ipmi: kcs_bmc: Turn the driver data-structures inside-out

Make the KCS device drivers responsible for allocating their own memory.

Until now the private data for the device driver was allocated internal
to the private data for the chardev interface. This coupling required
the slightly awkward API of passing through the struct size for the
driver private data to the chardev constructor, and then retrieving a
pointer to the driver private data from the allocated chardev memory.

In addition to being awkward, the arrangement prevents the
implementation of alternative userspace interfaces as the device driver
private data is not independent.

Peel a layer off the onion and turn the data-structures inside out by
exploiting container_of() and embedding `struct kcs_device` in the
driver private data.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
Message-Id: <20210608104757.582199-6-andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index ef5c48ffe74ab035bab1d52064102992db3656f3..07bb6747f29a74931965ed1145ac238a3b07d030 100644 (file)
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -44,12 +44,21 @@ int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc)
 }
 EXPORT_SYMBOL(kcs_bmc_handle_event);
 
-struct kcs_bmc *kcs_bmc_ipmi_alloc(struct device *dev, int sizeof_priv, u32 channel);
-struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv, u32 channel)
+int kcs_bmc_ipmi_add_device(struct kcs_bmc *kcs_bmc);
+int kcs_bmc_add_device(struct kcs_bmc *kcs_bmc)
 {
-       return kcs_bmc_ipmi_alloc(dev, sizeof_priv, channel);
+       return kcs_bmc_ipmi_add_device(kcs_bmc);
 }
-EXPORT_SYMBOL(kcs_bmc_alloc);
+EXPORT_SYMBOL(kcs_bmc_add_device);
+
+int kcs_bmc_ipmi_remove_device(struct kcs_bmc *kcs_bmc);
+void kcs_bmc_remove_device(struct kcs_bmc *kcs_bmc)
+{
+       if (kcs_bmc_ipmi_remove_device(kcs_bmc))
+               pr_warn("Failed to remove device for KCS channel %d\n",
+                       kcs_bmc->channel);
+}
+EXPORT_SYMBOL(kcs_bmc_remove_device);
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");

diff --git a/drivers/char/ipmi/kcs_bmc.h b/drivers/char/ipmi/kcs_bmc.h
index febea0c8deb40bf06c93d6dd2fca27e4ffb510b8..f3ed89e7da98e6b537c4be4125f08f80572a1051 100644 (file)
--- a/drivers/char/ipmi/kcs_bmc.h
+++ b/drivers/char/ipmi/kcs_bmc.h
@@ -67,6 +67,8 @@ struct kcs_ioreg {
 };
 
 struct kcs_bmc {
+       struct device *dev;
+
        spinlock_t lock;
 
        u32 channel;
@@ -94,17 +96,11 @@ struct kcs_bmc {
        u8 *kbuffer;
 
        struct miscdevice miscdev;
-
-       unsigned long priv[];
 };
 
-static inline void *kcs_bmc_priv(struct kcs_bmc *kcs_bmc)
-{
-       return kcs_bmc->priv;
-}
-
 int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc);
-struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv, u32 channel);
+int kcs_bmc_add_device(struct kcs_bmc *kcs_bmc);
+void kcs_bmc_remove_device(struct kcs_bmc *kcs_bmc);
 
 u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc);
 void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data);

diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index 01ebb9da3d49c42bf22e2c3e6abeb301b55f854e..b07cbc423dd59de146d7816929c9c3173b27b2d4 100644 (file)
--- a/drivers/char/ipmi/kcs_bmc_aspeed.c
+++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
@@ -61,6 +61,8 @@
 #define LPC_STR4             0x11C
 
 struct aspeed_kcs_bmc {
+       struct kcs_bmc kcs_bmc;
+
        struct regmap *map;
 };
 
@@ -69,9 +71,14 @@ struct aspeed_kcs_of_ops {
        int (*get_io_address)(struct platform_device *pdev);
 };
 
+static inline struct aspeed_kcs_bmc *to_aspeed_kcs_bmc(struct kcs_bmc *kcs_bmc)
+{
+       return container_of(kcs_bmc, struct aspeed_kcs_bmc, kcs_bmc);
+}
+
 static u8 aspeed_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
 {
-       struct aspeed_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+       struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
        u32 val = 0;
        int rc;
 
