Le 21/02/2020 à 04:27, Alastair D'Silva a écrit :
From: Alastair D'Silva <alast...@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 <alast...@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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