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-rw-r--r--Documentation/powerpc/cxl.txt55
1 files changed, 55 insertions, 0 deletions
diff --git a/Documentation/powerpc/cxl.txt b/Documentation/powerpc/cxl.txt
index 205c1b8..d5506ba0 100644
--- a/Documentation/powerpc/cxl.txt
+++ b/Documentation/powerpc/cxl.txt
@@ -116,6 +116,8 @@ Work Element Descriptor (WED)
User API
========
+1. AFU character devices
+
For AFUs operating in AFU directed mode, two character device
files will be created. /dev/cxl/afu0.0m will correspond to a
master context and /dev/cxl/afu0.0s will correspond to a slave
@@ -362,6 +364,59 @@ read
reserved fields:
For future extensions and padding
+
+2. Card character device (powerVM guest only)
+
+ In a powerVM guest, an extra character device is created for the
+ card. The device is only used to write (flash) a new image on the
+ FPGA accelerator. Once the image is written and verified, the
+ device tree is updated and the card is reset to reload the updated
+ image.
+
+open
+----
+
+ Opens the device and allocates a file descriptor to be used with
+ the rest of the API. The device can only be opened once.
+
+ioctl
+-----
+
+CXL_IOCTL_DOWNLOAD_IMAGE:
+CXL_IOCTL_VALIDATE_IMAGE:
+ Starts and controls flashing a new FPGA image. Partial
+ reconfiguration is not supported (yet), so the image must contain
+ a copy of the PSL and AFU(s). Since an image can be quite large,
+ the caller may have to iterate, splitting the image in smaller
+ chunks.
+
+ Takes a pointer to a struct cxl_adapter_image:
+ struct cxl_adapter_image {
+ __u64 flags;
+ __u64 data;
+ __u64 len_data;
+ __u64 len_image;
+ __u64 reserved1;
+ __u64 reserved2;
+ __u64 reserved3;
+ __u64 reserved4;
+ };
+
+ flags:
+ These flags indicate which optional fields are present in
+ this struct. Currently all fields are mandatory.
+
+ data:
+ Pointer to a buffer with part of the image to write to the
+ card.
+
+ len_data:
+ Size of the buffer pointed to by data.
+
+ len_image:
+ Full size of the image.
+
+
Sysfs Class
===========
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