diff options
| -rw-r--r-- | drivers/fsi/fsi-scom.c | 424 | ||||
| -rw-r--r-- | include/uapi/linux/fsi.h | 58 |
2 files changed, 452 insertions, 30 deletions
diff --git a/drivers/fsi/fsi-scom.c b/drivers/fsi/fsi-scom.c index e98573ecdae1..39c74351f1bf 100644 --- a/drivers/fsi/fsi-scom.c +++ b/drivers/fsi/fsi-scom.c @@ -24,6 +24,8 @@ #include <linux/list.h> #include <linux/idr.h> +#include <uapi/linux/fsi.h> + #define FSI_ENGID_SCOM 0x5 /* SCOM engine register set */ @@ -41,14 +43,36 @@ /* 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_ANY_ERR (SCOM_STATUS_ERR_SUMMARY | \ SCOM_STATUS_PROTECTION | \ + SCOM_STATUS_PARITY | \ SCOM_STATUS_PIB_ABORT | \ 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_RETRIES 100 /* Retries on busy */ +#define SCOM_MAX_IND_RETRIES 10 /* Retries indirect not ready */ struct scom_device { struct list_head link; @@ -56,7 +80,7 @@ struct scom_device { struct miscdevice mdev; struct mutex lock; char name[32]; - int idx; + int idx; }; #define to_scom_dev(x) container_of((x), struct scom_device, mdev) @@ -65,80 +89,304 @@ static struct list_head scom_devices; static DEFINE_IDA(scom_ida); -static int put_scom(struct scom_device *scom_dev, uint64_t value, - uint32_t addr) +static int __put_scom(struct scom_device *scom_dev, uint64_t value, + uint32_t addr, uint32_t *status) { - __be32 data; + __be32 data, raw_status; int rc; - mutex_lock(&scom_dev->lock); - data = cpu_to_be32((value >> 32) & 0xffffffff); rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA0_REG, &data, sizeof(uint32_t)); if (rc) - goto bail; + 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) - goto bail; + 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)); - bail: - mutex_unlock(&scom_dev->lock); - return rc; + 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) +static int __get_scom(struct scom_device *scom_dev, uint64_t *value, + uint32_t addr, uint32_t *status) { - __be32 result, data; + __be32 data, raw_status; int rc; - mutex_lock(&scom_dev->lock); *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) - goto bail; + return rc; + rc = fsi_device_read(scom_dev->fsi_dev, SCOM_STATUS_REG, &raw_status, + sizeof(uint32_t)); + if (rc) + return rc; - rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA0_REG, &result, + /* + * 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) - goto bail; - - *value |= (uint64_t)be32_to_cpu(result) << 32; - rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA1_REG, &result, + 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) - goto bail; + 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, retries, err = 0; + + 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; + + for (retries = 0; retries < SCOM_MAX_IND_RETRIES; retries++) { + 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; + if ((ind_data & XSCOM_DATA_IND_COMPLETE) || (err != SCOM_PIB_BLOCKED)) + return 0; + + msleep(1); + } + return rc; +} + +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, retries, err = 0; + + 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; + + for (retries = 0; retries < SCOM_MAX_IND_RETRIES; retries++) { + 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; + + if ((ind_data & XSCOM_DATA_IND_COMPLETE) || (err != SCOM_PIB_BLOCKED)) + return 0; + + msleep(1); + } + return rc; +} + +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_PROTECTION) + return -EPERM; + if (status & SCOM_STATUS_PARITY) { + fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy, + sizeof(uint32_t)); + return -EIO; + } + /* Return -EBUSY on PIB abort to force a retry */ + if (status & SCOM_STATUS_PIB_ABORT) + return -EBUSY; + if (status & SCOM_STATUS_ERR_SUMMARY) { + fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy, + sizeof(uint32_t)); + return -EIO; + } + 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; + } +} - *value |= be32_to_cpu(result); - bail: - mutex_unlock(&scom_dev->lock); +static int put_scom(struct scom_device *scom, uint64_t value, + uint64_t addr) +{ + uint32_t status, dummy = -1; + int rc, retries; + + for (retries = 0; retries < SCOM_MAX_RETRIES; retries++) { + rc = raw_put_scom(scom, value, addr, &status); + if (rc) { + /* Try resetting the bridge if FSI fails */ + if (rc != -ENODEV && retries == 0) { + fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, + &dummy, sizeof(uint32_t)); + rc = -EBUSY; + } else + return rc; + } else + rc = handle_fsi2pib_status(scom, status); + if (rc && rc != -EBUSY) + break; + if (rc == 0) { + rc = handle_pib_status(scom, + (status & SCOM_STATUS_PIB_RESP_MASK) + >> SCOM_STATUS_PIB_RESP_SHIFT); + if (rc && rc != -EBUSY) + break; + } + if (rc == 0) + break; + msleep(1); + } + return