drivers/target/iscsi/cxgbit/cxgbit_ddp.c - arm/linux - Git at Google

 /*
  * Copyright (c) 2016 Chelsio Communications, Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 #include "cxgbit.h"

 static void
 cxgbit_set_one_ppod(struct cxgbi_pagepod *ppod,
 		    struct cxgbi_task_tag_info *ttinfo,
 		    struct scatterlist **sg_pp, unsigned int *sg_off)
 {
 	struct scatterlist *sg = sg_pp ? *sg_pp : NULL;
 	unsigned int offset = sg_off ? *sg_off : 0;
 	dma_addr_t addr = 0UL;
 	unsigned int len = 0;
 	int i;

 	memcpy(ppod, &ttinfo->hdr, sizeof(struct cxgbi_pagepod_hdr));

 	if (sg) {
 		addr = sg_dma_address(sg);
 		len = sg_dma_len(sg);
 	}

 	for (i = 0; i < PPOD_PAGES_MAX; i++) {
 		if (sg) {
 			ppod->addr[i] = cpu_to_be64(addr + offset);
 			offset += PAGE_SIZE;
 			if (offset == (len + sg->offset)) {
 				offset = 0;
 				sg = sg_next(sg);
 				if (sg) {
 					addr = sg_dma_address(sg);
 					len = sg_dma_len(sg);
 				}
 			}
 		} else {
 			ppod->addr[i] = 0ULL;
 		}
 	}

 	/*
 	 * the fifth address needs to be repeated in the next ppod, so do
 	 * not move sg
 	 */
 	if (sg_pp) {
 		*sg_pp = sg;
 		*sg_off = offset;
 	}

 	if (offset == len) {
 		offset = 0;
 		if (sg) {
 			sg = sg_next(sg);
 			if (sg)
 				addr = sg_dma_address(sg);
 		}
 	}
 	ppod->addr[i] = sg ? cpu_to_be64(addr + offset) : 0ULL;
 }

 static struct sk_buff *
 cxgbit_ppod_init_idata(struct cxgbit_device *cdev, struct cxgbi_ppm *ppm,
 		       unsigned int idx, unsigned int npods, unsigned int tid)
 {
 	struct ulp_mem_io *req;
 	struct ulptx_idata *idata;
 	unsigned int pm_addr = (idx << PPOD_SIZE_SHIFT) + ppm->llimit;
 	unsigned int dlen = npods << PPOD_SIZE_SHIFT;
 	unsigned int wr_len = roundup(sizeof(struct ulp_mem_io) +
 				sizeof(struct ulptx_idata) + dlen, 16);
 	struct sk_buff *skb;

 	skb  = alloc_skb(wr_len, GFP_KERNEL);
 	if (!skb)
 		return NULL;

 	req = __skb_put(skb, wr_len);
 	INIT_ULPTX_WR(req, wr_len, 0, tid);
 	req->wr.wr_hi = htonl(FW_WR_OP_V(FW_ULPTX_WR) |
 		FW_WR_ATOMIC_V(0));
 	req->cmd = htonl(ULPTX_CMD_V(ULP_TX_MEM_WRITE) |
 		ULP_MEMIO_ORDER_V(0) |
 		T5_ULP_MEMIO_IMM_V(1));
 	req->dlen = htonl(ULP_MEMIO_DATA_LEN_V(dlen >> 5));
 	req->lock_addr = htonl(ULP_MEMIO_ADDR_V(pm_addr >> 5));
 	req->len16 = htonl(DIV_ROUND_UP(wr_len - sizeof(req->wr), 16));

 	idata = (struct ulptx_idata *)(req + 1);
 	idata->cmd_more = htonl(ULPTX_CMD_V(ULP_TX_SC_IMM));
 	idata->len = htonl(dlen);

 	return skb;
 }

 static int
 cxgbit_ppod_write_idata(struct cxgbi_ppm *ppm, struct cxgbit_sock *csk,
 			struct cxgbi_task_tag_info *ttinfo, unsigned int idx,
 			unsigned int npods, struct scatterlist **sg_pp,
 			unsigned int *sg_off)
 {
 	struct cxgbit_device *cdev = csk->com.cdev;
 	struct sk_buff *skb;
 	struct ulp_mem_io *req;
 	struct ulptx_idata *idata;
 	struct cxgbi_pagepod *ppod;
 	unsigned int i;

 	skb = cxgbit_ppod_init_idata(cdev, ppm, idx, npods, csk->tid);
 	if (!skb)
 		return -ENOMEM;

 	req = (struct ulp_mem_io *)skb->data;
 	idata = (struct ulptx_idata *)(req + 1);
 	ppod = (struct cxgbi_pagepod *)(idata + 1);

 	for (i = 0; i < npods; i++, ppod++)
 		cxgbit_set_one_ppod(ppod, ttinfo, sg_pp, sg_off);

