From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/include/linux/highmem.h | 281 +++++++++++++++++++++++++------------------------------
1 files changed, 129 insertions(+), 152 deletions(-)
diff --git a/kernel/include/linux/highmem.h b/kernel/include/linux/highmem.h
index d6c89c3..be24378 100644
--- a/kernel/include/linux/highmem.h
+++ b/kernel/include/linux/highmem.h
@@ -8,9 +8,121 @@
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
-#include <linux/sched.h>
#include <asm/cacheflush.h>
+
+#include "highmem-internal.h"
+
+/**
+ * kmap - Map a page for long term usage
+ * @page: Pointer to the page to be mapped
+ *
+ * Returns: The virtual address of the mapping
+ *
+ * Can only be invoked from preemptible task context because on 32bit
+ * systems with CONFIG_HIGHMEM enabled this function might sleep.
+ *
+ * For systems with CONFIG_HIGHMEM=n and for pages in the low memory area
+ * this returns the virtual address of the direct kernel mapping.
+ *
+ * The returned virtual address is globally visible and valid up to the
+ * point where it is unmapped via kunmap(). The pointer can be handed to
+ * other contexts.
+ *
+ * For highmem pages on 32bit systems this can be slow as the mapping space
+ * is limited and protected by a global lock. In case that there is no
+ * mapping slot available the function blocks until a slot is released via
+ * kunmap().
+ */
+static inline void *kmap(struct page *page);
+
+/**
+ * kunmap - Unmap the virtual address mapped by kmap()
+ * @addr: Virtual address to be unmapped
+ *
+ * Counterpart to kmap(). A NOOP for CONFIG_HIGHMEM=n and for mappings of
+ * pages in the low memory area.
+ */
+static inline void kunmap(struct page *page);
+
+/**
+ * kmap_to_page - Get the page for a kmap'ed address
+ * @addr: The address to look up
+ *
+ * Returns: The page which is mapped to @addr.
+ */
+static inline struct page *kmap_to_page(void *addr);
+
+/**
+ * kmap_flush_unused - Flush all unused kmap mappings in order to
+ * remove stray mappings
+ */
+static inline void kmap_flush_unused(void);
+
+/**
+ * kmap_local_page - Map a page for temporary usage
+ * @page: Pointer to the page to be mapped
+ *
+ * Returns: The virtual address of the mapping
+ *
+ * Can be invoked from any context.
+ *
+ * Requires careful handling when nesting multiple mappings because the map
+ * management is stack based. The unmap has to be in the reverse order of
+ * the map operation:
+ *
+ * addr1 = kmap_local_page(page1);
+ * addr2 = kmap_local_page(page2);
+ * ...
+ * kunmap_local(addr2);
+ * kunmap_local(addr1);
+ *
+ * Unmapping addr1 before addr2 is invalid and causes malfunction.
+ *
+ * Contrary to kmap() mappings the mapping is only valid in the context of
+ * the caller and cannot be handed to other contexts.
+ *
+ * On CONFIG_HIGHMEM=n kernels and for low memory pages this returns the
+ * virtual address of the direct mapping. Only real highmem pages are
+ * temporarily mapped.
+ *
+ * While it is significantly faster than kmap() for the higmem case it
+ * comes with restrictions about the pointer validity. Only use when really
+ * necessary.
+ *
+ * On HIGHMEM enabled systems mapping a highmem page has the side effect of
+ * disabling migration in order to keep the virtual address stable across
+ * preemption. No caller of kmap_local_page() can rely on this side effect.
+ */
+static inline void *kmap_local_page(struct page *page);
+
+/**
+ * kmap_atomic - Atomically map a page for temporary usage - Deprecated!
+ * @page: Pointer to the page to be mapped
+ *
+ * Returns: The virtual address of the mapping
+ *
+ * Effectively a wrapper around kmap_local_page() which disables pagefaults
+ * and preemption.
+ *
+ * Do not use in new code. Use kmap_local_page() instead.
+ */
+static inline void *kmap_atomic(struct page *page);
+
+/**
+ * kunmap_atomic - Unmap the virtual address mapped by kmap_atomic()
+ * @addr: Virtual address to be unmapped
+ *
+ * Counterpart to kmap_atomic().
+ *
+ * Effectively a wrapper around kunmap_local() which additionally undoes
+ * the side effects of kmap_atomic(), i.e. reenabling pagefaults and
+ * preemption.
