On 8/14/2024 4:03 PM, Greg KH wrote:
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On Wed, Aug 14, 2024 at 09:59:53AM +0000, Akshay Gupta wrote:
+The following IOCTL is defined:
+
+``#define SB_BASE_IOCTL_NR 0xF9``
+``#define SBRMI_IOCTL_CMD _IOWR(SB_BASE_IOCTL_NR, 0, struct apml_message)``
You only have 1 ioctl, so why are you saying that you are reserving
0-1F?
Currently we have only 1 IOCTL, but will add IOCTL for SBTSI.
I have reserved considering the future use cases.
However, we may not need up to 1F will restrict it to 0-Fh
+Data structure::
+ struct apml_message {
+ /* message ids:
+ * Mailbox Messages: 0x0 ... 0x999
+ * APML_CPUID: 0x1000
+ * APML_MCA_MSR: 0x1001
+ * APML_REG: 0x1002
+ */
+ __u32 cmd;
+ /*
+ * 8 bit data for reg read,
+ * 32 bit data in case of mailbox,
+ * up to 64 bit in case of cpuid and mca msr
+ */
+ union {
+ __u64 cpu_msr_out;
+ __u32 mb_out[2];
+ __u8 reg_out[8];
+ } data_out;
+ /*
+ * [0]...[3] mailbox 32bit input
+ * cpuid & mca msr,
+ * rmi rd/wr: reg_offset
+ * [4][5] cpuid & mca msr: thread
+ * [4] rmi reg wr: value
+ * [6] cpuid: ext function & read eax/ebx or ecx/edx
+ * [7:0] -> bits [7:4] -> ext function &
+ * bit [0] read eax/ebx or ecx/edx
+ * [7] read/write functionality
+ */
+ union {
+ __u64 cpu_msr_in;
+ __u32 mb_in[2];
+ __u8 reg_in[8];
+ } data_in;
+ /*
+ * Status code is returned in case of CPUID/MCA access
+ * Error code is returned in case of soft mailbox
+ */
+ __u32 fw_ret_code;
+ } __attribute__((packed));
This does not need to be here, pull it directly from the .h file using
kernel doc formatting please.
I will update this.
+The ioctl would return a non-zero on failure; user can read errno to see
+what happened.
That's not how the ioctl syscall works :(
I will document the errors returned in the header file.
The transaction returns 0 on success.
+
+User space C-APIs are made available by linking against the esmi_oob_library,
+which is provided by the E-SMS projecthttps://www.amd.com/en/developer/e-sms.html.
+Link:https://github.com/amd/esmi_oob_library
What is this last line for?
I will rewrite the statement as follows:
User space C-APIs are made available by esmi_oob_library hosted athttps://github.com/amd/esmi_oob_library
which is provided as part of E-SMS projecthttps://www.amd.com/en/developer/e-sms.html.
I will wait for feedback on other patches before submitting next version.
thanks,
greg k-h
