[ARM] Marvell Feroceon CPU core support

The Feroceon is a family of independent ARMv5TE compliant CPU core
implementations, supporting a variable depth pipeline and out-of-order
execution.  The Feroceon is configurable with VFP support, and the
later models in the series are superscalar with up to two instructions
per clock cycle.

This patch adds the initial low-level cache/TLB handling for this core.

Signed-off-by: Assaf Hoffman <hoffman@marvell.com>
Reviewed-by: Tzachi Perelstein <tzachi@marvell.com>
Reviewed-by: Nicolas Pitre <nico@marvell.com>
Reviewed-by: Lennert Buytenhek <buytenh@marvell.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>

3 files changed, 494 insertions, 2 deletions

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 7868f4dc1d00..378fb744abe2 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -342,6 +342,18 @@ config CPU_XSC3
         select CPU_TLB_V4WBI if MMU
         select IO_36
 
+# Feroceon
+config CPU_FEROCEON
+        bool
+        depends on ARCH_ORION
+        default y
+        select CPU_32v5
+        select CPU_ABRT_EV5T
+        select CPU_CACHE_VIVT
+        select CPU_CP15_MMU
+        select CPU_COPY_V4WB if MMU
+        select CPU_TLB_V4WBI if MMU
+
 # ARMv6
 config CPU_V6
         bool "Support ARM V6 processor"
@@ -538,7 +550,7 @@ comment "Processor Features"
 
 config ARM_THUMB
         bool "Support Thumb user binaries"
-        depends on CPU_ARM720T || CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || CPU_XSCALE || CPU_XSC3 || CPU_V6 || CPU_V7
+        depends on CPU_ARM720T || CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || CPU_XSCALE || CPU_XSC3 || CPU_V6 || CPU_V7 || CPU_FEROCEON
         default y
         help
           Say Y if you want to include kernel support for running user space
@@ -600,7 +612,7 @@ config CPU_DCACHE_SIZE
 
 config CPU_DCACHE_WRITETHROUGH
         bool "Force write through D-cache"
-        depends on (CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020) && !CPU_DCACHE_DISABLE
+        depends on (CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_FEROCEON) && !CPU_DCACHE_DISABLE
         default y if CPU_ARM925T
         help
           Say Y here to use the data cache in writethrough mode. Unless you
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 762702765fc3..44536a0b995a 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -68,6 +68,7 @@ obj-$(CONFIG_CPU_SA110)		+= proc-sa110.o
 obj-$(CONFIG_CPU_SA1100)        += proc-sa1100.o
 obj-$(CONFIG_CPU_XSCALE)        += proc-xscale.o
 obj-$(CONFIG_CPU_XSC3)          += proc-xsc3.o
+obj-$(CONFIG_CPU_FEROCEON)      += proc-feroceon.o
 obj-$(CONFIG_CPU_V6)            += proc-v6.o
 obj-$(CONFIG_CPU_V7)            += proc-v7.o
 
