misc: fastrpc: Add support to secure memory map

This patch adds support to secure memory allocations for DSP.
It repurposes the reserved field in struct fastrpc_invoke_args
to add attributes to invoke request, for example to setup a secure memory
map for dsp. Secure memory is assigned to DSP Virtual Machine IDs using
Qualcomm SCM calls.

Signed-off-by: Vamsi Krishna Gattupalli <quic_vgattupa@quicinc.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220214161002.6831-9-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index a2b2642..41d2bb0 100644 (file)
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -259,6 +259,7 @@ config QCOM_FASTRPC
        depends on ARCH_QCOM || COMPILE_TEST
        depends on RPMSG
        select DMA_SHARED_BUFFER
+       select QCOM_SCM
        help
          Provides a communication mechanism that allows for clients to
          make remote method invocations across processor boundary to

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 8fbb24d..ae7586d 100644 (file)
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -17,6 +17,7 @@
 #include <linux/rpmsg.h>
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
+#include <linux/qcom_scm.h>
 #include <uapi/misc/fastrpc.h>
 
 #define ADSP_DOMAIN_ID (0)
@@ -25,6 +26,7 @@
 #define CDSP_DOMAIN_ID (3)
 #define FASTRPC_DEV_MAX                4 /* adsp, mdsp, slpi, cdsp*/
 #define FASTRPC_MAX_SESSIONS   13 /*12 compute, 1 cpz*/
+#define FASTRPC_MAX_VMIDS      16
 #define FASTRPC_ALIGN          128
 #define FASTRPC_MAX_FDLIST     16
 #define FASTRPC_MAX_CRCLIST    64
@@ -195,6 +197,7 @@ struct fastrpc_map {
        void *va;
        u64 len;
        u64 raddr;
+       u32 attr;
        struct kref refcount;
 };
 
@@ -232,6 +235,9 @@ struct fastrpc_session_ctx {
 struct fastrpc_channel_ctx {
        int domain_id;
        int sesscount;
+       int vmcount;
+       u32 perms;
+       struct qcom_scm_vmperm vmperms[FASTRPC_MAX_VMIDS];
        struct rpmsg_device *rpdev;
        struct fastrpc_session_ctx session[FASTRPC_MAX_SESSIONS];
        spinlock_t lock;
@@ -279,6 +285,20 @@ static void fastrpc_free_map(struct kref *ref)
        map = container_of(ref, struct fastrpc_map, refcount);
 
        if (map->table) {
+               if (map->attr & FASTRPC_ATTR_SECUREMAP) {
+                       struct qcom_scm_vmperm perm;
+                       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->vmperms[0].vmid), &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);
+                               return;
+                       }
+               }
                dma_buf_unmap_attachment(map->attach, map->table,
                                         DMA_BIDIRECTIONAL);
                dma_buf_detach(map->buf, map->attach);
@@ -655,7 +675,7 @@ static const struct dma_buf_ops fastrpc_dma_buf_ops = {
 };
 
 static int fastrpc_map_create(struct fastrpc_user *fl, int fd,
-                             u64 len, struct fastrpc_map **ppmap)
+                             u64 len, u32 attr, struct fastrpc_map **ppmap)
 {
        struct fastrpc_session_ctx *sess = fl->sctx;
        struct fastrpc_map *map = NULL;
@@ -697,6 +717,22 @@ static int fastrpc_map_create(struct fastrpc_user *fl, int fd,
        map->len = len;
        kref_init(&map->refcount);
 
