[patch RFC 13/15] mm/highmem: Remove the old kmap_atomic cruft

From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: linux-arch@vger.kernel.org,
	Linus Torvalds <torvalds@linuxfoundation.org>,
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Subject: [patch RFC 13/15] mm/highmem: Remove the old kmap_atomic cruft
Date: Sat, 19 Sep 2020 11:18:04 +0200	[thread overview]
Message-ID: <20200919092617.183860899@linutronix.de> (raw)
In-Reply-To: 20200919091751.011116649@linutronix.de

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 include/linux/highmem.h |   65 ++----------------------------------------------
 mm/highmem.c            |   28 +++++++++++++++++---
 2 files changed, 28 insertions(+), 65 deletions(-)

--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -94,27 +94,6 @@ static inline void kunmap(struct page *p
  * be used in IRQ contexts, so in some (very limited) cases we need
  * it.
  */
-
-#ifndef CONFIG_KMAP_ATOMIC_GENERIC
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
-void kunmap_atomic_high(void *kvaddr);
-
-static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
-{
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-	return kmap_atomic_high_prot(page, prot);
-}
-
-static inline void __kunmap_atomic(void *vaddr)
-{
-	kunmap_atomic_high(vaddr);
-	pagefault_enable();
-}
-#else /* !CONFIG_KMAP_ATOMIC_GENERIC */
-
 static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 {
 	preempt_disable();
@@ -127,17 +106,14 @@ static inline void *kmap_atomic_pfn(unsi
 	return kmap_atomic_pfn_prot(pfn, kmap_prot);
 }
 
-static inline void __kunmap_atomic(void *addr)
+static inline void *kmap_atomic(struct page *page)
 {
-	kumap_atomic_indexed(addr);
+	return kmap_atomic_prot(page, kmap_prot);
 }
 
-
-#endif /* CONFIG_KMAP_ATOMIC_GENERIC */
-
-static inline void *kmap_atomic(struct page *page)
+static inline void __kunmap_atomic(void *addr)
 {
-	return kmap_atomic_prot(page, kmap_prot);
+	kumap_atomic_indexed(addr);
 }
 
 /* declarations for linux/mm/highmem.c */
@@ -233,39 +209,6 @@ static inline void __kunmap_atomic(void
 
 #endif /* CONFIG_HIGHMEM */
 
-#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
-
-DECLARE_PER_CPU(int, __kmap_atomic_idx);
-
-static inline int kmap_atomic_idx_push(void)
-{
-	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;
-}
-
-static inline int kmap_atomic_idx(void)
-{
-	return __this_cpu_read(__kmap_atomic_idx) - 1;
-}
-
-static inline void kmap_atomic_idx_pop(void)
-{
-#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
-}
-
-#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.
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -31,10 +31,6 @@
 #include <asm/tlbflush.h>
 #include <linux/vmalloc.h>
 
-#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
-DEFINE_PER_CPU(int, __kmap_atomic_idx);
-#endif
-
 /*
  * Virtual_count is not a pure "count".
  *  0 means that it is not mapped, and has not been mapped
@@ -380,6 +376,30 @@ static inline void kmap_high_unmap_tempo
 #endif /* CONFIG_HIGHMEM */
 
 #ifdef CONFIG_KMAP_ATOMIC_GENERIC
+
+static DEFINE_PER_CPU(int, __kmap_atomic_idx);
+
+static inline int kmap_atomic_idx_push(void)
+{
+	int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
+
+	WARN_ON_ONCE(in_irq() && !irqs_disabled());
+	BUG_ON(idx >= KM_TYPE_NR);
+	return idx;
+}
+
+static inline int kmap_atomic_idx(void)
+{
+	return __this_cpu_read(__kmap_atomic_idx) - 1;
+}
+
+static inline void kmap_atomic_idx_pop(void)
+{
+	int idx = __this_cpu_dec_return(__kmap_atomic_idx);
+
+	BUG_ON(idx < 0);
+}
+
 #ifndef arch_kmap_temp_post_map
 # define arch_kmap_temp_post_map(vaddr, pteval)	do { } while (0)
 #endif

