[ARM] nommu: add ARM946E-S core support

This patch adds ARM946E-S core support which has typically 8KB I&D cache.
It has a MPU and supports ARMv5TE instruction set.

Because the ARM946E-S core can be synthesizable with various cache size,
CONFIG_CPU_DCACHE_SIZE is defined for vendor specific configurations.

Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 424 insertions, 0 deletions

diff --git a/arch/arm/mm/proc-arm946.S b/arch/arm/mm/proc-arm946.S
new file mode 100644
index 000000000000..6dc7942c4cfe
--- /dev/null
+++ b/arch/arm/mm/proc-arm946.S
@@ -0,0 +1,424 @@
+/*
+ *  linux/arch/arm/mm/arm946.S: utility functions for ARM946E-S
+ *
+ *  Copyright (C) 2004-2006 Hyok S. Choi (hyok.choi@samsung.com)
+ *
+ *  (Many of cache codes are from proc-arm926.S)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/assembler.h>
+#include <asm/pgtable-hwdef.h>
+#include <asm/pgtable.h>
+#include <asm/procinfo.h>
+#include <asm/ptrace.h>
+
+/*
+ * ARM946E-S is synthesizable to have 0KB to 1MB sized D-Cache,
+ * comprising 256 lines of 32 bytes (8 words).
+ */
+#define CACHE_DSIZE     (CONFIG_CPU_DCACHE_SIZE) /* typically 8KB. */
+#define CACHE_DLINESIZE 32                      /* fixed */
+#define CACHE_DSEGMENTS 4                       /* fixed */
+#define CACHE_DENTRIES  (CACHE_DSIZE / CACHE_DSEGMENTS / CACHE_DLINESIZE)
+#define CACHE_DLIMIT    (CACHE_DSIZE * 4)       /* benchmark needed */
+
+        .text
+/*
+ * cpu_arm946_proc_init()
+ * cpu_arm946_switch_mm()
+ *
+ * These are not required.
+ */
+ENTRY(cpu_arm946_proc_init)
+ENTRY(cpu_arm946_switch_mm)
+        mov     pc, lr
+
+/*
+ * cpu_arm946_proc_fin()
+ */
+ENTRY(cpu_arm946_proc_fin)
+        stmfd   sp!, {lr}
+        mov     ip, #PSR_F_BIT | PSR_I_BIT | SVC_MODE
+        msr     cpsr_c, ip
+        bl      arm946_flush_kern_cache_all
+        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
+        ldmfd   sp!, {pc}
+
+/*
+ * cpu_arm946_reset(loc)
+ * Params  : r0 = address to jump to
+ * Notes   : This sets up everything for a reset
+ */
+ENTRY(cpu_arm946_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
+        mov     pc, r0
+
+/*
+ * cpu_arm946_do_idle()
+ */
+        .align  5
+ENTRY(cpu_arm946_do_idle)
+        mcr     p15, 0, r0, c7, c0, 4           @ Wait for interrupt
+        mov     pc, lr
+
+/*
+ *      flush_user_cache_all()
+ */
+ENTRY(arm946_flush_user_cache_all)
+        /* FALLTHROUGH */
+
+/*
+ *      flush_kern_cache_all()
+ *
+ *      Clean and invalidate the entire cache.
+ */
+ENTRY(arm946_flush_kern_cache_all)
+        mov     r2, #VM_EXEC
+        mov     ip, #0
+__flush_whole_cache:
+#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
+        mcr     p15, 0, ip, c7, c6, 0           @ flush D cache
+#else
+        mov     r1, #(CACHE_DSEGMENTS - 1) << 29 @ 4 segments
+1:      orr     r3, r1, #(CACHE_DENTRIES - 1) << 4 @ n entries
+2:      mcr     p15, 0, r3, c7, c14, 2          @ clean/flush D index
+        subs    r3, r3, #1 << 4
+        bcs     2b                              @ entries n to 0
+        subs    r1, r1, #1 << 29
+        bcs     1b                              @ segments 3 to 0
+#endif
+        tst     r2, #VM_EXEC
+        mcrne   p15, 0, ip, c7, c5, 0           @ flush I cache
+        mcrne   p15, 0, ip, c7, c10, 4          @ drain WB
+        mov     pc, lr
+
+/*
+ *      flush_user_cache_range(start, end, flags)
+ *
+ *      Clean and invalidate a range of cache entries in the
+ *      specified address range.