+       if (attr & FASTRPC_ATTR_SECUREMAP) {
+               /*
+                * 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,
+                               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",
+                                       map->phys, map->size, err);
+                       goto map_err;
+               }
+       }
        spin_lock(&fl->lock);
        list_add_tail(&map->node, &fl->maps);
        spin_unlock(&fl->lock);
@@ -781,16 +817,13 @@ static int fastrpc_create_maps(struct fastrpc_invoke_ctx *ctx)
        int i, err;
 
        for (i = 0; i < ctx->nscalars; ++i) {
-               /* Make sure reserved field is set to 0 */
-               if (ctx->args[i].reserved)
-                       return -EINVAL;
 
                if (ctx->args[i].fd == 0 || ctx->args[i].fd == -1 ||
                    ctx->args[i].length == 0)
                        continue;
 
                err = fastrpc_map_create(ctx->fl, ctx->args[i].fd,
-                                        ctx->args[i].length, &ctx->maps[i]);
+                        ctx->args[i].length, ctx->args[i].attr, &ctx->maps[i]);
                if (err) {
                        dev_err(dev, "Error Creating map %d\n", err);
                        return -EINVAL;
@@ -1124,7 +1157,7 @@ static int fastrpc_init_create_process(struct fastrpc_user *fl,
        fl->pd = USER_PD;
 
        if (init.filelen && init.filefd) {
-               err = fastrpc_map_create(fl, init.filefd, init.filelen, &map);
+               err = fastrpc_map_create(fl, init.filefd, init.filelen, 0, &map);
                if (err)
                        goto err;
        }
@@ -1233,7 +1266,6 @@ static int fastrpc_release_current_dsp_process(struct fastrpc_user *fl)
        args[0].ptr = (u64)(uintptr_t) &tgid;
        args[0].length = sizeof(tgid);
        args[0].fd = -1;
-       args[0].reserved = 0;
        sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_RELEASE, 1, 0);
 
        return fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE,
@@ -1381,7 +1413,6 @@ static int fastrpc_init_attach(struct fastrpc_user *fl, int pd)
        args[0].ptr = (u64)(uintptr_t) &tgid;
        args[0].length = sizeof(tgid);
        args[0].fd = -1;
-       args[0].reserved = 0;
        sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_ATTACH, 1, 0);
        fl->pd = pd;
 
@@ -1954,9 +1985,10 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 {
        struct device *rdev = &rpdev->dev;
        struct fastrpc_channel_ctx *data;
-       int i, err, domain_id = -1;
+       int i, err, domain_id = -1, vmcount;
        const char *domain;
        bool secure_dsp;
+       unsigned int vmids[FASTRPC_MAX_VMIDS];
 
        err = of_property_read_string(rdev->of_node, "label", &domain);
        if (err) {
@@ -1976,10 +2008,25 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
                return -EINVAL;
        }
 
+       vmcount = of_property_read_variable_u32_array(rdev->of_node,
+                               "qcom,vmids", &vmids[0], 0, FASTRPC_MAX_VMIDS);
+       if (vmcount < 0)
+               vmcount = 0;
+       else if (!qcom_scm_is_available())
+               return -EPROBE_DEFER;
+
        data = kzalloc(sizeof(*data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;
 
+       if (vmcount) {
+               data->vmcount = vmcount;
+               data->perms = BIT(QCOM_SCM_VMID_HLOS);
+               for (i = 0; i < data->vmcount; i++) {
+                       data->vmperms[i].vmid = vmids[i];
+                       data->vmperms[i].perm = QCOM_SCM_PERM_RWX;
+               }
+       }
 
        secure_dsp = !(of_property_read_bool(rdev->of_node, "qcom,non-secure-domain"));
        data->secure = secure_dsp;

diff --git a/include/uapi/misc/fastrpc.h b/include/uapi/misc/fastrpc.h
index f39edac..5e29f2c 100644 (file)
--- a/include/uapi/misc/fastrpc.h
+++ b/include/uapi/misc/fastrpc.h
@@ -63,11 +63,14 @@ enum fastrpc_proc_attr {
        FASTRPC_MODE_PRIVILEGED         = (1 << 6),
 };
 
+/* Fastrpc attribute for memory protection of buffers */
+#define FASTRPC_ATTR_SECUREMAP (1)
+
 struct fastrpc_invoke_args {
        __u64 ptr;
        __u64 length;
        __s32 fd;
-       __u32 reserved;
+       __u32 attr;
 };
 
 struct fastrpc_invoke {