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SubjectRe: [PATCH v3 23/27] powerpc/powernv/pmem: Add debug IOCTLs
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Le 21/02/2020 à 04:27, Alastair D'Silva a écrit :
> From: Alastair D'Silva <alastair@d-silva.org>
>
> These IOCTLs provide low level access to the card to aid in debugging
> controller/FPGA firmware.
>
> Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
> ---
> arch/powerpc/platforms/powernv/pmem/Kconfig | 6 +
> arch/powerpc/platforms/powernv/pmem/ocxl.c | 249 ++++++++++++++++++++
> include/uapi/nvdimm/ocxl-pmem.h | 32 +++
> 3 files changed, 287 insertions(+)
>
> diff --git a/arch/powerpc/platforms/powernv/pmem/Kconfig b/arch/powerpc/platforms/powernv/pmem/Kconfig
> index c5d927520920..3f44429d70c9 100644
> --- a/arch/powerpc/platforms/powernv/pmem/Kconfig
> +++ b/arch/powerpc/platforms/powernv/pmem/Kconfig
> @@ -12,4 +12,10 @@ config OCXL_PMEM
>
> Select N if unsure.
>
> +config OCXL_PMEM_DEBUG
> + bool "OpenCAPI Persistent Memory debugging"
> + depends on OCXL_PMEM
> + help
> + Enables low level IOCTLs for OpenCAPI Persistent Memory firmware development
> +
> endif
> diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl.c b/arch/powerpc/platforms/powernv/pmem/ocxl.c
> index e01f6f9fc180..d4ce5e9e0521 100644
> --- a/arch/powerpc/platforms/powernv/pmem/ocxl.c
> +++ b/arch/powerpc/platforms/powernv/pmem/ocxl.c
> @@ -1050,6 +1050,235 @@ int req_controller_health_perf(struct ocxlpmem *ocxlpmem)
> GLOBAL_MMIO_HCI_REQ_HEALTH_PERF);
> }
>
> +#ifdef CONFIG_OCXL_PMEM_DEBUG
> +/**
> + * enable_fwdebug() - Enable FW debug on the controller
> + * @ocxlpmem: the device metadata
> + * Return: 0 on success, negative on failure
> + */
> +static int enable_fwdebug(const struct ocxlpmem *ocxlpmem)
> +{
> + return ocxl_global_mmio_set64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_HCI,
> + OCXL_LITTLE_ENDIAN,
> + GLOBAL_MMIO_HCI_FW_DEBUG);
> +}
> +
> +/**
> + * disable_fwdebug() - Disable FW debug on the controller
> + * @ocxlpmem: the device metadata
> + * Return: 0 on success, negative on failure
> + */
> +static int disable_fwdebug(const struct ocxlpmem *ocxlpmem)
> +{
> + return ocxl_global_mmio_set64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_HCIC,
> + OCXL_LITTLE_ENDIAN,
> + GLOBAL_MMIO_HCI_FW_DEBUG);
> +}
> +
> +static int ioctl_fwdebug(struct ocxlpmem *ocxlpmem,
> + struct ioctl_ocxl_pmem_fwdebug __user *uarg)
> +{
> + struct ioctl_ocxl_pmem_fwdebug args;
> + u64 val;
> + int i;
> + int rc;
> +
> + if (copy_from_user(&args, uarg, sizeof(args)))
> + return -EFAULT;
> +
> + // Buffer size must be a multiple of 8
> + if ((args.buf_size & 0x07))
> + return -EINVAL;
> +
> + if (args.buf_size > ocxlpmem->admin_command.data_size)
> + return -EINVAL;
> +
> + mutex_lock(&ocxlpmem->admin_command.lock);
> +
> + rc = enable_fwdebug(ocxlpmem);
> + if (rc)
> + goto out;
> +
> + rc = admin_command_request(ocxlpmem, ADMIN_COMMAND_FW_DEBUG);
> + if (rc)
> + goto out;
> +
> + // Write DebugAction & FunctionCode
> + val = ((u64)args.debug_action << 56) | ((u64)args.function_code << 40);
> +
> + rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
> + ocxlpmem->admin_command.request_offset + 0x08,
> + OCXL_LITTLE_ENDIAN, val);
> + if (rc)
> + goto out;
> +
> + rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
> + ocxlpmem->admin_command.request_offset + 0x10,
> + OCXL_LITTLE_ENDIAN, args.debug_parameter_1);
> + if (rc)
> + goto out;
> +
> + rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
> + ocxlpmem->admin_command.request_offset + 0x18,
> + OCXL_LITTLE_ENDIAN, args.debug_parameter_2);
> + if (rc)
> + goto out;
> +
> + for (i = 0x20; i < 0x38; i += 0x08)
> + rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
> + ocxlpmem->admin_command.request_offset + i,
> + OCXL_LITTLE_ENDIAN, 0);
> + if (rc)
> + goto out;


rc is the for loop body. The rc test is not.