diff --git a/arch/arm/mm/proc-feroceon.S b/arch/arm/mm/proc-feroceon.S
new file mode 100644
index 000000000000..8ad341af7906
--- /dev/null
+++ b/arch/arm/mm/proc-feroceon.S
@@ -0,0 +1,479 @@
+/*
+ *  linux/arch/arm/mm/proc-feroceon.S: MMU functions for Feroceon
+ *
+ *  Heavily based on proc-arm926.S
+ *  Maintainer: Assaf Hoffman <hoffman@marvell.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/assembler.h>
+#include <asm/elf.h>
+#include <asm/pgtable-hwdef.h>
+#include <asm/pgtable.h>
+#include <asm/page.h>
+#include <asm/ptrace.h>
+#include "proc-macros.S"
+
+/*
+ * This is the maximum size of an area which will be invalidated
+ * using the single invalidate entry instructions.  Anything larger
+ * than this, and we go for the whole cache.
+ *
+ * This value should be chosen such that we choose the cheapest
+ * alternative.
+ */
+#define CACHE_DLIMIT    16384
+
+/*
+ * the cache line size of the I and D cache
+ */
+#define CACHE_DLINESIZE 32
+
+        .text
+/*
+ * cpu_feroceon_proc_init()
+ */
+ENTRY(cpu_feroceon_proc_init)
+        mov     pc, lr
+
+/*
+ * cpu_feroceon_proc_fin()
+ */
+ENTRY(cpu_feroceon_proc_fin)
+        stmfd   sp!, {lr}
+        mov     ip, #PSR_F_BIT | PSR_I_BIT | SVC_MODE
+        msr     cpsr_c, ip
+        bl      feroceon_flush_kern_cache_all
+        mrc     p15, 0, r0, c1, c0, 0           @ ctrl register
+        bic     r0, r0, #0x1000                 @ ...i............
+        bic     r0, r0, #0x000e                 @ ............wca.
+        mcr     p15, 0, r0, c1, c0, 0           @ disable caches
+        ldmfd   sp!, {pc}
+
+/*
+ * cpu_feroceon_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
+ENTRY(cpu_feroceon_reset)
+        mov     ip, #0
+        mcr     p15, 0, ip, c7, c7, 0           @ invalidate I,D caches
+        mcr     p15, 0, ip, c7, c10, 4          @ drain WB
+#ifdef CONFIG_MMU
+        mcr     p15, 0, ip, c8, c7, 0           @ invalidate I & D TLBs
+#endif
+        mrc     p15, 0, ip, c1, c0, 0           @ ctrl register
+        bic     ip, ip, #0x000f                 @ ............wcam
+        bic     ip, ip, #0x1100                 @ ...i...s........
+        mcr     p15, 0, ip, c1, c0, 0           @ ctrl register
+        mov     pc, r0
+
+/*
+ * cpu_feroceon_do_idle()
+ *
+ * Called with IRQs disabled
+ */
+        .align  10
+ENTRY(cpu_feroceon_do_idle)
+        mov     r0, #0
+        mcr     p15, 0, r0, c7, c10, 4          @ Drain write buffer
+        mcr     p15, 0, r0, c7, c0, 4           @ Wait for interrupt
+        mov     pc, lr
+
+/*
+ *      flush_user_cache_all()
+ *
+ *      Clean and invalidate all cache entries in a particular
+ *      address space.
+ */
+ENTRY(feroceon_flush_user_cache_all)
+        /* FALLTHROUGH */
+
+/*
+ *      flush_kern_cache_all()
+ *
+ *      Clean and invalidate the entire cache.
+ */
+ENTRY(feroceon_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           @ invalidate D cache
+#else
+1:      mrc     p15, 0, r15, c7, c14, 3         @ test,clean,invalidate
+        bne     1b
+#endif
+        tst     r2, #VM_EXEC
+        mcrne   p15, 0, ip, c7, c5, 0           @ invalidate 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
+ */
+ENTRY(feroceon_flush_user_cache_range)
+        mov     ip, #0
+        sub     r3, r1, r0                      @ calculate total size
+        cmp     r3, #CACHE_DLIMIT
+        bgt     __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(feroceon_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(feroceon_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
+ */
+ENTRY(feroceon_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 v4wb)
+ */
+ENTRY(feroceon_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 v4wb)
+ */
+ENTRY(feroceon_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
+ */
+ENTRY(feroceon_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(feroceon_cache_fns)
+        .long   feroceon_flush_kern_cache_all
+        .long   feroceon_flush_user_cache_all
+        .long   feroceon_flush_user_cache_range
+        .long   feroceon_coherent_kern_range
+        .long   feroceon_coherent_user_range
+        .long   feroceon_flush_kern_dcache_page
+        .long   feroceon_dma_inv_range
+        .long   feroceon_dma_clean_range
+        .long   feroceon_dma_flush_range
+
+ENTRY(cpu_feroceon_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
+
+/* =============================== PageTable ============================== */
+
+/*
+ * cpu_feroceon_switch_mm(pgd)
+ *
+ * Set the translation base pointer to be as described by pgd.
+ *
+ * pgd: new page tables
+ */
+        .align  5
+ENTRY(cpu_feroceon_switch_mm)
+#ifdef CONFIG_MMU
+        mov     ip, #0
+#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
+        mcr     p15, 0, ip, c7, c6, 0           @ invalidate D cache