 	__skb_queue_tail(&csk->ppodq, skb);

 	return 0;
 }

 static int
 cxgbit_ddp_set_map(struct cxgbi_ppm *ppm, struct cxgbit_sock *csk,
 		   struct cxgbi_task_tag_info *ttinfo)
 {
 	unsigned int pidx = ttinfo->idx;
 	unsigned int npods = ttinfo->npods;
 	unsigned int i, cnt;
 	struct scatterlist *sg = ttinfo->sgl;
 	unsigned int offset = 0;
 	int ret = 0;

 	for (i = 0; i < npods; i += cnt, pidx += cnt) {
 		cnt = npods - i;

 		if (cnt > ULPMEM_IDATA_MAX_NPPODS)
 			cnt = ULPMEM_IDATA_MAX_NPPODS;

 		ret = cxgbit_ppod_write_idata(ppm, csk, ttinfo, pidx, cnt,
 					      &sg, &offset);
 		if (ret < 0)
 			break;
 	}

 	return ret;
 }

 static int cxgbit_ddp_sgl_check(struct scatterlist *sg,
 				unsigned int nents)
 {
 	unsigned int last_sgidx = nents - 1;
 	unsigned int i;

 	for (i = 0; i < nents; i++, sg = sg_next(sg)) {
 		unsigned int len = sg->length + sg->offset;

 		if ((sg->offset & 0x3) || (i && sg->offset) ||
 		    ((i != last_sgidx) && (len != PAGE_SIZE))) {
 			return -EINVAL;
 		}
 	}

 	return 0;
 }

 static int
 cxgbit_ddp_reserve(struct cxgbit_sock *csk, struct cxgbi_task_tag_info *ttinfo,
 		   unsigned int xferlen)
 {
 	struct cxgbit_device *cdev = csk->com.cdev;
 	struct cxgbi_ppm *ppm = cdev2ppm(cdev);
 	struct scatterlist *sgl = ttinfo->sgl;
 	unsigned int sgcnt = ttinfo->nents;
 	unsigned int sg_offset = sgl->offset;
 	int ret;

 	if ((xferlen < DDP_THRESHOLD) || (!sgcnt)) {
 		pr_debug("ppm 0x%p, pgidx %u, xfer %u, sgcnt %u, NO ddp.\n",
 			 ppm, ppm->tformat.pgsz_idx_dflt,
 			 xferlen, ttinfo->nents);
 		return -EINVAL;
 	}

 	if (cxgbit_ddp_sgl_check(sgl, sgcnt) < 0)
 		return -EINVAL;

 	ttinfo->nr_pages = (xferlen + sgl->offset +
 			    (1 << PAGE_SHIFT) - 1) >> PAGE_SHIFT;

 	/*
 	 * the ddp tag will be used for the ttt in the outgoing r2t pdu
 	 */
 	ret = cxgbi_ppm_ppods_reserve(ppm, ttinfo->nr_pages, 0, &ttinfo->idx,
 				      &ttinfo->tag, 0);
 	if (ret < 0)
 		return ret;
 	ttinfo->npods = ret;

 	sgl->offset = 0;
 	ret = dma_map_sg(&ppm->pdev->dev, sgl, sgcnt, DMA_FROM_DEVICE);
 	sgl->offset = sg_offset;
 	if (!ret) {
 		pr_info("%s: 0x%x, xfer %u, sgl %u dma mapping err.\n",
 			__func__, 0, xferlen, sgcnt);
 		goto rel_ppods;
 	}

 	cxgbi_ppm_make_ppod_hdr(ppm, ttinfo->tag, csk->tid, sgl->offset,
 				xferlen, &ttinfo->hdr);