> +
> +
> + // Populate admin command buffer
> + if (args.buf_size) {
> + for (i = 0; i < args.buf_size; i += sizeof(u64)) {
> + u64 val;
> +
> + if (copy_from_user(&val, &args.buf[i], sizeof(u64)))
> + return -EFAULT;


need to get rc and goto out because of the mutex


> +
> + rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
> + ocxlpmem->admin_command.data_offset + i,
> + OCXL_HOST_ENDIAN, val);
> + if (rc)
> + goto out;
> + }
> + }
> +
> + rc = admin_command_execute(ocxlpmem);
> + if (rc)
> + goto out;
> +
> + rc = admin_command_complete_timeout(ocxlpmem,
> + ocxlpmem->timeouts[ADMIN_COMMAND_FW_DEBUG]);
> + if (rc < 0)
> + goto out;
> +
> + rc = admin_response(ocxlpmem);
> + if (rc < 0)
> + goto out;
> + if (rc != STATUS_SUCCESS) {
> + warn_status(ocxlpmem, "Unexpected status from FW Debug", rc);
> + goto out;
> + }
> +
> + if (args.buf_size) {
> + for (i = 0; i < args.buf_size; i += sizeof(u64)) {
> + u64 val;
> +
> + rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu,
> + ocxlpmem->admin_command.data_offset + i,
> + OCXL_HOST_ENDIAN, &val);
> + if (rc)
> + goto out;
> +
> + if (copy_to_user(&args.buf[i], &val, sizeof(u64))) {
> + rc = -EFAULT;
> + goto out;
> + }
> + }
> + }
> +
> + rc = admin_response_handled(ocxlpmem);
> + if (rc)
> + goto out;
> +
> + rc = disable_fwdebug(ocxlpmem);
> + if (rc)
> + goto out;
> +
> +out:
> + mutex_unlock(&ocxlpmem->admin_command.lock);
> + return rc;
> +}
> +
> +static int ioctl_shutdown(struct ocxlpmem *ocxlpmem)
> +{
> + int rc;
> +
> + mutex_lock(&ocxlpmem->admin_command.lock);
> +
> + rc = admin_command_request(ocxlpmem, ADMIN_COMMAND_SHUTDOWN);
> + if (rc)
> + goto out;
> +
> + rc = admin_command_execute(ocxlpmem);
> + if (rc)
> + goto out;
> +
> + rc = admin_command_complete_timeout(ocxlpmem, ADMIN_COMMAND_SHUTDOWN);
> + if (rc < 0) {
> + dev_warn(&ocxlpmem->dev, "Shutdown timed out\n");
> + goto out;
> + }
> +
> + rc = 0;
> + goto out;


We can remove that goto.

No admin_response_handled()? Is that shutting down the full adapter and
we have nobody to talk to? What happens next?


> +
> +out:
> + mutex_unlock(&ocxlpmem->admin_command.lock);
> + return rc;
> +}
> +
> +static int ioctl_mmio_write(struct ocxlpmem *ocxlpmem,
> + struct ioctl_ocxl_pmem_mmio __user *uarg)
> +{
> + struct scm_ioctl_mmio args;
> +
> + if (copy_from_user(&args, uarg, sizeof(args)))
> + return -EFAULT;
> +
> + return ocxl_global_mmio_write64(ocxlpmem->ocxl_afu, args.address,
> + OCXL_LITTLE_ENDIAN, args.val);
> +}
> +
> +static int ioctl_mmio_read(struct ocxlpmem *ocxlpmem,
> + struct ioctl_ocxl_pmem_mmio __user *uarg)
> +{
> + struct ioctl_ocxl_pmem_mmio args;
> + int rc;
> +
> + if (copy_from_user(&args, uarg, sizeof(args)))
> + return -EFAULT;
> +
> + rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu, args.address,
> + OCXL_LITTLE_ENDIAN, &args.val);
> + if (rc)
> + return rc;
> +
> + if (copy_to_user(uarg, &args, sizeof(args)))
> + return -EFAULT;
> +
> + return 0;
> +}
> +#else /* CONFIG_OCXL_PMEM_DEBUG */
> +static int ioctl_fwdebug(struct ocxlpmem *ocxlpmem,
> + struct ioctl_ocxl_pmem_fwdebug __user *uarg)
> +{
> + return -EPERM;
> +}
> +
> +static int ioctl_shutdown(struct ocxlpmem *ocxlpmem)
> +{
> + return -EPERM;
> +}
> +
> +static int ioctl_mmio_write(struct ocxlpmem *ocxlpmem,
> + struct ioctl_ocxl_pmem_mmio __user *uarg)
> +{
> + return -EPERM;
> +}
> +
> +static int ioctl_mmio_read(struct ocxlpmem *ocxlpmem,
> + struct ioctl_ocxl_pmem_mmio __user *uarg)
> +{
> + return -EPERM;
> +}


The 'else' clause could be dropped, the ioctls will return EINVAL, which
is fine, I think.



