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path: root/arch/powerpc/platforms/powernv/vas-fault.c (follow)
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* powerpc: Fix all occurences of duplicate wordsMichael Ellerman2022-07-251-1/+1
| | | | | | | | | | | | | | | | Since commit 87c78b612f4f ("powerpc: Fix all occurences of "the the"") fixed "the the", there's now a steady stream of patches fixing other duplicate words. Just fix them all at once, to save the overhead of dealing with individual patches for each case. This leaves a few cases of "that that", which in some contexts is correct. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220718095158.326606-1-mpe@ellerman.id.au
* powerpc/powernv/vas: Assign real address to rx_fifo in vas_rx_win_attrHaren Myneni2022-05-221-1/+1
| | | | | | | | | | | | | | | | In init_winctx_regs(), __pa() is called on winctx->rx_fifo and this function is called to initialize registers for receive and fault windows. But the real address is passed in winctx->rx_fifo for receive windows and the virtual address for fault windows which causes errors with DEBUG_VIRTUAL enabled. Fixes this issue by assigning only real address to rx_fifo in vas_rx_win_attr struct for both receive and fault windows. Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/338e958c7ab8f3b266fa794a1f80f99b9671829e.camel@linux.ibm.com
* powerpc/vas: Define and use common vas_window structHaren Myneni2021-06-201-10/+10
| | | | | | | | | | | | | | | | | Many elements in vas_struct are used on PowerNV and PowerVM platforms. vas_window is used for both TX and RX windows on PowerNV and for TX windows on PowerVM. So some elements are specific to these platforms. So this patch defines common vas_window and platform specific window structs (pnv_vas_window on PowerNV). Also adds the corresponding changes in PowerNV vas code. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1698c35c158dfe52c6d2166667823d3d4a463353.camel@linux.ibm.com
* powerpc/vas: Move update_csb/dump_crb to common book3s platformHaren Myneni2021-06-201-146/+9
| | | | | | | | | | | | | | If a coprocessor encounters an error translating an address, the VAS will cause an interrupt in the host. The kernel processes the fault by updating CSB. This functionality is same for both powerNV and pseries. So this patch moves these functions to common vas-api.c and the actual functionality is not changed. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bf8d5b0770fa1ef5cba88c96580caa08d999d3b5.camel@linux.ibm.com
* powerpc/vas: Create take/drop pid and mm reference functionsHaren Myneni2021-06-201-5/+5
| | | | | | | | | | | | | Take pid and mm references when each window opens and drops during close. This functionality is needed for powerNV and pseries. So this patch defines the existing code as functions in common book3s platform vas-api.c Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2fa40df962250a737c804e58202924717b39e381.camel@linux.ibm.com
* powerpc/vas: Report proper error code for address translation failureHaren Myneni2020-07-151-1/+1
| | | | | | | | | | | | | | | | | P9 DD2 NX workbook (Table 4-36) says DMA controller uses CC=5 internally for translation fault handling. NX reserves CC=250 for OS to notify user space when NX encounters address translation failure on the request buffer. Not an issue in earlier releases as NX does not get faults on kernel addresses. This patch defines CSB_CC_FAULT_ADDRESS(250) and updates CSB.CC with this proper error code for user space. Fixes: c96c4436aba4 ("powerpc/vas: Update CSB and notify process for fault CRBs") Signed-off-by: Haren Myneni <haren@linux.ibm.com> [mpe: Added Fixes tag and fix typo in comment] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/019fd53e7538c6f8f332d175df74b1815ef5aa8c.camel@linux.ibm.com
* kernel: better document the use_mm/unuse_mm API contractChristoph Hellwig2020-06-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch the function documentation to kerneldoc comments, and add WARN_ON_ONCE asserts that the calling thread is a kernel thread and does not have ->mm set (or has ->mm set in the case of unuse_mm). Also give the functions a kthread_ prefix to better document the use case. [hch@lst.de: fix a comment typo, cover the newly merged use_mm/unuse_mm caller in vfio] Link: http://lkml.kernel.org/r/20200416053158.586887-3-hch@lst.de [sfr@canb.auug.org.au: powerpc/vas: fix up for {un}use_mm() rename] Link: http://lkml.kernel.org/r/20200422163935.5aa93ba5@canb.auug.org.au Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Jens Axboe <axboe@kernel.dk> Acked-by: Felix Kuehling <Felix.Kuehling@amd.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [usb] Acked-by: Haren Myneni <haren@linux.ibm.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Felipe Balbi <balbi@kernel.org> Cc: Jason Wang <jasowang@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: Zhi Wang <zhi.a.wang@intel.com> Link: http://lkml.kernel.org/r/20200404094101.672954-6-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc/vas: Print CRB and FIFO valuesHaren Myneni2020-04-201-0/+41
| | | | | | | | | | Dump FIFO entries if could not find send window and print CRB for debugging. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1587017099.2275.1067.camel@hbabu-laptop
* powerpc/vas: Return credits after handling faultHaren Myneni2020-04-201-0/+9
| | | | | | | | | | | | | | | | | | NX uses credit mechanism to control the number of requests issued on a specific window at any point of time. Only send windows and fault window are used credits. When the request is issued on a given window, a credit is taken. This credit will be returned after that request is processed. If credits are not available, returns RMA_Busy for send window and RMA_Reject for fault window. NX expects OS to return credit for send window after processing fault CRB. Also credit has to be returned for fault window after handling the fault. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1587017059.2275.1064.camel@hbabu-laptop
* powerpc/vas: Update CSB and notify process for fault CRBsHaren Myneni2020-04-201-1/+125
| | | | | | | | | | | | | | | | | | | | | Applications polls on CSB for the status update after requests are issued. NX process these requests and update the CSB with the status. If it encounters translation error, pastes CRB in fault FIFO and raises an interrupt. The kernel handles fault by reading CRB from fault FIFO and process the fault CRB. For each fault CRB, update fault address in CRB (fault_storage_addr) and translation error status in CSB so that user space can touch the fault address and resend the request. If the user space passed invalid CSB address send signal to process with SIGSEGV. In the case of multi-thread applications, child thread may not be available. So if the task is not running, send signal to tgid. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1587017022.2275.1063.camel@hbabu-laptop
* powerpc/vas: Setup thread IRQ handler per VAS instanceHaren Myneni2020-04-201-0/+131
| | | | | | | | | | | | | | | | | | | | | | | When NX encounters translation error on CRB and any request buffer, raises an interrupt on the CPU to handle the fault. It can raise one interrupt for multiple faults. Expects OS to handle these faults and return credits for fault window after processing faults. Setup thread IRQ handler and IRQ thread function per each VAS instance. IRQ handler checks if the thread is already woken up and can handle new faults. If so returns with IRQ_HANDLED, otherwise wake up thread to process new faults. The thread functions reads each CRB entry from fault FIFO until sees invalid entry. After reading each CRB, determine the corresponding send window using pswid (from CRB) and process fault CRB. Then invalidate the entry and return credit. Processing fault CRB and return credit is described in subsequent patches. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1587016982.2275.1060.camel@hbabu-laptop
* powerpc/vas: Setup fault window per VAS instanceHaren Myneni2020-04-201-0/+77
Setup fault window for each VAS instance. When NX gets a fault on request buffer, pastes fault CRB in the corresponding fault FIFO and then raises an interrupt to the OS. The kernel handles this fault and process faults CRB from this FIFO. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1587016846.2275.1053.camel@hbabu-laptop