@@ -83,7 +90,7 @@ static u8 aspeed_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
 
 static void aspeed_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
 {
-       struct aspeed_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+       struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
        int rc;
 
        rc = regmap_write(priv->map, reg, data);
@@ -92,7 +99,7 @@ static void aspeed_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
 
 static void aspeed_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 val)
 {
-       struct aspeed_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+       struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
        int rc;
 
        rc = regmap_update_bits(priv->map, reg, mask, val);
@@ -114,7 +121,7 @@ static void aspeed_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 val
  */
 static void aspeed_kcs_set_address(struct kcs_bmc *kcs_bmc, u16 addr)
 {
-       struct aspeed_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+       struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 
        switch (kcs_bmc->channel) {
        case 1:
@@ -148,7 +155,7 @@ static void aspeed_kcs_set_address(struct kcs_bmc *kcs_bmc, u16 addr)
 
 static void aspeed_kcs_enable_channel(struct kcs_bmc *kcs_bmc, bool enable)
 {
-       struct aspeed_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+       struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 
        switch (kcs_bmc->channel) {
        case 1:
@@ -325,17 +332,16 @@ static int aspeed_kcs_of_v2_get_io_address(struct platform_device *pdev)
 static int aspeed_kcs_probe(struct platform_device *pdev)
 {
        const struct aspeed_kcs_of_ops *ops;
-       struct device *dev = &pdev->dev;
        struct aspeed_kcs_bmc *priv;
        struct kcs_bmc *kcs_bmc;
        struct device_node *np;
        int rc, channel, addr;
 
-       np = dev->of_node->parent;
+       np = pdev->dev.of_node->parent;
        if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") &&
            !of_device_is_compatible(np, "aspeed,ast2500-lpc-v2") &&
            !of_device_is_compatible(np, "aspeed,ast2600-lpc-v2")) {
-               dev_err(dev, "unsupported LPC device binding\n");
+               dev_err(&pdev->dev, "unsupported LPC device binding\n");
                return -ENODEV;
        }
        ops = of_device_get_match_data(&pdev->dev);
@@ -346,20 +352,22 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
        if (channel < 0)
                return channel;
 
-       kcs_bmc = kcs_bmc_alloc(&pdev->dev, sizeof(struct aspeed_kcs_bmc), channel);
-       if (!kcs_bmc)
+       addr = ops->get_io_address(pdev);
+       if (addr < 0)
+               return addr;
+
+       priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
                return -ENOMEM;
 
+       kcs_bmc = &priv->kcs_bmc;
+       kcs_bmc->dev = &pdev->dev;
+       kcs_bmc->channel = channel;
        kcs_bmc->ioreg = ast_kcs_bmc_ioregs[channel - 1];
        kcs_bmc->io_inputb = aspeed_kcs_inb;
        kcs_bmc->io_outputb = aspeed_kcs_outb;
        kcs_bmc->io_updateb = aspeed_kcs_updateb;
 
-       addr = ops->get_io_address(pdev);
-       if (addr < 0)
-               return addr;
-
-       priv = kcs_bmc_priv(kcs_bmc);
        priv->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
        if (IS_ERR(priv->map)) {
                dev_err(&pdev->dev, "Couldn't get regmap\n");
@@ -372,29 +380,27 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
        if (rc)
                return rc;
 
-       dev_set_drvdata(dev, kcs_bmc);
+       platform_set_drvdata(pdev, priv);
 
        aspeed_kcs_enable_channel(kcs_bmc, true);
 
-       rc = misc_register(&kcs_bmc->miscdev);
+       rc = kcs_bmc_add_device(&priv->kcs_bmc);
        if (rc) {
-               dev_err(dev, "Unable to register device\n");
+               dev_warn(&pdev->dev, "Failed to register channel %d: %d\n", kcs_bmc->channel, rc);
                return rc;
        }
 
-       dev_dbg(&pdev->dev,
-               "Probed KCS device %d (IDR=0x%x, ODR=0x%x, STR=0x%x)\n",
-               kcs_bmc->channel, kcs_bmc->ioreg.idr, kcs_bmc->ioreg.odr,
-               kcs_bmc->ioreg.str);
+       dev_info(&pdev->dev, "Initialised channel %d at 0x%x\n", kcs_bmc->channel, addr);
 
        return 0;
 }
 
 static int aspeed_kcs_remove(struct platform_device *pdev)
 {
-       struct kcs_bmc *kcs_bmc = dev_get_drvdata(&pdev->dev);
+       struct aspeed_kcs_bmc *priv = platform_get_drvdata(pdev);
+       struct kcs_bmc *kcs_bmc = &priv->kcs_bmc;
 
