kernel_5.10 no rt

hc

2023-12-11 6778948f9de86c3cfaf36725a7c87dcff9ba247f

 kernel/arch/xtensa/mm/highmem.c
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@@ -12,6 +12,8 @@
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 #include <linux/highmem.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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 #if DCACHE_WAY_SIZE > PAGE_SIZE
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 unsigned int last_pkmap_nr_arr[DCACHE_N_COLORS];
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 wait_queue_head_t pkmap_map_wait_arr[DCACHE_N_COLORS];
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@@ -31,25 +33,59 @@
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 static inline enum fixed_addresses kmap_idx(int type, unsigned long color)
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 {
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-	return (type + KM_MAX_IDX * smp_processor_id()) * DCACHE_N_COLORS +
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+	return (type + KM_TYPE_NR * smp_processor_id()) * DCACHE_N_COLORS +
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 		color;
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 }
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-enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn)
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+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
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 {
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-	return kmap_idx(type, DCACHE_ALIAS(pfn << PAGE_SHIFT));
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-}
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+	enum fixed_addresses idx;
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+	unsigned long vaddr;
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-enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr)
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-{
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-	return kmap_idx(type, DCACHE_ALIAS(addr));
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+	idx = kmap_idx(kmap_atomic_idx_push(),
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+		       DCACHE_ALIAS(page_to_phys(page)));
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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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+
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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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+	if (kvaddr >= (void *)FIXADDR_START &&
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+	    kvaddr < (void *)FIXADDR_TOP) {
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+		int idx = kmap_idx(kmap_atomic_idx(),
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+				   DCACHE_ALIAS((unsigned long)kvaddr));
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+
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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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+		pte_clear(&init_mm, kvaddr, kmap_pte + idx);
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+		local_flush_tlb_kernel_range((unsigned long)kvaddr,
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+					     (unsigned long)kvaddr + PAGE_SIZE);
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+
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+		kmap_atomic_idx_pop();
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+	}
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+}
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+EXPORT_SYMBOL(kunmap_atomic_high);
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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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 	/* Check if this memory layout is broken because PKMAP overlaps
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 	 * page table.
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 	 */
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 	BUILD_BUG_ON(PKMAP_BASE < TLBTEMP_BASE_1 + TLBTEMP_SIZE);
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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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 	kmap_waitqueues_init();
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 }