[PATCH v1] misc: fastrpc: Pass proper scm arguments for secure map request

[PATCH v1] misc: fastrpc: Pass proper scm arguments for secure map request

[Ekansh Gupta]

If a map request is made with securemap attribute, the memory
ownership needs to be reassigned to new VMID to allow access
from protection domain. Currently only DSP VMID is passed to
the reassign call which is incorrect as only a combination of
HLOS and DSP VMID is allowed for memory ownership reassignment
and passing only DSP VMID will cause assign call failure.

Also pass proper restoring permissions to HLOS as the source
permission will now carry both HLOS and DSP VMID permission.

Change is also made to get valid physical address from
scatter/gather for this allocation request.

Fixes: e90d91190619 ("misc: fastrpc: Add support to secure memory map")
Cc: stable <stable@kernel.org>
Tested-by: Ekansh Gupta <quic_ekangupt@quicinc.com>
Signed-off-by: Ekansh Gupta <quic_ekangupt@quicinc.com>
---
 drivers/misc/fastrpc.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index a701132..77a5930 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -316,12 +316,14 @@ static void fastrpc_free_map(struct kref *ref)
 	if (map->table) {
 		if (map->attr & FASTRPC_ATTR_SECUREMAP) {
 			struct qcom_scm_vmperm perm;
+			int vmid = map->fl->cctx->vmperms[0].vmid;
+			unsigned int src_perms = BIT(QCOM_SCM_VMID_HLOS) | BIT(vmid);
 			int err = 0;
 
 			perm.vmid = QCOM_SCM_VMID_HLOS;
 			perm.perm = QCOM_SCM_PERM_RWX;
 			err = qcom_scm_assign_mem(map->phys, map->size,
-				&map->fl->cctx->perms, &perm, 1);
+				&src_perms, &perm, 1);
 			if (err) {
 				dev_err(map->fl->sctx->dev, "Failed to assign memory phys 0x%llx size 0x%llx err %d",
 						map->phys, map->size, err);
@@ -787,8 +789,12 @@ static int fastrpc_map_create(struct fastrpc_user *fl, int fd,
 		goto map_err;
 	}
 
-	map->phys = sg_dma_address(map->table->sgl);
-	map->phys += ((u64)fl->sctx->sid << 32);
+	if (attr & FASTRPC_ATTR_SECUREMAP) {
+		map->phys = sg_phys(map->table->sgl);
+	} else {
+		map->phys = sg_dma_address(map->table->sgl);
+		map->phys += ((u64)fl->sctx->sid << 32);
+	}
 	map->size = len;
 	map->va = sg_virt(map->table->sgl);
 	map->len = len;
@@ -798,9 +804,15 @@ static int fastrpc_map_create(struct fastrpc_user *fl, int fd,
 		 * If subsystem VMIDs are defined in DTSI, then do
 		 * hyp_assign from HLOS to those VM(s)
 		 */
+		unsigned int src_perms = BIT(QCOM_SCM_VMID_HLOS);
+		struct qcom_scm_vmperm dst_perms[2] = {0};
+
+		dst_perms[0].vmid = QCOM_SCM_VMID_HLOS;
+		dst_perms[0].perm = QCOM_SCM_PERM_RW;
+		dst_perms[1].vmid = fl->cctx->vmperms[0].vmid;
+		dst_perms[1].perm = QCOM_SCM_PERM_RWX;
 		map->attr = attr;
-		err = qcom_scm_assign_mem(map->phys, (u64)map->size, &fl->cctx->perms,
-				fl->cctx->vmperms, fl->cctx->vmcount);
+		err = qcom_scm_assign_mem(map->phys, (u64)map->size, &src_perms, dst_perms, 2);
 		if (err) {
 			dev_err(sess->dev, "Failed to assign memory with phys 0x%llx size 0x%llx err %d",
 					map->phys, map->size, err);
-- 
2.7.4