[RFC PATCH 13/14] arm64: realm: Support nonsecure ITS emulation shared

[Steven Price <steven.price@arm.com>]

Within a realm guest the ITS is emulated by the host. This means the
allocations must have been made available to the host by a call to
set_memory_decrypted(). Introduce an allocation function which performs
this extra call.

Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 95 ++++++++++++++++++++++++--------
 1 file changed, 71 insertions(+), 24 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 973ede0197e3..5f9829376f6c 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -18,6 +18,7 @@
 #include <linux/irqdomain.h>
 #include <linux/list.h>
 #include <linux/log2.h>
+#include <linux/mem_encrypt.h>
 #include <linux/memblock.h>
 #include <linux/mm.h>
 #include <linux/msi.h>
@@ -27,6 +28,7 @@
 #include <linux/of_pci.h>
 #include <linux/of_platform.h>
 #include <linux/percpu.h>
+#include <linux/set_memory.h>
 #include <linux/slab.h>
 #include <linux/syscore_ops.h>
 
@@ -165,6 +167,7 @@ struct its_device {
 	struct its_node		*its;
 	struct event_lpi_map	event_map;
 	void			*itt;
+	u32			itt_order;
 	u32			nr_ites;
 	u32			device_id;
 	bool			shared;
@@ -200,6 +203,33 @@ static DEFINE_IDA(its_vpeid_ida);
 #define gic_data_rdist_rd_base()	(gic_data_rdist()->rd_base)
 #define gic_data_rdist_vlpi_base()	(gic_data_rdist_rd_base() + SZ_128K)
 
+static struct page *its_alloc_shared_pages_node(int node, gfp_t gfp,
+						unsigned int order)
+{
+	struct page *page;
+
+	if (node == NUMA_NO_NODE)
+		page = alloc_pages(gfp, order);
+	else
+		page = alloc_pages_node(node, gfp, order);
+
+	if (page)
+		set_memory_decrypted((unsigned long)page_address(page),
+				     1 << order);
+	return page;
+}
+
+static struct page *its_alloc_shared_pages(gfp_t gfp, unsigned int order)
+{
+	return its_alloc_shared_pages_node(NUMA_NO_NODE, gfp, order);
+}
+
+static void its_free_shared_pages(void *addr, unsigned int order)
+{
+	set_memory_encrypted((unsigned long)addr, 1 << order);
+	free_pages((unsigned long)addr, order);
+}
+
 /*
  * Skip ITSs that have no vLPIs mapped, unless we're on GICv4.1, as we
  * always have vSGIs mapped.
@@ -2178,7 +2208,8 @@ static struct page *its_allocate_prop_table(gfp_t gfp_flags)
 {
 	struct page *prop_page;
 
-	prop_page = alloc_pages(gfp_flags, get_order(LPI_PROPBASE_SZ));
+	prop_page = its_alloc_shared_pages(gfp_flags,
+					   get_order(LPI_PROPBASE_SZ));
 	if (!prop_page)
 		return NULL;
 
@@ -2189,8 +2220,8 @@ static struct page *its_allocate_prop_table(gfp_t gfp_flags)
 
 static void its_free_prop_table(struct page *prop_page)
 {
-	free_pages((unsigned long)page_address(prop_page),
-		   get_order(LPI_PROPBASE_SZ));
+	its_free_shared_pages(page_address(prop_page),
+			      get_order(LPI_PROPBASE_SZ));
 }
 
 static bool gic_check_reserved_range(phys_addr_t addr, unsigned long size)
@@ -2312,10 +2343,10 @@ static int its_setup_baser(struct its_node *its, struct its_baser *baser,
 		order = get_order(GITS_BASER_PAGES_MAX * psz);
 	}
 
