Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 19b4c62..9704f3f 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
  * 
@@ -6,20 +7,6 @@
  *               and  Ben. Herrenschmidt, IBM Corporation
  *
  * Dynamic DMA mapping support, bus-independent parts.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- * 
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * 
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
 
@@ -47,6 +34,7 @@
 #include <asm/fadump.h>
 #include <asm/vio.h>
 #include <asm/tce.h>
+#include <asm/mmu_context.h>
 
 #define DBG(...)
 
@@ -197,11 +185,11 @@
 	if (unlikely(npages == 0)) {
 		if (printk_ratelimit())
 			WARN_ON(1);
-		return IOMMU_MAPPING_ERROR;
+		return DMA_MAPPING_ERROR;
 	}
 
 	if (should_fail_iommu(dev))
-		return IOMMU_MAPPING_ERROR;
+		return DMA_MAPPING_ERROR;
 
 	/*
 	 * We don't need to disable preemption here because any CPU can
@@ -277,7 +265,7 @@
 		} else {
 			/* Give up */
 			spin_unlock_irqrestore(&(pool->lock), flags);
-			return IOMMU_MAPPING_ERROR;
+			return DMA_MAPPING_ERROR;
 		}
 	}
 
@@ -309,13 +297,13 @@
 			      unsigned long attrs)
 {
 	unsigned long entry;
-	dma_addr_t ret = IOMMU_MAPPING_ERROR;
+	dma_addr_t ret = DMA_MAPPING_ERROR;
 	int build_fail;
 
 	entry = iommu_range_alloc(dev, tbl, npages, NULL, mask, align_order);
 
-	if (unlikely(entry == IOMMU_MAPPING_ERROR))
-		return IOMMU_MAPPING_ERROR;
+	if (unlikely(entry == DMA_MAPPING_ERROR))
+		return DMA_MAPPING_ERROR;
 
 	entry += tbl->it_offset;	/* Offset into real TCE table */
 	ret = entry << tbl->it_page_shift;	/* Set the return dma address */
@@ -327,12 +315,12 @@
 
 	/* tbl->it_ops->set() only returns non-zero for transient errors.
 	 * Clean up the table bitmap in this case and return
-	 * IOMMU_MAPPING_ERROR. For all other errors the functionality is
+	 * DMA_MAPPING_ERROR. For all other errors the functionality is
 	 * not altered.
 	 */
 	if (unlikely(build_fail)) {
 		__iommu_free(tbl, ret, npages);
-		return IOMMU_MAPPING_ERROR;
+		return DMA_MAPPING_ERROR;
 	}
 
 	/* Flush/invalidate TLB caches if necessary */
@@ -477,7 +465,7 @@
 		DBG("  - vaddr: %lx, size: %lx\n", vaddr, slen);
 
 		/* Handle failure */
-		if (unlikely(entry == IOMMU_MAPPING_ERROR)) {
+		if (unlikely(entry == DMA_MAPPING_ERROR)) {
 			if (!(attrs & DMA_ATTR_NO_WARN) &&
 			    printk_ratelimit())
 				dev_info(dev, "iommu_alloc failed, tbl %p "
@@ -544,7 +532,7 @@
 	 */
 	if (outcount < incount) {
 		outs = sg_next(outs);
-		outs->dma_address = IOMMU_MAPPING_ERROR;
+		outs->dma_address = DMA_MAPPING_ERROR;
 		outs->dma_length = 0;
 	}
 
@@ -562,7 +550,7 @@
 			npages = iommu_num_pages(s->dma_address, s->dma_length,
 						 IOMMU_PAGE_SIZE(tbl));
 			__iommu_free(tbl, vaddr, npages);
-			s->dma_address = IOMMU_MAPPING_ERROR;
+			s->dma_address = DMA_MAPPING_ERROR;
 			s->dma_length = 0;
 		}
 		if (s == outs)
@@ -645,11 +633,54 @@
 #endif
 }
 
