[PATCH v6 2/9] irqchip/gic-v3-its: Align shared ITS allocations to the CoCo shared granule size

["Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>]

ITS tables allocated by the coco guest are shared with the hypervisor.
These allocations must satisfy the host shared-buffer granule size so that
the full converted range is safe for host access.

Allocate ITS pages using a size rounded up to the shared granule size and
use the same allocation order when encrypting, decrypting and freeing the
memory. Also grow the ITT cache in shared-granule sized chunks instead of
assuming PAGE_SIZE is sufficient.

Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
 drivers/irqchip/irq-gic-v3-its.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index e9807af23537..98d8fccbf0f2 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -216,6 +216,7 @@ static struct page *its_alloc_pages_node(int node, gfp_t gfp,
 	struct page *page;
 	int ret = 0;
 
+	order = get_order(mem_cc_align_to_shared_granule(PAGE_SIZE << order));
 	page = alloc_pages_node(node, gfp | gfp_flags_quirk, order);
 
 	if (!page)
@@ -241,6 +242,8 @@ static struct page *its_alloc_pages(gfp_t gfp, unsigned int order)
 
 static void its_free_pages(void *addr, unsigned int order)
 {
+
+	order = get_order(mem_cc_align_to_shared_granule(PAGE_SIZE << order));
 	/*
 	 * If the memory cannot be encrypted again then we must leak the pages.
 	 * set_memory_encrypted() will already have WARNed.
@@ -272,7 +275,8 @@ static void *itt_alloc_pool(int node, int size)
 		if (!page)
 			break;
 
-		gen_pool_add(itt_pool, (unsigned long)page_address(page), PAGE_SIZE, node);
+		gen_pool_add(itt_pool, (unsigned long)page_address(page),
+			     mem_cc_align_to_shared_granule(PAGE_SIZE), node);
 	} while (!addr);
 
 	return (void *)addr;
-- 
2.43.0