 	ret = cxgbit_ddp_set_map(ppm, csk, ttinfo);
 	if (ret < 0) {
 		__skb_queue_purge(&csk->ppodq);
 		dma_unmap_sg(&ppm->pdev->dev, sgl, sgcnt, DMA_FROM_DEVICE);
 		goto rel_ppods;
 	}

 	return 0;

 rel_ppods:
 	cxgbi_ppm_ppod_release(ppm, ttinfo->idx);
 	return -EINVAL;
 }

 void
 cxgbit_get_r2t_ttt(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
 		   struct iscsi_r2t *r2t)
 {
 	struct cxgbit_sock *csk = conn->context;
 	struct cxgbit_device *cdev = csk->com.cdev;
 	struct cxgbit_cmd *ccmd = iscsit_priv_cmd(cmd);
 	struct cxgbi_task_tag_info *ttinfo = &ccmd->ttinfo;
 	int ret = -EINVAL;

 	if ((!ccmd->setup_ddp) ||
 	    (!test_bit(CSK_DDP_ENABLE, &csk->com.flags)))
 		goto out;

 	ccmd->setup_ddp = false;

 	ttinfo->sgl = cmd->se_cmd.t_data_sg;
 	ttinfo->nents = cmd->se_cmd.t_data_nents;

 	ret = cxgbit_ddp_reserve(csk, ttinfo, cmd->se_cmd.data_length);
 	if (ret < 0) {
 		pr_info("csk 0x%p, cmd 0x%p, xfer len %u, sgcnt %u no ddp.\n",
 			csk, cmd, cmd->se_cmd.data_length, ttinfo->nents);

 		ttinfo->sgl = NULL;
 		ttinfo->nents = 0;
 	} else {
 		ccmd->release = true;
 	}
 out:
 	pr_debug("cdev 0x%p, cmd 0x%p, tag 0x%x\n", cdev, cmd, ttinfo->tag);
 	r2t->targ_xfer_tag = ttinfo->tag;
 }

 void cxgbit_release_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
 {
 	struct cxgbit_cmd *ccmd = iscsit_priv_cmd(cmd);

 	if (ccmd->release) {
 		struct cxgbi_task_tag_info *ttinfo = &ccmd->ttinfo;

 		if (ttinfo->sgl) {
 			struct cxgbit_sock *csk = conn->context;
 			struct cxgbit_device *cdev = csk->com.cdev;
 			struct cxgbi_ppm *ppm = cdev2ppm(cdev);

 			cxgbi_ppm_ppod_release(ppm, ttinfo->idx);

 			dma_unmap_sg(&ppm->pdev->dev, ttinfo->sgl,
 				     ttinfo->nents, DMA_FROM_DEVICE);
 		} else {
 			put_page(sg_page(&ccmd->sg));
 		}

 		ccmd->release = false;
 	}
 }

 int cxgbit_ddp_init(struct cxgbit_device *cdev)
 {
 	struct cxgb4_lld_info *lldi = &cdev->lldi;
 	struct net_device *ndev = cdev->lldi.ports[0];
 	struct cxgbi_tag_format tformat;
 	unsigned int ppmax;
 	int ret, i;

 	if (!lldi->vr->iscsi.size) {
 		pr_warn("%s, iscsi NOT enabled, check config!\n", ndev->name);
 		return -EACCES;
 	}

 	ppmax = lldi->vr->iscsi.size >> PPOD_SIZE_SHIFT;

 	memset(&tformat, 0, sizeof(struct cxgbi_tag_format));
 	for (i = 0; i < 4; i++)
 		tformat.pgsz_order[i] = (lldi->iscsi_pgsz_order >> (i << 3))
 					 & 0xF;
 	cxgbi_tagmask_check(lldi->iscsi_tagmask, &tformat);

 	ret = cxgbi_ppm_init(lldi->iscsi_ppm, cdev->lldi.ports[0],
 			     cdev->lldi.pdev, &cdev->lldi, &tformat,
 			     ppmax, lldi->iscsi_llimit,
 			     lldi->vr->iscsi.start, 2);
 	if (ret >= 0) {
 		struct cxgbi_ppm *ppm = (struct cxgbi_ppm *)(*lldi->iscsi_ppm);

