Commit 629ed3f7 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

xtensa/mm/highmem: Switch to generic kmap atomic 



No reason having the same code in every architecture

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20201103095858.311016780@linutronix.de
parent 3293efa9

arch/xtensa/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -666,6 +666,7 @@ endchoice 
config HIGHMEM

	bool "High Memory Support"

	depends on MMU

	select KMAP_LOCAL

	help

	  Linux can use the full amount of RAM in the system by

	  default. However, the default MMUv2 setup only maps the

arch/xtensa/include/asm/fixmap.h

+2 −2
Original line number Diff line number Diff line
@@ -16,7 +16,7 @@ 
#ifdef CONFIG_HIGHMEM

#include <linux/threads.h>

#include <linux/pgtable.h>

#include <asm/kmap_types.h>

#include <asm/kmap_size.h>

#endif



/*
@@ -39,7 +39,7 @@ enum fixed_addresses { 
	/* reserved pte's for temporary kernel mappings */

	FIX_KMAP_BEGIN,

	FIX_KMAP_END = FIX_KMAP_BEGIN +

		(KM_TYPE_NR * NR_CPUS * DCACHE_N_COLORS) - 1,

		(KM_MAX_IDX * NR_CPUS * DCACHE_N_COLORS) - 1,

#endif

	__end_of_fixed_addresses

};

arch/xtensa/include/asm/highmem.h

+10 −2
Original line number Diff line number Diff line
@@ -16,7 +16,6 @@ 
#include <linux/pgtable.h>

#include <asm/cacheflush.h>

#include <asm/fixmap.h>

#include <asm/kmap_types.h>



#define PKMAP_BASE		((FIXADDR_START -			\

				  (LAST_PKMAP + 1) * PAGE_SIZE) & PMD_MASK)
@@ -68,6 +67,15 @@ static inline void flush_cache_kmaps(void) 
	flush_cache_all();

}



enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn);

#define arch_kmap_local_map_idx		kmap_local_map_idx



enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr);

#define arch_kmap_local_unmap_idx	kmap_local_unmap_idx



#define arch_kmap_local_post_unmap(vaddr)	\

	local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE)



void kmap_init(void);



#endif

arch/xtensa/mm/highmem.c

+5 −41
Original line number Diff line number Diff line
@@ -12,8 +12,6 @@ 
#include <linux/highmem.h>

#include <asm/tlbflush.h>



static pte_t *kmap_pte;



#if DCACHE_WAY_SIZE > PAGE_SIZE

unsigned int last_pkmap_nr_arr[DCACHE_N_COLORS];

wait_queue_head_t pkmap_map_wait_arr[DCACHE_N_COLORS];
@@ -33,59 +31,25 @@ static inline void kmap_waitqueues_init(void) 


static inline enum fixed_addresses kmap_idx(int type, unsigned long color)

{

	return (type + KM_TYPE_NR * smp_processor_id()) * DCACHE_N_COLORS +

	return (type + KM_MAX_IDX * smp_processor_id()) * DCACHE_N_COLORS +

		color;

}



void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)

enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn)

{

	enum fixed_addresses idx;

	unsigned long vaddr;



	idx = kmap_idx(kmap_atomic_idx_push(),

		       DCACHE_ALIAS(page_to_phys(page)));

	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);

#ifdef CONFIG_DEBUG_HIGHMEM

	BUG_ON(!pte_none(*(kmap_pte + idx)));

#endif

	set_pte(kmap_pte + idx, mk_pte(page, prot));



	return (void *)vaddr;

	return kmap_idx(type, DCACHE_ALIAS(pfn << PAGE_SHIFT));

}

EXPORT_SYMBOL(kmap_atomic_high_prot);



void kunmap_atomic_high(void *kvaddr)

enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr)

{

	if (kvaddr >= (void *)FIXADDR_START &&

	    kvaddr < (void *)FIXADDR_TOP) {

		int idx = kmap_idx(kmap_atomic_idx(),

				   DCACHE_ALIAS((unsigned long)kvaddr));



		/*

		 * Force other mappings to Oops if they'll try to access this

		 * pte without first remap it.  Keeping stale mappings around

		 * is a bad idea also, in case the page changes cacheability

		 * attributes or becomes a protected page in a hypervisor.

		 */

		pte_clear(&init_mm, kvaddr, kmap_pte + idx);

		local_flush_tlb_kernel_range((unsigned long)kvaddr,

					     (unsigned long)kvaddr + PAGE_SIZE);



		kmap_atomic_idx_pop();

	return kmap_idx(type, DCACHE_ALIAS(addr));

}

}

EXPORT_SYMBOL(kunmap_atomic_high);



void __init kmap_init(void)

{

	unsigned long kmap_vstart;



	/* Check if this memory layout is broken because PKMAP overlaps

	 * page table.

	 */

	BUILD_BUG_ON(PKMAP_BASE < TLBTEMP_BASE_1 + TLBTEMP_SIZE);

	/* cache the first kmap pte */

	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);

	kmap_pte = virt_to_kpte(kmap_vstart);

	kmap_waitqueues_init();

}