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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * linux/arch/arm/mm/arm940.S: utility functions for ARM940T
+ *
+ * Copyright (C) 2004-2006 Hyok S. Choi (hyok.choi@samsung.com)
+ */
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <linux/pgtable.h>
+#include <asm/assembler.h>
+#include <asm/hwcap.h>
+#include <asm/pgtable-hwdef.h>
+#include <asm/ptrace.h>
+#include "proc-macros.S"
+
+/* ARM940T has a 4KB DCache comprising 256 lines of 4 words */
+#define CACHE_DLINESIZE 16
+#define CACHE_DSEGMENTS 4
+#define CACHE_DENTRIES 64
+
+ .text
+/*
+ * cpu_arm940_proc_init()
+ * cpu_arm940_switch_mm()
+ *
+ * These are not required.
+ */
+ENTRY(cpu_arm940_proc_init)
+ENTRY(cpu_arm940_switch_mm)
+ ret lr
+
+/*
+ * cpu_arm940_proc_fin()
+ */
+ENTRY(cpu_arm940_proc_fin)
+ mrc p15, 0, r0, c1, c0, 0 @ ctrl register
+ bic r0, r0, #0x00001000 @ i-cache
+ bic r0, r0, #0x00000004 @ d-cache
+ mcr p15, 0, r0, c1, c0, 0 @ disable caches
+ ret lr
+
+/*
+ * cpu_arm940_reset(loc)
+ * Params : r0 = address to jump to
+ * Notes : This sets up everything for a reset
+ */
+ .pushsection .idmap.text, "ax"
+ENTRY(cpu_arm940_reset)
+ mov ip, #0
+ mcr p15, 0, ip, c7, c5, 0 @ flush I cache
+ mcr p15, 0, ip, c7, c6, 0 @ flush D cache
+ mcr p15, 0, ip, c7, c10, 4 @ drain WB
+ mrc p15, 0, ip, c1, c0, 0 @ ctrl register
+ bic ip, ip, #0x00000005 @ .............c.p
+ bic ip, ip, #0x00001000 @ i-cache
+ mcr p15, 0, ip, c1, c0, 0 @ ctrl register
+ ret r0
+ENDPROC(cpu_arm940_reset)
+ .popsection
+
+/*
+ * cpu_arm940_do_idle()
+ */
+ .align 5
+ENTRY(cpu_arm940_do_idle)
+ mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt
+ ret lr
+
+/*
+ * flush_icache_all()
+ *
+ * Unconditionally clean and invalidate the entire icache.
+ */
+ENTRY(arm940_flush_icache_all)
+ mov r0, #0
+ mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
+ ret lr
+ENDPROC(arm940_flush_icache_all)
+
+/*
+ * flush_user_cache_all()
+ */
+ENTRY(arm940_flush_user_cache_all)
+ /* FALLTHROUGH */
+
+/*
+ * flush_kern_cache_all()
+ *
+ * Clean and invalidate the entire cache.
+ */
+ENTRY(arm940_flush_kern_cache_all)
+ mov r2, #VM_EXEC
+ /* FALLTHROUGH */
+
+/*
+ * flush_user_cache_range(start, end, flags)
+ *
+ * There is no efficient way to flush a range of cache entries
+ * in the specified address range. Thus, flushes all.
+ *
+ * - start - start address (inclusive)
+ * - end - end address (exclusive)
+ * - flags - vm_flags describing address space
+ */
+ENTRY(arm940_flush_user_cache_range)
+ mov ip, #0
+#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
+ mcr p15, 0, ip, c7, c6, 0 @ flush D cache
+#else
+ mov r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
+1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
+2: mcr p15, 0, r3, c7, c14, 2 @ clean/flush D index
+ subs r3, r3, #1 << 26
+ bcs 2b @ entries 63 to 0
+ subs r1, r1, #1 << 4
+ bcs 1b @ segments 3 to 0
+#endif
+ tst r2, #VM_EXEC
+ mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
+ mcrne p15, 0, ip, c7, c10, 4 @ drain WB
+ ret lr
+
+/*
+ * coherent_kern_range(start, end)
+ *
+ * Ensure coherency between the Icache and the Dcache in the
+ * region described by start, end. If you have non-snooping
+ * Harvard caches, you need to implement this function.