+static void iommu_table_reserve_pages(struct iommu_table *tbl,
+		unsigned long res_start, unsigned long res_end)
+{
+	int i;
+
+	WARN_ON_ONCE(res_end < res_start);
+	/*
+	 * Reserve page 0 so it will not be used for any mappings.
+	 * This avoids buggy drivers that consider page 0 to be invalid
+	 * to crash the machine or even lose data.
+	 */
+	if (tbl->it_offset == 0)
+		set_bit(0, tbl->it_map);
+
+	tbl->it_reserved_start = res_start;
+	tbl->it_reserved_end = res_end;
+
+	/* Check if res_start..res_end isn't empty and overlaps the table */
+	if (res_start && res_end &&
+			(tbl->it_offset + tbl->it_size < res_start ||
+			 res_end < tbl->it_offset))
+		return;
+
+	for (i = tbl->it_reserved_start; i < tbl->it_reserved_end; ++i)
+		set_bit(i - tbl->it_offset, tbl->it_map);
+}
+
+static void iommu_table_release_pages(struct iommu_table *tbl)
+{
+	int i;
+
+	/*
+	 * In case we have reserved the first bit, we should not emit
+	 * the warning below.
+	 */
+	if (tbl->it_offset == 0)
+		clear_bit(0, tbl->it_map);
+
+	for (i = tbl->it_reserved_start; i < tbl->it_reserved_end; ++i)
+		clear_bit(i - tbl->it_offset, tbl->it_map);
+}
+
 /*
  * Build a iommu_table structure.  This contains a bit map which
  * is used to manage allocation of the tce space.
  */
-struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid)
+struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid,
+		unsigned long res_start, unsigned long res_end)
 {
 	unsigned long sz;
 	static int welcomed = 0;
@@ -668,13 +699,7 @@
 	tbl->it_map = page_address(page);
 	memset(tbl->it_map, 0, sz);
 
-	/*
-	 * Reserve page 0 so it will not be used for any mappings.
-	 * This avoids buggy drivers that consider page 0 to be invalid
-	 * to crash the machine or even lose data.
-	 */
-	if (tbl->it_offset == 0)
-		set_bit(0, tbl->it_map);
+	iommu_table_reserve_pages(tbl, res_start, res_end);
 
 	/* We only split the IOMMU table if we have 1GB or more of space */
 	if ((tbl->it_size << tbl->it_page_shift) >= (1UL * 1024 * 1024 * 1024))
@@ -726,12 +751,7 @@
 		return;
 	}
 
-	/*
-	 * In case we have reserved the first bit, we should not emit
-	 * the warning below.
-	 */
-	if (tbl->it_offset == 0)
-		clear_bit(0, tbl->it_map);
+	iommu_table_release_pages(tbl);
 
 	/* verify that table contains no entries */
 	if (!bitmap_empty(tbl->it_map, tbl->it_size))
@@ -776,7 +796,7 @@
 			  unsigned long mask, enum dma_data_direction direction,
 			  unsigned long attrs)
 {
-	dma_addr_t dma_handle = IOMMU_MAPPING_ERROR;
+	dma_addr_t dma_handle = DMA_MAPPING_ERROR;
 	void *vaddr;
 	unsigned long uaddr;
 	unsigned int npages, align;
@@ -785,9 +805,9 @@
 
 	vaddr = page_address(page) + offset;
 	uaddr = (unsigned long)vaddr;
-	npages = iommu_num_pages(uaddr, size, IOMMU_PAGE_SIZE(tbl));
 
