1 files changed, 7 insertions, 77 deletions

diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
index fc8849e4f72e..c79912a6b196 100644
--- a/arch/arc/mm/highmem.c
+++ b/arch/arc/mm/highmem.c
@@ -6,8 +6,8 @@
 #include <linux/memblock.h>
 #include <linux/export.h>
 #include <linux/highmem.h>
+#include <linux/pgtable.h>
 #include <asm/processor.h>
-#include <asm/pgtable.h>
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
 
@@ -36,9 +36,8 @@
  *   This means each only has 1 PGDIR_SIZE worth of kvaddr mappings, which means
  *   2M of kvaddr space for typical config (8K page and 11:8:13 traversal split)
  *
- * - fixmap anyhow needs a limited number of mappings. So 2M kvaddr == 256 PTE
- *   slots across NR_CPUS would be more than sufficient (generic code defines
- *   KM_TYPE_NR as 20).
+ * - The fixed KMAP slots for kmap_local/atomic() require KM_MAX_IDX slots per
+ *   CPU. So the number of CPUs sharing a single PTE page is limited.
  *
  * - pkmap being preemptible, in theory could do with more than 256 concurrent
  *   mappings. However, generic pkmap code: map_new_virtual(), doesn't traverse
@@ -47,80 +46,12 @@
  */
 
 extern pte_t * pkmap_page_table;
-static pte_t * fixmap_page_table;
-
-void *kmap(struct page *page)
-{
-	BUG_ON(in_interrupt());
-	if (!PageHighMem(page))
-		return page_address(page);
-
-	return kmap_high(page);
-}
-EXPORT_SYMBOL(kmap);
-
-void *kmap_atomic(struct page *page)
-{
-	int idx, cpu_idx;
-	unsigned long vaddr;
-
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
-	cpu_idx = kmap_atomic_idx_push();
-	idx = cpu_idx + KM_TYPE_NR * smp_processor_id();
-	vaddr = FIXMAP_ADDR(idx);
-
-	set_pte_at(&init_mm, vaddr, fixmap_page_table + idx,
-		   mk_pte(page, kmap_prot));
-
-	return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic);
-
-void __kunmap_atomic(void *kv)
-{
-	unsigned long kvaddr = (unsigned long)kv;
-
-	if (kvaddr >= FIXMAP_BASE && kvaddr < (FIXMAP_BASE + FIXMAP_SIZE)) {
-
-		/*
-		 * Because preemption is disabled, this vaddr can be associated
-		 * with the current allocated index.
-		 * But in case of multiple live kmap_atomic(), it still relies on
-		 * callers to unmap in right order.
-		 */
-		int cpu_idx = kmap_atomic_idx();
-		int idx = cpu_idx + KM_TYPE_NR * smp_processor_id();
-
-		WARN_ON(kvaddr != FIXMAP_ADDR(idx));
-
-		pte_clear(&init_mm, kvaddr, fixmap_page_table + idx);
-		local_flush_tlb_kernel_range(kvaddr, kvaddr + PAGE_SIZE);
-
-		kmap_atomic_idx_pop();
-	}
-
-	pagefault_enable();
-	preempt_enable();
-}
-EXPORT_SYMBOL(__kunmap_atomic);
 
 static noinline pte_t * __init alloc_kmap_pgtable(unsigned long kvaddr)
 {
-	pgd_t *pgd_k;
-	p4d_t *p4d_k;
-	pud_t *pud_k;
-	pmd_t *pmd_k;
+	pmd_t *pmd_k = pmd_off_k(kvaddr);
 	pte_t *pte_k;
 
-	pgd_k = pgd_offset_k(kvaddr);
-	p4d_k = p4d_offset(pgd_k, kvaddr);
-	pud_k = pud_offset(p4d_k, kvaddr);
-	pmd_k = pmd_offset(pud_k, kvaddr);
-
 	pte_k = (pte_t *)memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
 	if (!pte_k)
 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
@@ -134,10 +65,9 @@ void __init kmap_init(void)
 {
 	/* Due to recursive include hell, we can't do this in processor.h */
 	BUILD_BUG_ON(PAGE_OFFSET < (VMALLOC_END + FIXMAP_SIZE + PKMAP_SIZE));
+	BUILD_BUG_ON(LAST_PKMAP > PTRS_PER_PTE);
+	BUILD_BUG_ON(FIX_KMAP_SLOTS > PTRS_PER_PTE);
 
-	BUILD_BUG_ON(KM_TYPE_NR > PTRS_PER_PTE);
 	pkmap_page_table = alloc_kmap_pgtable(PKMAP_BASE);
-
-	BUILD_BUG_ON(LAST_PKMAP > PTRS_PER_PTE);
-	fixmap_page_table = alloc_kmap_pgtable(FIXMAP_BASE);
+	alloc_kmap_pgtable(FIXMAP_BASE);
 }