> +#endif /* CONFIG_OCXL_PMEM_DEBUG */
> +
> static long file_ioctl(struct file *file, unsigned int cmd, unsigned long args)
> {
> struct ocxlpmem *ocxlpmem = file->private_data;
> @@ -1091,6 +1320,26 @@ static long file_ioctl(struct file *file, unsigned int cmd, unsigned long args)
> case IOCTL_OCXL_PMEM_REQUEST_HEALTH:
> rc = req_controller_health_perf(ocxlpmem);
> break;
> +
> + case IOCTL_OCXL_PMEM_FWDEBUG:
> + rc = ioctl_fwdebug(ocxlpmem,
> + (struct ioctl_ocxl_pmem_fwdebug __user *)args);
> + break;
> +
> + case IOCTL_OCXL_PMEM_SHUTDOWN:
> + rc = ioctl_shutdown(ocxlpmem);
> + break;
> +
> + case IOCTL_OCXL_PMEM_MMIO_WRITE:
> + rc = ioctl_mmio_write(ocxlpmem,
> + (struct ioctl_ocxl_pmem_mmio __user *)args);
> + break;
> +
> + case IOCTL_OCXL_PMEM_MMIO_READ:
> + rc = ioctl_mmio_read(ocxlpmem,
> + (struct ioctl_ocxl_pmem_mmio __user *)args);
> + break;
> +
> }
>
> return rc;
> diff --git a/include/uapi/nvdimm/ocxl-pmem.h b/include/uapi/nvdimm/ocxl-pmem.h
> index 0d03abb44001..e20a4f8be82a 100644
> --- a/include/uapi/nvdimm/ocxl-pmem.h
> +++ b/include/uapi/nvdimm/ocxl-pmem.h
> @@ -6,6 +6,28 @@
> #include <linux/types.h>
> #include <linux/ioctl.h>
>
> +enum ocxlpmem_fwdebug_action {
> + OCXL_PMEM_FWDEBUG_READ_CONTROLLER_MEMORY = 0x01,
> + OCXL_PMEM_FWDEBUG_WRITE_CONTROLLER_MEMORY = 0x02,
> + OCXL_PMEM_FWDEBUG_ENABLE_FUNCTION = 0x03,
> + OCXL_PMEM_FWDEBUG_DISABLE_FUNCTION = 0x04,
> + OCXL_PMEM_FWDEBUG_GET_PEL = 0x05, // Retrieve Persistent Error Log
> +};
> +
> +struct ioctl_ocxl_pmem_buffer_info {
> + __u32 admin_command_buffer_size; // out
> + __u32 near_storage_buffer_size; // out
> +};
> +
> +struct ioctl_ocxl_pmem_fwdebug { // All args are inputs
> + enum ocxlpmem_fwdebug_action debug_action;


More kernel ABI problems. My interpretation of the "enumeration
specifiers" section of C99 is that we can't rely on the size of the enum.


> + __u16 function_code;
> + __u16 buf_size; // Size of optional data buffer
> + __u64 debug_parameter_1;
> + __u64 debug_parameter_2;
> + __u8 *buf; // Pointer to optional in/out data buffer
> +};
> +
> #define OCXL_PMEM_ERROR_LOG_ACTION_RESET (1 << (32-32))
> #define OCXL_PMEM_ERROR_LOG_ACTION_CHKFW (1 << (53-32))
> #define OCXL_PMEM_ERROR_LOG_ACTION_REPLACE (1 << (54-32))
> @@ -66,6 +88,11 @@ struct ioctl_ocxl_pmem_controller_stats {
> __u64 cache_write_latency; /* nanoseconds */
> };
>
> +struct ioctl_ocxl_pmem_mmio {
> + __u64 address; /* Offset in global MMIO space */
> + __u64 val; /* value to write/was read */
> +};


Can we group all the debug data structures together in the header file,
with a comment indicating that they may not be available in the kernel,
depending on the config?

Fred


> +
> struct ioctl_ocxl_pmem_eventfd {
> __s32 eventfd;
> __u32 reserved;
> @@ -92,4 +119,9 @@ struct ioctl_ocxl_pmem_eventfd {
> #define IOCTL_OCXL_PMEM_EVENT_CHECK _IOR(OCXL_PMEM_MAGIC, 0x07, __u64)
> #define IOCTL_OCXL_PMEM_REQUEST_HEALTH _IO(OCXL_PMEM_MAGIC, 0x08)
>
> +#define IOCTL_OCXL_PMEM_FWDEBUG _IOWR(OCXL_PMEM_MAGIC, 0xf0, struct ioctl_ocxl_pmem_fwdebug)
> +#define IOCTL_OCXL_PMEM_MMIO_WRITE _IOW(OCXL_PMEM_MAGIC, 0xf1, struct ioctl_ocxl_pmem_mmio)
> +#define IOCTL_OCXL_PMEM_MMIO_READ _IOWR(OCXL_PMEM_MAGIC, 0xf2, struct ioctl_ocxl_pmem_mmio)
> +#define IOCTL_OCXL_PMEM_SHUTDOWN _IO(OCXL_PMEM_MAGIC, 0xf3)
> +
> #endif /* _UAPI_OCXL_SCM_H */
>

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