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-rw-r--r--debian/patches-rt/0029-highmem-Provide-generic-variant-of-kmap_atomic.patch346
1 files changed, 346 insertions, 0 deletions
diff --git a/debian/patches-rt/0029-highmem-Provide-generic-variant-of-kmap_atomic.patch b/debian/patches-rt/0029-highmem-Provide-generic-variant-of-kmap_atomic.patch
new file mode 100644
index 000000000..828708904
--- /dev/null
+++ b/debian/patches-rt/0029-highmem-Provide-generic-variant-of-kmap_atomic.patch
@@ -0,0 +1,346 @@
+From 4e1b14787f7a2c71a9347db23c402f5dbe2da206 Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Tue, 3 Nov 2020 10:27:18 +0100
+Subject: [PATCH 029/323] highmem: Provide generic variant of kmap_atomic*
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz
+
+The kmap_atomic* interfaces in all architectures are pretty much the same
+except for post map operations (flush) and pre- and post unmap operations.
+
+Provide a generic variant for that.
+
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Cc: Andrew Morton <akpm@linux-foundation.org>
+Cc: linux-mm@kvack.org
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ include/linux/highmem.h | 82 ++++++++++++++++++-----
+ mm/Kconfig | 3 +
+ mm/highmem.c | 144 +++++++++++++++++++++++++++++++++++++++-
+ 3 files changed, 211 insertions(+), 18 deletions(-)
+
+diff --git a/include/linux/highmem.h b/include/linux/highmem.h
+index 3297bfca78ed..14d5b4020c8c 100644
+--- a/include/linux/highmem.h
++++ b/include/linux/highmem.h
+@@ -31,9 +31,16 @@ static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
+
+ #include <asm/kmap_types.h>
+
++/*
++ * Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft.
++ */
++#ifdef CONFIG_KMAP_LOCAL
++void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
++void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
++void kunmap_local_indexed(void *vaddr);
++#endif
++
+ #ifdef CONFIG_HIGHMEM
+-extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
+-extern void kunmap_atomic_high(void *kvaddr);
+ #include <asm/highmem.h>
+
+ #ifndef ARCH_HAS_KMAP_FLUSH_TLB
+@@ -81,6 +88,11 @@ static inline void kunmap(struct page *page)
+ * be used in IRQ contexts, so in some (very limited) cases we need
+ * it.
+ */
++
++#ifndef CONFIG_KMAP_LOCAL
++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();
+@@ -89,7 +101,38 @@ static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+ return page_address(page);
+ return kmap_atomic_high_prot(page, prot);
+ }
+-#define kmap_atomic(page) kmap_atomic_prot(page, kmap_prot)
++
++static inline void __kunmap_atomic(void *vaddr)
++{
++ kunmap_atomic_high(vaddr);
++}
++#else /* !CONFIG_KMAP_LOCAL */
++
++static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
++{
++ preempt_disable();
++ pagefault_disable();
++ return __kmap_local_page_prot(page, prot);
++}
++
++static inline void *kmap_atomic_pfn(unsigned long pfn)
++{
++ preempt_disable();
++ pagefault_disable();
++ return __kmap_local_pfn_prot(pfn, kmap_prot);
++}
++
++static inline void __kunmap_atomic(void *addr)
++{
++ kunmap_local_indexed(addr);
++}
++
++#endif /* CONFIG_KMAP_LOCAL */
++
++static inline void *kmap_atomic(struct page *page)
++{
++ return kmap_atomic_prot(page, kmap_prot);
++}
+
+ /* declarations for linux/mm/highmem.c */
+ unsigned int nr_free_highpages(void);
+@@ -147,25 +190,33 @@ static inline void *kmap_atomic(struct page *page)
+ pagefault_disable();
+ return page_address(page);
+ }
+-#define kmap_atomic_prot(page, prot) kmap_atomic(page)
+
+-static inline void kunmap_atomic_high(void *addr)
++static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
++{
++ return kmap_atomic(page);
++}
++
++static inline void *kmap_atomic_pfn(unsigned long pfn)
++{
++ return kmap_atomic(pfn_to_page(pfn));
++}
++
++static inline void __kunmap_atomic(void *addr)
+ {
+ /*
+ * Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
+- * handles re-enabling faults + preemption
++ * handles re-enabling faults and preemption
+ */
+ #ifdef ARCH_HAS_FLUSH_ON_KUNMAP
+ kunmap_flush_on_unmap(addr);
+ #endif
+ }
+
+-#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
+-
+ #define kmap_flush_unused() do {} while(0)
+
+ #endif /* CONFIG_HIGHMEM */
+
++#if !defined(CONFIG_KMAP_LOCAL)
+ #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
+
+ DECLARE_PER_CPU(int, __kmap_atomic_idx);
+@@ -196,22 +247,21 @@ static inline void kmap_atomic_idx_pop(void)
+ __this_cpu_dec(__kmap_atomic_idx);
+ #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_high(addr); \
+- pagefault_enable(); \
+- preempt_enable(); \
++#define kunmap_atomic(__addr) \
++do { \
++ BUILD_BUG_ON(__same_type((__addr), struct page *)); \
++ __kunmap_atomic(__addr); \
++ pagefault_enable(); \
++ preempt_enable(); \
+ } 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)
+diff --git a/mm/Kconfig b/mm/Kconfig
+index 390165ffbb0f..8c49d09da214 100644
+--- a/mm/Kconfig
++++ b/mm/Kconfig
+@@ -859,4 +859,7 @@ config ARCH_HAS_HUGEPD
+ config MAPPING_DIRTY_HELPERS
+ bool
+
++config KMAP_LOCAL
++ bool
++
+ endmenu
+diff --git a/mm/highmem.c b/mm/highmem.c
+index 6abfd762eee7..bb4ce13ee7e7 100644
+--- a/mm/highmem.c
++++ b/mm/highmem.c
+@@ -31,9 +31,11 @@
+ #include <asm/tlbflush.h>
+ #include <linux/vmalloc.h>
+
++#ifndef CONFIG_KMAP_LOCAL
+ #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
+ DEFINE_PER_CPU(int, __kmap_atomic_idx);
+ #endif
++#endif
+
+ /*
+ * Virtual_count is not a pure "count".
