ANDROID: trusty: Make Trusty driver page size agnostic

The FW interface expects number of 4K pages when memory is shared.
However the driver and the FW share memory in contigous memory areas,
so converting the number of kernel size pages to Trusty FW size pages
makes the Trusty kernel driver page size agnostic.

Bug: 294914413
Bug: 265047549
Bug: 267220208
Change-Id: Ie0b88c9cb30a0a16ea67f8046c7d0def2886c93f
Signed-off-by: Gabor Kertesz <gabor.kertesz@arm.com>
[ Kalesh Singh - Round up vds buffer allocation size to page boundary ]
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>

3 files changed, 20 insertions, 5 deletions

diff --git a/drivers/trusty/trusty-ipc.c b/drivers/trusty/trusty-ipc.c
index aee0d66..853ac35 100644
--- a/drivers/trusty/trusty-ipc.c
+++ b/drivers/trusty/trusty-ipc.c
@@ -210,7 +210,7 @@ static struct tipc_msg_buf *vds_alloc_msg_buf(struct tipc_virtio_dev *vds,
 {
 	int ret;
 	struct tipc_msg_buf *mb;
-	size_t sz = vds->msg_buf_max_sz;
+	size_t sz = ALIGN(vds->msg_buf_max_sz, PAGE_SIZE);
 	pgprot_t pgprot = share_write ? PAGE_KERNEL : PAGE_KERNEL_RO;
 
 	/* allocate tracking structure */
diff --git a/drivers/trusty/trusty.c b/drivers/trusty/trusty.c
index 0ff1cf2..5017e0d 100644
--- a/drivers/trusty/trusty.c
+++ b/drivers/trusty/trusty.c
@@ -349,7 +349,7 @@ int trusty_transfer_memory(struct device *dev, u64 *id,
 		emad->comp_mrd_offset = comp_mrd_offset;
 		emad->reserved_8_15 = 0;
 	}
-	comp_mrd->total_page_count = len / PAGE_SIZE;
+	comp_mrd->total_page_count = len / FFA_PAGE_SIZE;
 	comp_mrd->address_range_count = nents;
 	comp_mrd->reserved_8_15 = 0;
 
@@ -364,7 +364,7 @@ int trusty_transfer_memory(struct device *dev, u64 *id,
 
 		for (i = 0; i < lcount; i++) {
 			cons_mrd[i].address = sg_dma_address(sg);
-			cons_mrd[i].page_count = sg_dma_len(sg) / PAGE_SIZE;
+			cons_mrd[i].page_count = sg_dma_len(sg) / FFA_PAGE_SIZE;
 			cons_mrd[i].reserved_12_15 = 0;
 			sg = sg_next(sg);
 		}
@@ -617,6 +617,14 @@ static int trusty_init_msg_buf(struct trusty_state *s, struct device *dev)
 	s->ffa_local_id = smc_ret.r2;
 	s->ffa_remote_id = 0x8000;
 
+	/*
+	 * The pKVM hypervisor uses the same page size as the host, including for
+	 * stage-2 mappings. So the rx/tx buffers need to be page-sized multiple,
+	 * and page-aligned.
+	 *
+	 * TODO: This can be made more generic by discovering the required size
+	 * through SMC_FC_FFA_FEATURES later.
+	 */
 	s->ffa_tx = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!s->ffa_tx) {
 		ret = -ENOMEM;
@@ -639,8 +647,8 @@ static int trusty_init_msg_buf(struct trusty_state *s, struct device *dev)
 		goto err_unaligned_rx_buf;
 	}
 
-	smc_ret = trusty_smc8(SMC_FCZ_FFA_RXTX_MAP, tx_paddr, rx_paddr, 1, 0,
-			      0, 0, 0);
+	smc_ret = trusty_smc8(SMC_FCZ_FFA_RXTX_MAP, tx_paddr, rx_paddr,
+				PAGE_SIZE / FFA_PAGE_SIZE, 0, 0, 0, 0);
 	if (smc_ret.r0 != SMC_FC_FFA_SUCCESS) {
 		dev_err(s->dev, "%s: SMC_FCZ_FFA_RXTX_MAP failed 0x%lx 0x%lx 0x%lx\n",
 			__func__, smc_ret.r0, smc_ret.r1, smc_ret.r2);
diff --git a/include/linux/trusty/arm_ffa.h b/include/linux/trusty/arm_ffa.h
index ab7b2af..95d31b3 100644
--- a/include/linux/trusty/arm_ffa.h
+++ b/include/linux/trusty/arm_ffa.h
@@ -36,6 +36,13 @@
 	SMC_FASTCALL64_NR(SMC_ENTITY_SHARED_MEMORY, nr)
 
 /**
+ * FF-A specification mentions explicitly about '4K pages'. This should
+ * not be confused with the kernel PAGE_SIZE, which is the translation
+ * granule kernel is configured and may be one among 4K, 16K and 64K.
+ */
+#define FFA_PAGE_SIZE		SZ_4K
+
+/**
  * typedef ffa_endpoint_id16_t - Endpoint ID
  *
  * Current implementation only supports VMIDs. FFA spec also support stream