rc; +} + +static int get_scom(struct scom_device *scom, uint64_t *value, + uint64_t addr) +{ + uint32_t status, dummy = -1; + int rc, retries; + + for (retries = 0; retries < SCOM_MAX_RETRIES; retries++) { + rc = raw_get_scom(scom, value, addr, &status); + if (rc) { + /* Try resetting the bridge if FSI fails */ + if (rc != -ENODEV && retries == 0) { + fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, + &dummy, sizeof(uint32_t)); + rc = -EBUSY; + } else + return rc; + } else + rc = handle_fsi2pib_status(scom, status); + if (rc && rc != -EBUSY) + break; + if (rc == 0) { + rc = handle_pib_status(scom, + (status & SCOM_STATUS_PIB_RESP_MASK) + >> SCOM_STATUS_PIB_RESP_SHIFT); + if (rc && rc != -EBUSY) + break; + } + if (rc == 0) + break; + msleep(1); + } return rc; } static ssize_t scom_read(struct file *filep, char __user *buf, size_t len, loff_t *offset) { - int rc; struct miscdevice *mdev = (struct miscdevice *)filep->private_data; struct scom_device *scom = to_scom_dev(mdev); struct device *dev = &scom->fsi_dev->dev; uint64_t val; + int rc; if (len != sizeof(uint64_t)) return -EINVAL; + mutex_lock(&scom->lock); rc = get_scom(scom, &val, *offset); + mutex_unlock(&scom->lock); if (rc) { dev_dbg(dev, "get_scom fail:%d\n", rc); return rc; @@ -169,7 +417,9 @@ static ssize_t scom_write(struct file *filep, const char __user *buf, return -EINVAL; } + mutex_lock(&scom->lock); rc = put_scom(scom, val, *offset); + mutex_unlock(&scom->lock); if (rc) { dev_dbg(dev, "put_scom failed with:%d\n", rc); return rc; @@ -193,11 +443,125 @@ static loff_t scom_llseek(struct file *file, loff_t offset, int whence) 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 miscdevice *mdev = file->private_data; + struct scom_device *scom = to_scom_dev(mdev); + void __user *argp = (void __user *)arg; + int rc = -ENOTTY; + + mutex_lock(&scom->lock); + 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 const struct file_operations scom_fops = { - .owner = THIS_MODULE, - .llseek = scom_llseek, - .read = scom_read, - .write = scom_write, + .owner = THIS_MODULE, + .llseek = scom_llseek, + .read = scom_read, + .write = scom_write, + .unlocked_ioctl = scom_ioctl, }; static int scom_probe(struct device *dev) diff --git a/include/uapi/linux/fsi.h b/include/uapi/linux/fsi.h new file mode 100644 index 000000000000..da577ecd90e7 --- /dev/null +++ b/include/uapi/linux/fsi.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ +#ifndef _UAPI_LINUX_FSI_H +#define _UAPI_LINUX_FSI_H + +#include <linux/types.h> +#include <linux/ioctl.h> + +/* + * /dev/scom "raw" ioctl interface + * + * The driver supports a high level "read/write" interface which + * handles retries and converts the status to Linux error codes, + * however low level tools an debugger need to access the "raw" + * HW status information and interpret it themselves, so this + * ioctl interface is also provided for their use case. + */ + +/* Structure for SCOM read/write */ +struct scom_access { + __u64 addr; /* SCOM address, supports indirect */ + __u64 data; /* SCOM data (in for write, out for read) */ + __u64 mask; /* Data mask for writes */ + __u32 intf_errors; /* Interface error flags */ +#define SCOM_INTF_ERR_PARITY 0x00000001 /* Parity error */ +#define SCOM_INTF_ERR_PROTECTION 0x00000002 /* Blocked by secure boot */ +#define SCOM_INTF_ERR_ABORT 0x00000004 /* PIB reset during access */ +#define SCOM_INTF_ERR_UNKNOWN 0x80000000 /* Unknown error */ + /* + * Note: Any other bit set in intf_errors need to be considered as an + * error. Future implementations may define new error conditions. The + * pib_status below is only valid if intf_errors is 0. + */ + __u8 pib_status; /* 3-bit PIB status */ +#define SCOM_PIB_SUCCESS 0 /* Access successful */ +#define SCOM_PIB_BLOCKED 1 /* PIB blocked, pls retry */ +#define SCOM_PIB_OFFLINE 2 /* Chiplet offline */ +#define SCOM_PIB_PARTIAL 3 /* Partial good */ +#define SCOM_PIB_BAD_ADDR 4 /* Invalid address */ +#define SCOM_PIB_CLK_ERR 5 /* Clock error */ +#define SCOM_PIB_PARITY_ERR 6 /* Parity error on the PIB bus */ +#define SCOM_PIB_TIMEOUT 7 /* Bus timeout */ + __u8 pad; +}; + +/* Flags for SCOM check */ +#define SCOM_CHECK_SUPPORTED 0x00000001 /* Interface supported */ +#define SCOM_CHECK_PROTECTED 0x00000002 /* Interface blocked by secure boot */ + +/* Flags for SCOM reset */ +#define SCOM_RESET_INTF 0x00000001 /* Reset interface */ +#define SCOM_RESET_PIB 0x00000002 /* Reset PIB */ + +#define FSI_SCOM_CHECK _IOR('s', 0x00, __u32) +#define FSI_SCOM_READ _IOWR('s', 0x01, struct scom_access) +#define FSI_SCOM_WRITE _IOWR('s', 0x02, struct scom_access) +#define FSI_SCOM_RESET _IOW('s', 0x03, __u32) + +#endif /* _UAPI_LINUX_FSI_H */ |