+@@ -365,9 +367,147 @@ void kunmap_high(struct page *page)
+ if (need_wakeup)
+ wake_up(pkmap_map_wait);
+ }
+-
+ EXPORT_SYMBOL(kunmap_high);
+-#endif /* CONFIG_HIGHMEM */
++#endif /* CONFIG_HIGHMEM */
++
++#ifdef CONFIG_KMAP_LOCAL
++
++#include <asm/kmap_size.h>
++
++static DEFINE_PER_CPU(int, __kmap_local_idx);
++
++static inline int kmap_local_idx_push(void)
++{
++ int idx = __this_cpu_inc_return(__kmap_local_idx) - 1;
++
++ WARN_ON_ONCE(in_irq() && !irqs_disabled());
++ BUG_ON(idx >= KM_MAX_IDX);
++ return idx;
++}
++
++static inline int kmap_local_idx(void)
++{
++ return __this_cpu_read(__kmap_local_idx) - 1;
++}
++
++static inline void kmap_local_idx_pop(void)
++{
++ int idx = __this_cpu_dec_return(__kmap_local_idx);
++
++ BUG_ON(idx < 0);
++}
++
++#ifndef arch_kmap_local_post_map
++# define arch_kmap_local_post_map(vaddr, pteval) do { } while (0)
++#endif
++#ifndef arch_kmap_local_pre_unmap
++# define arch_kmap_local_pre_unmap(vaddr) do { } while (0)
++#endif
++
++#ifndef arch_kmap_local_post_unmap
++# define arch_kmap_local_post_unmap(vaddr) do { } while (0)
++#endif
++
++#ifndef arch_kmap_local_map_idx
++#define arch_kmap_local_map_idx(idx, pfn) kmap_local_calc_idx(idx)
++#endif
++
++#ifndef arch_kmap_local_unmap_idx
++#define arch_kmap_local_unmap_idx(idx, vaddr) kmap_local_calc_idx(idx)
++#endif
++
++#ifndef arch_kmap_local_high_get
++static inline void *arch_kmap_local_high_get(struct page *page)
++{
++ return NULL;
++}
++#endif
++
++/* Unmap a local mapping which was obtained by kmap_high_get() */
++static inline void kmap_high_unmap_local(unsigned long vaddr)
++{
++#ifdef ARCH_NEEDS_KMAP_HIGH_GET
++ if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP))
++ kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
++#endif
++}
++
++static inline int kmap_local_calc_idx(int idx)
++{
++ return idx + KM_MAX_IDX * smp_processor_id();
++}
++
++static pte_t *__kmap_pte;
++
++static pte_t *kmap_get_pte(void)
++{
++ if (!__kmap_pte)
++ __kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
++ return __kmap_pte;
++}
++
++void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot)
++{
++ pte_t pteval, *kmap_pte = kmap_get_pte();
++ unsigned long vaddr;
++ int idx;
++
++ preempt_disable();
++ idx = arch_kmap_local_map_idx(kmap_local_idx_push(), pfn);
++ vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
++ BUG_ON(!pte_none(*(kmap_pte - idx)));
++ pteval = pfn_pte(pfn, prot);
++ set_pte_at(&init_mm, vaddr, kmap_pte - idx, pteval);
++ arch_kmap_local_post_map(vaddr, pteval);
++ preempt_enable();
++
++ return (void *)vaddr;
++}
++EXPORT_SYMBOL_GPL(__kmap_local_pfn_prot);
++
++void *__kmap_local_page_prot(struct page *page, pgprot_t prot)
++{
++ void *kmap;
++
++ if (!PageHighMem(page))
++ return page_address(page);
++
++ /* Try kmap_high_get() if architecture has it enabled */
++ kmap = arch_kmap_local_high_get(page);
++ if (kmap)
++ return kmap;
++
++ return __kmap_local_pfn_prot(page_to_pfn(page), prot);
++}
++EXPORT_SYMBOL(__kmap_local_page_prot);
++
++void kunmap_local_indexed(void *vaddr)
++{
++ unsigned long addr = (unsigned long) vaddr & PAGE_MASK;
++ pte_t *kmap_pte = kmap_get_pte();
++ int idx;
++
++ if (addr < __fix_to_virt(FIX_KMAP_END) ||
++ addr > __fix_to_virt(FIX_KMAP_BEGIN)) {
++ WARN_ON_ONCE(addr < PAGE_OFFSET);
++
++ /* Handle mappings which were obtained by kmap_high_get() */
++ kmap_high_unmap_local(addr);
++ return;
++ }
++
++ preempt_disable();
++ idx = arch_kmap_local_unmap_idx(kmap_local_idx(), addr);
++ WARN_ON_ONCE(addr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
++
++ arch_kmap_local_pre_unmap(addr);
++ pte_clear(&init_mm, addr, kmap_pte - idx);
++ arch_kmap_local_post_unmap(addr);
++ kmap_local_idx_pop();
++ preempt_enable();
++}
++EXPORT_SYMBOL(kunmap_local_indexed);
++#endif
+
+ #if defined(HASHED_PAGE_VIRTUAL)
+
+--
+2.43.0
+