From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753365AbeBZUrB (ORCPT ); Mon, 26 Feb 2018 15:47:01 -0500 Received: from mail-pl0-f66.google.com ([209.85.160.66]:38142 "EHLO mail-pl0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753172AbeBZUq6 (ORCPT ); Mon, 26 Feb 2018 15:46:58 -0500 X-Google-Smtp-Source: AG47ELsOIF0uWQDE1q186HMqcyQ9QTUNF0HUbbv0i26rIlCSD86debym8jfwEleZsfS6PbqjmtHi/A== From: Guenter Roeck To: Jean Delvare Cc: Wolfram Sang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Guenter Roeck Subject: [PATCH v2 2/2] i2c: piix4: Use request_muxed_region Date: Mon, 26 Feb 2018 12:46:53 -0800 Message-Id: <1519678013-32749-2-git-send-email-linux@roeck-us.net> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1519678013-32749-1-git-send-email-linux@roeck-us.net> References: <1519678013-32749-1-git-send-email-linux@roeck-us.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Accesses to SB800_PIIX4_SMB_IDX can occur from multiple drivers. One example for another driver is the sp5100_tco driver. Use request_muxed_region() to ensure synchronization. Signed-off-by: Guenter Roeck --- v2: Dropped now unnecessary include of linux/mutex.h Added error message if request_muxed_region() fails Spell out affected driver in commit message Note that I did not try to do a performance analysis. Doing so seemed excessive, even more so in the context of piix4_imc_sleep() already using request_muxed_region(). drivers/i2c/busses/i2c-piix4.c | 55 +++++++++++++++++++----------------------- 1 file changed, 25 insertions(+), 30 deletions(-) diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c index 4c1f6aaec0fc..90946a8b9a75 100644 --- a/drivers/i2c/busses/i2c-piix4.c +++ b/drivers/i2c/busses/i2c-piix4.c @@ -40,7 +40,6 @@ #include #include #include -#include /* PIIX4 SMBus address offsets */ @@ -153,10 +152,7 @@ static const struct dmi_system_id piix4_dmi_ibm[] = { /* * SB800 globals - * piix4_mutex_sb800 protects piix4_port_sel_sb800 and the pair - * of I/O ports at SB800_PIIX4_SMB_IDX. */ -static DEFINE_MUTEX(piix4_mutex_sb800); static u8 piix4_port_sel_sb800; static u8 piix4_port_mask_sb800; static u8 piix4_port_shift_sb800; @@ -298,12 +294,19 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev, else smb_en = (aux) ? 0x28 : 0x2c; - mutex_lock(&piix4_mutex_sb800); + if (!request_muxed_region(SB800_PIIX4_SMB_IDX, 2, "sb800_piix4_smb")) { + dev_err(&PIIX4_dev->dev, + "SMB base address index region 0x%x already in use.\n", + SB800_PIIX4_SMB_IDX); + return -EBUSY; + } + outb_p(smb_en, SB800_PIIX4_SMB_IDX); smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1); outb_p(smb_en + 1, SB800_PIIX4_SMB_IDX); smba_en_hi = inb_p(SB800_PIIX4_SMB_IDX + 1); - mutex_unlock(&piix4_mutex_sb800); + + release_region(SB800_PIIX4_SMB_IDX, 2); if (!smb_en) { smb_en_status = smba_en_lo & 0x10; @@ -373,7 +376,12 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev, break; } } else { - mutex_lock(&piix4_mutex_sb800); + if (!request_muxed_region(SB800_PIIX4_SMB_IDX, 2, + "sb800_piix4_smb")) { + release_region(piix4_smba, SMBIOSIZE); + return -EBUSY; + } + outb_p(SB800_PIIX4_PORT_IDX_SEL, SB800_PIIX4_SMB_IDX); port_sel = inb_p(SB800_PIIX4_SMB_IDX + 1); piix4_port_sel_sb800 = (port_sel & 0x01) ? @@ -381,7 +389,7 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev, SB800_PIIX4_PORT_IDX; piix4_port_mask_sb800 = SB800_PIIX4_PORT_IDX_MASK; piix4_port_shift_sb800 = SB800_PIIX4_PORT_IDX_SHIFT; - mutex_unlock(&piix4_mutex_sb800); + release_region(SB800_PIIX4_SMB_IDX, 2); } dev_info(&PIIX4_dev->dev, @@ -679,7 +687,8 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr, u8 port; int retval; - mutex_lock(&piix4_mutex_sb800); + if (!request_muxed_region(SB800_PIIX4_SMB_IDX, 2, "sb800_piix4_smb")) + return -EBUSY; /* Request the SMBUS semaphore, avoid conflicts with the IMC */ smbslvcnt = inb_p(SMBSLVCNT); @@ -695,8 +704,8 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr, } while (--retries); /* SMBus is still owned by the IMC, we give up */ if (!retries) { - mutex_unlock(&piix4_mutex_sb800); - return -EBUSY; + retval = -EBUSY; + goto release; } /* @@ -753,8 +762,8 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr, if ((size == I2C_SMBUS_BLOCK_DATA) && adapdata->notify_imc) piix4_imc_wakeup(); - mutex_unlock(&piix4_mutex_sb800); - +release: + release_region(SB800_PIIX4_SMB_IDX, 2); return retval; } @@ -899,13 +908,6 @@ static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id) bool notify_imc = false; is_sb800 = true; - if (!request_region(SB800_PIIX4_SMB_IDX, 2, "smba_idx")) { - dev_err(&dev->dev, - "SMBus base address index region 0x%x already in use!\n", - SB800_PIIX4_SMB_IDX); - return -EBUSY; - } - if (dev->vendor == PCI_VENDOR_ID_AMD && dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) { u8 imc; @@ -922,20 +924,16 @@ static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id) /* base address location etc changed in SB800 */ retval = piix4_setup_sb800(dev, id, 0); - if (retval < 0) { - release_region(SB800_PIIX4_SMB_IDX, 2); + if (retval < 0) return retval; - } /* * Try to register multiplexed main SMBus adapter, * give up if we can't */ retval = piix4_add_adapters_sb800(dev, retval, notify_imc); - if (retval < 0) { - release_region(SB800_PIIX4_SMB_IDX, 2); + if (retval < 0) return retval; - } } else { retval = piix4_setup(dev, id); if (retval < 0) @@ -983,11 +981,8 @@ static void piix4_adap_remove(struct i2c_adapter *adap) if (adapdata->smba) { i2c_del_adapter(adap); - if (adapdata->port == (0 << piix4_port_shift_sb800)) { + if (adapdata->port == (0 << piix4_port_shift_sb800)) release_region(adapdata->smba, SMBIOSIZE); - if (adapdata->sb800_main) - release_region(SB800_PIIX4_SMB_IDX, 2); - } kfree(adapdata); kfree(adap); } -- 2.7.4