diff options
Diffstat (limited to 'arch/x86/mm/highmem_32.c')
| -rw-r--r-- | arch/x86/mm/highmem_32.c | 47 |
1 files changed, 46 insertions, 1 deletions
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c index 1c3bf95f735..3d936f23270 100644 --- a/arch/x86/mm/highmem_32.c +++ b/arch/x86/mm/highmem_32.c @@ -18,6 +18,49 @@ 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 @@ -30,8 +73,10 @@ void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot) { enum fixed_addresses idx; unsigned long vaddr; - /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ + + debug_kmap_atomic_prot(type); + pagefault_disable(); if (!PageHighMem(page)) |