+ */
+
+/* Highmem related interfaces for management code */
+static inline unsigned int nr_free_highpages(void);
+static inline unsigned long totalhigh_pages(void);
#ifndef ARCH_HAS_FLUSH_ANON_PAGE
static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
@@ -30,125 +142,6 @@
}
#endif
-#include <asm/kmap_types.h>
-
-#ifdef CONFIG_HIGHMEM
-#include <asm/highmem.h>
-
-/* declarations for linux/mm/highmem.c */
-unsigned int nr_free_highpages(void);
-extern unsigned long totalhigh_pages;
-
-void kmap_flush_unused(void);
-
-struct page *kmap_to_page(void *addr);
-
-#else /* CONFIG_HIGHMEM */
-
-static inline unsigned int nr_free_highpages(void) { return 0; }
-
-static inline struct page *kmap_to_page(void *addr)
-{
- return virt_to_page(addr);
-}
-
-#define totalhigh_pages 0UL
-
-#ifndef ARCH_HAS_KMAP
-static inline void *kmap(struct page *page)
-{
- might_sleep();
- return page_address(page);
-}
-
-static inline void kunmap(struct page *page)
-{
-}
-
-static inline void *kmap_atomic(struct page *page)
-{
- preempt_disable_nort();
- pagefault_disable();
- return page_address(page);
-}
-#define kmap_atomic_prot(page, prot) kmap_atomic(page)
-
-static inline void __kunmap_atomic(void *addr)
-{
- pagefault_enable();
- preempt_enable_nort();
-}
-
-#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
-
-#define kmap_flush_unused() do {} while(0)
-#endif
-
-#endif /* CONFIG_HIGHMEM */
-
-#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
-
-#ifndef CONFIG_PREEMPT_RT_FULL
-DECLARE_PER_CPU(int, __kmap_atomic_idx);
-#endif
-
-static inline int kmap_atomic_idx_push(void)
-{
-#ifndef CONFIG_PREEMPT_RT_FULL
- int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
-
-# ifdef CONFIG_DEBUG_HIGHMEM
- WARN_ON_ONCE(in_irq() && !irqs_disabled());
- BUG_ON(idx >= KM_TYPE_NR);
-# endif
- return idx;
-#else
- current->kmap_idx++;
- BUG_ON(current->kmap_idx > KM_TYPE_NR);
- return current->kmap_idx - 1;
-#endif
-}
-
-static inline int kmap_atomic_idx(void)
-{
-#ifndef CONFIG_PREEMPT_RT_FULL
- return __this_cpu_read(__kmap_atomic_idx) - 1;
-#else
- return current->kmap_idx - 1;
-#endif
-}
-
-static inline void kmap_atomic_idx_pop(void)
-{
-#ifndef CONFIG_PREEMPT_RT_FULL
-# ifdef CONFIG_DEBUG_HIGHMEM
- int idx = __this_cpu_dec_return(__kmap_atomic_idx);
-
- BUG_ON(idx < 0);
-# else
- __this_cpu_dec(__kmap_atomic_idx);
-# endif
-#else
- current->kmap_idx--;
-# ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(current->kmap_idx < 0);
-# endif
-#endif
-}
-
-#endif
-
-/*
- * Prevent people trying to call kunmap_atomic() as if it were kunmap()
- * kunmap_atomic() should get the return value of kmap_atomic, not the page.
- */
-#define kunmap_atomic(addr) \
-do { \
- BUILD_BUG_ON(__same_type((addr), struct page *)); \
- __kunmap_atomic(addr); \
-} while (0)
-
-
/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
#ifndef clear_user_highpage
static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
@@ -159,28 +152,24 @@
}
#endif
-#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
+#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE
/**
- * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
- * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
+ * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
* @vma: The VMA the page is to be allocated for
* @vaddr: The virtual address the page will be inserted into
*
- * This function will allocate a page for a VMA but the caller is expected
- * to specify via movableflags whether the page will be movable in the
- * future or not
+ * This function will allocate a page for a VMA that the caller knows will
+ * be able to migrate in the future using move_pages() or reclaimed
*
* An architecture may override this function by defining
- * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
+ * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE and providing their own
* implementation.
*/
static inline struct page *
-__alloc_zeroed_user_highpage(gfp_t movableflags,
- struct vm_area_struct *vma,
- unsigned long vaddr)
+alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
+ unsigned long vaddr)
{
- struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
- vma, vaddr);
+ struct page *page = alloc_page_vma(GFP_HIGHUSER_MOVABLE | __GFP_CMA, vma, vaddr);
if (page)
clear_user_highpage(page, vaddr);
@@ -189,26 +178,6 @@
}
#endif
-/**
- * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
- * @vma: The VMA the page is to be allocated for
- * @vaddr: The virtual address the page will be inserted into
- *
- * This function will allocate a page for a VMA that the caller knows will
- * be able to migrate in the future using move_pages() or reclaimed
- */
-static inline struct page *
-alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
- unsigned long vaddr)
-{
-#ifndef CONFIG_CMA
- return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
-#else
- return __alloc_zeroed_user_highpage(__GFP_MOVABLE|__GFP_CMA, vma,
- vaddr);
-#endif
-}
-
static inline void clear_highpage(struct page *page)
{
void *kaddr = kmap_atomic(page);
@@ -216,6 +185,14 @@
kunmap_atomic(kaddr);
}
+#ifndef __HAVE_ARCH_TAG_CLEAR_HIGHPAGE
+
+static inline void tag_clear_highpage(struct page *page)
+{
+}
+
+#endif
+
static inline void zero_user_segments(struct page *page,
unsigned start1, unsigned end1,
unsigned start2, unsigned end2)
--
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