Commit 3e4d3af5 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Linus Torvalds
Browse files

mm: stack based kmap_atomic() 



Keep the current interface but ignore the KM_type and use a stack based
approach.

The advantage is that we get rid of crappy code like:

	#define __KM_PTE			\
		(in_nmi() ? KM_NMI_PTE : 	\
		 in_irq() ? KM_IRQ_PTE :	\
		 KM_PTE0)

and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.

The downside is that FRV kmap_atomic() gets more expensive.

For now we use a CPP trick suggested by Andrew:

  #define kmap_atomic(page, args...) __kmap_atomic(page)

to avoid having to touch all kmap_atomic() users in a single patch.

[ not compiled on:
  - mn10300: the arch doesn't actually build with highmem to begin with ]

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: default avatarRik van Riel <riel@redhat.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: default avatarChris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 61ecdb80

arch/arm/include/asm/highmem.h

+3 −3
Original line number Diff line number Diff line
@@ -35,9 +35,9 @@ extern void kunmap_high_l1_vipt(struct page *page, pte_t saved_pte); 
#ifdef CONFIG_HIGHMEM

extern void *kmap(struct page *page);

extern void kunmap(struct page *page);

extern void *kmap_atomic(struct page *page, enum km_type type);

extern void kunmap_atomic_notypecheck(void *kvaddr, enum km_type type);

extern void *kmap_atomic_pfn(unsigned long pfn, enum km_type type);

extern void *__kmap_atomic(struct page *page);

extern void __kunmap_atomic(void *kvaddr);

extern void *kmap_atomic_pfn(unsigned long pfn);

extern struct page *kmap_atomic_to_page(const void *ptr);

#endif

arch/arm/mm/highmem.c

+14 −9
Original line number Diff line number Diff line
@@ -36,18 +36,17 @@ void kunmap(struct page *page) 
}

EXPORT_SYMBOL(kunmap);



void *kmap_atomic(struct page *page, enum km_type type)

void *__kmap_atomic(struct page *page)

{

	unsigned int idx;

	unsigned long vaddr;

	void *kmap;

	int type;



	pagefault_disable();

	if (!PageHighMem(page))

		return page_address(page);



	debug_kmap_atomic(type);



#ifdef CONFIG_DEBUG_HIGHMEM

	/*

	 * There is no cache coherency issue when non VIVT, so force the
@@ -61,6 +60,8 @@ void *kmap_atomic(struct page *page, enum km_type type) 
	if (kmap)

		return kmap;



	type = kmap_atomic_idx_push();



	idx = type + KM_TYPE_NR * smp_processor_id();

	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);

#ifdef CONFIG_DEBUG_HIGHMEM
@@ -80,14 +81,17 @@ void *kmap_atomic(struct page *page, enum km_type type) 


	return (void *)vaddr;

}

EXPORT_SYMBOL(kmap_atomic);

EXPORT_SYMBOL(__kmap_atomic);



void kunmap_atomic_notypecheck(void *kvaddr, enum km_type type)

void __kunmap_atomic(void *kvaddr)

{

	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;

	unsigned int idx = type + KM_TYPE_NR * smp_processor_id();

	int idx, type;



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

		type = kmap_atomic_idx_pop();

		idx = type + KM_TYPE_NR * smp_processor_id();



		if (cache_is_vivt())

			__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);

#ifdef CONFIG_DEBUG_HIGHMEM
@@ -103,15 +107,16 @@ void kunmap_atomic_notypecheck(void *kvaddr, enum km_type type) 
	}

	pagefault_enable();

}

EXPORT_SYMBOL(kunmap_atomic_notypecheck);

EXPORT_SYMBOL(__kunmap_atomic);



void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)

void *kmap_atomic_pfn(unsigned long pfn)

{

	unsigned int idx;

	unsigned long vaddr;

	int idx, type;



	pagefault_disable();



	type = kmap_atomic_idx_push();

	idx = type + KM_TYPE_NR * smp_processor_id();

	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);

#ifdef CONFIG_DEBUG_HIGHMEM

arch/frv/include/asm/highmem.h

+5 −20
Original line number Diff line number Diff line
@@ -112,12 +112,11 @@ extern struct page *kmap_atomic_to_page(void *ptr); 
	(void *) damlr;										  \

})



static inline void *kmap_atomic(struct page *page, enum km_type type)

static inline void *kmap_atomic_primary(struct page *page, enum km_type type)

