The mapping code is odd and looks broken. See FIXME in the comment.
Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Nick Hu nickhu@andestech.com Cc: Greentime Hu green.hu@gmail.com Cc: Vincent Chen deanbo422@gmail.com --- Note: Completely untested --- arch/nds32/Kconfig.cpu | 1 arch/nds32/include/asm/highmem.h | 21 +++++++++++++---- arch/nds32/mm/Makefile | 1 arch/nds32/mm/highmem.c | 48 --------------------------------------- 4 files changed, 17 insertions(+), 54 deletions(-)
--- a/arch/nds32/Kconfig.cpu +++ b/arch/nds32/Kconfig.cpu @@ -157,6 +157,7 @@ config HW_SUPPORT_UNALIGNMENT_ACCESS config HIGHMEM bool "High Memory Support" depends on MMU && !CPU_CACHE_ALIASING + select KMAP_ATOMIC_GENERIC help The address space of Andes processors is only 4 Gigabytes large and it has to accommodate user address space, kernel address --- a/arch/nds32/include/asm/highmem.h +++ b/arch/nds32/include/asm/highmem.h @@ -45,11 +45,22 @@ extern pte_t *pkmap_page_table; extern void kmap_init(void);
/* - * The following functions are already defined by <linux/highmem.h> - * when CONFIG_HIGHMEM is not set. + * FIXME: The below looks broken vs. a kmap_atomic() in task context which + * is interupted and another kmap_atomic() happens in interrupt context. + * But what do I know about nds32. -- tglx */ -#ifdef CONFIG_HIGHMEM -extern void *kmap_atomic_pfn(unsigned long pfn); -#endif +#define arch_kmap_temp_post_map(vaddr, pteval) \ + do { \ + __nds32__tlbop_inv(vaddr); \ + __nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN); \ + __nds32__tlbop_rwr(pteval); \ + __nds32__isb(); \ + } while (0) + +#define arch_kmap_temp_pre_unmap(vaddr, pte) \ + do { \ + __nds32__tlbop_inv(vaddr); \ + __nds32__isb(); \ + } while (0)
#endif --- a/arch/nds32/mm/Makefile +++ b/arch/nds32/mm/Makefile @@ -3,7 +3,6 @@ obj-y := extable.o tlb.o fault.o init mm-nds32.o cacheflush.o proc.o
obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o -obj-$(CONFIG_HIGHMEM) += highmem.o
ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_proc.o = $(CC_FLAGS_FTRACE) --- a/arch/nds32/mm/highmem.c +++ /dev/null @@ -1,48 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -// Copyright (C) 2005-2017 Andes Technology Corporation - -#include <linux/export.h> -#include <linux/highmem.h> -#include <linux/sched.h> -#include <linux/smp.h> -#include <linux/interrupt.h> -#include <linux/memblock.h> -#include <asm/fixmap.h> -#include <asm/tlbflush.h> - -void *kmap_atomic_high_prot(struct page *page, pgprot_t prot) -{ - unsigned int idx; - unsigned long vaddr, pte; - int type; - pte_t *ptep; - - type = kmap_atomic_idx_push(); - - idx = type + KM_TYPE_NR * smp_processor_id(); - vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); - pte = (page_to_pfn(page) << PAGE_SHIFT) | prot; - ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr); - set_pte(ptep, pte); - - __nds32__tlbop_inv(vaddr); - __nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN); - __nds32__tlbop_rwr(pte); - __nds32__isb(); - return (void *)vaddr; -} -EXPORT_SYMBOL(kmap_atomic_high_prot); - -void kunmap_atomic_high(void *kvaddr) -{ - if (kvaddr >= (void *)FIXADDR_START) { - unsigned long vaddr = (unsigned long)kvaddr; - pte_t *ptep; - kmap_atomic_idx_pop(); - __nds32__tlbop_inv(vaddr); - __nds32__isb(); - ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr); - set_pte(ptep, 0); - } -} -EXPORT_SYMBOL(kunmap_atomic_high);