[v1,2/2] misc: fastrpc: Add persistent header buffer support

Message ID 1686307187-15199-3-git-send-email-quic_ekangupt@quicinc.com
State New
Headers
Series Add changes for cached buffer and persistent header buffers |

Commit Message

Ekansh Gupta June 9, 2023, 10:39 a.m. UTC
  This change enables the usage of persistent header buffers which
are allocated during process initialization and is mapped to CDSP.
This mechanism helps in reducing the RPC overhead for remote calls.

For any user process remote RPC call to CDSP, it is tried to use
persistent header buffers. In case all persistent buffers are
already in use, there is a fallback to cached buffer usage and
allocation using DMA API.

Co-developed-by: Anandu Krishnan E <quic_anane@quicinc.com>
Signed-off-by: Anandu Krishnan E <quic_anane@quicinc.com>
Signed-off-by: Ekansh Gupta <quic_ekangupt@quicinc.com>
---
 drivers/misc/fastrpc.c | 215 +++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 173 insertions(+), 42 deletions(-)
  

Comments

kernel test robot June 9, 2023, 6:13 p.m. UTC | #1
Hi Ekansh,

kernel test robot noticed the following build warnings:

[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on char-misc/char-misc-next char-misc/char-misc-linus linus/master v6.4-rc5 next-20230609]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Ekansh-Gupta/misc-fastrpc-Add-cached-buffer-support/20230609-184517
base:   char-misc/char-misc-testing
patch link:    https://lore.kernel.org/r/1686307187-15199-3-git-send-email-quic_ekangupt%40quicinc.com
patch subject: [PATCH v1 2/2] misc: fastrpc: Add persistent header buffer support
config: arm64-randconfig-r024-20230608 (https://download.01.org/0day-ci/archive/20230610/202306100111.JeCyQ9wW-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project.git f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build):
        mkdir -p ~/bin
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        git remote add char-misc https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
        git fetch char-misc char-misc-testing
        git checkout char-misc/char-misc-testing
        b4 shazam https://lore.kernel.org/r/1686307187-15199-3-git-send-email-quic_ekangupt@quicinc.com
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=arm64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash drivers/misc/

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306100111.JeCyQ9wW-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/misc/fastrpc.c:1400:8: warning: format specifies type 'unsigned long long' but the argument has type 'u32' (aka 'unsigned int') [-Wformat]
                           fd, va, size);
                               ^~
   include/linux/dev_printk.h:144:65: note: expanded from macro 'dev_err'
           dev_printk_index_wrap(_dev_err, KERN_ERR, dev, dev_fmt(fmt), ##__VA_ARGS__)
                                                                  ~~~     ^~~~~~~~~~~
   include/linux/dev_printk.h:110:23: note: expanded from macro 'dev_printk_index_wrap'
                   _p_func(dev, fmt, ##__VA_ARGS__);                       \
                                ~~~    ^~~~~~~~~~~
>> drivers/misc/fastrpc.c:1400:12: warning: format specifies type 'long long' but the argument has type 'size_t' (aka 'unsigned long') [-Wformat]
                           fd, va, size);
                                   ^~~~
   include/linux/dev_printk.h:144:65: note: expanded from macro 'dev_err'
           dev_printk_index_wrap(_dev_err, KERN_ERR, dev, dev_fmt(fmt), ##__VA_ARGS__)
                                                                  ~~~     ^~~~~~~~~~~
   include/linux/dev_printk.h:110:23: note: expanded from macro 'dev_printk_index_wrap'
                   _p_func(dev, fmt, ##__VA_ARGS__);                       \
                                ~~~    ^~~~~~~~~~~
   2 warnings generated.


