zsmalloc: replace kmap_atomic with kmap_local_page

The use of kmap_atomic/kunmap_atomic is deprecated.  Replace it will
kmap_local_page/kunmap_local all over the place.  Also fix SPDX missing
license header.

WARNING: Missing or malformed SPDX-License-Identifier tag in line 1

WARNING: Deprecated use of 'kmap_atomic', prefer 'kmap_local_page' instead
+               vaddr = kmap_atomic(page);

Link: https://lkml.kernel.org/r/20241001175358.12970-1-quic_pintu@quicinc.com
Signed-off-by: Pintu Kumar <quic_pintu@quicinc.com>
Cc: Joe Perches <joe@perches.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pintu Agarwal <pintu.ping@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Pintu Kumar

mm/zsmalloc.c

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
 /*
  * zsmalloc memory allocator
  *
@@ -898,7 +900,7 @@ static void init_zspage(struct size_class *class, struct zspage *zspage)
 
 		set_first_obj_offset(page, off);
 
-		vaddr = kmap_atomic(page);
+		vaddr = kmap_local_page(page);
 		link = (struct link_free *)vaddr + off / sizeof(*link);
 
 		while ((off += class->size) < PAGE_SIZE) {
@@ -921,7 +923,7 @@ static void init_zspage(struct size_class *class, struct zspage *zspage)
 			 */
 			link->next = -1UL << OBJ_TAG_BITS;
 		}
-		kunmap_atomic(vaddr);
+		kunmap_local(vaddr);
 		page = next_page;
 		off %= PAGE_SIZE;
 	}
@@ -1059,12 +1061,12 @@ static void *__zs_map_object(struct mapping_area *area,
 	sizes[1] = size - sizes[0];
 
 	/* copy object to per-cpu buffer */
-	addr = kmap_atomic(pages[0]);
+	addr = kmap_local_page(pages[0]);
 	memcpy(buf, addr + off, sizes[0]);
-	kunmap_atomic(addr);
-	addr = kmap_atomic(pages[1]);
+	kunmap_local(addr);
+	addr = kmap_local_page(pages[1]);
 	memcpy(buf + sizes[0], addr, sizes[1]);
-	kunmap_atomic(addr);
+	kunmap_local(addr);
 out:
 	return area->vm_buf;
 }
@@ -1089,12 +1091,12 @@ static void __zs_unmap_object(struct mapping_area *area,
 	sizes[1] = size - sizes[0];
 
 	/* copy per-cpu buffer to object */
-	addr = kmap_atomic(pages[0]);
+	addr = kmap_local_page(pages[0]);
 	memcpy(addr + off, buf, sizes[0]);
-	kunmap_atomic(addr);
-	addr = kmap_atomic(pages[1]);
+	kunmap_local(addr);
+	addr = kmap_local_page(pages[1]);
 	memcpy(addr, buf + sizes[0], sizes[1]);
-	kunmap_atomic(addr);
+	kunmap_local(addr);
 
 out:
 	/* enable page faults to match kunmap_atomic() return conditions */
@@ -1223,7 +1225,7 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle,
 	area->vm_mm = mm;
 	if (off + class->size <= PAGE_SIZE) {
 		/* this object is contained entirely within a page */
-		area->vm_addr = kmap_atomic(page);
+		area->vm_addr = kmap_local_page(page);
 		ret = area->vm_addr + off;
 		goto out;
 	}
@@ -1260,7 +1262,7 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
 
 	area = this_cpu_ptr(&zs_map_area);
 	if (off + class->size <= PAGE_SIZE)
-		kunmap_atomic(area->vm_addr);
+		kunmap_local(area->vm_addr);
 	else {
 		struct page *pages[2];
 
@@ -1318,7 +1320,7 @@ static unsigned long obj_malloc(struct zs_pool *pool,
 	for (i = 0; i < nr_page; i++)
 		m_page = get_next_page(m_page);
 
-	vaddr = kmap_atomic(m_page);
+	vaddr = kmap_local_page(m_page);
 	link = (struct link_free *)vaddr + m_offset / sizeof(*link);
 	set_freeobj(zspage, link->next >> OBJ_TAG_BITS);
 	if (likely(!ZsHugePage(zspage)))
@@ -1328,7 +1330,7 @@ static unsigned long obj_malloc(struct zs_pool *pool,
 		/* record handle to page->index */
 		zspage->first_page->index = handle | OBJ_ALLOCATED_TAG;
 
