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-rw-r--r--drivers/fsi/fsi-scom.c628
1 files changed, 628 insertions, 0 deletions
diff --git a/drivers/fsi/fsi-scom.c b/drivers/fsi/fsi-scom.c
new file mode 100644
index 0000000000..61dbda9dbe
--- /dev/null
+++ b/drivers/fsi/fsi-scom.c
@@ -0,0 +1,628 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SCOM FSI Client device driver
+ *
+ * Copyright (C) IBM Corporation 2016
+ */
+
+#include <linux/fsi.h>
+#include <linux/module.h>
+#include <linux/cdev.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/mod_devicetable.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+
+#include <uapi/linux/fsi.h>
+
+#define FSI_ENGID_SCOM 0x5
+
+/* SCOM engine register set */
+#define SCOM_DATA0_REG 0x00
+#define SCOM_DATA1_REG 0x04
+#define SCOM_CMD_REG 0x08
+#define SCOM_FSI2PIB_RESET_REG 0x18
+#define SCOM_STATUS_REG 0x1C /* Read */
+#define SCOM_PIB_RESET_REG 0x1C /* Write */
+
+/* Command register */
+#define SCOM_WRITE_CMD 0x80000000
+#define SCOM_READ_CMD 0x00000000
+
+/* Status register bits */
+#define SCOM_STATUS_ERR_SUMMARY 0x80000000
+#define SCOM_STATUS_PROTECTION 0x01000000
+#define SCOM_STATUS_PARITY 0x04000000
+#define SCOM_STATUS_PIB_ABORT 0x00100000
+#define SCOM_STATUS_PIB_RESP_MASK 0x00007000
+#define SCOM_STATUS_PIB_RESP_SHIFT 12
+
+#define SCOM_STATUS_FSI2PIB_ERROR (SCOM_STATUS_PROTECTION | \
+ SCOM_STATUS_PARITY | \
+ SCOM_STATUS_PIB_ABORT)
+#define SCOM_STATUS_ANY_ERR (SCOM_STATUS_FSI2PIB_ERROR | \
+ SCOM_STATUS_PIB_RESP_MASK)
+/* SCOM address encodings */
+#define XSCOM_ADDR_IND_FLAG BIT_ULL(63)
+#define XSCOM_ADDR_INF_FORM1 BIT_ULL(60)
+
+/* SCOM indirect stuff */
+#define XSCOM_ADDR_DIRECT_PART 0x7fffffffull
+#define XSCOM_ADDR_INDIRECT_PART 0x000fffff00000000ull
+#define XSCOM_DATA_IND_READ BIT_ULL(63)
+#define XSCOM_DATA_IND_COMPLETE BIT_ULL(31)
+#define XSCOM_DATA_IND_ERR_MASK 0x70000000ull
+#define XSCOM_DATA_IND_ERR_SHIFT 28
+#define XSCOM_DATA_IND_DATA 0x0000ffffull
+#define XSCOM_DATA_IND_FORM1_DATA 0x000fffffffffffffull
+#define XSCOM_ADDR_FORM1_LOW 0x000ffffffffull
+#define XSCOM_ADDR_FORM1_HI 0xfff00000000ull
+#define XSCOM_ADDR_FORM1_HI_SHIFT 20
+
+/* Retries */
+#define SCOM_MAX_IND_RETRIES 10 /* Retries indirect not ready */
+
+struct scom_device {
+ struct list_head link;
+ struct fsi_device *fsi_dev;
+ struct device dev;
+ struct cdev cdev;
+ struct mutex lock;
+ bool dead;
+};
+
+static int __put_scom(struct scom_device *scom_dev, uint64_t value,
+ uint32_t addr, uint32_t *status)
+{
+ __be32 data, raw_status;
+ int rc;
+
+ data = cpu_to_be32((value >> 32) & 0xffffffff);
+ rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA0_REG, &data,
+ sizeof(uint32_t));
+ if (rc)
+ return rc;
+
+ data = cpu_to_be32(value & 0xffffffff);
+ rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA1_REG, &data,
+ sizeof(uint32_t));
+ if (rc)
+ return rc;
+
+ data = cpu_to_be32(SCOM_WRITE_CMD | addr);
+ rc = fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data,
+ sizeof(uint32_t));
+ if (rc)
+ return rc;
+ rc = fsi_device_read(scom_dev->fsi_dev, SCOM_STATUS_REG, &raw_status,
+ sizeof(uint32_t));
+ if (rc)
+ return rc;
+ *status = be32_to_cpu(raw_status);
+
+ return 0;
+}
+
+static int __get_scom(struct scom_device *scom_dev, uint64_t *value,
+ uint32_t addr, uint32_t *status)
+{
+ __be32 data, raw_status;
+ int rc;
+
+
+ *value = 0ULL;
+ data = cpu_to_be32(SCOM_READ_CMD | addr);
+ rc = fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data,
+ sizeof(uint32_t));
+ if (rc)
+ return rc;
+ rc = fsi_device_read(scom_dev->fsi_dev, SCOM_STATUS_REG, &raw_status,
+ sizeof(uint32_t));
+ if (rc)
+ return rc;
+
+ /*
+ * Read the data registers even on error, so we don't have
+ * to interpret the status register here.