vim +1400 drivers/misc/fastrpc.c

  1360	
  1361	static int fastrpc_mem_map_to_dsp(struct fastrpc_user *fl, int fd, int offset,
  1362					u32 flags, u32 va, u64 phys,
  1363					size_t size, uintptr_t *raddr)
  1364	{
  1365		struct fastrpc_invoke_args args[4] = { [0 ... 3] = { 0 } };
  1366		struct fastrpc_mem_map_req_msg req_msg = { 0 };
  1367		struct fastrpc_mmap_rsp_msg rsp_msg = { 0 };
  1368		struct fastrpc_phy_page pages = { 0 };
  1369		struct device *dev = fl->sctx->dev;
  1370		int err = 0;
  1371		u32 sc;
  1372	
  1373		req_msg.pgid = fl->tgid;
  1374		req_msg.fd = fd;
  1375		req_msg.offset = offset;
  1376		req_msg.vaddrin = va;
  1377		req_msg.flags = flags;
  1378		req_msg.num = sizeof(pages);
  1379		req_msg.data_len = 0;
  1380	
  1381		args[0].ptr = (u64) (uintptr_t) &req_msg;
  1382		args[0].length = sizeof(req_msg);
  1383	
  1384		pages.addr = phys;
  1385		pages.size = size;
  1386	
  1387		args[1].ptr = (u64) (uintptr_t) &pages;
  1388		args[1].length = sizeof(pages);
  1389	
  1390		args[2].ptr = (u64) (uintptr_t) &pages;
  1391		args[2].length = 0;
  1392	
  1393		args[3].ptr = (u64) (uintptr_t) &rsp_msg;
  1394		args[3].length = sizeof(rsp_msg);
  1395	
  1396		sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_MEM_MAP, 3, 1);
  1397		err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc, &args[0]);
  1398		if (err) {
  1399			dev_err(dev, "mem mmap error, fd %d, vaddr %llx, size %lld\n",
> 1400				fd, va, size);
  1401			return err;
  1402		}
  1403		*raddr = rsp_msg.vaddr;
  1404	
  1405		return 0;
  1406	}
  1407
  

Patch

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index a961a66..0132b63 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -44,6 +44,8 @@ 
 /* Maximum buffers cached in cached buffer list */
 #define FASTRPC_MAX_CACHED_BUFS (32)
 #define FASTRPC_MAX_CACHE_BUF_SIZE (8*1024*1024)
+/* Max no. of persistent headers pre-allocated per user process */
+#define FASTRPC_MAX_PERSISTENT_HEADERS    (25)
 
 /* Add memory to static PD pool, protection thru XPU */
 #define ADSP_MMAP_HEAP_ADDR  4
@@ -54,7 +56,9 @@ 
 /* Add memory to userPD pool, for user heap */
 #define ADSP_MMAP_ADD_PAGES 0x1000
 /* Add memory to userPD pool, for LLC heap */
-#define ADSP_MMAP_ADD_PAGES_LLC 0x3000,
+#define ADSP_MMAP_ADD_PAGES_LLC 0x3000
+/* Map persistent header buffer on DSP */
+#define ADSP_MMAP_PERSIST_HDR  0x4000
 
 #define DSP_UNSUPPORTED_API (0x80000414)
 /* MAX NUMBER of DSP ATTRIBUTES SUPPORTED */
@@ -208,6 +212,7 @@  struct fastrpc_buf {
 	/* mmap support */
 	struct list_head node; /* list of user requested mmaps */
 	uintptr_t raddr;
+	bool in_use;
 };
 
 struct fastrpc_dma_buf_attachment {
@@ -303,11 +308,17 @@  struct fastrpc_user {
 	struct fastrpc_channel_ctx *cctx;
 	struct fastrpc_session_ctx *sctx;
 	struct fastrpc_buf *init_mem;
+	/* Pre-allocated header buffer */
+	struct fastrpc_buf *pers_hdr_buf;
+	/* Pre-allocated buffer divided into N chunks */
+	struct fastrpc_buf *hdr_bufs;
 
 	int tgid;
 	int pd;
 	/* total cached buffers */
 	u32 num_cached_buf;
+	/* total persistent headers */
+	u32 num_pers_hdrs;
 	bool is_secure_dev;
 	/* Lock for lists */
 	spinlock_t lock;
@@ -399,6 +410,37 @@  static int fastrpc_map_lookup(struct fastrpc_user *fl, int fd,
 	return ret;
 }
 