 		if ((ppm->tformat.pgsz_idx_dflt < DDP_PGIDX_MAX) &&
 		    (ppm->ppmax >= 1024))
 			set_bit(CDEV_DDP_ENABLE, &cdev->flags);
 		ret = 0;
 	}

 	return ret;
 }
	/*
	* Copyright (c) 2016 Chelsio Communications, Inc.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#include "cxgbit.h"

	static void
	cxgbit_set_one_ppod(struct cxgbi_pagepod *ppod,
	struct cxgbi_task_tag_info *ttinfo,
	struct scatterlist *sg_pp, unsigned int sg_off)
	{
	struct scatterlist sg = sg_pp ? sg_pp : NULL;
	unsigned int offset = sg_off ? *sg_off : 0;
	dma_addr_t addr = 0UL;
	unsigned int len = 0;
	int i;

	memcpy(ppod, &ttinfo->hdr, sizeof(struct cxgbi_pagepod_hdr));

	if (sg) {
	addr = sg_dma_address(sg);
	len = sg_dma_len(sg);
	}

	for (i = 0; i < PPOD_PAGES_MAX; i++) {
	if (sg) {
	ppod->addr[i] = cpu_to_be64(addr + offset);
	offset += PAGE_SIZE;
	if (offset == (len + sg->offset)) {
	offset = 0;
	sg = sg_next(sg);
	if (sg) {
	addr = sg_dma_address(sg);
	len = sg_dma_len(sg);
	}
	}
	} else {
	ppod->addr[i] = 0ULL;
	}
	}

	/*
	* the fifth address needs to be repeated in the next ppod, so do
	* not move sg
	*/
	if (sg_pp) {
	*sg_pp = sg;
	*sg_off = offset;
	}

	if (offset == len) {
	offset = 0;
	if (sg) {
	sg = sg_next(sg);
	if (sg)
	addr = sg_dma_address(sg);
	}
	}
	ppod->addr[i] = sg ? cpu_to_be64(addr + offset) : 0ULL;
	}

	static struct sk_buff *
	cxgbit_ppod_init_idata(struct cxgbit_device cdev, struct cxgbi_ppm ppm,
	unsigned int idx, unsigned int npods, unsigned int tid)
	{
	struct ulp_mem_io *req;
	struct ulptx_idata *idata;
	unsigned int pm_addr = (idx << PPOD_SIZE_SHIFT) + ppm->llimit;
	unsigned int dlen = npods << PPOD_SIZE_SHIFT;
	unsigned int wr_len = roundup(sizeof(struct ulp_mem_io) +
	sizeof(struct ulptx_idata) + dlen, 16);
	struct sk_buff *skb;

	skb = alloc_skb(wr_len, GFP_KERNEL);
	if (!skb)
	return NULL;

	req = __skb_put(skb, wr_len);
	INIT_ULPTX_WR(req, wr_len, 0, tid);
	req->wr.wr_hi = htonl(FW_WR_OP_V(FW_ULPTX_WR) \|
	FW_WR_ATOMIC_V(0));
	req->cmd = htonl(ULPTX_CMD_V(ULP_TX_MEM_WRITE) \|
	ULP_MEMIO_ORDER_V(0) \|
	T5_ULP_MEMIO_IMM_V(1));
	req->dlen = htonl(ULP_MEMIO_DATA_LEN_V(dlen >> 5));
	req->lock_addr = htonl(ULP_MEMIO_ADDR_V(pm_addr >> 5));
	req->len16 = htonl(DIV_ROUND_UP(wr_len - sizeof(req->wr), 16));

	idata = (struct ulptx_idata *)(req + 1);
	idata->cmd_more = htonl(ULPTX_CMD_V(ULP_TX_SC_IMM));
	idata->len = htonl(dlen);

	return skb;
	}

	static int
	cxgbit_ppod_write_idata(struct cxgbi_ppm ppm, struct cxgbit_sock csk,
	struct cxgbi_task_tag_info *ttinfo, unsigned int idx,
	unsigned int npods, struct scatterlist **sg_pp,
	unsigned int *sg_off)
	{
	struct cxgbit_device *cdev = csk->com.cdev;
	struct sk_buff *skb;
	struct ulp_mem_io *req;
	struct ulptx_idata *idata;
	struct cxgbi_pagepod *ppod;
	unsigned int i;

	skb = cxgbit_ppod_init_idata(cdev, ppm, idx, npods, csk->tid);
	if (!skb)
	return -ENOMEM;

	req = (struct ulp_mem_io *)skb->data;
	idata = (struct ulptx_idata *)(req + 1);
	ppod = (struct cxgbi_pagepod *)(idata + 1);

	for (i = 0; i < npods; i++, ppod++)
	cxgbit_set_one_ppod(ppod, ttinfo, sg_pp, sg_off);