-       misc_deregister(&kcs_bmc->miscdev);
+       kcs_bmc_remove_device(kcs_bmc);
 
        return 0;
 }

diff --git a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
index 82c77994e4810aa251ebbc723b0d01b168f20d1f..5060643bf5301b3732a627a0c2fb067fbeaa51f1 100644 (file)
--- a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
+++ b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
@@ -382,7 +382,7 @@ static int kcs_bmc_ipmi_release(struct inode *inode, struct file *filp)
        return 0;
 }
 
-static const struct file_operations kcs_bmc_fops = {
+static const struct file_operations kcs_bmc_ipmi_fops = {
        .owner          = THIS_MODULE,
        .open           = kcs_bmc_ipmi_open,
        .read           = kcs_bmc_ipmi_read,
@@ -392,36 +392,58 @@ static const struct file_operations kcs_bmc_fops = {
        .unlocked_ioctl = kcs_bmc_ipmi_ioctl,
 };
 
-struct kcs_bmc *kcs_bmc_ipmi_alloc(struct device *dev, int sizeof_priv, u32 channel);
-struct kcs_bmc *kcs_bmc_ipmi_alloc(struct device *dev, int sizeof_priv, u32 channel)
+int kcs_bmc_ipmi_add_device(struct kcs_bmc *kcs_bmc);
+int kcs_bmc_ipmi_add_device(struct kcs_bmc *kcs_bmc)
 {
-       struct kcs_bmc *kcs_bmc;
-
-       kcs_bmc = devm_kzalloc(dev, sizeof(*kcs_bmc) + sizeof_priv, GFP_KERNEL);
-       if (!kcs_bmc)
-               return NULL;
+       int rc;
 
        spin_lock_init(&kcs_bmc->lock);
-       kcs_bmc->channel = channel;
-
        mutex_init(&kcs_bmc->mutex);
        init_waitqueue_head(&kcs_bmc->queue);
 
-       kcs_bmc->data_in = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-       kcs_bmc->data_out = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-       kcs_bmc->kbuffer = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+       kcs_bmc->data_in = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+       kcs_bmc->data_out = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+       kcs_bmc->kbuffer = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
 
        kcs_bmc->miscdev.minor = MISC_DYNAMIC_MINOR;
-       kcs_bmc->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s%u",
-                                              DEVICE_NAME, channel);
+       kcs_bmc->miscdev.name = devm_kasprintf(kcs_bmc->dev, GFP_KERNEL, "%s%u",
+                                              DEVICE_NAME, kcs_bmc->channel);
        if (!kcs_bmc->data_in || !kcs_bmc->data_out || !kcs_bmc->kbuffer ||
            !kcs_bmc->miscdev.name)
-               return NULL;
-       kcs_bmc->miscdev.fops = &kcs_bmc_fops;
+               return -ENOMEM;
+
+       kcs_bmc->miscdev.fops = &kcs_bmc_ipmi_fops;
+
+       rc = misc_register(&kcs_bmc->miscdev);
+       if (rc) {
+               dev_err(kcs_bmc->dev, "Unable to register device: %d\n", rc);
+               return rc;
+       }
+
+       dev_info(kcs_bmc->dev, "Initialised IPMI client for channel %d", kcs_bmc->channel);
+
+       return 0;
+}
+EXPORT_SYMBOL(kcs_bmc_ipmi_add_device);
 
-       return kcs_bmc;
+int kcs_bmc_ipmi_remove_device(struct kcs_bmc *kcs_bmc);
+int kcs_bmc_ipmi_remove_device(struct kcs_bmc *kcs_bmc)
+{
+       misc_deregister(&kcs_bmc->miscdev);
+
+       spin_lock_irq(&kcs_bmc->lock);
+       kcs_bmc->running = 0;
+       kcs_bmc_ipmi_force_abort(kcs_bmc);
+       spin_unlock_irq(&kcs_bmc->lock);
+
+       devm_kfree(kcs_bmc->dev, kcs_bmc->kbuffer);
+       devm_kfree(kcs_bmc->dev, kcs_bmc->data_out);
+       devm_kfree(kcs_bmc->dev, kcs_bmc->data_in);
+       devm_kfree(kcs_bmc->dev, kcs_bmc);
+
+       return 0;
 }
-EXPORT_SYMBOL(kcs_bmc_ipmi_alloc);
+EXPORT_SYMBOL(kcs_bmc_ipmi_remove_device);
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");

