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From:   Elliot Berman <quic_eberman@quicinc.com>
To:     Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Amol Maheshwari <amahesh@qti.qualcomm.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Vamsi Krishna Gattupalli <quic_vgattupa@quicinc.com>,
        Abel Vesa <abel.vesa@linaro.org>
CC:     Elliot Berman <quic_eberman@quicinc.com>,
        <linux-arm-msm@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH] misc: fastrpc: Pass bitfield into qcom_scm_assign_mem
Date:   Thu, 12 Jan 2023 10:23:12 -0800
Message-ID: <20230112182313.521467-1-quic_eberman@quicinc.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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Precedence: bulk

The srcvm parameter of qcom_scm_assign_mem is a pointer to a bitfield of
VMIDs. The  bitfield is updated with which VMIDs have permissions
after the qcom_scm_assign_mem call. This makes it simpler for clients to
make qcom_scm_assign_mem calls later, they always pass in same srcvm
bitfield and do not need to closely track whether memory was originally
shared. 

When restoring permissions to HLOS, fastrpc is incorrectly using the
first VMID directly -- neither the BIT nor the other possible VMIDs the
memory was already assigned to.  We already have a field intended for
this purpose: "perms" in the struct fastrpc_channel_ctx, but it was
never used. Start using the perms field.
 
Cc: Abel Vesa <abel.vesa@linaro.org>
Cc: Vamsi Krishna Gattupalli <quic_vgattupa@quicinc.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Fixes: e90d91190619 ("misc: fastrpc: Add support to secure memory map")
Fixes: 0871561055e6 ("misc: fastrpc: Add support for audiopd")
Fixes: 532ad70c6d44 ("misc: fastrpc: Add mmap request assigning for static PD pool")
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>

 drivers/misc/fastrpc.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index c9902a1dcf5d..0f1329f35d89 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -321,7 +321,7 @@ static void fastrpc_free_map(struct kref *ref)
 			perm.vmid = QCOM_SCM_VMID_HLOS;
 			perm.perm = QCOM_SCM_PERM_RWX;
 			err = qcom_scm_assign_mem(map->phys, map->size,
-				&(map->fl->cctx->vmperms[0].vmid), &perm, 1);
+				&map->fl->cctx->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);
@@ -788,10 +788,8 @@ 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 perms = BIT(QCOM_SCM_VMID_HLOS);
-
 		map->attr = attr;
-		err = qcom_scm_assign_mem(map->phys, (u64)map->size, &perms,
+		err = qcom_scm_assign_mem(map->phys, (u64)map->size, &fl->cctx->perms,
 				fl->cctx->vmperms, fl->cctx->vmcount);
 		if (err) {
 			dev_err(sess->dev, "Failed to assign memory with phys 0x%llx size 0x%llx err %d",
@@ -1258,10 +1256,9 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 
 		/* Map if we have any heap VMIDs associated with this ADSP Static Process. */
 		if (fl->cctx->vmcount) {
-			unsigned int perms = BIT(QCOM_SCM_VMID_HLOS);
-
 			err = qcom_scm_assign_mem(fl->cctx->remote_heap->phys,
-							(u64)fl->cctx->remote_heap->size, &perms,
+							(u64)fl->cctx->remote_heap->size,
+							&fl->cctx->perms,
 							fl->cctx->vmperms, fl->cctx->vmcount);
 			if (err) {
 				dev_err(fl->sctx->dev, "Failed to assign memory with phys 0x%llx size 0x%llx err %d",
@@ -1309,7 +1306,7 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 		perm.perm = QCOM_SCM_PERM_RWX;
 		err = qcom_scm_assign_mem(fl->cctx->remote_heap->phys,
 						(u64)fl->cctx->remote_heap->size,
-						&(fl->cctx->vmperms[0].vmid), &perm, 1);
+						&fl->cctx->perms, &perm, 1);
 		if (err)
 			dev_err(fl->sctx->dev, "Failed to assign memory phys 0x%llx size 0x%llx err %d",
 				fl->cctx->remote_heap->phys, fl->cctx->remote_heap->size, err);
@@ -1899,7 +1896,7 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
 		perm.vmid = QCOM_SCM_VMID_HLOS;
 		perm.perm = QCOM_SCM_PERM_RWX;
 		err = qcom_scm_assign_mem(buf->phys, buf->size,
-			&(fl->cctx->vmperms[0].vmid), &perm, 1);
+			&fl->cctx->perms, &perm, 1);
 		if (err) {
 			dev_err(fl->sctx->dev, "Failed to assign memory phys 0x%llx size 0x%llx err %d",
 					buf->phys, buf->size, err);

base-commit: ffe9e52965a6396bb935fee5ea80567e0cd2d68a
-- 
2.39.0