Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
new file mode 100644
index 0000000..3317b77
--- /dev/null
+++ b/arch/csky/mm/highmem.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/module.h>
+#include <linux/highmem.h>
+#include <linux/smp.h>
+#include <linux/memblock.h>
+#include <asm/fixmap.h>
+#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
+
+static pte_t *kmap_pte;
+
+unsigned long highstart_pfn, highend_pfn;
+
+void *kmap(struct page *page)
+{
+ void *addr;
+
+ might_sleep();
+ if (!PageHighMem(page))
+ return page_address(page);
+ addr = kmap_high(page);
+ flush_tlb_one((unsigned long)addr);
+
+ return addr;
+}
+EXPORT_SYMBOL(kmap);
+
+void kunmap(struct page *page)
+{
+ BUG_ON(in_interrupt());
+ if (!PageHighMem(page))
+ return;
+ kunmap_high(page);
+}
+EXPORT_SYMBOL(kunmap);
+
+void *kmap_atomic(struct page *page)
+{
+ unsigned long vaddr;
+ int idx, type;
+
+ preempt_disable();
+ pagefault_disable();
+ if (!PageHighMem(page))
+ 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);
+#ifdef CONFIG_DEBUG_HIGHMEM
+ BUG_ON(!pte_none(*(kmap_pte - idx)));
+#endif
+ set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL));
+ flush_tlb_one((unsigned long)vaddr);
+
+ return (void *)vaddr;
+}
+EXPORT_SYMBOL(kmap_atomic);
+
+void __kunmap_atomic(void *kvaddr)
+{
+ unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
+ int idx;
+
+ if (vaddr < FIXADDR_START)
+ goto out;
+
+#ifdef CONFIG_DEBUG_HIGHMEM
+ idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
+
+ BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
+
+ pte_clear(&init_mm, vaddr, kmap_pte - idx);
+ flush_tlb_one(vaddr);
+#else
+ (void) idx; /* to kill a warning */
+#endif
+ kmap_atomic_idx_pop();
+out:
+ pagefault_enable();
+ preempt_enable();
+}
+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;
+ pte_t *pte;
+
+ if (vaddr < FIXADDR_START)
+ return virt_to_page(ptr);
+
+ idx = virt_to_fix(vaddr);
+ pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
+ return pte_page(*pte);
+}
+
+static void __init fixrange_init(unsigned long start, unsigned long end,
+ pgd_t *pgd_base)
+{
+#ifdef CONFIG_HIGHMEM
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+ int i, j, k;
+ unsigned long vaddr;
+
+ vaddr = start;
+ i = __pgd_offset(vaddr);
+ j = __pud_offset(vaddr);
+ k = __pmd_offset(vaddr);
+ pgd = pgd_base + i;
+
+ for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
+ pud = (pud_t *)pgd;
+ for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
+ pmd = (pmd_t *)pud;
+ for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
+ if (pmd_none(*pmd)) {
+ pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
+ if (!pte)
+ panic("%s: Failed to allocate %lu bytes align=%lx\n",
+ __func__, PAGE_SIZE,
+ PAGE_SIZE);
+
+ set_pmd(pmd, __pmd(__pa(pte)));
+ BUG_ON(pte != pte_offset_kernel(pmd, 0));
+ }
+ vaddr += PMD_SIZE;
+ }
+ k = 0;
+ }
+ j = 0;
+ }
+#endif
+}
+
+void __init fixaddr_kmap_pages_init(void)
+{
+ unsigned long vaddr;
+ pgd_t *pgd_base;
+#ifdef CONFIG_HIGHMEM
+ pgd_t *pgd;
+ pmd_t *pmd;
+ pud_t *pud;
+ pte_t *pte;
+#endif
+ pgd_base = swapper_pg_dir;
+
+ /*
+ * Fixed mappings:
+ */
+ vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
+ fixrange_init(vaddr, 0, pgd_base);
+
+#ifdef CONFIG_HIGHMEM
+ /*
+ * Permanent kmaps:
+ */
+ vaddr = PKMAP_BASE;
+ fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
+
+ pgd = swapper_pg_dir + __pgd_offset(vaddr);
+ pud = (pud_t *)pgd;
+ pmd = pmd_offset(pud, vaddr);
+ pte = pte_offset_kernel(pmd, vaddr);
+ pkmap_page_table = pte;
+#endif
+}
+
+void __init kmap_init(void)
+{
+ unsigned long vaddr;
+
+ fixaddr_kmap_pages_init();
+
+ vaddr = __fix_to_virt(FIX_KMAP_BEGIN);
+
+ kmap_pte = pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr);
+}