	__skb_queue_tail(&csk->ppodq, skb);

	return 0;
	}

	static int
	cxgbit_ddp_set_map(struct cxgbi_ppm ppm, struct cxgbit_sock csk,
	struct cxgbi_task_tag_info *ttinfo)
	{
	unsigned int pidx = ttinfo->idx;
	unsigned int npods = ttinfo->npods;
	unsigned int i, cnt;
	struct scatterlist *sg = ttinfo->sgl;
	unsigned int offset = 0;
	int ret = 0;

	for (i = 0; i < npods; i += cnt, pidx += cnt) {
	cnt = npods - i;

	if (cnt > ULPMEM_IDATA_MAX_NPPODS)
	cnt = ULPMEM_IDATA_MAX_NPPODS;

	ret = cxgbit_ppod_write_idata(ppm, csk, ttinfo, pidx, cnt,
	&sg, &offset);
	if (ret < 0)
	break;
	}

	return ret;
	}

	static int cxgbit_ddp_sgl_check(struct scatterlist *sg,
	unsigned int nents)
	{
	unsigned int last_sgidx = nents - 1;
	unsigned int i;

	for (i = 0; i < nents; i++, sg = sg_next(sg)) {
	unsigned int len = sg->length + sg->offset;

	if ((sg->offset & 0x3) \|\| (i && sg->offset) \|\|
	((i != last_sgidx) && (len != PAGE_SIZE))) {
	return -EINVAL;
	}
	}

	return 0;
	}

	static int
	cxgbit_ddp_reserve(struct cxgbit_sock csk, struct cxgbi_task_tag_info ttinfo,
	unsigned int xferlen)
	{
	struct cxgbit_device *cdev = csk->com.cdev;
	struct cxgbi_ppm *ppm = cdev2ppm(cdev);
	struct scatterlist *sgl = ttinfo->sgl;
	unsigned int sgcnt = ttinfo->nents;
	unsigned int sg_offset = sgl->offset;
	int ret;

	if ((xferlen < DDP_THRESHOLD) \|\| (!sgcnt)) {
	pr_debug("ppm 0x%p, pgidx %u, xfer %u, sgcnt %u, NO ddp.\n",
	ppm, ppm->tformat.pgsz_idx_dflt,
	xferlen, ttinfo->nents);
	return -EINVAL;
	}

	if (cxgbit_ddp_sgl_check(sgl, sgcnt) < 0)
	return -EINVAL;

	ttinfo->nr_pages = (xferlen + sgl->offset +
	(1 << PAGE_SHIFT) - 1) >> PAGE_SHIFT;

	/*
	* the ddp tag will be used for the ttt in the outgoing r2t pdu
	*/
	ret = cxgbi_ppm_ppods_reserve(ppm, ttinfo->nr_pages, 0, &ttinfo->idx,
	&ttinfo->tag, 0);
	if (ret < 0)
	return ret;
	ttinfo->npods = ret;

	sgl->offset = 0;
	ret = dma_map_sg(&ppm->pdev->dev, sgl, sgcnt, DMA_FROM_DEVICE);
	sgl->offset = sg_offset;
	if (!ret) {
	pr_info("%s: 0x%x, xfer %u, sgl %u dma mapping err.\n",
	__func__, 0, xferlen, sgcnt);
	goto rel_ppods;
	}

	cxgbi_ppm_make_ppod_hdr(ppm, ttinfo->tag, csk->tid, sgl->offset,
	xferlen, &ttinfo->hdr);

	ret = cxgbit_ddp_set_map(ppm, csk, ttinfo);
	if (ret < 0) {
	__skb_queue_purge(&csk->ppodq);
	dma_unmap_sg(&ppm->pdev->dev, sgl, sgcnt, DMA_FROM_DEVICE);
	goto rel_ppods;
	}

