kernel_5.10 no rt

hc

2023-12-11 6778948f9de86c3cfaf36725a7c87dcff9ba247f

 kernel/arch/mips/mm/highmem.c
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@@ -8,6 +8,8 @@
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 #include <asm/fixmap.h>
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 #include <asm/tlbflush.h>
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+static pte_t *kmap_pte;
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+
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 unsigned long highstart_pfn, highend_pfn;
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 void kmap_flush_tlb(unsigned long addr)
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@@ -15,3 +17,78 @@
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 	flush_tlb_one(addr);
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 }
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 EXPORT_SYMBOL(kmap_flush_tlb);
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+
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+void *kmap_atomic_high_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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+
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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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+#ifdef CONFIG_DEBUG_HIGHMEM
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+	BUG_ON(!pte_none(*(kmap_pte - idx)));
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+#endif
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+	set_pte(kmap_pte-idx, mk_pte(page, prot));
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+	local_flush_tlb_one((unsigned long)vaddr);
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+
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+	return (void*) vaddr;
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+}
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+EXPORT_SYMBOL(kmap_atomic_high_prot);
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+
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+void kunmap_atomic_high(void *kvaddr)
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+{
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+	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
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+	int type __maybe_unused;
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+
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+	if (vaddr < FIXADDR_START)
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+		return;
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+
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+	type = kmap_atomic_idx();
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+#ifdef CONFIG_DEBUG_HIGHMEM
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+	{
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+		int idx = type + KM_TYPE_NR * smp_processor_id();
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+
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+		BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
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+
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+		/*
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+		 * force other mappings to Oops if they'll try to access
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+		 * this pte without first remap it
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+		 */
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+		pte_clear(&init_mm, vaddr, kmap_pte-idx);
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+		local_flush_tlb_one(vaddr);
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+	}
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+#endif
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+	kmap_atomic_idx_pop();
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+}
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+EXPORT_SYMBOL(kunmap_atomic_high);
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+
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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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+	unsigned long vaddr;
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+	int idx, type;
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+
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+	preempt_disable();
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+	pagefault_disable();
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+
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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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+	set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
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+	flush_tlb_one(vaddr);
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+
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+	return (void*) vaddr;
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+}
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+
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+void __init kmap_init(void)
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+{
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+	unsigned long kmap_vstart;
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+
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+	/* cache the first kmap pte */
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+	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
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+	kmap_pte = virt_to_kpte(kmap_vstart);
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+}