ ldmfd sp!, {r4- r9, pc}
+ENDPROC(cpu_v6_do_suspend)
+
+ENTRY(cpu_v6_do_resume)
+ mov ip, #0
+ mcr p15, 0, ip, c7, c14, 0 @ clean+invalidate D cache
+ mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
+ mcr p15, 0, ip, c7, c15, 0 @ clean+invalidate cache
+ mcr p15, 0, ip, c7, c10, 4 @ drain write buffer
+ mcr p15, 0, ip, c13, c0, 1 @ set reserved context ID
+ ldmia r0, {r4 - r9}
+ mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID
+#ifdef CONFIG_MMU
+ mcr p15, 0, r5, c3, c0, 0 @ Domain ID
+ ALT_SMP(orr r1, r1, #TTB_FLAGS_SMP)
+ ALT_UP(orr r1, r1, #TTB_FLAGS_UP)
+ mcr p15, 0, r1, c2, c0, 0 @ Translation table base 0
+ mcr p15, 0, r6, c2, c0, 1 @ Translation table base 1
+ mcr p15, 0, ip, c2, c0, 2 @ TTB control register
+#endif
+ mcr p15, 0, r7, c1, c0, 1 @ auxiliary control register
+ mcr p15, 0, r8, c1, c0, 2 @ co-processor access control
+ mcr p15, 0, ip, c7, c5, 4 @ ISB
+ mov r0, r9 @ control register
+ b cpu_resume_mmu
+ENDPROC(cpu_v6_do_resume)
+#endif
+
+ string cpu_v6_name, "ARMv6-compatible processor"
+
+ .align
+
+/*
+ * __v6_setup
+ *
+ * Initialise TLB, Caches, and MMU state ready to switch the MMU
+ * on. Return in r0 the new CP15 C1 control register setting.
+ *
+ * We automatically detect if we have a Harvard cache, and use the
+ * Harvard cache control instructions insead of the unified cache
+ * control instructions.
+ *
+ * This should be able to cover all ARMv6 cores.
+ *
+ * It is assumed that:
+ * - cache type register is implemented
+ */
+__v6_setup:
+#ifdef CONFIG_SMP
+ ALT_SMP(mrc p15, 0, r0, c1, c0, 1) @ Enable SMP/nAMP mode
+ ALT_UP(nop)
+ orr r0, r0, #0x20
+ ALT_SMP(mcr p15, 0, r0, c1, c0, 1)
+ ALT_UP(nop)
+#endif
+
+ mov r0, #0
+ mcr p15, 0, r0, c7, c14, 0 @ clean+invalidate D cache
+ mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
+ mcr p15, 0, r0, c7, c15, 0 @ clean+invalidate cache
+#ifdef CONFIG_MMU
+ mcr p15, 0, r0, c8, c7, 0 @ invalidate I + D TLBs
+ mcr p15, 0, r0, c2, c0, 2 @ TTB control register
+ ALT_SMP(orr r4, r4, #TTB_FLAGS_SMP)
+ ALT_UP(orr r4, r4, #TTB_FLAGS_UP)
+ ALT_SMP(orr r8, r8, #TTB_FLAGS_SMP)
+ ALT_UP(orr r8, r8, #TTB_FLAGS_UP)
+ mcr p15, 0, r8, c2, c0, 1 @ load TTB1
+#endif /* CONFIG_MMU */
+ mcr p15, 0, r0, c7, c10, 4 @ drain write buffer and
+ @ complete invalidations
+ adr r5, v6_crval
+ ldmia r5, {r5, r6}
+ ARM_BE8(orr r6, r6, #1 << 25) @ big-endian page tables
+ mrc p15, 0, r0, c1, c0, 0 @ read control register
+ bic r0, r0, r5 @ clear bits them
+ orr r0, r0, r6 @ set them
+#ifdef CONFIG_ARM_ERRATA_364296
+ /*
+ * Workaround for the 364296 ARM1136 r0p2 erratum (possible cache data
+ * corruption with hit-under-miss enabled). The conditional code below
+ * (setting the undocumented bit 31 in the auxiliary control register
+ * and the FI bit in the control register) disables hit-under-miss
+ * without putting the processor into full low interrupt latency mode.
+ */
+ ldr r6, =0x4107b362 @ id for ARM1136 r0p2
+ mrc p15, 0, r5, c0, c0, 0 @ get processor id
+ teq r5, r6 @ check for the faulty core
+ mrceq p15, 0, r5, c1, c0, 1 @ load aux control reg
+ orreq r5, r5, #(1 << 31) @ set the undocumented bit 31
+ mcreq p15, 0, r5, c1, c0, 1 @ write aux control reg
+ orreq r0, r0, #(1 << 21) @ low interrupt latency configuration
+#endif
+ ret lr @ return to head.S:__ret
+
+ /*
+ * V X F I D LR
+ * .... ...E PUI. .T.T 4RVI ZFRS BLDP WCAM
+ * rrrr rrrx xxx0 0101 xxxx xxxx x111 xxxx < forced
+ * 0 110 0011 1.00 .111 1101 < we want
+ */
+ .type v6_crval, #object
+v6_crval:
+ crval clear=0x01e0fb7f, mmuset=0x00c0387d, ucset=0x00c0187c
+
+ __INITDATA
+
+ @ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
+ define_processor_functions v6, dabort=v6_early_abort, pabort=v6_pabort, suspend=1
+
+ .section ".rodata"
+
+ string cpu_arch_name, "armv6"
+ string cpu_elf_name, "v6"
+ .align
+
+ .section ".proc.info.init", "a"
+
+ /*
+ * Match any ARMv6 processor core.
+ */
+ .type __v6_proc_info, #object
+__v6_proc_info:
+ .long 0x0007b000
+ .long 0x0007f000
+ ALT_SMP(.long \
+ PMD_TYPE_SECT | \
+ PMD_SECT_AP_WRITE | \
+ PMD_SECT_AP_READ | \
+ PMD_FLAGS_SMP)
+ ALT_UP(.long \
+ PMD_TYPE_SECT | \
+ PMD_SECT_AP_WRITE | \
+ PMD_SECT_AP_READ | \
+ PMD_FLAGS_UP)
+ .long PMD_TYPE_SECT | \
+ PMD_SECT_XN | \
+ PMD_SECT_AP_WRITE | \
+ PMD_SECT_AP_READ
+ initfn __v6_setup, __v6_proc_info
+ .long cpu_arch_name
+ .long cpu_elf_name
+ /* See also feat_v6_fixup() for HWCAP_TLS */
+ .long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA|HWCAP_TLS
+ .long cpu_v6_name
+ .long v6_processor_functions
+ .long v6wbi_tlb_fns
+ .long v6_user_fns
+ .long v6_cache_fns
+ .size __v6_proc_info, . - __v6_proc_info