1 files changed, 58 insertions, 7 deletions

diff --git a/drivers/iommu/io-pgtable-dart.c b/drivers/iommu/io-pgtable-dart.c
index 74b1ef2b96be..8459772bfefe 100644
--- a/drivers/iommu/io-pgtable-dart.c
+++ b/drivers/iommu/io-pgtable-dart.c
@@ -16,6 +16,8 @@
 #include <linux/atomic.h>
 #include <linux/bitfield.h>
 #include <linux/bitops.h>
+#include "linux/export.h"
+#include <linux/io.h>
 #include <linux/io-pgtable.h>
 #include <linux/kernel.h>
 #include <linux/sizes.h>
@@ -24,6 +26,8 @@
 
 #include <asm/barrier.h>
 
+#include "io-pgtable-dart.h"
+
 #define DART1_MAX_ADDR_BITS	36
 
 #define DART_MAX_TABLES		4
@@ -106,8 +110,7 @@ static phys_addr_t iopte_to_paddr(dart_iopte pte,
 	return paddr;
 }
 
-static void *__dart_alloc_pages(size_t size, gfp_t gfp,
-				    struct io_pgtable_cfg *cfg)
+static void *__dart_alloc_pages(size_t size, gfp_t gfp)
 {
 	int order = get_order(size);
 	struct page *p;
@@ -262,7 +265,7 @@ static int dart_map_pages(struct io_pgtable_ops *ops, unsigned long iova,
 
 	/* no L2 table present */
 	if (!pte) {
-		cptep = __dart_alloc_pages(tblsz, gfp, cfg);
+		cptep = __dart_alloc_pages(tblsz, gfp);
 		if (!cptep)
 			return -ENOMEM;
 
@@ -363,6 +366,32 @@ static phys_addr_t dart_iova_to_phys(struct io_pgtable_ops *ops,
 	return 0;
 }
 
+int io_pgtable_dart_setup_locked(struct io_pgtable_ops *ops)
+{
+	void *l1tbl;
+	struct dart_io_pgtable *data = io_pgtable_ops_to_data(ops);
+	struct io_pgtable_cfg *cfg = &data->iop.cfg;
+	size_t size;
+
+	if (!(cfg->quirks & IO_PGTABLE_QUIRK_APPLE_LOCKED))
+		return 0;
+
+	size = cfg->pgsize_bitmap;
+	l1tbl = devm_memremap(cfg->iommu_dev, cfg->apple_dart_cfg.ttbr[0], size,
+			      MEMREMAP_WB);
+	if (!l1tbl)
+		return -ENOMEM;
+
+	for (int entry = 0; entry < DART_PTES_PER_TABLE(data); entry++)
+		((dart_iopte *)l1tbl)[entry] = ((dart_iopte *)data->pgd[0])[entry];
+
+	free_pages((unsigned long)data->pgd[0], get_order(DART_GRANULE(data)));
+	data->pgd[0] = l1tbl;
+
+	return 0;
+}
+EXPORT_SYMBOL(io_pgtable_dart_setup_locked);
+
 static struct dart_io_pgtable *
 dart_alloc_pgtable(struct io_pgtable_cfg *cfg)
 {
@@ -418,30 +447,52 @@ apple_dart_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
 
 	cfg->apple_dart_cfg.n_ttbrs = 1 << data->tbl_bits;
 
+	/* Locked DARTs can not modify the TTBR registers. Allocate first a shadow
+	 * page table so locked DARTs (disp0, dcp, dcpext*) can map their reserved
+	 * memory regions. They will be later in io_pgtable_dart_setup_locked()
+	 * copied to the locked L1 table.
+	 */
+	if (cfg->quirks & IO_PGTABLE_QUIRK_APPLE_LOCKED) {
+		if (cfg->apple_dart_cfg.n_ttbrs > 1)
+			goto out_free_data;
+
+		data->pgd[0] = __dart_alloc_pages(DART_GRANULE(data), GFP_KERNEL);
+		if (!data->pgd[0])
+			goto out_free_data;
+
+		return &data->iop;
+	}
+
 	for (i = 0; i < cfg->apple_dart_cfg.n_ttbrs; ++i) {
-		data->pgd[i] = __dart_alloc_pages(DART_GRANULE(data), GFP_KERNEL,
-					   cfg);
+		data->pgd[i] = __dart_alloc_pages(DART_GRANULE(data), GFP_KERNEL);
 		if (!data->pgd[i])
-			goto out_free_data;
+			goto out_free_pages;
 		cfg->apple_dart_cfg.ttbr[i] = virt_to_phys(data->pgd[i]);
 	}
 
 	return &data->iop;
 
-out_free_data:
+out_free_pages:
 	while (--i >= 0)
 		free_pages((unsigned long)data->pgd[i],
 			   get_order(DART_GRANULE(data)));
+out_free_data:
 	kfree(data);
 	return NULL;
 }
 
 static void apple_dart_free_pgtable(struct io_pgtable *iop)
 {
+	struct io_pgtable_cfg *cfg = &iop->cfg;
 	struct dart_io_pgtable *data = io_pgtable_to_data(iop);
 	dart_iopte *ptep, *end;
 	int i;
 
+        if (cfg->quirks & IO_PGTABLE_QUIRK_APPLE_LOCKED) {
+		kfree(data);
+		return;
+	}
+
 	for (i = 0; i < (1 << data->tbl_bits) && data->pgd[i]; ++i) {
 		ptep = data->pgd[i];
 		end = (void *)ptep + DART_GRANULE(data);