+ */
+ rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA0_REG, &data,
+ sizeof(uint32_t));
+ if (rc)
+ return rc;
+ *value |= (uint64_t)be32_to_cpu(data) << 32;
+ rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA1_REG, &data,
+ sizeof(uint32_t));
+ if (rc)
+ return rc;
+ *value |= be32_to_cpu(data);
+ *status = be32_to_cpu(raw_status);
+
+ return rc;
+}
+
+static int put_indirect_scom_form0(struct scom_device *scom, uint64_t value,
+ uint64_t addr, uint32_t *status)
+{
+ uint64_t ind_data, ind_addr;
+ int rc, err;
+
+ if (value & ~XSCOM_DATA_IND_DATA)
+ return -EINVAL;
+
+ ind_addr = addr & XSCOM_ADDR_DIRECT_PART;
+ ind_data = (addr & XSCOM_ADDR_INDIRECT_PART) | value;
+ rc = __put_scom(scom, ind_data, ind_addr, status);
+ if (rc || (*status & SCOM_STATUS_ANY_ERR))
+ return rc;
+
+ rc = __get_scom(scom, &ind_data, addr, status);
+ if (rc || (*status & SCOM_STATUS_ANY_ERR))
+ return rc;
+
+ err = (ind_data & XSCOM_DATA_IND_ERR_MASK) >> XSCOM_DATA_IND_ERR_SHIFT;
+ *status = err << SCOM_STATUS_PIB_RESP_SHIFT;
+
+ return 0;
+}
+
+static int put_indirect_scom_form1(struct scom_device *scom, uint64_t value,
+ uint64_t addr, uint32_t *status)
+{
+ uint64_t ind_data, ind_addr;
+
+ if (value & ~XSCOM_DATA_IND_FORM1_DATA)
+ return -EINVAL;
+
+ ind_addr = addr & XSCOM_ADDR_FORM1_LOW;
+ ind_data = value | (addr & XSCOM_ADDR_FORM1_HI) << XSCOM_ADDR_FORM1_HI_SHIFT;
+ return __put_scom(scom, ind_data, ind_addr, status);
+}
+
+static int get_indirect_scom_form0(struct scom_device *scom, uint64_t *value,
+ uint64_t addr, uint32_t *status)
+{
+ uint64_t ind_data, ind_addr;
+ int rc, err;
+
+ ind_addr = addr & XSCOM_ADDR_DIRECT_PART;
+ ind_data = (addr & XSCOM_ADDR_INDIRECT_PART) | XSCOM_DATA_IND_READ;
+ rc = __put_scom(scom, ind_data, ind_addr, status);
+ if (rc || (*status & SCOM_STATUS_ANY_ERR))
+ return rc;
+
+ rc = __get_scom(scom, &ind_data, addr, status);
+ if (rc || (*status & SCOM_STATUS_ANY_ERR))
+ return rc;
+
+ err = (ind_data & XSCOM_DATA_IND_ERR_MASK) >> XSCOM_DATA_IND_ERR_SHIFT;
+ *status = err << SCOM_STATUS_PIB_RESP_SHIFT;
+ *value = ind_data & XSCOM_DATA_IND_DATA;
+
+ return 0;
+}
+
+static int raw_put_scom(struct scom_device *scom, uint64_t value,
+ uint64_t addr, uint32_t *status)
+{
+ if (addr & XSCOM_ADDR_IND_FLAG) {
+ if (addr & XSCOM_ADDR_INF_FORM1)
+ return put_indirect_scom_form1(scom, value, addr, status);
+ else
+ return put_indirect_scom_form0(scom, value, addr, status);
+ } else
+ return __put_scom(scom, value, addr, status);
+}
+
+static int raw_get_scom(struct scom_device *scom, uint64_t *value,
+ uint64_t addr, uint32_t *status)
+{
+ if (addr & XSCOM_ADDR_IND_FLAG) {
+ if (addr & XSCOM_ADDR_INF_FORM1)
+ return -ENXIO;
+ return get_indirect_scom_form0(scom, value, addr, status);
+ } else
+ return __get_scom(scom, value, addr, status);
+}
+
+static int handle_fsi2pib_status(struct scom_device *scom, uint32_t status)
+{
+ uint32_t dummy = -1;
