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: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 4c1f6aaec0fc885fc65bdb063e593f46f7b7a53f..90946a8b9a75a94a8eadc4d50071b166a9d44c81 100644 (file)
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -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);
        }