+static bool fastrpc_get_persistent_buf(struct fastrpc_user *fl,
+		size_t size, int buf_type, struct fastrpc_buf **obuf)
+{
+	u32 i = 0;
+	bool found = false;
+	struct fastrpc_buf *buf = NULL;
+
+	spin_lock(&fl->lock);
+	/*
+	 * Persistent header buffer can be used only if
+	 * metadata length is less than 1 page size.
+	 */
+	if (!fl->num_pers_hdrs || buf_type != METADATA_BUF || size > PAGE_SIZE) {
+		spin_unlock(&fl->lock);
+		return found;
+	}
+
+	for (i = 0; i < fl->num_pers_hdrs; i++) {
+		buf = &fl->hdr_bufs[i];
+		/* If buffer not in use, then assign it for requested alloc */
+		if (!buf->in_use) {
+			buf->in_use = true;
+			*obuf = buf;
+			found = true;
+			break;
+		}
+	}
+	spin_unlock(&fl->lock);
+	return found;
+}
+
 static void __fastrpc_buf_free(struct fastrpc_buf *buf)
 {
 	dma_free_coherent(buf->dev, buf->size, buf->virt,
@@ -430,6 +472,15 @@  static void fastrpc_cached_buf_list_add(struct fastrpc_buf *buf)
 
 static void fastrpc_buf_free(struct fastrpc_buf *buf, bool cache)
 {
+	struct fastrpc_user *fl = buf->fl;
+
+	if (buf->in_use) {
+		/* Don't free persistent header buf. Just mark as available */
+		spin_lock(&fl->lock);
+		buf->in_use = false;
+		spin_unlock(&fl->lock);
+		return;
+	}
 	if (cache)
 		fastrpc_cached_buf_list_add(buf);
 	else
@@ -523,6 +574,8 @@  static int fastrpc_buf_alloc(struct fastrpc_user *fl, struct device *dev,
 	int ret;
 	struct fastrpc_buf *buf;
 
+	if (fastrpc_get_persistent_buf(fl, size, buf_type, obuf))
+		return 0;
 	if (fastrpc_get_cached_buf(fl, size, buf_type, obuf))
 		return 0;
 	ret = __fastrpc_buf_alloc(fl, dev, size, obuf);
@@ -1305,6 +1358,107 @@  static int fastrpc_internal_invoke(struct fastrpc_user *fl,  u32 kernel,
 	return err;
 }
 
