/* * helpers for managing a buffer for many packets * * Copyright (c) Clemens Ladisch * Licensed under the terms of the GNU General Public License, version 2. */ #include #include #include #include "packets-buffer.h" /** * iso_packets_buffer_init - allocates the memory for packets * @b: the buffer structure to initialize * @unit: the device at the other end of the stream * @count: the number of packets * @packet_size: the (maximum) size of a packet, in bytes * @direction: %DMA_TO_DEVICE or %DMA_FROM_DEVICE */ int iso_packets_buffer_init(struct iso_packets_buffer *b, struct fw_unit *unit, unsigned int count, unsigned int packet_size, enum dma_data_direction direction) { unsigned int packets_per_page, pages; unsigned int i, page_index, offset_in_page; void *p; int err; b->packets = kmalloc(count * sizeof(*b->packets), GFP_KERNEL); if (!b->packets) { err = -ENOMEM; goto error; } packet_size = L1_CACHE_ALIGN(packet_size); packets_per_page = PAGE_SIZE / packet_size; if (WARN_ON(!packets_per_page)) { err = -EINVAL; goto error; } pages = DIV_ROUND_UP(count, packets_per_page); err = fw_iso_buffer_init(&b->iso_buffer, fw_parent_device(unit)->card, pages, direction); if (err < 0) goto err_packets; for (i = 0; i < count; ++i) { page_index = i / packets_per_page; p = page_address(b->iso_buffer.pages[page_index]); offset_in_page = (i % packets_per_page) * packet_size; b->packets[i].buffer = p + offset_in_page; b->packets[i].offset = page_index * PAGE_SIZE + offset_in_page; } return 0; err_packets: kfree(b->packets); error: return err; } EXPORT_SYMBOL(iso_packets_buffer_init); /** * iso_packets_buffer_destroy - frees packet buffer resources * @b: the buffer structure to free * @unit: the device at the other end of the stream */ void iso_packets_buffer_destroy(struct iso_packets_buffer *b, struct fw_unit *unit) { fw_iso_buffer_destroy(&b->iso_buffer, fw_parent_device(unit)->card); kfree(b->packets); } EXPORT_SYMBOL(iso_packets_buffer_destroy); c05a88e4996e8177f91b'>commitdiff
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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2017-02-03 17:10:28 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2017-02-08 23:36:29 +1100
commitd7df2443cd5f67fc6ee7c05a88e4996e8177f91b (patch)
tree098a7c0ca4fceb8a65cb1f693c9d71990388933d /net/wireless/regdb.h
parenta0615a16f7d0ceb5804d295203c302d496d8ee91 (diff)
powerpc/mm: Fix spurrious segfaults on radix with autonuma
When autonuma (Automatic NUMA balancing) marks a PTE inaccessible it clears all the protection bits but leave the PTE valid. With the Radix MMU, an attempt at executing from such a PTE will take a fault with bit 35 of SRR1 set "SRR1_ISI_N_OR_G". It is thus incorrect to treat all such faults as errors. We should pass them to handle_mm_fault() for autonuma to deal with. The case of pages that are really not executable is handled by the existing test for VM_EXEC further down. That leaves us with catching the kernel attempts at executing user pages. We can catch that earlier, even before we do find_vma. It is never valid on powerpc for the kernel to take an exec fault to begin with. So fold that test with the existing test for the kernel faulting on kernel addresses to bail out early. Fixes: 1d18ad026844 ("powerpc/mm: Detect instruction fetch denied and report") Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'net/wireless/regdb.h')