+
+ if (status & SCOM_STATUS_FSI2PIB_ERROR)
+ fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy,
+ sizeof(uint32_t));
+
+ if (status & SCOM_STATUS_PROTECTION)
+ return -EPERM;
+ if (status & SCOM_STATUS_PARITY)
+ return -EIO;
+
+ if (status & SCOM_STATUS_PIB_ABORT)
+ return -EBUSY;
+ return 0;
+}
+
+static int handle_pib_status(struct scom_device *scom, uint8_t status)
+{
+ uint32_t dummy = -1;
+
+ if (status == SCOM_PIB_SUCCESS)
+ return 0;
+ if (status == SCOM_PIB_BLOCKED)
+ return -EBUSY;
+
+ /* Reset the bridge */
+ fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy,
+ sizeof(uint32_t));
+
+ switch(status) {
+ case SCOM_PIB_OFFLINE:
+ return -ENODEV;
+ case SCOM_PIB_BAD_ADDR:
+ return -ENXIO;
+ case SCOM_PIB_TIMEOUT:
+ return -ETIMEDOUT;
+ case SCOM_PIB_PARTIAL:
+ case SCOM_PIB_CLK_ERR:
+ case SCOM_PIB_PARITY_ERR:
+ default:
+ return -EIO;
+ }
+}
+
+static int put_scom(struct scom_device *scom, uint64_t value,
+ uint64_t addr)
+{
+ uint32_t status;
+ int rc;
+
+ rc = raw_put_scom(scom, value, addr, &status);
+ if (rc)
+ return rc;
+
+ rc = handle_fsi2pib_status(scom, status);
+ if (rc)
+ return rc;
+
+ return handle_pib_status(scom,
+ (status & SCOM_STATUS_PIB_RESP_MASK)
+ >> SCOM_STATUS_PIB_RESP_SHIFT);
+}
+
+static int get_scom(struct scom_device *scom, uint64_t *value,
+ uint64_t addr)
+{
+ uint32_t status;
+ int rc;
+
+ rc = raw_get_scom(scom, value, addr, &status);
+ if (rc)
+ return rc;
+
+ rc = handle_fsi2pib_status(scom, status);
+ if (rc)
+ return rc;
+
+ return handle_pib_status(scom,
+ (status & SCOM_STATUS_PIB_RESP_MASK)
+ >> SCOM_STATUS_PIB_RESP_SHIFT);
+}
+
+static ssize_t scom_read(struct file *filep, char __user *buf, size_t len,
+ loff_t *offset)
+{
+ struct scom_device *scom = filep->private_data;
+ struct device *dev = &scom->fsi_dev->dev;
+ uint64_t val;
+ int rc;
+
+ if (len != sizeof(uint64_t))
+ return -EINVAL;
+
+ mutex_lock(&scom->lock);
+ if (scom->dead)
+ rc = -ENODEV;
+ else
+ rc = get_scom(scom, &val, *offset);
+ mutex_unlock(&scom->lock);
+ if (rc) {
+ dev_dbg(dev, "get_scom fail:%d\n", rc);
+ return rc;
+ }
+
+ rc = copy_to_user(buf, &val, len);
+ if (rc)
+ dev_dbg(dev, "copy to user failed:%d\n", rc);
+
+ return rc ? rc : len;
+}
+
+static ssize_t scom_write(struct file *filep, const char __user *buf,
+ size_t len, loff_t *offset)
+{
+ int rc;
+ struct scom_device *scom = filep->private_data;
+ struct device *dev = &scom->fsi_dev->dev;
+ uint64_t val;
+
+ if (len != sizeof(uint64_t))
+ return -EINVAL;
+
+ rc = copy_from_user(&val, buf, len);
+ if (rc) {
+ dev_dbg(dev, "copy from user failed:%d\n", rc);
+ return -EINVAL;
+ }
+
+ mutex_lock(&scom->lock);
+ if (scom->dead)
+ rc = -ENODEV;
+ else
+ rc = put_scom(scom, val, *offset);
+ mutex_unlock(&scom->lock);
+ if (rc) {
+ dev_dbg(dev, "put_scom failed with:%d\n", rc);
+ return rc;
+ }
+
+ return len;
+}
+
+static loff_t scom_llseek(struct file *file, loff_t offset, int whence)