+static int fastrpc_mem_map_to_dsp(struct fastrpc_user *fl, int fd, int offset,
+				u32 flags, u32 va, u64 phys,
+				size_t size, uintptr_t *raddr)
+{
+	struct fastrpc_invoke_args args[4] = { [0 ... 3] = { 0 } };
+	struct fastrpc_mem_map_req_msg req_msg = { 0 };
+	struct fastrpc_mmap_rsp_msg rsp_msg = { 0 };
+	struct fastrpc_phy_page pages = { 0 };
+	struct device *dev = fl->sctx->dev;
+	int err = 0;
+	u32 sc;
+
+	req_msg.pgid = fl->tgid;
+	req_msg.fd = fd;
+	req_msg.offset = offset;
+	req_msg.vaddrin = va;
+	req_msg.flags = flags;
+	req_msg.num = sizeof(pages);
+	req_msg.data_len = 0;
+
+	args[0].ptr = (u64) (uintptr_t) &req_msg;
+	args[0].length = sizeof(req_msg);
+
+	pages.addr = phys;
+	pages.size = size;
+
+	args[1].ptr = (u64) (uintptr_t) &pages;
+	args[1].length = sizeof(pages);
+
+	args[2].ptr = (u64) (uintptr_t) &pages;
+	args[2].length = 0;
+
+	args[3].ptr = (u64) (uintptr_t) &rsp_msg;
+	args[3].length = sizeof(rsp_msg);
+
+	sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_MEM_MAP, 3, 1);
+	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc, &args[0]);
+	if (err) {
+		dev_err(dev, "mem mmap error, fd %d, vaddr %llx, size %lld\n",
+			fd, va, size);
+		return err;
+	}
+	*raddr = rsp_msg.vaddr;
+
+	return 0;
+}
+
+static int fastrpc_create_persistent_headers(struct fastrpc_user *fl)
+{
+	int err = 0;
+	int i = 0;
+	u64 virtb = 0;
+	struct device *dev = fl->sctx->dev;
+	struct fastrpc_buf *hdr_bufs, *buf, *pers_hdr_buf = NULL;
+	u32 num_pers_hdrs = 0;
+	size_t hdr_buf_alloc_len = 0;
+
+	/*
+	 * Pre-allocate memory for persistent header buffers based
+	 * on concurrency info passed by user. Upper limit enforced.
+	 */
+	num_pers_hdrs = FASTRPC_MAX_PERSISTENT_HEADERS;
+	hdr_buf_alloc_len = num_pers_hdrs * PAGE_SIZE;
+	err = fastrpc_buf_alloc(fl, dev, hdr_buf_alloc_len,
+			METADATA_BUF, &pers_hdr_buf);
+	if (err)
+		return err;
+
+	virtb = (u64) (uintptr_t)(pers_hdr_buf->virt);
+	err = fastrpc_mem_map_to_dsp(fl, -1, 0,
+				ADSP_MMAP_PERSIST_HDR, 0, (u64) (uintptr_t)(pers_hdr_buf->phys),
+				pers_hdr_buf->size, &pers_hdr_buf->raddr);
+	if (err)
+		goto err_dsp_map;
+
+	hdr_bufs = kcalloc(num_pers_hdrs, sizeof(struct fastrpc_buf),
+				GFP_KERNEL);
+	if (!hdr_bufs)
+		return -ENOMEM;
+
+	spin_lock(&fl->lock);
+	fl->pers_hdr_buf = pers_hdr_buf;
+	fl->num_pers_hdrs = num_pers_hdrs;
+	fl->hdr_bufs = hdr_bufs;
+	for (i = 0; i < num_pers_hdrs; i++) {
+		buf = &fl->hdr_bufs[i];
+		buf->fl = fl;
+		buf->virt = (void *)(virtb + (i * PAGE_SIZE));
+		buf->phys = pers_hdr_buf->phys + (i * PAGE_SIZE);
+		buf->size = PAGE_SIZE;
+		buf->type = pers_hdr_buf->type;
+		buf->in_use = false;
+	}
+	spin_unlock(&fl->lock);
+
+	return 0;
+err_dsp_map:
+	fastrpc_buf_free(pers_hdr_buf, 0);
+	return err;
+}
+
 static bool is_session_rejected(struct fastrpc_user *fl, bool unsigned_pd_request)
 {
 	/* Check if the device node is non-secure and channel is secure*/
@@ -1537,6 +1691,12 @@  static int fastrpc_init_create_process(struct fastrpc_user *fl,
 	if (err)
 		goto err_invoke;
 
+	if (fl->cctx->domain_id == CDSP_DOMAIN_ID) {
+		err = fastrpc_create_persistent_headers(fl);
+		if (err)
+			goto err_invoke;
+	}
+
 	kfree(args);
 
 	return 0;
@@ -1629,6 +1789,10 @@  static int fastrpc_device_release(struct inode *inode, struct file *file)
 		fastrpc_buf_free(buf, false);
 	}
 
