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From: Ekansh Gupta <quic_ekangupt@quicinc.com>
To: <srinivas.kandagatla@linaro.org>, <linux-arm-msm@vger.kernel.org>
CC: <gregkh@linuxfoundation.org>, <quic_bkumar@quicinc.com>,
        <linux-kernel@vger.kernel.org>, <quic_chennak@quicinc.com>
Subject: [PATCH v3 5/9] misc: fastrpc: Redesign remote heap management
Date: Thu, 30 May 2024 15:50:23 +0530
Message-ID: <20240530102032.27179-6-quic_ekangupt@quicinc.com>
In-Reply-To: <20240530102032.27179-1-quic_ekangupt@quicinc.com>
References: <20240530102032.27179-1-quic_ekangupt@quicinc.com>
Precedence: bulk
MIME-Version: 1.0
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Current remote heap design comes with problems where all types of
buffers are getting added to interrupted list and also user unmap
request is not handling the request to unmap remote heap buffer
type. Add changes to maintain list in a way that it can be used to
to support remote heap grow/shrink request and the remote heap
buffers cleanup during static PD restart.

Signed-off-by: Ekansh Gupta <quic_ekangupt@quicinc.com>
---
 drivers/misc/fastrpc.c | 221 ++++++++++++++++++++++++++++++++---------
 1 file changed, 175 insertions(+), 46 deletions(-)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index d115860fc356..ef9bbd8c3dd1 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -210,6 +210,7 @@ struct fastrpc_buf {
 	struct dma_buf *dmabuf;
 	struct device *dev;
 	void *virt;
+	u32 flag;
 	u64 phys;
 	u64 size;
 	/* Lock for dma buf attachments */
@@ -274,6 +275,7 @@ struct fastrpc_session_ctx {
 };
 
 struct fastrpc_static_pd {
+	struct list_head rmaps;
 	char *servloc_name;
 	char *spdname;
 	void *pdrhandle;
@@ -299,7 +301,6 @@ struct fastrpc_channel_ctx {
 	u32 dsp_attributes[FASTRPC_MAX_DSP_ATTRIBUTES];
 	struct fastrpc_device *secure_fdevice;
 	struct fastrpc_device *fdevice;
-	struct fastrpc_buf *remote_heap;
 	struct list_head invoke_interrupted_mmaps;
 	bool secure;
 	bool unsigned_support;
@@ -1256,6 +1257,53 @@ static bool is_session_rejected(struct fastrpc_user *fl, bool unsigned_pd_reques
 	return false;
 }
 
+static void fastrpc_mmap_remove_pdr(struct fastrpc_static_pd *spd)
+{
+	struct fastrpc_buf *buf, *b;
+	struct fastrpc_channel_ctx *cctx;
+	int err;
+
+	if (!spd || !spd->fl)
+		return;
+
+	cctx = spd->cctx;
+
+	spin_lock(&spd->fl->lock);
+	list_for_each_entry_safe(buf, b, &spd->rmaps, node) {
+		list_del(&buf->node);
+		spin_unlock(&spd->fl->lock);
+		if (cctx->vmcount) {
+			u64 src_perms = 0;
+			struct qcom_scm_vmperm dst_perms;
+			u32 i;
+
+			for (i = 0; i < cctx->vmcount; i++)
+				src_perms |= BIT(cctx->vmperms[i].vmid);
+
+			dst_perms.vmid = QCOM_SCM_VMID_HLOS;
+			dst_perms.perm = QCOM_SCM_PERM_RWX;
+			err = qcom_scm_assign_mem(buf->phys, (u64)buf->size,
+				&src_perms, &dst_perms, 1);
+			if (err) {
+				pr_err("%s: Failed to assign memory phys 0x%llx size 0x%llx err %d\n",
+					__func__, buf->phys, buf->size, err);
+				return;
+			}
+		}
+		fastrpc_buf_free(buf);
+		spin_lock(&spd->fl->lock);
+	}
+	spin_unlock(&spd->fl->lock);
+}
+
+static void fastrpc_mmap_remove_ssr(struct fastrpc_channel_ctx *cctx)
+{
+	int i;
+
+	for (i = 0; i < FASTRPC_MAX_SPD; i++)
+		fastrpc_mmap_remove_pdr(&cctx->spd[i]);
+}
+
 static struct fastrpc_static_pd *fastrpc_get_spd_session(
 				struct fastrpc_user *fl)
 {
@@ -1282,9 +1330,12 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 	struct fastrpc_init_create_static init;
 	struct fastrpc_invoke_args *args;
 	struct fastrpc_phy_page pages[1];
+	struct fastrpc_buf *buf = NULL;
 	struct fastrpc_static_pd *spd = NULL;
+	u64 phys = 0, size = 0;
 	char *name;
 	int err;
+	bool scm_done = false;
 	struct {
 		int pgid;
 		u32 namelen;
@@ -1330,25 +1381,26 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 		goto err_name;
 	}
 	fl->spd = spd;
-	if (!fl->cctx->remote_heap) {
-		err = fastrpc_remote_heap_alloc(fl, fl->sctx->dev, init.memlen,
-						&fl->cctx->remote_heap);
+	if (list_empty(&spd->rmaps)) {
+		err = fastrpc_remote_heap_alloc(fl, fl->sctx->dev, init.memlen, &buf);
 		if (err)
 			goto err_name;
 
