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From:   yu kuai <yukuai3@huawei.com>
To:     <ysato@users.sourceforge.jp>, <dalias@libc.org>,
        <aacraid@microsemi.com>, <jejb@linux.ibm.com>,
        <martin.petersen@oracle.com>, <sathya.prakash@broadcom.com>,
        <chaitra.basappa@broadcom.com>,
        <suganath-prabu.subramani@broadcom.com>
CC:     <linux-sh@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-scsi@vger.kernel.org>, <MPT-FusionLinux.pdl@broadcom.com>,
        <yukuai3@huawei.com>, <zhengbin13@huawei.com>,
        <yi.zhang@huawei.com>
Subject: [PATCH] scsi: don't memset to zero after dma_alloc_coherent
Date:   Wed, 25 Dec 2019 21:23:27 +0800
Message-ID: <20191225132327.7121-1-yukuai3@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

dma_alloc_coherent already zeros out memory, so memset to zero is not
needed.

Signed-off-by: yu kuai <yukuai3@huawei.com>
---
 arch/sh/mm/consistent.c             | 2 --
 drivers/scsi/dpt_i2o.c              | 4 ----
 drivers/scsi/mpt3sas/mpt3sas_base.c | 1 -
 drivers/scsi/mvsas/mv_init.c        | 4 ----
 drivers/scsi/pmcraid.c              | 1 -
 5 files changed, 12 deletions(-)

diff --git a/arch/sh/mm/consistent.c b/arch/sh/mm/consistent.c
index 3169a343a5ab..0de206c1acfe 100644
--- a/arch/sh/mm/consistent.c
+++ b/arch/sh/mm/consistent.c
@@ -57,8 +57,6 @@ int __init platform_resource_setup_memory(struct platform_device *pdev,
 		return -ENOMEM;
 	}
 
-	memset(buf, 0, memsize);
-
 	r->flags = IORESOURCE_MEM;
 	r->start = dma_handle;
 	r->end = r->start + memsize - 1;
diff --git a/drivers/scsi/dpt_i2o.c b/drivers/scsi/dpt_i2o.c
index abc74fd474dc..b1b879beebfb 100644
--- a/drivers/scsi/dpt_i2o.c
+++ b/drivers/scsi/dpt_i2o.c
@@ -1331,7 +1331,6 @@ static s32 adpt_i2o_reset_hba(adpt_hba* pHba)
 		printk(KERN_ERR"IOP reset failed - no free memory.\n");
 		return -ENOMEM;
 	}
-	memset(status,0,4);
 
 	msg[0]=EIGHT_WORD_MSG_SIZE|SGL_OFFSET_0;
 	msg[1]=I2O_CMD_ADAPTER_RESET<<24|HOST_TID<<12|ADAPTER_TID;
@@ -2803,7 +2802,6 @@ static s32 adpt_i2o_init_outbound_q(adpt_hba* pHba)
 			pHba->name);
 		return -ENOMEM;
 	}
-	memset(status, 0, 4);
 
 	writel(EIGHT_WORD_MSG_SIZE| SGL_OFFSET_6, &msg[0]);
 	writel(I2O_CMD_OUTBOUND_INIT<<24 | HOST_TID<<12 | ADAPTER_TID, &msg[1]);
@@ -2857,7 +2855,6 @@ static s32 adpt_i2o_init_outbound_q(adpt_hba* pHba)
 		printk(KERN_ERR "%s: Could not allocate reply pool\n", pHba->name);
 		return -ENOMEM;
 	}
-	memset(pHba->reply_pool, 0 , pHba->reply_fifo_size * REPLY_FRAME_SIZE * 4);
 
 	for(i = 0; i < pHba->reply_fifo_size; i++) {
 		writel(pHba->reply_pool_pa + (i * REPLY_FRAME_SIZE * 4),
@@ -3092,7 +3089,6 @@ static int adpt_i2o_build_sys_table(void)
 		printk(KERN_WARNING "SysTab Set failed. Out of memory.\n");	
 		return -ENOMEM;
 	}
-	memset(sys_tbl, 0, sys_tbl_len);
 
 	sys_tbl->num_entries = hba_count;
 	sys_tbl->version = I2OVERSION;
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 45fd8dfb7c40..663dd4df03e3 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -5090,7 +5090,6 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc)
 		_base_release_memory_pools(ioc);
 		goto retry_allocation;
 	}
-	memset(ioc->request, 0, sz);
 
 	if (retry_sz)
 		ioc_err(ioc, "request pool: dma_alloc_coherent succeed: hba_depth(%d), chains_per_io(%d), frame_sz(%d), total(%d kb)\n",
diff --git a/drivers/scsi/mvsas/mv_init.c b/drivers/scsi/mvsas/mv_init.c
index 7af9173c4925..e77f4d5a049c 100644
--- a/drivers/scsi/mvsas/mv_init.c
+++ b/drivers/scsi/mvsas/mv_init.c
@@ -244,19 +244,16 @@ static int mvs_alloc(struct mvs_info *mvi, struct Scsi_Host *shost)
 				     &mvi->tx_dma, GFP_KERNEL);
 	if (!mvi->tx)
 		goto err_out;
-	memset(mvi->tx, 0, sizeof(*mvi->tx) * MVS_CHIP_SLOT_SZ);
 	mvi->rx_fis = dma_alloc_coherent(mvi->dev, MVS_RX_FISL_SZ,
 					 &mvi->rx_fis_dma, GFP_KERNEL);
 	if (!mvi->rx_fis)
 		goto err_out;
-	memset(mvi->rx_fis, 0, MVS_RX_FISL_SZ);
 
 	mvi->rx = dma_alloc_coherent(mvi->dev,
 				     sizeof(*mvi->rx) * (MVS_RX_RING_SZ + 1),
 				     &mvi->rx_dma, GFP_KERNEL);
 	if (!mvi->rx)
 		goto err_out;
-	memset(mvi->rx, 0, sizeof(*mvi->rx) * (MVS_RX_RING_SZ + 1));
 	mvi->rx[0] = cpu_to_le32(0xfff);
 	mvi->rx_cons = 0xfff;
 
@@ -265,7 +262,6 @@ static int mvs_alloc(struct mvs_info *mvi, struct Scsi_Host *shost)
 				       &mvi->slot_dma, GFP_KERNEL);
 	if (!mvi->slot)
 		goto err_out;
-	memset(mvi->slot, 0, sizeof(*mvi->slot) * slot_nr);
 
 	mvi->bulk_buffer = dma_alloc_coherent(mvi->dev,
 				       TRASH_BUCKET_SIZE,
diff --git a/drivers/scsi/pmcraid.c b/drivers/scsi/pmcraid.c
index 7eb88fe1eb0b..6976013cf4c7 100644
--- a/drivers/scsi/pmcraid.c
+++ b/drivers/scsi/pmcraid.c
@@ -4718,7 +4718,6 @@ static int pmcraid_allocate_host_rrqs(struct pmcraid_instance *pinstance)
 			return -ENOMEM;
 		}
 
-		memset(pinstance->hrrq_start[i], 0, buffer_size);
 		pinstance->hrrq_curr[i] = pinstance->hrrq_start[i];
 		pinstance->hrrq_end[i] =
 			pinstance->hrrq_start[i] + PMCRAID_MAX_CMD - 1;
-- 
2.17.2