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path: root/drivers/misc/ocxl/link.c
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2020-12-04ocxl: Add new kernel tracesChristophe Lombard
Add specific kernel traces which provide information on mmu notifier and on pages range. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201125155013.39955-6-clombard@linux.vnet.ibm.com
2020-12-04ocxl: Add mmu notifierChristophe Lombard
Add invalidate_range mmu notifier, when required (ATSD access of MMIO registers is available), to initiate TLB invalidation commands. For the time being, the ATSD0 set of registers is used by default. The pasid and bdf values have to be configured in the Process Element Entry. The PEE must be set up to match the BDF/PASID of the AFU. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201125155013.39955-5-clombard@linux.vnet.ibm.com
2020-12-04ocxl: Update the Process Element EntryChristophe Lombard
To complete the MMIO based mechanism, the fields: PASID, bus, device and function of the Process Element Entry have to be filled. (See OpenCAPI Power Platform Architecture document) Hypervisor Process Element Entry Word 0 1 .... 7 8 ...... 12 13 ..15 16.... 19 20 ........... 31 0 OSL Configuration State (0:31) 1 OSL Configuration State (32:63) 2 PASID | Reserved 3 Bus | Device |Function | Reserved 4 Reserved 5 Reserved 6 .... Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201125155013.39955-4-clombard@linux.vnet.ibm.com
2020-08-25ocxl: Don't return trigger page when allocating an interruptFrederic Barrat
Existing users of ocxl_link_irq_alloc() have been converted to obtain the trigger page of an interrupt through xive directly, we therefore have no need to return the trigger page when allocating an interrupt. It also allows ocxl to use the xive native interface to allocate interrupts, instead of its custom service. Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com> Reviewed-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: Greg Kurz <groug@kaod.org> Acked-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200403153838.29224-4-fbarrat@linux.ibm.com
2019-07-03ocxl: Allow contexts to be attached with a NULL mmAlastair D'Silva
If an OpenCAPI context is to be used directly by a kernel driver, there may not be a suitable mm to use. The patch makes the mm parameter to ocxl_context_attach optional. Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Acked-by: Andrew Donnellan <ajd@linux.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> Acked-by: Nicholas Piggin <npiggin@gmail.com> Link: https://lore.kernel.org/r/20190620041203.12274-1-alastair@au1.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-03ocxl: Rename struct link to ocxl_linkAlastair D'Silva
The term 'link' is ambiguous (especially when the struct is used for a list), so rename it for clarity. Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Reviewed-by: Greg Kurz <groug@kaod.org> Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-01ocxl: remove set but not used variables 'tid' and 'lpid'YueHaibing
Fixes gcc '-Wunused-but-set-variable' warning: drivers/misc/ocxl/link.c: In function 'xsl_fault_handler': drivers/misc/ocxl/link.c:187:17: warning: variable 'tid' set but not used drivers/misc/ocxl/link.c:187:6: warning: variable 'lpid' set but not used They are never used and can be removed. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Mukesh Ojha <mojha@codeaurora.org> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-21powerpc/mm/hash64: Map all the kernel regions in the same 0xc rangeAneesh Kumar K.V
This patch maps vmalloc, IO and vmemap regions in the 0xc address range instead of the current 0xd and 0xf range. This brings the mapping closer to radix translation mode. With hash 64K page size each of this region is 512TB whereas with 4K config we are limited by the max page table range of 64TB and hence there regions are of 16TB size. The kernel mapping is now: On 4K hash kernel_region_map_size = 16TB kernel vmalloc start = 0xc000100000000000 kernel IO start = 0xc000200000000000 kernel vmemmap start = 0xc000300000000000 64K hash, 64K radix and 4k radix: kernel_region_map_size = 512TB kernel vmalloc start = 0xc008000000000000 kernel IO start = 0xc00a000000000000 kernel vmemmap start = 0xc00c000000000000 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20ocxl: Clarify error path in setup_xsl_irq()Greg Kurz
Implementing rollback with goto and labels is a common practice that leads to prettier and more maintainable code. FWIW, this design pattern is already being used in alloc_link() a few lines below in this file. Do the same in setup_xsl_irq(). Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20ocxl: Fix endiannes bug in ocxl_link_update_pe()Greg Kurz
All fields in the PE are big-endian. Use cpu_to_be32() like everywhere else something is written to the PE. Otherwise a wrong TID will be used by the NPU. If this TID happens to point to an existing thread sharing the same mm, it could be woken up by error. This is highly improbable though. The likely outcome of this is the NPU not finding the target thread and forcing the AFU into sending an interrupt, which userspace is supposed to handle anyway. Fixes: e948e06fc63a ("ocxl: Expose the thread_id needed for wait on POWER9") Cc: stable@vger.kernel.org # v4.18 Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-17Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge updates from Andrew Morton: - a few misc things - a few Y2038 fixes - ntfs fixes - arch/sh tweaks - ocfs2 updates - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (111 commits) mm/hmm.c: remove unused variables align_start and align_end fs/userfaultfd.c: remove redundant pointer uwq mm, vmacache: hash addresses based on pmd mm/list_lru: introduce list_lru_shrink_walk_irq() mm/list_lru.c: pass struct list_lru_node* as an argument to __list_lru_walk_one() mm/list_lru.c: move locking from __list_lru_walk_one() to its caller mm/list_lru.c: use list_lru_walk_one() in list_lru_walk_node() mm, swap: make CONFIG_THP_SWAP depend on CONFIG_SWAP mm/sparse: delete old sparse_init and enable new one mm/sparse: add new sparse_init_nid() and sparse_init() mm/sparse: move buffer init/fini to the common place mm/sparse: use the new sparse buffer functions in non-vmemmap mm/sparse: abstract sparse buffer allocations mm/hugetlb.c: don't zero 1GiB bootmem pages mm, page_alloc: double zone's batchsize mm/oom_kill.c: document oom_lock mm/hugetlb: remove gigantic page support for HIGHMEM mm, oom: remove sleep from under oom_lock kernel/dma: remove unsupported gfp_mask parameter from dma_alloc_from_contiguous() mm/cma: remove unsupported gfp_mask parameter from cma_alloc() ...