diff --git a/drivers/char/ipmi/kcs_bmc_npcm7xx.c b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
index 1f44aadec9e843fe97a50ce0a9d97ba602ad37ff..e062502851133bfdea6ad07405ce5d37d7792873 100644 (file)
--- a/drivers/char/ipmi/kcs_bmc_npcm7xx.c
+++ b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
@@ -65,6 +65,8 @@ struct npcm7xx_kcs_reg {
 };
 
 struct npcm7xx_kcs_bmc {
+       struct kcs_bmc kcs_bmc;
+
        struct regmap *map;
 
        const struct npcm7xx_kcs_reg *reg;
@@ -76,9 +78,14 @@ static const struct npcm7xx_kcs_reg npcm7xx_kcs_reg_tbl[KCS_CHANNEL_MAX] = {
        { .sts = KCS3ST, .dob = KCS3DO, .dib = KCS3DI, .ctl = KCS3CTL, .ie = KCS3IE },
 };
 
+static inline struct npcm7xx_kcs_bmc *to_npcm7xx_kcs_bmc(struct kcs_bmc *kcs_bmc)
+{
+       return container_of(kcs_bmc, struct npcm7xx_kcs_bmc, kcs_bmc);
+}
+
 static u8 npcm7xx_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
 {
-       struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+       struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
        u32 val = 0;
        int rc;
 
@@ -90,7 +97,7 @@ static u8 npcm7xx_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
 
 static void npcm7xx_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
 {
-       struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+       struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
        int rc;
 
        rc = regmap_write(priv->map, reg, data);
@@ -99,7 +106,7 @@ static void npcm7xx_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
 
 static void npcm7xx_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 data)
 {
-       struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+       struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
        int rc;
 
        rc = regmap_update_bits(priv->map, reg, mask, data);
@@ -108,7 +115,7 @@ static void npcm7xx_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 da
 
 static void npcm7xx_kcs_enable_channel(struct kcs_bmc *kcs_bmc, bool enable)
 {
-       struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+       struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
 
        regmap_update_bits(priv->map, priv->reg->ctl, KCS_CTL_IBFIE,
                           enable ? KCS_CTL_IBFIE : 0);
@@ -155,11 +162,10 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
                return -ENODEV;
        }
 
-       kcs_bmc = kcs_bmc_alloc(dev, sizeof(*priv), chan);
-       if (!kcs_bmc)
+       priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
                return -ENOMEM;
 
-       priv = kcs_bmc_priv(kcs_bmc);
        priv->map = syscon_node_to_regmap(dev->parent->of_node);
        if (IS_ERR(priv->map)) {
                dev_err(dev, "Couldn't get regmap\n");
@@ -167,6 +173,9 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
        }
        priv->reg = &npcm7xx_kcs_reg_tbl[chan - 1];
 
+       kcs_bmc = &priv->kcs_bmc;
+       kcs_bmc->dev = &pdev->dev;
+       kcs_bmc->channel = chan;
        kcs_bmc->ioreg.idr = priv->reg->dib;
        kcs_bmc->ioreg.odr = priv->reg->dob;
        kcs_bmc->ioreg.str = priv->reg->sts;
@@ -174,16 +183,16 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
        kcs_bmc->io_outputb = npcm7xx_kcs_outb;
        kcs_bmc->io_updateb = npcm7xx_kcs_updateb;
 
-       dev_set_drvdata(dev, kcs_bmc);
+       platform_set_drvdata(pdev, priv);
 
        npcm7xx_kcs_enable_channel(kcs_bmc, true);
        rc = npcm7xx_kcs_config_irq(kcs_bmc, pdev);
        if (rc)
                return rc;
 
-       rc = misc_register(&kcs_bmc->miscdev);
+       rc = kcs_bmc_add_device(kcs_bmc);
        if (rc) {
-               dev_err(dev, "Unable to register device\n");
+               dev_warn(&pdev->dev, "Failed to register channel %d: %d\n", kcs_bmc->channel, rc);
                return rc;
        }
 
@@ -196,9 +205,10 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
 
 static int npcm7xx_kcs_remove(struct platform_device *pdev)
 {
-       struct kcs_bmc *kcs_bmc = dev_get_drvdata(&pdev->dev);
+       struct npcm7xx_kcs_bmc *priv = platform_get_drvdata(pdev);
+       struct kcs_bmc *kcs_bmc = &priv->kcs_bmc;
 
-       misc_deregister(&kcs_bmc->miscdev);
+       kcs_bmc_remove_device(kcs_bmc);
 
        return 0;
 }