-	page = alloc_pages_node(its->numa_node, GFP_KERNEL | __GFP_ZERO, order);
+	page = its_alloc_shared_pages_node(its->numa_node,
+					   GFP_KERNEL | __GFP_ZERO, order);
 	if (!page)
 		return -ENOMEM;
-
 	base = (void *)page_address(page);
 	baser_phys = virt_to_phys(base);
 
@@ -2325,7 +2356,7 @@ static int its_setup_baser(struct its_node *its, struct its_baser *baser,
 		/* 52bit PA is supported only when PageSize=64K */
 		if (psz != SZ_64K) {
 			pr_err("ITS: no 52bit PA support when psz=%d\n", psz);
-			free_pages((unsigned long)base, order);
+			its_free_shared_pages(base, order);
 			return -ENXIO;
 		}
 
@@ -2379,7 +2410,7 @@ static int its_setup_baser(struct its_node *its, struct its_baser *baser,
 		pr_err("ITS@%pa: %s doesn't stick: %llx %llx\n",
 		       &its->phys_base, its_base_type_string[type],
 		       val, tmp);
-		free_pages((unsigned long)base, order);
+		its_free_shared_pages(base, order);
 		return -ENXIO;
 	}
 
@@ -2518,8 +2549,8 @@ static void its_free_tables(struct its_node *its)
 
 	for (i = 0; i < GITS_BASER_NR_REGS; i++) {
 		if (its->tables[i].base) {
-			free_pages((unsigned long)its->tables[i].base,
-				   its->tables[i].order);
+			its_free_shared_pages(its->tables[i].base,
+					      its->tables[i].order);
 			its->tables[i].base = NULL;
 		}
 	}
@@ -2778,7 +2809,8 @@ static bool allocate_vpe_l2_table(int cpu, u32 id)
 
 	/* Allocate memory for 2nd level table */
 	if (!table[idx]) {
-		page = alloc_pages(GFP_KERNEL | __GFP_ZERO, get_order(psz));
+		page = its_alloc_shared_pages(GFP_KERNEL | __GFP_ZERO,
+					      get_order(psz));
 		if (!page)
 			return false;
 
@@ -2897,7 +2929,8 @@ static int allocate_vpe_l1_table(void)
 
 	pr_debug("np = %d, npg = %lld, psz = %d, epp = %d, esz = %d\n",
 		 np, npg, psz, epp, esz);
-	page = alloc_pages(GFP_ATOMIC | __GFP_ZERO, get_order(np * PAGE_SIZE));
+	page = its_alloc_shared_pages(GFP_ATOMIC | __GFP_ZERO,
+				      get_order(np * PAGE_SIZE));
 	if (!page)
 		return -ENOMEM;
 
@@ -2941,8 +2974,8 @@ static struct page *its_allocate_pending_table(gfp_t gfp_flags)
 {
 	struct page *pend_page;
 
-	pend_page = alloc_pages(gfp_flags | __GFP_ZERO,
-				get_order(LPI_PENDBASE_SZ));
+	pend_page = its_alloc_shared_pages(gfp_flags | __GFP_ZERO,
+					   get_order(LPI_PENDBASE_SZ));
 	if (!pend_page)
 		return NULL;
 
@@ -2954,7 +2987,8 @@ static struct page *its_allocate_pending_table(gfp_t gfp_flags)
 
 static void its_free_pending_table(struct page *pt)
 {
-	free_pages((unsigned long)page_address(pt), get_order(LPI_PENDBASE_SZ));
+	its_free_shared_pages(page_address(pt),
+			      get_order(LPI_PENDBASE_SZ));
 }
 
 /*
@@ -3283,8 +3317,9 @@ static bool its_alloc_table_entry(struct its_node *its,
 
 	/* Allocate memory for 2nd level table */
 	if (!table[idx]) {
-		page = alloc_pages_node(its->numa_node, GFP_KERNEL | __GFP_ZERO,
-					get_order(baser->psz));
+		page = its_alloc_shared_pages_node(its->numa_node,
+						   GFP_KERNEL | __GFP_ZERO,
+						   get_order(baser->psz));
 		if (!page)
 			return false;
 