 	if (tbl) {
+		npages = iommu_num_pages(uaddr, size, IOMMU_PAGE_SIZE(tbl));
 		align = 0;
 		if (tbl->it_page_shift < PAGE_SHIFT && size >= PAGE_SIZE &&
 		    ((unsigned long)vaddr & ~PAGE_MASK) == 0)
@@ -796,7 +816,7 @@
 		dma_handle = iommu_alloc(dev, tbl, vaddr, npages, direction,
 					 mask >> tbl->it_page_shift, align,
 					 attrs);
-		if (dma_handle == IOMMU_MAPPING_ERROR) {
+		if (dma_handle == DMA_MAPPING_ERROR) {
 			if (!(attrs & DMA_ATTR_NO_WARN) &&
 			    printk_ratelimit())  {
 				dev_info(dev, "iommu_alloc failed, tbl %p "
@@ -868,7 +888,7 @@
 	io_order = get_iommu_order(size, tbl);
 	mapping = iommu_alloc(dev, tbl, ret, nio_pages, DMA_BIDIRECTIONAL,
 			      mask >> tbl->it_page_shift, io_order, 0);
-	if (mapping == IOMMU_MAPPING_ERROR) {
+	if (mapping == DMA_MAPPING_ERROR) {
 		free_pages((unsigned long)ret, order);
 		return NULL;
 	}
@@ -993,25 +1013,32 @@
 }
 EXPORT_SYMBOL_GPL(iommu_tce_check_gpa);
 
-long iommu_tce_xchg(struct iommu_table *tbl, unsigned long entry,
-		unsigned long *hpa, enum dma_data_direction *direction)
+extern long iommu_tce_xchg_no_kill(struct mm_struct *mm,
+		struct iommu_table *tbl,
+		unsigned long entry, unsigned long *hpa,
+		enum dma_data_direction *direction)
 {
 	long ret;
+	unsigned long size = 0;
 
-	ret = tbl->it_ops->exchange(tbl, entry, hpa, direction);
-
+	ret = tbl->it_ops->xchg_no_kill(tbl, entry, hpa, direction, false);
 	if (!ret && ((*direction == DMA_FROM_DEVICE) ||
-			(*direction == DMA_BIDIRECTIONAL)))
+			(*direction == DMA_BIDIRECTIONAL)) &&
+			!mm_iommu_is_devmem(mm, *hpa, tbl->it_page_shift,
+					&size))
 		SetPageDirty(pfn_to_page(*hpa >> PAGE_SHIFT));
 
-	/* if (unlikely(ret))
-		pr_err("iommu_tce: %s failed on hwaddr=%lx ioba=%lx kva=%lx ret=%d\n",
-			__func__, hwaddr, entry << tbl->it_page_shift,
-				hwaddr, ret); */
-
 	return ret;
 }
-EXPORT_SYMBOL_GPL(iommu_tce_xchg);
+EXPORT_SYMBOL_GPL(iommu_tce_xchg_no_kill);
+
+void iommu_tce_kill(struct iommu_table *tbl,
+		unsigned long entry, unsigned long pages)
+{
+	if (tbl->it_ops->tce_kill)
+		tbl->it_ops->tce_kill(tbl, entry, pages, false);
+}
+EXPORT_SYMBOL_GPL(iommu_tce_kill);
 
 int iommu_take_ownership(struct iommu_table *tbl)
 {
@@ -1025,22 +1052,21 @@
 	 * requires exchange() callback defined so if it is not
 	 * implemented, we disallow taking ownership over the table.
 	 */
-	if (!tbl->it_ops->exchange)
+	if (!tbl->it_ops->xchg_no_kill)
 		return -EINVAL;
 
 	spin_lock_irqsave(&tbl->large_pool.lock, flags);
 	for (i = 0; i < tbl->nr_pools; i++)
 		spin_lock(&tbl->pools[i].lock);
 
-	if (tbl->it_offset == 0)
-		clear_bit(0, tbl->it_map);
+	iommu_table_release_pages(tbl);
 
 	if (!bitmap_empty(tbl->it_map, tbl->it_size)) {
 		pr_err("iommu_tce: it_map is not empty");
 		ret = -EBUSY;
-		/* Restore bit#0 set by iommu_init_table() */
-		if (tbl->it_offset == 0)
-			set_bit(0, tbl->it_map);
+		/* Undo iommu_table_release_pages, i.e. restore bit#0, etc */
+		iommu_table_reserve_pages(tbl, tbl->it_reserved_start,
+				tbl->it_reserved_end);
 	} else {
 		memset(tbl->it_map, 0xff, sz);
 	}
@@ -1063,9 +1089,8 @@
 
 	memset(tbl->it_map, 0, sz);
 
