--- zzzz-none-000/linux-3.10.107/arch/mips/mm/highmem.c	2017-06-27 09:49:32.000000000 +0000
+++ vr9-7490-729/linux-3.10.107/arch/mips/mm/highmem.c	2021-11-10 11:53:54.000000000 +0000
@@ -9,6 +9,7 @@
 static pte_t *kmap_pte;
 
 unsigned long highstart_pfn, highend_pfn;
+unsigned int  last_pkmap_nr_arr[FIX_N_COLOURS] = { 0, 1, 2, 3, 4, 5, 6, 7 };
 
 void *kmap(struct page *page)
 {
@@ -53,8 +54,12 @@
 		return page_address(page);
 
 	type = kmap_atomic_idx_push();
-	idx = type + KM_TYPE_NR*smp_processor_id();
-	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+
+	idx = (((unsigned long)lowmem_page_address(page)) >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
+	idx = (FIX_N_COLOURS - idx);
+	idx = idx + FIX_N_COLOURS * (smp_processor_id() + NR_CPUS * type);
+	vaddr = __fix_to_virt(FIX_KMAP_BEGIN - 1 + idx);    /* actually - FIX_CMAP_END */
+
 #ifdef CONFIG_DEBUG_HIGHMEM
 	BUG_ON(!pte_none(*(kmap_pte - idx)));
 #endif
@@ -75,12 +80,16 @@
 		return;
 	}
 
-	type = kmap_atomic_idx();
 #ifdef CONFIG_DEBUG_HIGHMEM
 	{
-		int idx = type + KM_TYPE_NR * smp_processor_id();
+		int idx;
+		type = kmap_atomic_idx();
 
-		BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
+		idx = ((unsigned long)kvaddr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
+		idx = (FIX_N_COLOURS - idx);
+		idx = idx + FIX_N_COLOURS * (smp_processor_id() + NR_CPUS * type);
+
+		BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN -1 + idx));
 
 		/*
 		 * force other mappings to Oops if they'll try to access
@@ -95,26 +104,6 @@
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
-/*
- * This is the same as kmap_atomic() but can map memory that doesn't
- * have a struct page associated with it.
- */
-void *kmap_atomic_pfn(unsigned long pfn)
-{
-	unsigned long vaddr;
-	int idx, type;
-
-	pagefault_disable();
-
-	type = kmap_atomic_idx_push();
-	idx = type + KM_TYPE_NR*smp_processor_id();
-	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-	set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
-	flush_tlb_one(vaddr);
-
-	return (void*) vaddr;
-}
-
 struct page *kmap_atomic_to_page(void *ptr)
 {
 	unsigned long idx, vaddr = (unsigned long)ptr;
@@ -124,7 +113,7 @@
 		return virt_to_page(ptr);
 
 	idx = virt_to_fix(vaddr);
-	pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
+	pte = kmap_pte - (idx - FIX_KMAP_BEGIN + 1);
 	return pte_page(*pte);
 }
 
@@ -133,6 +122,6 @@
 	unsigned long kmap_vstart;
 
 	/* cache the first kmap pte */
-	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
+	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN - 1); /* actually - FIX_CMAP_END */
 	kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
 }