linux/arch/arm/mm/proc-feroceon.S
Ard Biesheuvel 4a0548c668 ARM: vfp: Remove workaround for Feroceon CPUs
Feroceon CPUs have a non-standard implementation of VFP which reports
synchronous VFP exceptions using the async VFP flag. This requires a
workaround which is difficult to reconcile with other implementations,
making it tricky to support both versions in a single image.

Since this is a v5 CPU, it is not supported by armhf and so the
likelihood that anybody is using this with recent distros/kernels and
rely on the VFP at the same time is extremely low. So let's just disable
VFP support on these cores, so we can remove the workaround.

This will help future development to support v5 and v6 CPUs with a
single kernel image.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-05-17 13:11:38 +02:00

618 lines
16 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* linux/arch/arm/mm/proc-feroceon.S: MMU functions for Feroceon
*
* Heavily based on proc-arm926.S
* Maintainer: Assaf Hoffman <hoffman@marvell.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/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
.bss
.align 3
__cache_params_loc:
.space 8
.text
__cache_params:
.word __cache_params_loc
/*
* cpu_feroceon_proc_init()
*/
ENTRY(cpu_feroceon_proc_init)
mrc p15, 0, r0, c0, c0, 1 @ read cache type register
ldr r1, __cache_params
mov r2, #(16 << 5)
tst r0, #(1 << 16) @ get way
mov r0, r0, lsr #18 @ get cache size order
movne r3, #((4 - 1) << 30) @ 4-way
and r0, r0, #0xf
moveq r3, #0 @ 1-way
mov r2, r2, lsl r0 @ actual cache size
movne r2, r2, lsr #2 @ turned into # of sets
sub r2, r2, #(1 << 5)
stmia r1, {r2, r3}
#ifdef CONFIG_VFP
mov r1, #1 @ disable quirky VFP
str_l r1, VFP_arch_feroceon, r2
#endif
ret lr
/*
* cpu_feroceon_proc_fin()
*/
ENTRY(cpu_feroceon_proc_fin)
#if defined(CONFIG_CACHE_FEROCEON_L2) && \
!defined(CONFIG_CACHE_FEROCEON_L2_WRITETHROUGH)
mov r0, #0
mcr p15, 1, r0, c15, c9, 0 @ clean L2
mcr p15, 0, r0, c7, c10, 4 @ drain WB
#endif
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
ret lr
/*
* 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
.pushsection .idmap.text, "ax"
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
ret r0
ENDPROC(cpu_feroceon_reset)
.popsection
/*
* cpu_feroceon_do_idle()
*
* Called with IRQs disabled
*/
.align 5
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
ret lr
/*
* flush_icache_all()
*
* Unconditionally clean and invalidate the entire icache.
*/
ENTRY(feroceon_flush_icache_all)
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
ret lr
ENDPROC(feroceon_flush_icache_all)
/*
* flush_user_cache_all()
*
* Clean and invalidate all cache entries in a particular
* address space.
*/
.align 5
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
__flush_whole_cache:
ldr r1, __cache_params
ldmia r1, {r1, r3}
1: orr ip, r1, r3
2: mcr p15, 0, ip, c7, c14, 2 @ clean + invalidate D set/way
subs ip, ip, #(1 << 30) @ next way
bcs 2b
subs r1, r1, #(1 << 5) @ next set
bcs 1b
tst r2, #VM_EXEC
mov ip, #0
mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcrne p15, 0, ip, c7, c10, 4 @ drain WB
ret 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
*/
.align 5
ENTRY(feroceon_flush_user_cache_range)
sub r3, r1, r0 @ calculate total size
cmp r3, #CACHE_DLIMIT
bgt __flush_whole_cache
1: tst r2, #VM_EXEC
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
cmp r0, r1
blo 1b
tst r2, #VM_EXEC
mov ip, #0
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
*/
.align 5
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 r0, #0
ret lr
/*
* 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
*/
.align 5
ENTRY(feroceon_flush_kern_dcache_area)
add r1, r0, r1
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
ret lr
.align 5
ENTRY(feroceon_range_flush_kern_dcache_area)
mrs r2, cpsr
add r1, r0, #PAGE_SZ - CACHE_DLINESIZE @ top addr is inclusive
orr r3, r2, #PSR_I_BIT
msr cpsr_c, r3 @ disable interrupts
mcr p15, 5, r0, c15, c15, 0 @ D clean/inv range start
mcr p15, 5, r1, c15, c15, 1 @ D clean/inv range top
msr cpsr_c, r2 @ restore interrupts
mov r0, #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)
*
* 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)
*/
.align 5
feroceon_dma_inv_range:
tst r0, #CACHE_DLINESIZE - 1
bic r0, 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
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
ret lr
.align 5
feroceon_range_dma_inv_range:
mrs r2, cpsr
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
cmp r1, r0
subne r1, r1, #1 @ top address is inclusive
orr r3, r2, #PSR_I_BIT
msr cpsr_c, r3 @ disable interrupts
mcr p15, 5, r0, c15, c14, 0 @ D inv range start
mcr p15, 5, r1, c15, c14, 1 @ D inv range top
msr cpsr_c, r2 @ restore interrupts
ret lr
/*
* dma_clean_range(start, end)
*
* Clean the specified virtual address range.