-	/* Restore bit#0 set by iommu_init_table() */
-	if (tbl->it_offset == 0)
-		set_bit(0, tbl->it_map);
+	iommu_table_reserve_pages(tbl, tbl->it_reserved_start,
+			tbl->it_reserved_end);
 
 	for (i = 0; i < tbl->nr_pools; i++)
 		spin_unlock(&tbl->pools[i].lock);
@@ -1073,11 +1098,8 @@
 }
 EXPORT_SYMBOL_GPL(iommu_release_ownership);
 
-int iommu_add_device(struct device *dev)
+int iommu_add_device(struct iommu_table_group *table_group, struct device *dev)
 {
-	struct iommu_table *tbl;
-	struct iommu_table_group_link *tgl;
-
 	/*
 	 * The sysfs entries should be populated before
 	 * binding IOMMU group. If sysfs entries isn't
@@ -1086,39 +1108,17 @@
 	if (!device_is_registered(dev))
 		return -ENOENT;
 
-	if (dev->iommu_group) {
+	if (device_iommu_mapped(dev)) {
 		pr_debug("%s: Skipping device %s with iommu group %d\n",
 			 __func__, dev_name(dev),
 			 iommu_group_id(dev->iommu_group));
 		return -EBUSY;
 	}
 
-	tbl = get_iommu_table_base(dev);
-	if (!tbl) {
-		pr_debug("%s: Skipping device %s with no tbl\n",
-			 __func__, dev_name(dev));
-		return 0;
-	}
-
-	tgl = list_first_entry_or_null(&tbl->it_group_list,
-			struct iommu_table_group_link, next);
-	if (!tgl) {
-		pr_debug("%s: Skipping device %s with no group\n",
-			 __func__, dev_name(dev));
-		return 0;
-	}
 	pr_debug("%s: Adding %s to iommu group %d\n",
-		 __func__, dev_name(dev),
-		 iommu_group_id(tgl->table_group->group));
+		 __func__, dev_name(dev),  iommu_group_id(table_group->group));
 
-	if (PAGE_SIZE < IOMMU_PAGE_SIZE(tbl)) {
-		pr_err("%s: Invalid IOMMU page size %lx (%lx) on %s\n",
-		       __func__, IOMMU_PAGE_SIZE(tbl),
-		       PAGE_SIZE, dev_name(dev));
-		return -EINVAL;
-	}
-
-	return iommu_group_add_device(tgl->table_group->group, dev);
+	return iommu_group_add_device(table_group->group, dev);
 }
 EXPORT_SYMBOL_GPL(iommu_add_device);
 
@@ -1129,7 +1129,7 @@
 	 * and we needn't detach them from the associated
 	 * IOMMU groups
 	 */
-	if (!dev->iommu_group) {
+	if (!device_iommu_mapped(dev)) {
 		pr_debug("iommu_tce: skipping device %s with no tbl\n",
 			 dev_name(dev));
 		return;
@@ -1138,31 +1138,4 @@
 	iommu_group_remove_device(dev);
 }
 EXPORT_SYMBOL_GPL(iommu_del_device);
-
-static int tce_iommu_bus_notifier(struct notifier_block *nb,
-                unsigned long action, void *data)
-{
-        struct device *dev = data;
-
-        switch (action) {
-        case BUS_NOTIFY_ADD_DEVICE:
-                return iommu_add_device(dev);
-        case BUS_NOTIFY_DEL_DEVICE:
-                if (dev->iommu_group)
-                        iommu_del_device(dev);
-                return 0;
-        default:
-                return 0;
-        }
-}
-
-static struct notifier_block tce_iommu_bus_nb = {
-        .notifier_call = tce_iommu_bus_notifier,
-};
-
-int __init tce_iommu_bus_notifier_init(void)
-{
-        bus_register_notifier(&pci_bus_type, &tce_iommu_bus_nb);
-        return 0;
-}
 #endif /* CONFIG_IOMMU_API */