-	kunmap_atomic(vaddr);
+	kunmap_local(vaddr);
 	mod_zspage_inuse(zspage, 1);
 
 	obj = location_to_obj(m_page, obj);
@@ -1419,7 +1421,7 @@ static void obj_free(int class_size, unsigned long obj)
 	f_offset = offset_in_page(class_size * f_objidx);
 	zspage = get_zspage(f_page);
 
-	vaddr = kmap_atomic(f_page);
+	vaddr = kmap_local_page(f_page);
 	link = (struct link_free *)(vaddr + f_offset);
 
 	/* Insert this object in containing zspage's freelist */
@@ -1429,7 +1431,7 @@ static void obj_free(int class_size, unsigned long obj)
 		f_page->index = 0;
 	set_freeobj(zspage, f_objidx);
 
-	kunmap_atomic(vaddr);
+	kunmap_local(vaddr);
 	mod_zspage_inuse(zspage, -1);
 }
 
@@ -1492,8 +1494,8 @@ static void zs_object_copy(struct size_class *class, unsigned long dst,
 	if (d_off + class->size > PAGE_SIZE)
 		d_size = PAGE_SIZE - d_off;
 
-	s_addr = kmap_atomic(s_page);
-	d_addr = kmap_atomic(d_page);
+	s_addr = kmap_local_page(s_page);
+	d_addr = kmap_local_page(d_page);
 
 	while (1) {
 		size = min(s_size, d_size);
@@ -1516,26 +1518,26 @@ static void zs_object_copy(struct size_class *class, unsigned long dst,
 		 * Documentation/mm/highmem.rst.
 		 */
 		if (s_off >= PAGE_SIZE) {
-			kunmap_atomic(d_addr);
-			kunmap_atomic(s_addr);
+			kunmap_local(d_addr);
+			kunmap_local(s_addr);
 			s_page = get_next_page(s_page);
-			s_addr = kmap_atomic(s_page);
-			d_addr = kmap_atomic(d_page);
+			s_addr = kmap_local_page(s_page);
+			d_addr = kmap_local_page(d_page);
 			s_size = class->size - written;
 			s_off = 0;
 		}
 
 		if (d_off >= PAGE_SIZE) {
-			kunmap_atomic(d_addr);
+			kunmap_local(d_addr);
 			d_page = get_next_page(d_page);
-			d_addr = kmap_atomic(d_page);
+			d_addr = kmap_local_page(d_page);
 			d_size = class->size - written;
 			d_off = 0;
 		}
 	}
 
-	kunmap_atomic(d_addr);
-	kunmap_atomic(s_addr);
+	kunmap_local(d_addr);
+	kunmap_local(s_addr);
 }
 
 /*
@@ -1548,7 +1550,7 @@ static unsigned long find_alloced_obj(struct size_class *class,
 	unsigned int offset;
 	int index = *obj_idx;
 	unsigned long handle = 0;
-	void *addr = kmap_atomic(page);
+	void *addr = kmap_local_page(page);
 
 	offset = get_first_obj_offset(page);
 	offset += class->size * index;
@@ -1561,7 +1563,7 @@ static unsigned long find_alloced_obj(struct size_class *class,
 		index++;
 	}
 
-	kunmap_atomic(addr);
+	kunmap_local(addr);
 
 	*obj_idx = index;
 
@@ -1798,14 +1800,14 @@ static int zs_page_migrate(struct page *newpage, struct page *page,
 	migrate_write_lock(zspage);
 
 	offset = get_first_obj_offset(page);
-	s_addr = kmap_atomic(page);
+	s_addr = kmap_local_page(page);
 
 	/*
 	 * Here, any user cannot access all objects in the zspage so let's move.
 	 */
-	d_addr = kmap_atomic(newpage);
+	d_addr = kmap_local_page(newpage);
 	copy_page(d_addr, s_addr);
-	kunmap_atomic(d_addr);
+	kunmap_local(d_addr);
 
 	for (addr = s_addr + offset; addr < s_addr + PAGE_SIZE;
 					addr += class->size) {
@@ -1818,7 +1820,7 @@ static int zs_page_migrate(struct page *newpage, struct page *page,
 			record_obj(handle, new_obj);
 		}
 	}
-	kunmap_atomic(s_addr);
+	kunmap_local(s_addr);
 
 	replace_sub_page(class, zspage, newpage, page);
 	/*