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path: root/include/linux/lp.h
AgeCommit message (Expand)Author
2008-02-06Parallel port: convert port_mutex to the mutex APIMatthias Kaehlcke
2005-04-16Linux-2.6.12-rc2Linus Torvalds
generated by cgit v1.2.3 (git 2.46.0) at 2026-07-17 00:35:38 +0000
y not interleave calls to ibm,get-indices for different indicator or sensor types. Means other RTAS calls with different type should not be issued while the previous type sequence is in progress. So collect the entire list of indices and copied to buffer BLOB during ioctl() and expose this buffer to the user space with the file descriptor. - The hypervisor fills the work area with a specific format but does not return the number of bytes written to the buffer. Instead of parsing the data for each call to determine the data length, copy the work area size (RTAS_GET_INDICES_BUF_SIZE) to the buffer. Return work-area size of data to the user space for each read() call. Expose these interfaces to user space with a /dev/papr-indices character device using the following programming model: int devfd = open("/dev/papr-indices", O_RDONLY); int fd = ioctl(devfd, PAPR_INDICES_IOC_GET, struct papr_indices_io_block) - Collect all indices data for the specified token to the buffer char *buf = malloc(RTAS_GET_INDICES_BUF_SIZE); length = read(fd, buf, RTAS_GET_INDICES_BUF_SIZE) - RTAS_GET_INDICES_BUF_SIZE of data is returned to the user space. - The user space retrieves the indices and their location codes from the buffer - Should issue multiple read() calls until reaches the end of BLOB buffer. The read() should use the file descriptor obtained from ioctl to get the data that is exposed to file descriptor. Implemented support in librtas (rtas_get_indices()) for this new ABI for system lockdown. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Tested-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20250416225743.596462-4-haren@linux.ibm.com powerpc/pseries/dlpar: Remove device tree node for DLPAR IO remove 2024-08-30T11:31:25Z Haren Myneni haren@linux.ibm.com 2024-08-22T02:50:27Z urn:sha1:17a51171c20d590d3d3c632bcdd946f5fc3c0061 In the powerpc-pseries specific implementation, the IO hotplug event is handled in the user space (drmgr tool). But update the device tree and /dev/mem access to allocate buffers for some RTAS calls are restricted when the kernel lockdown feature is enabled. For the DLPAR IO REMOVE, the corresponding device tree nodes and properties have to be removed from the device tree after the device disable. The user space removes the device tree nodes by updating /proc/ppc64/ofdt which is not allowed under system lockdown is enabled. This restriction can be resolved by moving the complete IO hotplug handling in the kernel. But the pseries implementation need user interaction to power off and to remove device from the slot during hotplug event handling. To overcome the /proc/ppc64/ofdt restriction, this patch extends the /sys/kernel/dlpar interface and provides ‘dt remove index <drc_index>’ to the user space so that drmgr tool can remove the corresponding device tree nodes based on DRC index from the device tree. Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com> Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240822025028.938332-2-haren@linux.ibm.com