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![Paul Gortmaker](/assets/img/avatar_default.png)
Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance for the presence of either and replace accordingly where needed. Note that some bool/obj-y instances remain since module.h is the header for some exception table entry stuff, and for things like __init_or_module (code that is tossed when MODULES=n). Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160714001901.31603-3-paul.gortmaker@windriver.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
133 lines
3.2 KiB
C
133 lines
3.2 KiB
C
#include <linux/highmem.h>
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#include <linux/export.h>
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#include <linux/swap.h> /* for totalram_pages */
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#include <linux/bootmem.h>
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void *kmap(struct page *page)
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{
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might_sleep();
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if (!PageHighMem(page))
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return page_address(page);
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return kmap_high(page);
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}
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EXPORT_SYMBOL(kmap);
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void kunmap(struct page *page)
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{
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if (in_interrupt())
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BUG();
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if (!PageHighMem(page))
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return;
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kunmap_high(page);
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}
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EXPORT_SYMBOL(kunmap);
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/*
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* kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
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* no global lock is needed and because the kmap code must perform a global TLB
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* invalidation when the kmap pool wraps.
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*
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* However when holding an atomic kmap it is not legal to sleep, so atomic
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* kmaps are appropriate for short, tight code paths only.
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*/
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void *kmap_atomic_prot(struct page *page, pgprot_t prot)
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{
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unsigned long vaddr;
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int idx, type;
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preempt_disable();
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pagefault_disable();
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if (!PageHighMem(page))
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return page_address(page);
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type = kmap_atomic_idx_push();
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idx = type + KM_TYPE_NR*smp_processor_id();
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vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
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BUG_ON(!pte_none(*(kmap_pte-idx)));
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set_pte(kmap_pte-idx, mk_pte(page, prot));
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arch_flush_lazy_mmu_mode();
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return (void *)vaddr;
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}
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EXPORT_SYMBOL(kmap_atomic_prot);
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void *kmap_atomic(struct page *page)
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{
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return kmap_atomic_prot(page, kmap_prot);
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}
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EXPORT_SYMBOL(kmap_atomic);
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/*
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* This is the same as kmap_atomic() but can map memory that doesn't
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* have a struct page associated with it.
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*/
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void *kmap_atomic_pfn(unsigned long pfn)
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{
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return kmap_atomic_prot_pfn(pfn, kmap_prot);
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}
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EXPORT_SYMBOL_GPL(kmap_atomic_pfn);
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void __kunmap_atomic(void *kvaddr)
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{
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unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
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if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
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vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
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int idx, type;
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type = kmap_atomic_idx();
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idx = type + KM_TYPE_NR * smp_processor_id();
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#ifdef CONFIG_DEBUG_HIGHMEM
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WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
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#endif
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/*
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* Force other mappings to Oops if they'll try to access this
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* pte without first remap it. Keeping stale mappings around
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* is a bad idea also, in case the page changes cacheability
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* attributes or becomes a protected page in a hypervisor.
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*/
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kpte_clear_flush(kmap_pte-idx, vaddr);
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kmap_atomic_idx_pop();
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arch_flush_lazy_mmu_mode();
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}
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#ifdef CONFIG_DEBUG_HIGHMEM
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else {
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BUG_ON(vaddr < PAGE_OFFSET);
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BUG_ON(vaddr >= (unsigned long)high_memory);
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}
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#endif
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pagefault_enable();
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preempt_enable();
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}
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EXPORT_SYMBOL(__kunmap_atomic);
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void __init set_highmem_pages_init(void)
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{
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struct zone *zone;
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int nid;
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/*
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* Explicitly reset zone->managed_pages because set_highmem_pages_init()
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* is invoked before free_all_bootmem()
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*/
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reset_all_zones_managed_pages();
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for_each_zone(zone) {
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unsigned long zone_start_pfn, zone_end_pfn;
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if (!is_highmem(zone))
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continue;
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zone_start_pfn = zone->zone_start_pfn;
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zone_end_pfn = zone_start_pfn + zone->spanned_pages;
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nid = zone_to_nid(zone);
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printk(KERN_INFO "Initializing %s for node %d (%08lx:%08lx)\n",
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zone->name, nid, zone_start_pfn, zone_end_pfn);
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add_highpages_with_active_regions(nid, zone_start_pfn,
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zone_end_pfn);
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}
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}
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