Skip to content

Commit

Permalink
mm: introduce debug_kmap_atomic
Browse files Browse the repository at this point in the history
x86 has debug_kmap_atomic_prot() which is error checking function for
kmap_atomic.  It is usefull for the other architectures, although it needs
CONFIG_TRACE_IRQFLAGS_SUPPORT.

This patch exposes it to the other architectures.

Signed-off-by: Akinobu Mita <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
  • Loading branch information
mita authored and torvalds committed Apr 1, 2009
1 parent 851a039 commit f4112de
Show file tree
Hide file tree
Showing 3 changed files with 58 additions and 44 deletions.
45 changes: 1 addition & 44 deletions arch/x86/mm/highmem_32.c
Original file line number Diff line number Diff line change
Expand Up @@ -19,49 +19,6 @@ void kunmap(struct page *page)
kunmap_high(page);
}

static void debug_kmap_atomic_prot(enum km_type type)
{
#ifdef CONFIG_DEBUG_HIGHMEM
static unsigned warn_count = 10;

if (unlikely(warn_count == 0))
return;

if (unlikely(in_interrupt())) {
if (in_irq()) {
if (type != KM_IRQ0 && type != KM_IRQ1 &&
type != KM_BIO_SRC_IRQ && type != KM_BIO_DST_IRQ &&
type != KM_BOUNCE_READ) {
WARN_ON(1);
warn_count--;
}
} else if (!irqs_disabled()) { /* softirq */
if (type != KM_IRQ0 && type != KM_IRQ1 &&
type != KM_SOFTIRQ0 && type != KM_SOFTIRQ1 &&
type != KM_SKB_SUNRPC_DATA &&
type != KM_SKB_DATA_SOFTIRQ &&
type != KM_BOUNCE_READ) {
WARN_ON(1);
warn_count--;
}
}
}

if (type == KM_IRQ0 || type == KM_IRQ1 || type == KM_BOUNCE_READ ||
type == KM_BIO_SRC_IRQ || type == KM_BIO_DST_IRQ) {
if (!irqs_disabled()) {
WARN_ON(1);
warn_count--;
}
} else if (type == KM_SOFTIRQ0 || type == KM_SOFTIRQ1) {
if (irq_count() == 0 && !irqs_disabled()) {
WARN_ON(1);
warn_count--;
}
}
#endif
}

/*
* kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
* no global lock is needed and because the kmap code must perform a global TLB
Expand All @@ -81,7 +38,7 @@ void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
if (!PageHighMem(page))
return page_address(page);

debug_kmap_atomic_prot(type);
debug_kmap_atomic(type);

idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
Expand Down
12 changes: 12 additions & 0 deletions include/linux/highmem.h
Original file line number Diff line number Diff line change
Expand Up @@ -187,4 +187,16 @@ static inline void copy_highpage(struct page *to, struct page *from)
kunmap_atomic(vto, KM_USER1);
}

#if defined(CONFIG_DEBUG_HIGHMEM) && defined(CONFIG_TRACE_IRQFLAGS_SUPPORT)

void debug_kmap_atomic(enum km_type type);

#else

static inline void debug_kmap_atomic(enum km_type type)
{
}

#endif

#endif /* _LINUX_HIGHMEM_H */
45 changes: 45 additions & 0 deletions mm/highmem.c
Original file line number Diff line number Diff line change
Expand Up @@ -422,3 +422,48 @@ void __init page_address_init(void)
}

#endif /* defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL) */

#if defined(CONFIG_DEBUG_HIGHMEM) && defined(CONFIG_TRACE_IRQFLAGS_SUPPORT)

void debug_kmap_atomic(enum km_type type)
{
static unsigned warn_count = 10;

if (unlikely(warn_count == 0))
return;

if (unlikely(in_interrupt())) {
if (in_irq()) {
if (type != KM_IRQ0 && type != KM_IRQ1 &&
type != KM_BIO_SRC_IRQ && type != KM_BIO_DST_IRQ &&
type != KM_BOUNCE_READ) {
WARN_ON(1);
warn_count--;
}
} else if (!irqs_disabled()) { /* softirq */
if (type != KM_IRQ0 && type != KM_IRQ1 &&
type != KM_SOFTIRQ0 && type != KM_SOFTIRQ1 &&
type != KM_SKB_SUNRPC_DATA &&
type != KM_SKB_DATA_SOFTIRQ &&
type != KM_BOUNCE_READ) {
WARN_ON(1);
warn_count--;
}
}
}

if (type == KM_IRQ0 || type == KM_IRQ1 || type == KM_BOUNCE_READ ||
type == KM_BIO_SRC_IRQ || type == KM_BIO_DST_IRQ) {
if (!irqs_disabled()) {
WARN_ON(1);
warn_count--;
}
} else if (type == KM_SOFTIRQ0 || type == KM_SOFTIRQ1) {
if (irq_count() == 0 && !irqs_disabled()) {
WARN_ON(1);
warn_count--;
}
}
}

#endif

0 comments on commit f4112de

Please sign in to comment.