+ *
+ *      - start - start address (inclusive)
+ *      - end   - end address (exclusive)
+ *      - flags - vm_flags describing address space
+ * (same as arm926)
+ */
+ENTRY(arm946_flush_user_cache_range)
+        mov     ip, #0
+        sub     r3, r1, r0                      @ calculate total size
+        cmp     r3, #CACHE_DLIMIT
+        bhs     __flush_whole_cache
+
+1:      tst     r2, #VM_EXEC
+#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
+        mcr     p15, 0, r0, c7, c6, 1           @ invalidate D entry
+        mcrne   p15, 0, r0, c7, c5, 1           @ invalidate I entry
+        add     r0, r0, #CACHE_DLINESIZE
+        mcr     p15, 0, r0, c7, c6, 1           @ invalidate D entry
+        mcrne   p15, 0, r0, c7, c5, 1           @ invalidate I entry
+        add     r0, r0, #CACHE_DLINESIZE
+#else
+        mcr     p15, 0, r0, c7, c14, 1          @ clean and invalidate D entry
+        mcrne   p15, 0, r0, c7, c5, 1           @ invalidate I entry
+        add     r0, r0, #CACHE_DLINESIZE
+        mcr     p15, 0, r0, c7, c14, 1          @ clean and invalidate D entry
+        mcrne   p15, 0, r0, c7, c5, 1           @ invalidate I entry
+        add     r0, r0, #CACHE_DLINESIZE
+#endif
+        cmp     r0, r1
+        blo     1b
+        tst     r2, #VM_EXEC
+        mcrne   p15, 0, ip, c7, c10, 4          @ drain WB
+        mov     pc, 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(arm946_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
+ * (same as arm926)
+ */
+ENTRY(arm946_coherent_user_range)
+        bic     r0, r0, #CACHE_DLINESIZE - 1
+1:      mcr     p15, 0, r0, c7, c10, 1          @ clean D entry
+        mcr     p15, 0, r0, c7, c5, 1           @ invalidate I entry
+        add     r0, r0, #CACHE_DLINESIZE
+        cmp     r0, r1
+        blo     1b
+        mcr     p15, 0, r0, c7, c10, 4          @ drain WB
+        mov     pc, lr
+
+/*
+ *      flush_kern_dcache_page(void *page)
+ *
+ *      Ensure no D cache aliasing occurs, either with itself or
+ *      the I cache
+ *
+ *      - addr  - page aligned address
+ * (same as arm926)
+ */
+ENTRY(arm946_flush_kern_dcache_page)
+        add     r1, r0, #PAGE_SZ
+1:      mcr     p15, 0, r0, c7, c14, 1          @ clean+invalidate D entry
+        add     r0, r0, #CACHE_DLINESIZE
+        cmp     r0, r1
+        blo     1b
+        mov     r0, #0
+        mcr     p15, 0, r0, c7, c5, 0           @ invalidate I cache
+        mcr     p15, 0, r0, c7, c10, 4          @ drain WB
+        mov     pc, lr
+
+/*
+ *      dma_inv_range(start, end)
+ *
+ *      Invalidate (discard) the specified virtual address range.
+ *      May not write back any entries.  If 'start' or 'end'
+ *      are not cache line aligned, those lines must be written
+ *      back.