+ *
+ * - start - virtual start address
+ * - end - virtual end address
+ */
+ENTRY(arm940_coherent_kern_range)
+ /* FALLTHROUGH */
+
+/*
+ * coherent_user_range(start, end)
+ *
+ * Ensure coherency between the Icache and the Dcache in the
+ * region described by start, end. If you have non-snooping
+ * Harvard caches, you need to implement this function.
+ *
+ * - start - virtual start address
+ * - end - virtual end address
+ */
+ENTRY(arm940_coherent_user_range)
+ /* FALLTHROUGH */
+
+/*
+ * flush_kern_dcache_area(void *addr, size_t size)
+ *
+ * Ensure no D cache aliasing occurs, either with itself or
+ * the I cache
+ *
+ * - addr - kernel address
+ * - size - region size
+ */
+ENTRY(arm940_flush_kern_dcache_area)
+ mov r0, #0
+ mov r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
+1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
+2: mcr p15, 0, r3, c7, c14, 2 @ clean/flush D index
+ subs r3, r3, #1 << 26
+ bcs 2b @ entries 63 to 0
+ subs r1, r1, #1 << 4
+ bcs 1b @ segments 7 to 0
+ mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
+ mcr p15, 0, r0, c7, c10, 4 @ drain WB
+ ret lr
+
+/*
+ * dma_inv_range(start, end)
+ *
+ * There is no efficient way to invalidate a specifid virtual
+ * address range. Thus, invalidates all.
+ *
+ * - start - virtual start address
+ * - end - virtual end address
+ */
+arm940_dma_inv_range:
+ mov ip, #0
+ mov r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
+1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
+2: mcr p15, 0, r3, c7, c6, 2 @ flush D entry
+ subs r3, r3, #1 << 26
+ bcs 2b @ entries 63 to 0
+ subs r1, r1, #1 << 4
+ bcs 1b @ segments 7 to 0
+ mcr p15, 0, ip, c7, c10, 4 @ drain WB
+ ret lr
+
+/*
+ * dma_clean_range(start, end)
+ *
+ * There is no efficient way to clean a specifid virtual
+ * address range. Thus, cleans all.
+ *
+ * - start - virtual start address
+ * - end - virtual end address
+ */
+arm940_dma_clean_range:
+ENTRY(cpu_arm940_dcache_clean_area)
+ mov ip, #0
+#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
+ mov r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
+1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
+2: mcr p15, 0, r3, c7, c10, 2 @ clean D entry
+ subs r3, r3, #1 << 26
+ bcs 2b @ entries 63 to 0
+ subs r1, r1, #1 << 4
+ bcs 1b @ segments 7 to 0
+#endif
+ mcr p15, 0, ip, c7, c10, 4 @ drain WB
+ ret lr
+
+/*
+ * dma_flush_range(start, end)
+ *
+ * There is no efficient way to clean and invalidate a specifid
+ * virtual address range.