+	if (fl->pers_hdr_buf)
+		fastrpc_buf_free(fl->pers_hdr_buf, false);
+	kfree(fl->hdr_bufs);
+
 	fastrpc_cached_buf_list_free(fl);
 	fastrpc_session_free(cctx, fl->sctx);
 	fastrpc_channel_ctx_put(cctx);
@@ -2089,16 +2253,11 @@  static int fastrpc_req_mem_unmap(struct fastrpc_user *fl, char __user *argp)
 
 static int fastrpc_req_mem_map(struct fastrpc_user *fl, char __user *argp)
 {
-	struct fastrpc_invoke_args args[4] = { [0 ... 3] = { 0 } };
-	struct fastrpc_mem_map_req_msg req_msg = { 0 };
-	struct fastrpc_mmap_rsp_msg rsp_msg = { 0 };
 	struct fastrpc_mem_unmap req_unmap = { 0 };
-	struct fastrpc_phy_page pages = { 0 };
-	struct fastrpc_mem_map req;
+	struct fastrpc_mem_map req = {0};
 	struct device *dev = fl->sctx->dev;
 	struct fastrpc_map *map = NULL;
 	int err;
-	u32 sc;
 
 	if (copy_from_user(&req, argp, sizeof(req)))
 		return -EFAULT;
@@ -2110,57 +2269,29 @@  static int fastrpc_req_mem_map(struct fastrpc_user *fl, char __user *argp)
 		return err;
 	}
 
-	req_msg.pgid = fl->tgid;
-	req_msg.fd = req.fd;
-	req_msg.offset = req.offset;
-	req_msg.vaddrin = req.vaddrin;
 	map->va = (void *) (uintptr_t) req.vaddrin;
-	req_msg.flags = req.flags;
-	req_msg.num = sizeof(pages);
-	req_msg.data_len = 0;
-
-	args[0].ptr = (u64) (uintptr_t) &req_msg;
-	args[0].length = sizeof(req_msg);
-
-	pages.addr = map->phys;
-	pages.size = map->size;
-
-	args[1].ptr = (u64) (uintptr_t) &pages;
-	args[1].length = sizeof(pages);
-
-	args[2].ptr = (u64) (uintptr_t) &pages;
-	args[2].length = 0;
-
-	args[3].ptr = (u64) (uintptr_t) &rsp_msg;
-	args[3].length = sizeof(rsp_msg);
-
-	sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_MEM_MAP, 3, 1);
-	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc, &args[0]);
+	/* map to dsp, get virtual adrress for the user*/
+	err = fastrpc_mem_map_to_dsp(fl, map->fd, req.offset,
+					req.flags, req.vaddrin, map->phys,
+					map->size, (uintptr_t *)&req.vaddrout);
 	if (err) {
-		dev_err(dev, "mem mmap error, fd %d, vaddr %llx, size %lld\n",
-			req.fd, req.vaddrin, map->size);
+		dev_err(dev, "failed to map buffer on dsp, fd = %d\n", map->fd);
 		goto err_invoke;
 	}
 
 	/* update the buffer to be able to deallocate the memory on the DSP */
-	map->raddr = rsp_msg.vaddr;
-
-	/* let the client know the address to use */
-	req.vaddrout = rsp_msg.vaddr;
+	map->raddr = req.vaddrout;
 
 	if (copy_to_user((void __user *)argp, &req, sizeof(req))) {
 		/* unmap the memory and release the buffer */
-		req_unmap.vaddr = (uintptr_t) rsp_msg.vaddr;
+		req_unmap.vaddr = (uintptr_t)req.vaddrout;
 		req_unmap.length = map->size;
 		fastrpc_req_mem_unmap_impl(fl, &req_unmap);
 		return -EFAULT;
 	}
-
 	return 0;
-
 err_invoke:
 	fastrpc_map_put(map);
-
 	return err;
 }