Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 91 insertions, 0 deletions

diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c
new file mode 100644
index 000000000..673196fe8
--- /dev/null
+++ b/arch/xtensa/mm/highmem.c
@@ -0,0 +1,91 @@
+/*
+ * High memory support for Xtensa architecture
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file "COPYING" in the main directory of
+ * this archive for more details.
+ *
+ * Copyright (C) 2014 Cadence Design Systems Inc.
+ */
+
+#include <linux/export.h>
+#include <linux/highmem.h>
+#include <asm/tlbflush.h>
+
+static pte_t *kmap_pte;
+
+#if DCACHE_WAY_SIZE > PAGE_SIZE
+unsigned int last_pkmap_nr_arr[DCACHE_N_COLORS];
+wait_queue_head_t pkmap_map_wait_arr[DCACHE_N_COLORS];
+
+static void __init kmap_waitqueues_init(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(pkmap_map_wait_arr); ++i)
+		init_waitqueue_head(pkmap_map_wait_arr + i);
+}
+#else
+static inline void kmap_waitqueues_init(void)
+{
+}
+#endif
+
+static inline enum fixed_addresses kmap_idx(int type, unsigned long color)
+{
+	return (type + KM_TYPE_NR * smp_processor_id()) * DCACHE_N_COLORS +
+		color;
+}
+
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
+{
+	enum fixed_addresses idx;
+	unsigned long vaddr;
+
+	idx = kmap_idx(kmap_atomic_idx_push(),
+		       DCACHE_ALIAS(page_to_phys(page)));
+	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, prot));
+
+	return (void *)vaddr;
+}
+EXPORT_SYMBOL(kmap_atomic_high_prot);
+
+void kunmap_atomic_high(void *kvaddr)
+{
+	if (kvaddr >= (void *)FIXADDR_START &&
+	    kvaddr < (void *)FIXADDR_TOP) {
+		int idx = kmap_idx(kmap_atomic_idx(),
+				   DCACHE_ALIAS((unsigned long)kvaddr));
+
+		/*
+		 * Force other mappings to Oops if they'll try to access this
+		 * pte without first remap it.  Keeping stale mappings around
+		 * is a bad idea also, in case the page changes cacheability
+		 * attributes or becomes a protected page in a hypervisor.
+		 */
+		pte_clear(&init_mm, kvaddr, kmap_pte + idx);
+		local_flush_tlb_kernel_range((unsigned long)kvaddr,
+					     (unsigned long)kvaddr + PAGE_SIZE);
+
+		kmap_atomic_idx_pop();
+	}
+}
+EXPORT_SYMBOL(kunmap_atomic_high);
+
+void __init kmap_init(void)
+{
+	unsigned long kmap_vstart;
+
+	/* Check if this memory layout is broken because PKMAP overlaps
+	 * page table.
+	 */
+	BUILD_BUG_ON(PKMAP_BASE < TLBTEMP_BASE_1 + TLBTEMP_SIZE);
+	/* cache the first kmap pte */
+	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
+	kmap_pte = virt_to_kpte(kmap_vstart);
+	kmap_waitqueues_init();
+}