{

	unsigned long paddr;



	pagefault_disable();

	debug_kmap_atomic(type);

	paddr = page_to_phys(page);



	switch (type) {
@@ -125,14 +124,6 @@ static inline void *kmap_atomic(struct page *page, enum km_type type) 
        case 1:		return __kmap_atomic_primary(1, paddr, 3);

        case 2:		return __kmap_atomic_primary(2, paddr, 4);

        case 3:		return __kmap_atomic_primary(3, paddr, 5);

        case 4:		return __kmap_atomic_primary(4, paddr, 6);

        case 5:		return __kmap_atomic_primary(5, paddr, 7);

        case 6:		return __kmap_atomic_primary(6, paddr, 8);

        case 7:		return __kmap_atomic_primary(7, paddr, 9);

        case 8:		return __kmap_atomic_primary(8, paddr, 10);



	case 9 ... 9 + NR_TLB_LINES - 1:

		return __kmap_atomic_secondary(type - 9, paddr);



	default:

		BUG();
@@ -152,22 +143,13 @@ do { \ 
	asm volatile("tlbpr %0,gr0,#4,#1" : : "r"(vaddr) : "memory");	\

} while(0)



static inline void kunmap_atomic_notypecheck(void *kvaddr, enum km_type type)

static inline void kunmap_atomic_primary(void *kvaddr, enum km_type type)

{

	switch (type) {

        case 0:		__kunmap_atomic_primary(0, 2);	break;

        case 1:		__kunmap_atomic_primary(1, 3);	break;

        case 2:		__kunmap_atomic_primary(2, 4);	break;

        case 3:		__kunmap_atomic_primary(3, 5);	break;

        case 4:		__kunmap_atomic_primary(4, 6);	break;

        case 5:		__kunmap_atomic_primary(5, 7);	break;

        case 6:		__kunmap_atomic_primary(6, 8);	break;

        case 7:		__kunmap_atomic_primary(7, 9);	break;

        case 8:		__kunmap_atomic_primary(8, 10);	break;



	case 9 ... 9 + NR_TLB_LINES - 1:

		__kunmap_atomic_secondary(type - 9, kvaddr);

		break;



	default:

		BUG();
@@ -175,6 +157,9 @@ static inline void kunmap_atomic_notypecheck(void *kvaddr, enum km_type type) 
	pagefault_enable();

}



void *__kmap_atomic(struct page *page);

void __kunmap_atomic(void *kvaddr);



#endif /* !__ASSEMBLY__ */



#endif /* __KERNEL__ */

arch/frv/mb93090-mb00/pci-dma.c

+2 −2
Original line number Diff line number Diff line
@@ -61,14 +61,14 @@ int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, 
	dampr2 = __get_DAMPR(2);



	for (i = 0; i < nents; i++) {

		vaddr = kmap_atomic(sg_page(&sg[i]), __KM_CACHE);

		vaddr = kmap_atomic_primary(sg_page(&sg[i]), __KM_CACHE);



		frv_dcache_writeback((unsigned long) vaddr,

				     (unsigned long) vaddr + PAGE_SIZE);



	}



	kunmap_atomic(vaddr, __KM_CACHE);

	kunmap_atomic_primary(vaddr, __KM_CACHE);

	if (dampr2) {

		__set_DAMPR(2, dampr2);

		__set_IAMPR(2, dampr2);

arch/frv/mm/cache-page.c

+4 −4
Original line number Diff line number Diff line
@@ -26,11 +26,11 @@ void flush_dcache_page(struct page *page) 


	dampr2 = __get_DAMPR(2);



	vaddr = kmap_atomic(page, __KM_CACHE);

	vaddr = kmap_atomic_primary(page, __KM_CACHE);



	frv_dcache_writeback((unsigned long) vaddr, (unsigned long) vaddr + PAGE_SIZE);



	kunmap_atomic(vaddr, __KM_CACHE);

	kunmap_atomic_primary(vaddr, __KM_CACHE);



	if (dampr2) {

		__set_DAMPR(2, dampr2);
@@ -54,12 +54,12 @@ void flush_icache_user_range(struct vm_area_struct *vma, struct page *page, 


	dampr2 = __get_DAMPR(2);



	vaddr = kmap_atomic(page, __KM_CACHE);

	vaddr = kmap_atomic_primary(page, __KM_CACHE);



	start = (start & ~PAGE_MASK) | (unsigned long) vaddr;

	frv_cache_wback_inv(start, start + len);



	kunmap_atomic(vaddr, __KM_CACHE);

	kunmap_atomic_primary(vaddr, __KM_CACHE);



	if (dampr2) {

		__set_DAMPR(2, dampr2);

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