+		phys = buf->phys;
+		size = buf->size;
 		/* Map if we have any heap VMIDs associated with this ADSP Static Process. */
 		if (fl->cctx->vmcount) {
 			u64 src_perms = BIT(QCOM_SCM_VMID_HLOS);
 
-			err = qcom_scm_assign_mem(fl->cctx->remote_heap->phys,
-							(u64)fl->cctx->remote_heap->size,
+			err = qcom_scm_assign_mem(phys, (u64)size,
 							&src_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\n",
-					fl->cctx->remote_heap->phys, fl->cctx->remote_heap->size, err);
+					phys, size, err);
 				goto err_map;
 			}
+			scm_done = true;
 		}
 	}
 
@@ -1365,8 +1417,8 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 	args[1].length = inbuf.namelen;
 	args[1].fd = -1;
 
-	pages[0].addr = fl->cctx->remote_heap->phys;
-	pages[0].size = fl->cctx->remote_heap->size;
+	pages[0].addr = phys;
+	pages[0].size = size;
 
 	args[2].ptr = (u64)(uintptr_t) pages;
 	args[2].length = sizeof(*pages);
@@ -1380,10 +1432,17 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 		goto err_invoke;
 
 	kfree(args);
+	kfree(name);
+
+	if (buf) {
+		spin_lock(&fl->lock);
+		list_add_tail(&buf->node, &spd->rmaps);
+		spin_unlock(&fl->lock);
+	}
 
 	return 0;
 err_invoke:
-	if (fl->cctx->vmcount) {
+	if (fl->cctx->vmcount && scm_done) {
 		u64 src_perms = 0;
 		struct qcom_scm_vmperm dst_perms;
 		u32 i;
@@ -1393,15 +1452,15 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 
 		dst_perms.vmid = QCOM_SCM_VMID_HLOS;
 		dst_perms.perm = QCOM_SCM_PERM_RWX;
-		err = qcom_scm_assign_mem(fl->cctx->remote_heap->phys,
-						(u64)fl->cctx->remote_heap->size,
+		err = qcom_scm_assign_mem(phys, (u64)size,
 						&src_perms, &dst_perms, 1);
 		if (err)
 			dev_err(fl->sctx->dev, "Failed to assign memory phys 0x%llx size 0x%llx err %d\n",
-				fl->cctx->remote_heap->phys, fl->cctx->remote_heap->size, err);
+				phys, size, err);
 	}
 err_map:
-	fastrpc_buf_free(fl->cctx->remote_heap);
+	if (buf)
+		fastrpc_buf_free(buf);
 err_name:
 	kfree(name);
 err:
@@ -1866,17 +1925,16 @@ static int fastrpc_get_dsp_info(struct fastrpc_user *fl, char __user *argp)
 	return 0;
 }
 
-static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, struct fastrpc_buf *buf)
+static int fastrpc_req_munmap_dsp(struct fastrpc_user *fl, uintptr_t raddr, u64 size)
 {
 	struct fastrpc_invoke_args args[1] = { [0] = { 0 } };
 	struct fastrpc_munmap_req_msg req_msg;
-	struct device *dev = fl->sctx->dev;
 	int err;
 	u32 sc;
 
 	req_msg.pgid = fl->tgid;
-	req_msg.size = buf->size;
-	req_msg.vaddr = buf->raddr;
+	req_msg.size = size;
+	req_msg.vaddr = raddr;
 
