[net/9p] Preparation and helper functions for zero copy (022cae36) · Commits · e / devices / android_kernel_oneplus_sm7250

include/net/9p/9p.h

+8 −0

Original line number	Original line	Diff line number	Diff line
	@@ -689,6 +689,10 @@ struct p9_rwstat {
	* @tag: transaction id of the request		* @tag: transaction id of the request
	* @offset: used by marshalling routines to track currentposition in buffer		* @offset: used by marshalling routines to track currentposition in buffer
	* @capacity: used by marshalling routines to track total capacity		* @capacity: used by marshalling routines to track total capacity
			* @pubuf: Payload user buffer given by the caller
			* @pubuf: Payload kernel buffer given by the caller
			* @pbuf_size: pubuf/pkbuf(only one will be !NULL) size to be read/write.
			* @private: For transport layer's use.
	* @sdata: payload		* @sdata: payload
	*		*
	* &p9_fcall represents the structure for all 9P RPC		* &p9_fcall represents the structure for all 9P RPC
	@@ -705,6 +709,10 @@ struct p9_fcall {

	size_t offset;		size_t offset;
	size_t capacity;		size_t capacity;
			char __user *pubuf;
			char *pkbuf;
			size_t pbuf_size;
			void *private;

	uint8_t *sdata;		uint8_t *sdata;
	};		};

net/9p/Makefile

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -9,6 +9,7 @@ obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
	util.o \		util.o \
	protocol.o \		protocol.o \
	trans_fd.o \		trans_fd.o \
			trans_common.o \

	9pnet_virtio-objs := \		9pnet_virtio-objs := \
	trans_virtio.o \		trans_virtio.o \

net/9p/protocol.c

+4 −0

Original line number	Original line	Diff line number	Diff line
	@@ -606,6 +606,10 @@ void p9pdu_reset(struct p9_fcall *pdu)
	{		{
	pdu->offset = 0;		pdu->offset = 0;
	pdu->size = 0;		pdu->size = 0;
			pdu->private = NULL;
			pdu->pubuf = NULL;
			pdu->pkbuf = NULL;
			pdu->pbuf_size = 0;
	}		}

	int p9dirent_read(char buf, int len, struct p9_dirent dirent,		int p9dirent_read(char buf, int len, struct p9_dirent dirent,

net/9p/trans_common.c

0 → 100644

+97 −0

Original line number	Original line	Diff line number	Diff line
			/*
			* Copyright IBM Corporation, 2010
			* Author Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
			*
			* This program is free software; you can redistribute it and/or modify it
			* under the terms of version 2.1 of the GNU Lesser General Public License
			* as published by the Free Software Foundation.
			*
			* This program is distributed in the hope that it would be useful, but
			* WITHOUT ANY WARRANTY; without even the implied warranty of
			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
			*
			*/

			#include <linux/slab.h>
			#include <linux/module.h>
			#include <net/9p/9p.h>
			#include <net/9p/client.h>
			#include <linux/scatterlist.h>
			#include "trans_common.h"

			/**
			* p9_release_req_pages - Release pages after the transaction.
			* @*private: PDU's private page of struct trans_rpage_info
			*/
			void
			p9_release_req_pages(struct trans_rpage_info *rpinfo)
			{
			int i = 0;

			while (rpinfo->rp_data[i] && rpinfo->rp_nr_pages--) {
			put_page(rpinfo->rp_data[i]);
			i++;
			}
			}
			EXPORT_SYMBOL(p9_release_req_pages);

			/**
			* p9_nr_pages - Return number of pages needed to accomodate the payload.
			*/
			int
			p9_nr_pages(struct p9_req_t *req)
			{
			int start_page, end_page;
			start_page = (unsigned long long)req->tc->pubuf >> PAGE_SHIFT;
			end_page = ((unsigned long long)req->tc->pubuf + req->tc->pbuf_size +
			PAGE_SIZE - 1) >> PAGE_SHIFT;
			return end_page - start_page;
			}
			EXPORT_SYMBOL(p9_nr_pages);

			/**
			* payload_gup - Translates user buffer into kernel pages and
			* pins them either for read/write through get_user_pages_fast().
			* @req: Request to be sent to server.
			* @pdata_off: data offset into the first page after translation (gup).
			* @pdata_len: Total length of the IO. gup may not return requested # of pages.
			* @nr_pages: number of pages to accomodate the payload
			* @rw: Indicates if the pages are for read or write.
			*/
			int
			p9_payload_gup(struct p9_req_t req, size_t pdata_off, int *pdata_len,
			int nr_pages, u8 rw)
			{
			uint32_t first_page_bytes = 0;
			uint32_t pdata_mapped_pages;
			struct trans_rpage_info *rpinfo;

			*pdata_off = (size_t)req->tc->pubuf & (PAGE_SIZE-1);

			if (*pdata_off)
			first_page_bytes = min((PAGE_SIZE - *pdata_off),
			req->tc->pbuf_size);

			rpinfo = req->tc->private;
			pdata_mapped_pages = get_user_pages_fast((unsigned long)req->tc->pubuf,
			nr_pages, rw, &rpinfo->rp_data[0]);

			if (pdata_mapped_pages < 0) {
			printk(KERN_ERR "get_user_pages_fast failed:%d udata:%p"
			"nr_pages:%d\n", pdata_mapped_pages,
			req->tc->pubuf, nr_pages);
			pdata_mapped_pages = 0;
			return -EIO;
			}
			rpinfo->rp_nr_pages = pdata_mapped_pages;
			if (*pdata_off) {
			*pdata_len = first_page_bytes;
			pdata_len += min((req->tc->pbuf_size - pdata_len),
			((size_t)pdata_mapped_pages - 1) << PAGE_SHIFT);
			} else {
			*pdata_len = min(req->tc->pbuf_size,
			(size_t)pdata_mapped_pages << PAGE_SHIFT);
			}
			return 0;
			}
			EXPORT_SYMBOL(p9_payload_gup);

net/9p/trans_common.h

0 → 100644

+29 −0

Original line number	Original line	Diff line number	Diff line
			/*
			* Copyright IBM Corporation, 2010
			* Author Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
			*
			* This program is free software; you can redistribute it and/or modify it
			* under the terms of version 2.1 of the GNU Lesser General Public License
			* as published by the Free Software Foundation.
			*
			* This program is distributed in the hope that it would be useful, but
			* WITHOUT ANY WARRANTY; without even the implied warranty of
			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
			*
			*/

			/**
			* struct trans_rpage_info - To store mapped page information in PDU.
			* @rp_alloc:Set if this structure is allocd, not a reuse unused space in pdu.
			* @rp_nr_pages: Number of mapped pages
			* @rp_data: Array of page pointers
			*/
			struct trans_rpage_info {
			u8 rp_alloc;
			int rp_nr_pages;
			struct page *rp_data[0];
			};

			void p9_release_req_pages(struct trans_rpage_info *);
			int p9_payload_gup(struct p9_req_t , size_t , int *, int, u8);
			int p9_nr_pages(struct p9_req_t *);