Commit f4112de6 authored by Akinobu Mita's avatar Akinobu Mita Committed by Linus Torvalds
Browse files

mm: introduce debug_kmap_atomic



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: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 851a039c
......@@ -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
......@@ -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);
......
......@@ -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 */
......@@ -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
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