@@ -3367,7 +3402,9 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
 	unsigned long *lpi_map = NULL;
 	unsigned long flags;
 	u16 *col_map = NULL;
+	struct page *page;
 	void *itt;
+	int itt_order;
 	int lpi_base;
 	int nr_lpis;
 	int nr_ites;
@@ -3379,7 +3416,6 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
 	if (WARN_ON(!is_power_of_2(nvecs)))
 		nvecs = roundup_pow_of_two(nvecs);
 
-	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 	/*
 	 * Even if the device wants a single LPI, the ITT must be
 	 * sized as a power of two (and you need at least one bit...).
@@ -3387,7 +3423,16 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
 	nr_ites = max(2, nvecs);
 	sz = nr_ites * (FIELD_GET(GITS_TYPER_ITT_ENTRY_SIZE, its->typer) + 1);
 	sz = max(sz, ITS_ITT_ALIGN) + ITS_ITT_ALIGN - 1;
-	itt = kzalloc_node(sz, GFP_KERNEL, its->numa_node);
+	itt_order = get_order(sz);
+	page = its_alloc_shared_pages_node(its->numa_node,
+					   GFP_KERNEL | __GFP_ZERO,
+					   itt_order);
+	if (!page)
+		return NULL;
+	itt = (void *)page_address(page);
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+
 	if (alloc_lpis) {
 		lpi_map = its_lpi_alloc(nvecs, &lpi_base, &nr_lpis);
 		if (lpi_map)
@@ -3399,9 +3444,9 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
 		lpi_base = 0;
 	}
 
-	if (!dev || !itt ||  !col_map || (!lpi_map && alloc_lpis)) {
+	if (!dev || !col_map || (!lpi_map && alloc_lpis)) {
 		kfree(dev);
-		kfree(itt);
+		its_free_shared_pages(itt, itt_order);
 		bitmap_free(lpi_map);
 		kfree(col_map);
 		return NULL;
@@ -3411,6 +3456,7 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
 
 	dev->its = its;
 	dev->itt = itt;
+	dev->itt_order = itt_order;
 	dev->nr_ites = nr_ites;
 	dev->event_map.lpi_map = lpi_map;
 	dev->event_map.col_map = col_map;
@@ -3438,7 +3484,7 @@ static void its_free_device(struct its_device *its_dev)
 	list_del(&its_dev->entry);
 	raw_spin_unlock_irqrestore(&its_dev->its->lock, flags);
 	kfree(its_dev->event_map.col_map);
-	kfree(its_dev->itt);
+	its_free_shared_pages(its_dev->itt, its_dev->itt_order);
 	kfree(its_dev);
 }
 
@@ -5064,8 +5110,9 @@ static int __init its_probe_one(struct resource *res,
 
 	its->numa_node = numa_node;
 
-	page = alloc_pages_node(its->numa_node, GFP_KERNEL | __GFP_ZERO,
-				get_order(ITS_CMD_QUEUE_SZ));
+	page = its_alloc_shared_pages_node(its->numa_node,
+					   GFP_KERNEL | __GFP_ZERO,
+					   get_order(ITS_CMD_QUEUE_SZ));
 	if (!page) {
 		err = -ENOMEM;
 		goto out_unmap_sgir;
@@ -5131,7 +5178,7 @@ static int __init its_probe_one(struct resource *res,
 out_free_tables:
 	its_free_tables(its);
 out_free_cmd:
-	free_pages((unsigned long)its->cmd_base, get_order(ITS_CMD_QUEUE_SZ));
+	its_free_shared_pages(its->cmd_base, get_order(ITS_CMD_QUEUE_SZ));
 out_unmap_sgir:
 	if (its->sgir_base)
 		iounmap(its->sgir_base);
-- 
2.34.1