*
* - start - virtual start address
* - end - virtual end address
*
* (same as v4wb)
*/
.align 5
feroceon_dma_clean_range:
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
mcr p15, 0, r0, c7, c10, 4 @ drain WB
ret lr
.align 5
feroceon_range_dma_clean_range:
mrs r2, cpsr
cmp r1, r0
subne r1, r1, #1 @ top address is inclusive
orr r3, r2, #PSR_I_BIT
msr cpsr_c, r3 @ disable interrupts
mcr p15, 5, r0, c15, c13, 0 @ D clean range start
mcr p15, 5, r1, c15, c13, 1 @ D clean range top
msr cpsr_c, r2 @ restore interrupts
mcr p15, 0, r0, c7, c10, 4 @ drain WB
ret lr
/*
* dma_flush_range(start, end)
*
* Clean and invalidate the specified virtual address range.
*
* - start - virtual start address
* - end - virtual end address
*/
.align 5
ENTRY(feroceon_dma_flush_range)
bic r0, r0, #CACHE_DLINESIZE - 1
1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
ret lr
.align 5
ENTRY(feroceon_range_dma_flush_range)
mrs r2, cpsr
cmp r1, r0
subne r1, r1, #1 @ top address is inclusive
orr r3, r2, #PSR_I_BIT
msr cpsr_c, r3 @ disable interrupts
mcr p15, 5, r0, c15, c15, 0 @ D clean/inv range start
mcr p15, 5, r1, c15, c15, 1 @ D clean/inv range top
msr cpsr_c, r2 @ restore interrupts
mcr p15, 0, r0, 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(feroceon_dma_map_area)
add r1, r1, r0
cmp r2, #DMA_TO_DEVICE
beq feroceon_dma_clean_range
bcs feroceon_dma_inv_range
b feroceon_dma_flush_range
ENDPROC(feroceon_dma_map_area)
/*
* dma_map_area(start, size, dir)
* - start - kernel virtual start address
* - size - size of region
* - dir - DMA direction
*/
ENTRY(feroceon_range_dma_map_area)
add r1, r1, r0
cmp r2, #DMA_TO_DEVICE
beq feroceon_range_dma_clean_range
bcs feroceon_range_dma_inv_range
b feroceon_range_dma_flush_range
ENDPROC(feroceon_range_dma_map_area)
/*
* dma_unmap_area(start, size, dir)
* - start - kernel virtual start address
* - size - size of region
* - dir - DMA direction
*/
ENTRY(feroceon_dma_unmap_area)
ret lr
ENDPROC(feroceon_dma_unmap_area)
.globl feroceon_flush_kern_cache_louis
.equ feroceon_flush_kern_cache_louis, feroceon_flush_kern_cache_all
@ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
define_cache_functions feroceon
.macro range_alias basename
.globl feroceon_range_\basename
.type feroceon_range_\basename , %function
.equ feroceon_range_\basename , feroceon_\basename
.endm
/*
* Most of the cache functions are unchanged for this case.
* Export suitable alias symbols for the unchanged functions:
*/
range_alias flush_icache_all
range_alias flush_user_cache_all
range_alias flush_kern_cache_all
range_alias flush_kern_cache_louis
range_alias flush_user_cache_range
range_alias coherent_kern_range
range_alias coherent_user_range
range_alias dma_unmap_area
define_cache_functions feroceon_range
.align 5
ENTRY(cpu_feroceon_dcache_clean_area)
#if defined(CONFIG_CACHE_FEROCEON_L2) && \
!defined(CONFIG_CACHE_FEROCEON_L2_WRITETHROUGH)
mov r2, r0
mov r3, r1
#endif
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
add r0, r0, #CACHE_DLINESIZE
subs r1, r1, #CACHE_DLINESIZE
bhi 1b
#if defined(CONFIG_CACHE_FEROCEON_L2) && \
!defined(CONFIG_CACHE_FEROCEON_L2_WRITETHROUGH)
1: mcr p15, 1, r2, c15, c9, 1 @ clean L2 entry
add r2, r2, #CACHE_DLINESIZE
subs r3, r3, #CACHE_DLINESIZE
bhi 1b
#endif
mcr p15, 0, r0, c7, c10, 4 @ drain WB
ret 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
/*
* Note: we wish to call __flush_whole_cache but we need to preserve
* lr to do so. The only way without touching main memory is to
* use r2 which is normally used to test the VM_EXEC flag, and
* compensate locally for the skipped ops if it is not set.