+#else
+@ && 'Clean & Invalidate whole DCache'
+1:      mrc     p15, 0, r15, c7, c14, 3         @ test,clean,invalidate
+        bne     1b
+#endif
+        mcr     p15, 0, ip, c7, c5, 0           @ invalidate I cache
+        mcr     p15, 0, ip, c7, c10, 4          @ drain WB
+        mcr     p15, 0, r0, c2, c0, 0           @ load page table pointer
+        mcr     p15, 0, ip, c8, c7, 0           @ invalidate I & D TLBs
+#endif
+        mov     pc, lr
+
+/*
+ * cpu_feroceon_set_pte_ext(ptep, pte, ext)
+ *
+ * Set a PTE and flush it out
+ */
+        .align  5
+ENTRY(cpu_feroceon_set_pte_ext)
+#ifdef CONFIG_MMU
+        str     r1, [r0], #-2048                @ linux version
+
+        eor     r1, r1, #L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_WRITE | L_PTE_DIRTY
+
+        bic     r2, r1, #PTE_SMALL_AP_MASK
+        bic     r2, r2, #PTE_TYPE_MASK
+        orr     r2, r2, #PTE_TYPE_SMALL
+
+        tst     r1, #L_PTE_USER                 @ User?
+        orrne   r2, r2, #PTE_SMALL_AP_URO_SRW
+
+        tst     r1, #L_PTE_WRITE | L_PTE_DIRTY  @ Write and Dirty?
+        orreq   r2, r2, #PTE_SMALL_AP_UNO_SRW
+
+        tst     r1, #L_PTE_PRESENT | L_PTE_YOUNG        @ Present and Young?
+        movne   r2, #0
+
+#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
+        eor     r3, r2, #0x0a                   @ C & small page?
+        tst     r3, #0x0b
+        biceq   r2, r2, #4
+#endif
+        str     r2, [r0]                        @ hardware version
+        mov     r0, r0
+#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
+        mcr     p15, 0, r0, c7, c10, 1          @ clean D entry
+#endif
+        mcr     p15, 0, r0, c7, c10, 4          @ drain WB
+#endif
+        mov     pc, lr
+
+        __INIT
+
+        .type   __feroceon_setup, #function
+__feroceon_setup:
+        mov     r0, #0
+        mcr     p15, 0, r0, c7, c7              @ invalidate I,D caches on v4
+        mcr     p15, 0, r0, c7, c10, 4          @ drain write buffer on v4
+#ifdef CONFIG_MMU
+        mcr     p15, 0, r0, c8, c7              @ invalidate I,D TLBs on v4
+#endif
+
+
+#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
+        mov     r0, #4                          @ disable write-back on caches explicitly
+        mcr     p15, 7, r0, c15, c0, 0
+#endif
+
+        adr     r5, feroceon_crval
+        ldmia   r5, {r5, r6}
+        mrc     p15, 0, r0, c1, c0              @ get control register v4
+        bic     r0, r0, r5
+        orr     r0, r0, r6
+#ifdef CONFIG_CPU_CACHE_ROUND_ROBIN
+        orr     r0, r0, #0x4000                 @ .1.. .... .... ....
+#endif
+        mov     pc, lr
+        .size   __feroceon_setup, . - __feroceon_setup
+
+        /*
+         *  R
+         * .RVI ZFRS BLDP WCAM
+         * .011 0001 ..11 0101
+         *
+         */
+        .type   feroceon_crval, #object
+feroceon_crval:
+        crval   clear=0x00007f3f, mmuset=0x00003135, ucset=0x00001134
+
+        __INITDATA
+
+/*
+ * Purpose : Function pointers used to access above functions - all calls
+ *           come through these
+ */
+        .type   feroceon_processor_functions, #object
+feroceon_processor_functions:
+        .word   v5t_early_abort
+        .word   cpu_feroceon_proc_init
+        .word   cpu_feroceon_proc_fin
+        .word   cpu_feroceon_reset
+        .word   cpu_feroceon_do_idle
+        .word   cpu_feroceon_dcache_clean_area
+        .word   cpu_feroceon_switch_mm
+        .word   cpu_feroceon_set_pte_ext
+        .size   feroceon_processor_functions, . - feroceon_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  "v5"
+        .size   cpu_elf_name, . - cpu_elf_name
+
+        .type   cpu_feroceon_name, #object
+cpu_feroceon_name:
+        .asciz  "Feroceon"
+        .size   cpu_feroceon_name, . - cpu_feroceon_name
+
+        .align
+
+        .section ".proc.info.init", #alloc, #execinstr
+
+        .type   __feroceon_proc_info,#object
+__feroceon_proc_info:
+        .long   0x56055310
+        .long   0xfffffff0
+        .long   PMD_TYPE_SECT | \
+                PMD_SECT_BUFFERABLE | \
+                PMD_SECT_CACHEABLE | \
+                PMD_BIT4 | \
+                PMD_SECT_AP_WRITE | \
+                PMD_SECT_AP_READ
+        .long   PMD_TYPE_SECT | \
+                PMD_BIT4 | \
+                PMD_SECT_AP_WRITE | \
+                PMD_SECT_AP_READ
+        b       __feroceon_setup
+        .long   cpu_arch_name
+        .long   cpu_elf_name
+        .long   HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP
+        .long   cpu_feroceon_name
+        .long   feroceon_processor_functions
+        .long   v4wbi_tlb_fns
+        .long   v4wb_user_fns
+        .long   feroceon_cache_fns
+        .size   __feroceon_proc_info, . - __feroceon_proc_info