+{
+ switch (whence) {
+ case SEEK_CUR:
+ break;
+ case SEEK_SET:
+ file->f_pos = offset;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return offset;
+}
+
+static void raw_convert_status(struct scom_access *acc, uint32_t status)
+{
+ acc->pib_status = (status & SCOM_STATUS_PIB_RESP_MASK) >>
+ SCOM_STATUS_PIB_RESP_SHIFT;
+ acc->intf_errors = 0;
+
+ if (status & SCOM_STATUS_PROTECTION)
+ acc->intf_errors |= SCOM_INTF_ERR_PROTECTION;
+ else if (status & SCOM_STATUS_PARITY)
+ acc->intf_errors |= SCOM_INTF_ERR_PARITY;
+ else if (status & SCOM_STATUS_PIB_ABORT)
+ acc->intf_errors |= SCOM_INTF_ERR_ABORT;
+ else if (status & SCOM_STATUS_ERR_SUMMARY)
+ acc->intf_errors |= SCOM_INTF_ERR_UNKNOWN;
+}
+
+static int scom_raw_read(struct scom_device *scom, void __user *argp)
+{
+ struct scom_access acc;
+ uint32_t status;
+ int rc;
+
+ if (copy_from_user(&acc, argp, sizeof(struct scom_access)))
+ return -EFAULT;
+
+ rc = raw_get_scom(scom, &acc.data, acc.addr, &status);
+ if (rc)
+ return rc;
+ raw_convert_status(&acc, status);
+ if (copy_to_user(argp, &acc, sizeof(struct scom_access)))
+ return -EFAULT;
+ return 0;
+}
+
+static int scom_raw_write(struct scom_device *scom, void __user *argp)
+{
+ u64 prev_data, mask, data;
+ struct scom_access acc;
+ uint32_t status;
+ int rc;
+
+ if (copy_from_user(&acc, argp, sizeof(struct scom_access)))
+ return -EFAULT;
+
+ if (acc.mask) {
+ rc = raw_get_scom(scom, &prev_data, acc.addr, &status);
+ if (rc)
+ return rc;
+ if (status & SCOM_STATUS_ANY_ERR)
+ goto fail;
+ mask = acc.mask;
+ } else {
+ prev_data = mask = -1ull;
+ }
+ data = (prev_data & ~mask) | (acc.data & mask);
+ rc = raw_put_scom(scom, data, acc.addr, &status);
+ if (rc)
+ return rc;
+ fail:
+ raw_convert_status(&acc, status);
+ if (copy_to_user(argp, &acc, sizeof(struct scom_access)))
+ return -EFAULT;
+ return 0;
+}
+
+static int scom_reset(struct scom_device *scom, void __user *argp)
+{
+ uint32_t flags, dummy = -1;
+ int rc = 0;
+
+ if (get_user(flags, (__u32 __user *)argp))
+ return -EFAULT;
+ if (flags & SCOM_RESET_PIB)
+ rc = fsi_device_write(scom->fsi_dev, SCOM_PIB_RESET_REG, &dummy,
+ sizeof(uint32_t));
+ if (!rc && (flags & (SCOM_RESET_PIB | SCOM_RESET_INTF)))
+ rc = fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy,
+ sizeof(uint32_t));
+ return rc;
+}
+
+static int scom_check(struct scom_device *scom, void __user *argp)
+{
+ /* Still need to find out how to get "protected" */
+ return put_user(SCOM_CHECK_SUPPORTED, (__u32 __user *)argp);
+}
+
+static long scom_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct scom_device *scom = file->private_data;
+ void __user *argp = (void __user *)arg;
+ int rc = -ENOTTY;
+
+ mutex_lock(&scom->lock);
+ if (scom->dead) {
+ mutex_unlock(&scom->lock);
+ return -ENODEV;
+ }
+ switch(cmd) {
+ case FSI_SCOM_CHECK:
+ rc = scom_check(scom, argp);
+ break;
+ case FSI_SCOM_READ:
+ rc = scom_raw_read(scom, argp);
