Commit 04b6fcab authored by Guenter Roeck's avatar Guenter Roeck Committed by Wolfram Sang
Browse files

i2c: piix4: Use request_muxed_region 



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: default avatarGuenter Roeck <linux@roeck-us.net>
Reviewed-by: default avatarJean Delvare <jdelvare@suse.de>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 0e89b2fe

drivers/i2c/busses/i2c-piix4.c

+25 −30
Original line number Diff line number Diff line
@@ -40,7 +40,6 @@ 
#include <linux/dmi.h>

#include <linux/acpi.h>

#include <linux/io.h>

#include <linux/mutex.h>





/* 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);

	}

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