linux-kernel - [PATCH v3 2/2] bus: mhi: host: Optimize and update MMIO register write method

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 13 Apr 2022 09:56:46 -0600
From:   Jeffrey Hugo <quic_jhugo@...cinc.com>
To:     <loic.poulain@...aro.org>, <mani@...nel.org>,
        <quic_hemantk@...cinc.com>, <quic_bbhatt@...cinc.com>
CC:     <mhi@...ts.linux.dev>, <linux-arm-msm@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>,
        Bhaumik Bhatt <bbhatt@...eaurora.org>,
        Jeffrey Hugo <quic_jhugo@...cinc.com>
Subject: [PATCH v3 2/2] bus: mhi: host: Optimize and update MMIO register write method

From: Bhaumik Bhatt <bbhatt@...eaurora.org>

As of now, MMIO writes done after ready state transition use the
mhi_write_reg_field() API even though the whole register is being
written in most cases. Optimize this process by using mhi_write_reg()
API instead for those writes and use the mhi_write_reg_field()
API for MHI config registers only.

Signed-off-by: Bhaumik Bhatt <bbhatt@...eaurora.org>
Reviewed-by: Hemant Kumar <hemantk@...eaurora.org>
Reviewed-by: Jeffrey Hugo <quic_jhugo@...cinc.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
Signed-off-by: Jeffrey Hugo <quic_jhugo@...cinc.com>
---
 drivers/bus/mhi/host/init.c | 62 ++++++++++++++++++++++-----------------------
 1 file changed, 31 insertions(+), 31 deletions(-)

diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
index 9ac93b7..04c409b 100644
--- a/drivers/bus/mhi/host/init.c
+++ b/drivers/bus/mhi/host/init.c
@@ -425,74 +425,65 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 	struct {
 		u32 offset;
-		u32 mask;
 		u32 val;
 	} reg_info[] = {
 		{
-			CCABAP_HIGHER, U32_MAX,
+			CCABAP_HIGHER,
 			upper_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
 		},
 		{
-			CCABAP_LOWER, U32_MAX,
+			CCABAP_LOWER,
 			lower_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
 		},
 		{
-			ECABAP_HIGHER, U32_MAX,
+			ECABAP_HIGHER,
 			upper_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
 		},
 		{
-			ECABAP_LOWER, U32_MAX,
+			ECABAP_LOWER,
 			lower_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
 		},
 		{
-			CRCBAP_HIGHER, U32_MAX,
+			CRCBAP_HIGHER,
 			upper_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
 		},
 		{
-			CRCBAP_LOWER, U32_MAX,
+			CRCBAP_LOWER,
 			lower_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
 		},
 		{
-			MHICFG, MHICFG_NER_MASK,
-			mhi_cntrl->total_ev_rings,
-		},
-		{
-			MHICFG, MHICFG_NHWER_MASK,
-			mhi_cntrl->hw_ev_rings,
-		},
-		{
-			MHICTRLBASE_HIGHER, U32_MAX,
+			MHICTRLBASE_HIGHER,
 			upper_32_bits(mhi_cntrl->iova_start),
 		},
 		{
-			MHICTRLBASE_LOWER, U32_MAX,
+			MHICTRLBASE_LOWER,
 			lower_32_bits(mhi_cntrl->iova_start),
 		},
 		{
-			MHIDATABASE_HIGHER, U32_MAX,
+			MHIDATABASE_HIGHER,
 			upper_32_bits(mhi_cntrl->iova_start),
 		},
 		{
-			MHIDATABASE_LOWER, U32_MAX,
+			MHIDATABASE_LOWER,
 			lower_32_bits(mhi_cntrl->iova_start),
 		},
 		{
-			MHICTRLLIMIT_HIGHER, U32_MAX,
+			MHICTRLLIMIT_HIGHER,
 			upper_32_bits(mhi_cntrl->iova_stop),
 		},
 		{
-			MHICTRLLIMIT_LOWER, U32_MAX,
+			MHICTRLLIMIT_LOWER,
 			lower_32_bits(mhi_cntrl->iova_stop),
 		},
 		{
-			MHIDATALIMIT_HIGHER, U32_MAX,
+			MHIDATALIMIT_HIGHER,
 			upper_32_bits(mhi_cntrl->iova_stop),
 		},
 		{
-			MHIDATALIMIT_LOWER, U32_MAX,
+			MHIDATALIMIT_LOWER,
 			lower_32_bits(mhi_cntrl->iova_stop),
 		},
-		{ 0, 0, 0 }
+		{0, 0}
 	};
 
 	dev_dbg(dev, "Initializing MHI registers\n");
@@ -533,13 +524,22 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
 	mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING].ring.db_addr = base + CRDB_LOWER;
 
 	/* Write to MMIO registers */
-	for (i = 0; reg_info[i].offset; i++) {
-		ret = mhi_write_reg_field(mhi_cntrl, base, reg_info[i].offset,
-					  reg_info[i].mask, reg_info[i].val);
-		if (ret) {
-			dev_err(dev, "Unable to write to MMIO registers");
-			return ret;
-		}
+	for (i = 0; reg_info[i].offset; i++)
+		mhi_write_reg(mhi_cntrl, base, reg_info[i].offset,
+			      reg_info[i].val);
+
+	ret = mhi_write_reg_field(mhi_cntrl, base, MHICFG, MHICFG_NER_MASK,
+				  mhi_cntrl->total_ev_rings);
+	if (ret) {
+		dev_err(dev, "Unable to read MHICFG register\n");
+		return ret;
+	}
+
+	ret = mhi_write_reg_field(mhi_cntrl, base, MHICFG, MHICFG_NHWER_MASK,
+				  mhi_cntrl->hw_ev_rings);
+	if (ret) {
+		dev_err(dev, "Unable to read MHICFG register\n");
+		return ret;
 	}
 
 	return 0;
-- 
2.7.4