+ break;
+ case FSI_SCOM_WRITE:
+ rc = scom_raw_write(scom, argp);
+ break;
+ case FSI_SCOM_RESET:
+ rc = scom_reset(scom, argp);
+ break;
+ }
+ mutex_unlock(&scom->lock);
+ return rc;
+}
+
+static int scom_open(struct inode *inode, struct file *file)
+{
+ struct scom_device *scom = container_of(inode->i_cdev, struct scom_device, cdev);
+
+ file->private_data = scom;
+
+ return 0;
+}
+
+static const struct file_operations scom_fops = {
+ .owner = THIS_MODULE,
+ .open = scom_open,
+ .llseek = scom_llseek,
+ .read = scom_read,
+ .write = scom_write,
+ .unlocked_ioctl = scom_ioctl,
+};
+
+static void scom_free(struct device *dev)
+{
+ struct scom_device *scom = container_of(dev, struct scom_device, dev);
+
+ put_device(&scom->fsi_dev->dev);
+ kfree(scom);
+}
+
+static int scom_probe(struct device *dev)
+{
+ struct fsi_device *fsi_dev = to_fsi_dev(dev);
+ struct scom_device *scom;
+ int rc, didx;
+
+ scom = kzalloc(sizeof(*scom), GFP_KERNEL);
+ if (!scom)
+ return -ENOMEM;
+ dev_set_drvdata(dev, scom);
+ mutex_init(&scom->lock);
+
+ /* Grab a reference to the device (parent of our cdev), we'll drop it later */
+ if (!get_device(dev)) {
+ kfree(scom);
+ return -ENODEV;
+ }
+ scom->fsi_dev = fsi_dev;
+
+ /* Create chardev for userspace access */
+ scom->dev.type = &fsi_cdev_type;
+ scom->dev.parent = dev;
+ scom->dev.release = scom_free;
+ device_initialize(&scom->dev);
+
+ /* Allocate a minor in the FSI space */
+ rc = fsi_get_new_minor(fsi_dev, fsi_dev_scom, &scom->dev.devt, &didx);
+ if (rc)
+ goto err;
+
+ dev_set_name(&scom->dev, "scom%d", didx);
+ cdev_init(&scom->cdev, &scom_fops);
+ rc = cdev_device_add(&scom->cdev, &scom->dev);
+ if (rc) {
+ dev_err(dev, "Error %d creating char device %s\n",
+ rc, dev_name(&scom->dev));
+ goto err_free_minor;
+ }
+
+ return 0;
+ err_free_minor:
+ fsi_free_minor(scom->dev.devt);
+ err:
+ put_device(&scom->dev);
+ return rc;
+}
+
+static int scom_remove(struct device *dev)
+{
+ struct scom_device *scom = dev_get_drvdata(dev);
+
+ mutex_lock(&scom->lock);
+ scom->dead = true;
+ mutex_unlock(&scom->lock);
+ cdev_device_del(&scom->cdev, &scom->dev);
+ fsi_free_minor(scom->dev.devt);
+ put_device(&scom->dev);
+
+ return 0;
+}
+
+static const struct of_device_id scom_of_ids[] = {
+ { .compatible = "ibm,fsi2pib" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, scom_of_ids);
+
+static const struct fsi_device_id scom_ids[] = {
+ {
+ .engine_type = FSI_ENGID_SCOM,
+ .version = FSI_VERSION_ANY,
+ },
+ { 0 }
+};
+
+static struct fsi_driver scom_drv = {
+ .id_table = scom_ids,
+ .drv = {
+ .name = "scom",
+ .bus = &fsi_bus_type,
+ .of_match_table = scom_of_ids,
+ .probe = scom_probe,
+ .remove = scom_remove,
+ }
+};
+
+static int scom_init(void)
+{
+ return fsi_driver_register(&scom_drv);
+}
+
+static void scom_exit(void)
+{
+ fsi_driver_unregister(&scom_drv);
+}
+
+module_init(scom_init);
+module_exit(scom_exit);
+MODULE_LICENSE("GPL");