 	args[0].ptr = (u64) (uintptr_t) &req_msg;
 	args[0].length = sizeof(req_msg);
@@ -1884,11 +1942,38 @@ static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, struct fastrpc_buf *
 	sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_MUNMAP, 1, 0);
 	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc,
 				      &args[0]);
+
+	return err;
+}
+
+static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, struct fastrpc_buf *buf)
+{
+	struct device *dev = fl->sctx->dev;
+	int err;
+
+	err = fastrpc_req_munmap_dsp(fl, buf->raddr, buf->size);
 	if (!err) {
+		if (buf->flag == ADSP_MMAP_REMOTE_HEAP_ADDR) {
+			if (fl->cctx->vmcount) {
+				u64 src_perms = 0;
+				struct qcom_scm_vmperm dst_perms;
+				u32 i;
+
+				for (i = 0; i < fl->cctx->vmcount; i++)
+					src_perms |= BIT(fl->cctx->vmperms[i].vmid);
+
+				dst_perms.vmid = QCOM_SCM_VMID_HLOS;
+				dst_perms.perm = QCOM_SCM_PERM_RWX;
+				err = qcom_scm_assign_mem(buf->phys, (u64)buf->size,
+								&src_perms, &dst_perms, 1);
+				if (err) {
+					dev_err(dev, "Failed to assign memory phys 0x%llx size 0x%llx err %d\n",
+						buf->phys, buf->size, err);
+					return err;
+				}
+			}
+		}
 		dev_dbg(dev, "unmmap\tpt 0x%09lx OK\n", buf->raddr);
-		spin_lock(&fl->lock);
-		list_del(&buf->node);
-		spin_unlock(&fl->lock);
 		fastrpc_buf_free(buf);
 	} else {
 		dev_err(dev, "unmmap\tpt 0x%09lx ERROR\n", buf->raddr);
@@ -1902,6 +1987,7 @@ static int fastrpc_req_munmap(struct fastrpc_user *fl, char __user *argp)
 	struct fastrpc_buf *buf = NULL, *iter, *b;
 	struct fastrpc_req_munmap req;
 	struct device *dev = fl->sctx->dev;
+	int err = 0;
 
 	if (copy_from_user(&req, argp, sizeof(req)))
 		return -EFAULT;
@@ -1910,20 +1996,48 @@ static int fastrpc_req_munmap(struct fastrpc_user *fl, char __user *argp)
 	list_for_each_entry_safe(iter, b, &fl->mmaps, node) {
 		if ((iter->raddr == req.vaddrout) && (iter->size == req.size)) {
 			buf = iter;
+			list_del(&buf->node);
 			break;
 		}
 	}
 	spin_unlock(&fl->lock);
 
-	if (!buf) {
-		dev_err(dev, "mmap\t\tpt 0x%09llx [len 0x%08llx] not in list\n",
-			req.vaddrout, req.size);
-		return -EINVAL;
+	if (buf) {
+		err = fastrpc_req_munmap_impl(fl, buf);
+		if (err) {
+			spin_lock(&fl->lock);
+			list_add_tail(&buf->node, &fl->mmaps);
+			spin_unlock(&fl->lock);
+		}
+		return err;
 	}
 
-	return fastrpc_req_munmap_impl(fl, buf);
+	spin_lock(&fl->lock);
+	if (fl->spd) {
+		list_for_each_entry_safe(iter, b, &fl->spd->rmaps, node) {
+			if ((iter->raddr == req.vaddrout) && (iter->size == req.size)) {
+				buf = iter;
+				list_del(&buf->node);
+				break;
+			}
+		}
+	}
+	spin_unlock(&fl->lock);
+	if (buf) {
+		err = fastrpc_req_munmap_impl(fl, buf);
+		if (err) {
+			spin_lock(&fl->lock);
+			list_add_tail(&buf->node, &fl->spd->rmaps);
+			spin_unlock(&fl->lock);
+		}
+		return err;
+	}
+	dev_err(dev, "buffer not found addr 0x%09lx, len 0x%08llx\n",
+			req.vaddrout, req.size);
+	return -EINVAL;
 }
 
+
 static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
 {
 	struct fastrpc_invoke_args args[3] = { [0 ... 2] = { 0 } };
@@ -1950,16 +2064,34 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
 		return -EINVAL;
 	}
 
-	if (req.flags == ADSP_MMAP_REMOTE_HEAP_ADDR)
+	if (req.flags == ADSP_MMAP_REMOTE_HEAP_ADDR) {
+		if (!fl->spd || !fl->spd->ispdup) {
+			dev_err(dev, "remote heap request supported only for active static PD\n");
+			return -EINVAL;
+		}
 		err = fastrpc_remote_heap_alloc(fl, dev, req.size, &buf);
-	else
+	} else {
 		err = fastrpc_buf_alloc(fl, dev, req.size, &buf);
+	}
 
 	if (err) {
 		dev_err(dev, "failed to allocate buffer\n");
 		return err;
 	}
+	buf->flag = req.flags;
 