*/
mov r2, lr @ abuse r2 to preserve lr
bl __flush_whole_cache
@ if r2 contains the VM_EXEC bit then the next 2 ops are done already
tst r2, #VM_EXEC
mcreq p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcreq 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
ret r2
#else
ret lr
#endif
/*
* 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
armv3_set_pte_ext wc_disable=0
mov r0, r0
mcr p15, 0, r0, c7, c10, 1 @ clean D entry
#if defined(CONFIG_CACHE_FEROCEON_L2) && \
!defined(CONFIG_CACHE_FEROCEON_L2_WRITETHROUGH)
mcr p15, 1, r0, c15, c9, 1 @ clean L2 entry
#endif
mcr p15, 0, r0, c7, c10, 4 @ drain WB
#endif
ret lr
/* Suspend/resume support: taken from arch/arm/mm/proc-arm926.S */
.globl cpu_feroceon_suspend_size
.equ cpu_feroceon_suspend_size, 4 * 3
#ifdef CONFIG_ARM_CPU_SUSPEND
ENTRY(cpu_feroceon_do_suspend)
stmfd sp!, {r4 - r6, lr}
mrc p15, 0, r4, c13, c0, 0 @ PID
mrc p15, 0, r5, c3, c0, 0 @ Domain ID
mrc p15, 0, r6, c1, c0, 0 @ Control register
stmia r0, {r4 - r6}
ldmfd sp!, {r4 - r6, pc}
ENDPROC(cpu_feroceon_do_suspend)
ENTRY(cpu_feroceon_do_resume)
mov ip, #0
mcr p15, 0, ip, c8, c7, 0 @ invalidate I+D TLBs
mcr p15, 0, ip, c7, c7, 0 @ invalidate I+D caches
ldmia r0, {r4 - r6}
mcr p15, 0, r4, c13, c0, 0 @ PID
mcr p15, 0, r5, c3, c0, 0 @ Domain ID
mcr p15, 0, r1, c2, c0, 0 @ TTB address
mov r0, r6 @ control register
b cpu_resume_mmu
ENDPROC(cpu_feroceon_do_resume)
#endif
.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
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
ret lr
.size __feroceon_setup, . - __feroceon_setup
/*
* B
* R P
* .RVI UFRS BLDP WCAM
* .011 .001 ..11 0101
*
*/
.type feroceon_crval, #object
feroceon_crval:
crval clear=0x0000773f, mmuset=0x00003135, ucset=0x00001134
__INITDATA
@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
define_processor_functions feroceon, dabort=v5t_early_abort, pabort=legacy_pabort
.section ".rodata"
string cpu_arch_name, "armv5te"
string cpu_elf_name, "v5"
string cpu_feroceon_name, "Feroceon"
string cpu_88fr531_name, "Feroceon 88FR531-vd"
string cpu_88fr571_name, "Feroceon 88FR571-vd"
string cpu_88fr131_name, "Feroceon 88FR131"
.align
.section ".proc.info.init", "a"
.macro feroceon_proc_info name:req, cpu_val:req, cpu_mask:req, cpu_name:req, cache:req
.type __\name\()_proc_info,#object
__\name\()_proc_info:
.long \cpu_val
.long \cpu_mask
.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
initfn __feroceon_setup, __\name\()_proc_info
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP
.long \cpu_name
.long feroceon_processor_functions
.long v4wbi_tlb_fns
.long feroceon_user_fns
.long \cache
.size __\name\()_proc_info, . - __\name\()_proc_info
.endm
#ifdef CONFIG_CPU_FEROCEON_OLD_ID
feroceon_proc_info feroceon_old_id, 0x41009260, 0xff00fff0, \
cpu_name=cpu_feroceon_name, cache=feroceon_cache_fns
#endif
feroceon_proc_info 88fr531, 0x56055310, 0xfffffff0, cpu_88fr531_name, \
cache=feroceon_cache_fns
feroceon_proc_info 88fr571, 0x56155710, 0xfffffff0, cpu_88fr571_name, \
cache=feroceon_range_cache_fns
feroceon_proc_info 88fr131, 0x56251310, 0xfffffff0, cpu_88fr131_name, \
cache=feroceon_range_cache_fns