+ *
+ *      - start - virtual start address
+ *      - end   - virtual end address
+ * (same as arm926)
+ */
+ENTRY(arm946_dma_inv_range)
+#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
+        tst     r0, #CACHE_DLINESIZE - 1
+        mcrne   p15, 0, r0, c7, c10, 1          @ clean D entry
+        tst     r1, #CACHE_DLINESIZE - 1
+        mcrne   p15, 0, r1, c7, c10, 1          @ clean D entry
+#endif
+        bic     r0, r0, #CACHE_DLINESIZE - 1
+1:      mcr     p15, 0, r0, c7, c6, 1           @ invalidate D entry
+        add     r0, r0, #CACHE_DLINESIZE
+        cmp     r0, r1
+        blo     1b
+        mcr     p15, 0, r0, c7, c10, 4          @ drain WB
+        mov     pc, lr
+
+/*
+ *      dma_clean_range(start, end)
+ *
+ *      Clean the specified virtual address range.
+ *
+ *      - start - virtual start address
+ *      - end   - virtual end address
+ *
+ * (same as arm926)
+ */
+ENTRY(arm946_dma_clean_range)
+#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
+        bic     r0, r0, #CACHE_DLINESIZE - 1
+1:      mcr     p15, 0, r0, c7, c10, 1          @ clean D entry
+        add     r0, r0, #CACHE_DLINESIZE
+        cmp     r0, r1
+        blo     1b
+#endif
+        mcr     p15, 0, r0, c7, c10, 4          @ drain WB
+        mov     pc, lr
+
+/*
+ *      dma_flush_range(start, end)
+ *
+ *      Clean and invalidate the specified virtual address range.
+ *
+ *      - start - virtual start address
+ *      - end   - virtual end address
+ *
+ * (same as arm926)
+ */
+ENTRY(arm946_dma_flush_range)
+        bic     r0, r0, #CACHE_DLINESIZE - 1
+1:
+#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
+        mcr     p15, 0, r0, c7, c14, 1          @ clean+invalidate D entry
+#else
+        mcr     p15, 0, r0, c7, c10, 1          @ clean D entry
+#endif
+        add     r0, r0, #CACHE_DLINESIZE
+        cmp     r0, r1
+        blo     1b
+        mcr     p15, 0, r0, c7, c10, 4          @ drain WB
+        mov     pc, lr
+
+ENTRY(arm946_cache_fns)
+        .long   arm946_flush_kern_cache_all
+        .long   arm946_flush_user_cache_all
+        .long   arm946_flush_user_cache_range
+        .long   arm946_coherent_kern_range
+        .long   arm946_coherent_user_range
+        .long   arm946_flush_kern_dcache_page
+        .long   arm946_dma_inv_range
+        .long   arm946_dma_clean_range
+        .long   arm946_dma_flush_range
+
+
+ENTRY(cpu_arm946_dcache_clean_area)
+#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
+1:      mcr     p15, 0, r0, c7, c10, 1          @ clean D entry
+        add     r0, r0, #CACHE_DLINESIZE
+        subs    r1, r1, #CACHE_DLINESIZE
+        bhi     1b
+#endif
+        mcr     p15, 0, r0, c7, c10, 4          @ drain WB
+        mov     pc, lr
+
+        __INIT
+
+        .type   __arm946_setup, #function
+__arm946_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 memory region 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
+
+        mov     r0, #0x0000003F                 @ base = 0, size = 4GB
+        mcr     p15, 0, r0, c6, c0, 0           @ set region 0, default
+
+        ldr     r0, =(CONFIG_DRAM_BASE & 0xFFFFF000) @ base[31:12] of RAM
+        ldr     r1, =(CONFIG_DRAM_SIZE >> 12)   @ size of RAM (must be >= 4KB)
+        mov     r2, #10                         @ 11 is the minimum (4KB)
+1:      add     r2, r2, #1                      @ area size *= 2
+        mov     r1, r1, lsr #1
+        bne     1b                              @ count not zero r-shift
+        orr     r0, r0, r2, lsl #1              @ the region register value
+        orr     r0, r0, #1                      @ set enable bit
+        mcr     p15, 0, r0, c6, c1, 0           @ set region 1, RAM
+
+        ldr     r0, =(CONFIG_FLASH_MEM_BASE & 0xFFFFF000) @ base[31:12] of FLASH
+        ldr     r1, =(CONFIG_FLASH_SIZE >> 12)  @ size of FLASH (must be >= 4KB)
+        mov     r2, #10                         @ 11 is the minimum (4KB)
+1:      add     r2, r2, #1                      @ area size *= 2
+        mov     r1, r1, lsr #1
+        bne     1b                              @ count not zero r-shift
+        orr     r0, r0, r2, lsl #1              @ the region register value
+        orr     r0, r0, #1                      @ set enable bit
+        mcr     p15, 0, r0, c6, c2, 0           @ set region 2, ROM/FLASH
+
+        mov     r0, #0x06
+        mcr     p15, 0, r0, c2, c0, 0           @ region 1,2 d-cacheable
+        mcr     p15, 0, r0, c2, c0, 1           @ region 1,2 i-cacheable
+#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
+
+/*
+ *  Access Permission Settings for future permission control by PU.