+	/* Add memory to static PD pool, protection through hypervisor */
+	if ((req.flags == ADSP_MMAP_REMOTE_HEAP_ADDR) && fl->cctx->vmcount) {
+		u64 src_perms = BIT(QCOM_SCM_VMID_HLOS);
+
+		err = qcom_scm_assign_mem(buf->phys, (u64)buf->size,
+			&src_perms, fl->cctx->vmperms, fl->cctx->vmcount);
+		if (err) {
+			dev_err(fl->sctx->dev, "Failed to assign memory phys 0x%llx size 0x%llx err %d\n",
+					buf->phys, buf->size, err);
+			goto err_invoke;
+		}
+	}
 	req_msg.pgid = fl->tgid;
 	req_msg.flags = req.flags;
 	req_msg.vaddr = req.vaddrin;
@@ -1991,26 +2123,17 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
 	/* let the client know the address to use */
 	req.vaddrout = rsp_msg.vaddr;
 
-	/* Add memory to static PD pool, protection thru hypervisor */
-	if (req.flags == ADSP_MMAP_REMOTE_HEAP_ADDR && fl->cctx->vmcount) {
-		u64 src_perms = BIT(QCOM_SCM_VMID_HLOS);
-
-		err = qcom_scm_assign_mem(buf->phys, (u64)buf->size,
-			&src_perms, fl->cctx->vmperms, fl->cctx->vmcount);
-		if (err) {
-			dev_err(fl->sctx->dev, "Failed to assign memory phys 0x%llx size 0x%llx err %d",
-					buf->phys, buf->size, err);
-			goto err_assign;
-		}
-	}
 
 	spin_lock(&fl->lock);
-	list_add_tail(&buf->node, &fl->mmaps);
+	if (req.flags == ADSP_MMAP_REMOTE_HEAP_ADDR)
+		list_add_tail(&buf->node, &fl->spd->rmaps);
+	else
+		list_add_tail(&buf->node, &fl->mmaps);
 	spin_unlock(&fl->lock);
 
 	if (copy_to_user((void __user *)argp, &req, sizeof(req))) {
 		err = -EFAULT;
-		goto err_assign;
+		goto err_copy;
 	}
 
 	dev_dbg(dev, "mmap\t\tpt 0x%09lx OK [len 0x%08llx]\n",
@@ -2018,14 +2141,19 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
 
 	return 0;
 
-err_assign:
+err_copy:
+	spin_lock(&fl->lock);
+	list_del(&buf->node);
+	spin_unlock(&fl->lock);
 	fastrpc_req_munmap_impl(fl, buf);
+	buf = NULL;
 err_invoke:
 	fastrpc_buf_free(buf);
 
 	return err;
 }
 
+
 static int fastrpc_req_mem_unmap_impl(struct fastrpc_user *fl, struct fastrpc_mem_unmap *req)
 {
 	struct fastrpc_invoke_args args[1] = { [0] = { 0 } };
@@ -2249,6 +2377,7 @@ static void fastrpc_pdr_cb(int state, char *service_path, void *priv)
 			spd->servloc_name,
 			domains[cctx->domain_id]);
 		spd->ispdup = false;
+		fastrpc_mmap_remove_pdr(spd);
 		fastrpc_notify_pdr_drivers(cctx, spd->servloc_name);
 		break;
 	case SERVREG_SERVICE_STATE_UP:
@@ -2400,6 +2529,7 @@ static int fastrpc_setup_service_locator(struct fastrpc_channel_ctx *cctx, char
 	cctx->spd[spd_session].servloc_name = client_name;
 	cctx->spd[spd_session].spdname = service_path;
 	cctx->spd[spd_session].cctx = cctx;
+	INIT_LIST_HEAD(&cctx->spd[spd_session].rmaps);
 	service = pdr_add_lookup(handle, service_name, service_path);
 	if (IS_ERR(service)) {
 		err = PTR_ERR(service);
@@ -2566,9 +2696,6 @@ static void fastrpc_rpmsg_remove(struct rpmsg_device *rpdev)
 	list_for_each_entry_safe(buf, b, &cctx->invoke_interrupted_mmaps, node)
 		list_del(&buf->node);
 
-	if (cctx->remote_heap)
-		fastrpc_buf_free(cctx->remote_heap);
-
 	for (i = 0; i < FASTRPC_MAX_SPD; i++) {
 		if (cctx->spd[i].pdrhandle)
 			pdr_handle_release(cctx->spd[i].pdrhandle);
@@ -2576,6 +2703,8 @@ static void fastrpc_rpmsg_remove(struct rpmsg_device *rpdev)
 
 	of_platform_depopulate(&rpdev->dev);
 
+	fastrpc_mmap_remove_ssr(cctx);
+
 	fastrpc_channel_ctx_put(cctx);
 }
 
-- 
2.43.0