	return 0;

	rel_ppods:
	cxgbi_ppm_ppod_release(ppm, ttinfo->idx);
	return -EINVAL;
	}

	void
	cxgbit_get_r2t_ttt(struct iscsi_conn conn, struct iscsi_cmd cmd,
	struct iscsi_r2t *r2t)
	{
	struct cxgbit_sock *csk = conn->context;
	struct cxgbit_device *cdev = csk->com.cdev;
	struct cxgbit_cmd *ccmd = iscsit_priv_cmd(cmd);
	struct cxgbi_task_tag_info *ttinfo = &ccmd->ttinfo;
	int ret = -EINVAL;

	if ((!ccmd->setup_ddp) \|\|
	(!test_bit(CSK_DDP_ENABLE, &csk->com.flags)))
	goto out;

	ccmd->setup_ddp = false;

	ttinfo->sgl = cmd->se_cmd.t_data_sg;
	ttinfo->nents = cmd->se_cmd.t_data_nents;

	ret = cxgbit_ddp_reserve(csk, ttinfo, cmd->se_cmd.data_length);
	if (ret < 0) {
	pr_info("csk 0x%p, cmd 0x%p, xfer len %u, sgcnt %u no ddp.\n",
	csk, cmd, cmd->se_cmd.data_length, ttinfo->nents);

	ttinfo->sgl = NULL;
	ttinfo->nents = 0;
	} else {
	ccmd->release = true;
	}
	out:
	pr_debug("cdev 0x%p, cmd 0x%p, tag 0x%x\n", cdev, cmd, ttinfo->tag);
	r2t->targ_xfer_tag = ttinfo->tag;
	}

	void cxgbit_release_cmd(struct iscsi_conn conn, struct iscsi_cmd cmd)
	{
	struct cxgbit_cmd *ccmd = iscsit_priv_cmd(cmd);

	if (ccmd->release) {
	struct cxgbi_task_tag_info *ttinfo = &ccmd->ttinfo;

	if (ttinfo->sgl) {
	struct cxgbit_sock *csk = conn->context;
	struct cxgbit_device *cdev = csk->com.cdev;
	struct cxgbi_ppm *ppm = cdev2ppm(cdev);

	cxgbi_ppm_ppod_release(ppm, ttinfo->idx);

	dma_unmap_sg(&ppm->pdev->dev, ttinfo->sgl,
	ttinfo->nents, DMA_FROM_DEVICE);
	} else {
	put_page(sg_page(&ccmd->sg));
	}

	ccmd->release = false;
	}
	}

	int cxgbit_ddp_init(struct cxgbit_device *cdev)
	{
	struct cxgb4_lld_info *lldi = &cdev->lldi;
	struct net_device *ndev = cdev->lldi.ports[0];
	struct cxgbi_tag_format tformat;
	unsigned int ppmax;
	int ret, i;

	if (!lldi->vr->iscsi.size) {
	pr_warn("%s, iscsi NOT enabled, check config!\n", ndev->name);
	return -EACCES;
	}

	ppmax = lldi->vr->iscsi.size >> PPOD_SIZE_SHIFT;

	memset(&tformat, 0, sizeof(struct cxgbi_tag_format));
	for (i = 0; i < 4; i++)
	tformat.pgsz_order[i] = (lldi->iscsi_pgsz_order >> (i << 3))
	& 0xF;
	cxgbi_tagmask_check(lldi->iscsi_tagmask, &tformat);

	ret = cxgbi_ppm_init(lldi->iscsi_ppm, cdev->lldi.ports[0],
	cdev->lldi.pdev, &cdev->lldi, &tformat,
	ppmax, lldi->iscsi_llimit,
	lldi->vr->iscsi.start, 2);
	if (ret >= 0) {
	struct cxgbi_ppm ppm = (struct cxgbi_ppm )(*lldi->iscsi_ppm);

	if ((ppm->tformat.pgsz_idx_dflt < DDP_PGIDX_MAX) &&
	(ppm->ppmax >= 1024))
	set_bit(CDEV_DDP_ENABLE, &cdev->flags);
	ret = 0;
	}

	return ret;
	}