kernel/linux.git/drivers/misc/amd-sbi, branch v6.18.22

misc: amd-sbi: Clarify that this is a BMC driver

2025-10-22T06:02:57+00:00

Add a sentence to the driver description to clarify that the sbrmi-i2c driver is intended to run on the BMC and not on the managed node. Add platform dependencies accordingly. Signed-off-by: Jean Delvare Link: https://lore.kernel.org/r/5c9f7100-0e59-4237-a252-43c3ee4802a2@amd.com Link: https://patch.msgid.link/20251016155040.0e86c102@endymion Signed-off-by: Greg Kroah-Hartman

drivers/misc/amd-sbi/Kconfig: select REGMAP_I2C

2025-09-06T14:00:50+00:00

Without CONFIG_REGMAP, rmi-i2c.c fails to build because struct regmap_config is not defined: drivers/misc/amd-sbi/rmi-i2c.c: In function ‘sbrmi_i2c_probe’: drivers/misc/amd-sbi/rmi-i2c.c:57:16: error: variable ‘sbrmi_i2c_regmap_config’ has initializer but incomplete type 57 | struct regmap_config sbrmi_i2c_regmap_config = { | ^~~~~~~~~~~~~ Additionally, CONFIG_REGMAP_I2C is needed for devm_regmap_init_i2c(): ld: drivers/misc/amd-sbi/rmi-i2c.o: in function `sbrmi_i2c_probe': drivers/misc/amd-sbi/rmi-i2c.c:69:(.text+0x1c0): undefined reference to `__devm_regmap_init_i2c' Fixes: 013f7e7131bd ("misc: amd-sbi: Use regmap subsystem") Cc: stable@vger.kernel.org Signed-off-by: Max Kellermann Tested-by: Akshay Gupta Reviewed-by: Akshay Gupta Link: https://lore.kernel.org/r/20250829091442.1112106-1-max.kellermann@ionos.com Signed-off-by: Greg Kroah-Hartman

misc: amd-sbi: Explicitly clear in/out arg "mb_in_out"

2025-07-16T13:02:45+00:00

- New AMD processor will support different input/output for same command. - In some scenarios the input value is not cleared, which will be added to output before reporting the data. - Clearing input explicitly will be a cleaner and safer approach. Reviewed-by: Naveen Krishna Chatradhi Signed-off-by: Akshay Gupta Link: https://lore.kernel.org/r/20250716110729.2193725-3-akshay.gupta@amd.com Signed-off-by: Greg Kroah-Hartman

misc: amd-sbi: Address copy_to/from_user() warning reported in smatch

2025-07-16T13:02:45+00:00

Smatch warnings are reported for below commit, Commit bb13a84ed6b7 ("misc: amd-sbi: Add support for CPUID protocol") from Apr 28, 2025 (linux-next), leads to the following Smatch static checker warning: drivers/misc/amd-sbi/rmi-core.c:376 apml_rmi_reg_xfer() warn: maybe return -EFAULT instead of the bytes remaining? drivers/misc/amd-sbi/rmi-core.c:394 apml_mailbox_xfer() warn: maybe return -EFAULT instead of the bytes remaining? drivers/misc/amd-sbi/rmi-core.c:411 apml_cpuid_xfer() warn: maybe return -EFAULT instead of the bytes remaining? drivers/misc/amd-sbi/rmi-core.c:428 apml_mcamsr_xfer() warn: maybe return -EFAULT instead of the bytes remaining? copy_to/from_user() returns number of bytes, not copied. In case data not copied, return "-EFAULT". Additionally, fixes the "-EPROTOTYPE" error return as intended. Fixes: 35ac2034db72 ("misc: amd-sbi: Add support for AMD_SBI IOCTL") Fixes: bb13a84ed6b7 ("misc: amd-sbi: Add support for CPUID protocol") Fixes: 69b1ba83d21c ("misc: amd-sbi: Add support for read MCA register protocol") Fixes: cf141287b774 ("misc: amd-sbi: Add support for register xfer") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/all/aDVyO8ByVsceybk9@stanley.mountain/ Reviewed-by: Naveen Krishna Chatradhi Signed-off-by: Akshay Gupta Link: https://lore.kernel.org/r/20250716110729.2193725-2-akshay.gupta@amd.com Signed-off-by: Greg Kroah-Hartman