+ *
+ *                              priv.   user
+ *      region 0 (whole)        rw      --      : b0001
+ *      region 1 (RAM)          rw      rw      : b0011
+ *      region 2 (FLASH)        rw      r-      : b0010
+ *      region 3~7 (none)       --      --      : b0000
+ */
+        mov     r0, #0x00000031
+        orr     r0, r0, #0x00000200
+        mcr     p15, 0, r0, c5, c0, 2           @ set data access permission
+        mcr     p15, 0, r0, c5, c0, 3           @ set inst. access permission
+
+        mrc     p15, 0, r0, c1, c0              @ get control register
+        orr     r0, r0, #0x00001000             @ I-cache
+        orr     r0, r0, #0x00000005             @ MPU/D-cache
+#ifdef CONFIG_CPU_CACHE_ROUND_ROBIN
+        orr     r0, r0, #0x00004000             @ .1.. .... .... ....
+#endif
+        mov     pc, lr
+
+        .size   __arm946_setup, . - __arm946_setup
+
+        __INITDATA
+
+/*
+ * Purpose : Function pointers used to access above functions - all calls
+ *           come through these
+ */
+        .type   arm946_processor_functions, #object
+ENTRY(arm946_processor_functions)
+        .word   v5t_early_abort
+        .word   cpu_arm946_proc_init
+        .word   cpu_arm946_proc_fin
+        .word   cpu_arm946_reset
+        .word   cpu_arm946_do_idle
+
+        .word   cpu_arm946_dcache_clean_area
+        .word   cpu_arm946_switch_mm
+        .word   0               @ cpu_*_set_pte
+        .size   arm946_processor_functions, . - arm946_processor_functions
+
+        .section ".rodata"
+
+        .type   cpu_arch_name, #object
+cpu_arch_name:
+        .asciz  "armv5te"
+        .size   cpu_arch_name, . - cpu_arch_name
+
+        .type   cpu_elf_name, #object
+cpu_elf_name:
+        .asciz  "v5t"
+        .size   cpu_elf_name, . - cpu_elf_name
+
+        .type   cpu_arm946_name, #object
+cpu_arm946_name:
+        .ascii  "ARM946E-S"
+        .size   cpu_arm946_name, . - cpu_arm946_name
+
+        .align
+
+        .section ".proc.info.init", #alloc, #execinstr
+        .type   __arm946_proc_info,#object
+__arm946_proc_info:
+        .long   0x41009460
+        .long   0xff00fff0
+        .long   0
+        b       __arm946_setup
+        .long   cpu_arch_name
+        .long   cpu_elf_name
+        .long   HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB
+        .long   cpu_arm946_name
+        .long   arm946_processor_functions
+        .long   0
+        .long   0
+        .long   arm940_cache_fns
+        .size   __arm946_proc_info, . - __arm946_proc_info
+