2018-08-17mm: convert return type of handle_mm_fault() caller to vm_fault_tSouptick Joarder
Use new return type vm_fault_t for fault handler. For now, this is just documenting that the function returns a VM_FAULT value rather than an errno. Once all instances are converted, vm_fault_t will become a distinct type. Ref-> commit 1c8f422059ae ("mm: change return type to vm_fault_t") In this patch all the caller of handle_mm_fault() are changed to return vm_fault_t type. Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Tony Luck <tony.luck@intel.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: James Hogan <jhogan@kernel.org> Cc: Ley Foon Tan <lftan@altera.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: David S. Miller <davem@davemloft.net> Cc: Richard Weinberger <richard@nod.at> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-02ocxl: Fix page fault handler in case of fault on dying processFrederic Barrat
If a process exits without doing proper cleanup, there's a window where an opencapi device can try to access the memory of the dying process and may trigger a page fault. That's an expected scenario and the ocxl driver holds a reference on the mm_struct of the process until the opencapi device is notified of the process exiting. However, if mm_users is already at 0, i.e. the address space of the process has already been destroyed, the driver shouldn't try resolving the page fault, as it will fail, but it can also try accessing already freed data. It is fixed by only calling the bottom half of the page fault handler if mm_users is greater than 0 and get a reference on mm_users instead of mm_count. Otherwise, we can safely return a translation fault to the device, as its associated memory context is being removed. The opencapi device will be properly cleaned up shortly after when closing the file descriptors. Fixes: 5ef3166e8a32 ("ocxl: Driver code for 'generic' opencapi devices") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com> Reviewed-By: Alastair D'Silva <alastair@d-silva.org> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03ocxl: Expose the thread_id needed for wait on POWER9Alastair D'Silva
In order to successfully issue as_notify, an AFU needs to know the TID to notify, which in turn means that this information should be available in userspace so it can be communicated to the AFU. Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03ocxl: Rename pnv_ocxl_spa_remove_pe to clarify it's actionAlastair D'Silva
The function removes the process element from NPU cache. Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-24ocxl: Add trace pointsFrederic Barrat
Define a few trace points so that we can use the standard tracing mechanism for debug and/or monitoring. Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-24ocxl: Add a kernel API for other opencapi driversFrederic Barrat
Some of the functions done by the generic driver should also be needed by other opencapi drivers: attaching a context to an adapter, translation fault handling, AFU interrupt allocation... So to avoid code duplication, the driver provides a kernel API that other drivers can use, similar to calling a in-kernel library. It is still a bit theoretical, for lack of real hardware, and will likely need adjustements down the road. But we used the cxlflash driver as a guinea pig. Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-24ocxl: Add AFU interrupt supportFrederic Barrat
Add user APIs through ioctl to allocate, free, and be notified of an AFU interrupt. For opencapi, an AFU can trigger an interrupt on the host by sending a specific command targeting a 64-bit object handle. On POWER9, this is implemented by mapping a special page in the address space of a process and a write to that page will trigger an interrupt. Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-24ocxl: Driver code for 'generic' opencapi devicesFrederic Barrat
Add an ocxl driver to handle generic opencapi devices. Of course, it's not meant to be the only opencapi driver, any device is free to implement its own. But if a host application only needs basic services like attaching to an opencapi adapter, have translation faults handled or allocate AFU interrupts, it should suffice. The AFU config space must follow the opencapi specification and use the expected vendor/device ID to be seen by the generic driver. The driver exposes the device AFUs as a char device in /dev/ocxl/ Note that the driver currently doesn't handle memory attached to the opencapi device. Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>