misc: amd-sbi: Address potential integer overflow issue reported in smatch

2025-07-16T13:02:45+00:00

Smatch warnings are reported for below commit, Commit bb13a84ed6b7 ("misc: amd-sbi: Add support for CPUID protocol") from Apr 28, 2025 (linux-next), leads to the following Smatch static checker warning: drivers/misc/amd-sbi/rmi-core.c:132 rmi_cpuid_read() warn: bitwise OR is zero '0xffffffff00000000 & 0xffff' drivers/misc/amd-sbi/rmi-core.c:132 rmi_cpuid_read() warn: potential integer overflow from user 'msg->cpu_in_out << 32' drivers/misc/amd-sbi/rmi-core.c:213 rmi_mca_msr_read() warn: bitwise OR is zero '0xffffffff00000000 & 0xffff' drivers/misc/amd-sbi/rmi-core.c:213 rmi_mca_msr_read() warn: potential integer overflow from user 'msg->mcamsr_in_out << 32' CPUID & MCAMSR thread data from input is available at byte 4 & 5, this patch fixes to copy the user data correctly in the argument. Previously, CPUID and MCAMSR data is return only for thread 0. Fixes: bb13a84ed6b7 ("misc: amd-sbi: Add support for CPUID protocol") Fixes: 69b1ba83d21c ("misc: amd-sbi: Add support for read MCA register protocol") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/all/aDVyO8ByVsceybk9@stanley.mountain/ Reviewed-by: Naveen Krishna Chatradhi Signed-off-by: Akshay Gupta Link: https://lore.kernel.org/r/20250716110729.2193725-1-akshay.gupta@amd.com Signed-off-by: Greg Kroah-Hartman

misc: amd-sbi: Add support for register xfer

2025-05-21T12:44:41+00:00

- Provide user register access over IOCTL. Both register read and write are supported. - APML interface does not provide a synchronization method. By defining, a register access path, we use APML modules and library for all APML transactions. Without having to use external tools such as i2c-tools, which may cause race conditions. Reviewed-by: Naveen Krishna Chatradhi Signed-off-by: Akshay Gupta Link: https://lore.kernel.org/r/20250428063034.2145566-10-akshay.gupta@amd.com Signed-off-by: Greg Kroah-Hartman

misc: amd-sbi: Add support for read MCA register protocol

2025-05-21T12:44:41+00:00

- AMD provides custom protocol to read Machine Check Architecture(MCA) registers over sideband. The information is accessed for range of MCA registers by passing register address and thread ID to the protocol. MCA register read command using the register address to access Core::X86::Msr::MCG_CAP which determines the number of MCA banks. Access is read-only Reviewed-by: Naveen Krishna Chatradhi Signed-off-by: Akshay Gupta Link: https://lore.kernel.org/r/20250428063034.2145566-9-akshay.gupta@amd.com Signed-off-by: Greg Kroah-Hartman

misc: amd-sbi: Add support for CPUID protocol

2025-05-21T12:44:40+00:00

- AMD provides custom protocol to read Processor feature capabilities and configuration information through side band. The information is accessed by providing CPUID Function, extended function and thread ID to the protocol. Undefined function returns 0. Reviewed-by: Naveen Krishna Chatradhi Signed-off-by: Akshay Gupta Link: https://lore.kernel.org/r/20250428063034.2145566-8-akshay.gupta@amd.com Signed-off-by: Greg Kroah-Hartman

misc: amd-sbi: Add support for AMD_SBI IOCTL

2025-05-21T12:44:40+00:00

The present sbrmi module only support reporting power via hwmon. However, AMD data center range of processors support various system management functionality using custom protocols defined in Advanced Platform Management Link (APML) specification. Register a miscdevice, which creates a device /dev/sbrmiX with an IOCTL interface for the user space to invoke the APML Mailbox protocol, which is already defined in sbrmi_mailbox_xfer(). The APML protocols depend on a set of RMI registers. Having an IOCTL as a single entry point will help in providing synchronization among these protocols as multiple transactions on RMI register set may create race condition. Support for other protocols will be added in subsequent patches. APML mailbox protocol returns additional error codes written by SMU firmware in the out-bound register 0x37. These errors include, invalid core, message not supported over platform and others. This additional error codes can be used to provide more details to user space. Open-sourced and widely used https://github.com/amd/esmi_oob_library will continue to provide user-space programmable API. Reviewed-by: Naveen Krishna Chatradhi Signed-off-by: Akshay Gupta Link: https://lore.kernel.org/r/20250428063034.2145566-7-akshay.gupta@amd.com Signed-off-by: Greg Kroah-Hartman

misc: amd-sbi: Optimize the wait condition for mailbox command completion

2025-05-21T12:44:40+00:00

- optimize the wait condition to indicate command completion by replacing the do while loop with regmap subsystem API regmap_read_poll_timeout() Reviewed-by: Naveen Krishna Chatradhi Signed-off-by: Akshay Gupta Link: https://lore.kernel.org/r/20250428063034.2145566-6-akshay.gupta@amd.com Signed-off-by: Greg Kroah-Hartman