+ *
+ * - start - virtual start address
+ * - end - virtual end address
+ */
+ENTRY(arm940_dma_flush_range)
+ mov ip, #0
+ mov r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
+1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
+2:
+#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
+ mcr p15, 0, r3, c7, c14, 2 @ clean/flush D entry
+#else
+ mcr p15, 0, r3, c7, c6, 2 @ invalidate D entry
+#endif
+ subs r3, r3, #1 << 26
+ bcs 2b @ entries 63 to 0
+ subs r1, r1, #1 << 4
+ bcs 1b @ segments 7 to 0
+ mcr p15, 0, ip, c7, c10, 4 @ drain WB
+ ret lr
+
+/*
+ * dma_map_area(start, size, dir)
+ * - start - kernel virtual start address
+ * - size - size of region
+ * - dir - DMA direction
+ */
+ENTRY(arm940_dma_map_area)
+ add r1, r1, r0
+ cmp r2, #DMA_TO_DEVICE
+ beq arm940_dma_clean_range
+ bcs arm940_dma_inv_range
+ b arm940_dma_flush_range
+ENDPROC(arm940_dma_map_area)
+
+/*
+ * dma_unmap_area(start, size, dir)
+ * - start - kernel virtual start address
+ * - size - size of region
+ * - dir - DMA direction
+ */
+ENTRY(arm940_dma_unmap_area)
+ ret lr
+ENDPROC(arm940_dma_unmap_area)
+
+ .globl arm940_flush_kern_cache_louis
+ .equ arm940_flush_kern_cache_louis, arm940_flush_kern_cache_all
+
+ @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
+ define_cache_functions arm940
+
+ .type __arm940_setup, #function
+__arm940_setup:
+ mov r0, #0
+ mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
+ mcr p15, 0, r0, c7, c6, 0 @ invalidate D cache
+ mcr p15, 0, r0, c7, c10, 4 @ drain WB
+
+ mcr p15, 0, r0, c6, c3, 0 @ disable data area 3~7
+ mcr p15, 0, r0, c6, c4, 0
+ mcr p15, 0, r0, c6, c5, 0
+ mcr p15, 0, r0, c6, c6, 0
+ mcr p15, 0, r0, c6, c7, 0
+
+ mcr p15, 0, r0, c6, c3, 1 @ disable instruction area 3~7
+ mcr p15, 0, r0, c6, c4, 1
+ mcr p15, 0, r0, c6, c5, 1
+ mcr p15, 0, r0, c6, c6, 1
+ mcr p15, 0, r0, c6, c7, 1
+
+ mov r0, #0x0000003F @ base = 0, size = 4GB
+ mcr p15, 0, r0, c6, c0, 0 @ set area 0, default
+ mcr p15, 0, r0, c6, c0, 1
+
+ ldr r0, =(CONFIG_DRAM_BASE & 0xFFFFF000) @ base[31:12] of RAM
+ ldr r7, =CONFIG_DRAM_SIZE >> 12 @ size of RAM (must be >= 4KB)
+ pr_val r3, r0, r7, #1
+ mcr p15, 0, r3, c6, c1, 0 @ set area 1, RAM
+ mcr p15, 0, r3, c6, c1, 1
+
+ ldr r0, =(CONFIG_FLASH_MEM_BASE & 0xFFFFF000) @ base[31:12] of FLASH
+ ldr r7, =CONFIG_FLASH_SIZE @ size of FLASH (must be >= 4KB)
+ pr_val r3, r0, r6, #1
+ mcr p15, 0, r3, c6, c2, 0 @ set area 2, ROM/FLASH
+ mcr p15, 0, r3, c6, c2, 1
+
+ mov r0, #0x06
+ mcr p15, 0, r0, c2, c0, 0 @ Region 1&2 cacheable
+ mcr p15, 0, r0, c2, c0, 1
+#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
+ mov r0, #0x00 @ disable whole write buffer
+#else
+ mov r0, #0x02 @ Region 1 write bufferred
+#endif
+ mcr p15, 0, r0, c3, c0, 0
+
+ mov r0, #0x10000
+ sub r0, r0, #1 @ r0 = 0xffff
+ mcr p15, 0, r0, c5, c0, 0 @ all read/write access
+ mcr p15, 0, r0, c5, c0, 1
+
+ mrc p15, 0, r0, c1, c0 @ get control register
+ orr r0, r0, #0x00001000 @ I-cache
+ orr r0, r0, #0x00000005 @ MPU/D-cache
+
+ ret lr
+
+ .size __arm940_setup, . - __arm940_setup
+
+ __INITDATA
+
+ @ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
+ define_processor_functions arm940, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
+
+ .section ".rodata"
+
+ string cpu_arch_name, "armv4t"
+ string cpu_elf_name, "v4"
+ string cpu_arm940_name, "ARM940T"
+
+ .align
+
+ .section ".proc.info.init", "a"
+
+ .type __arm940_proc_info,#object
+__arm940_proc_info:
+ .long 0x41009400
+ .long 0xff00fff0
+ .long 0
+ initfn __arm940_setup, __arm940_proc_info
+ .long cpu_arch_name
+ .long cpu_elf_name
+ .long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB
+ .long cpu_arm940_name
+ .long arm940_processor_functions
+ .long 0
+ .long 0
+ .long arm940_cache_fns
+ .size __arm940_proc_info, . - __arm940_proc_info
+