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![Alexander Shishkin](/assets/img/avatar_default.png)
The 'nr_pages' attribute of the 'msc' subdevices parses a comma-separated
list of window sizes, passed from userspace. However, there is a bug in
the string parsing logic wherein it doesn't exclude the comma character
from the range of characters as it consumes them. This leads to an
out-of-bounds access given a sufficiently long list. For example:
> # echo 8,8,8,8 > /sys/bus/intel_th/devices/0-msc0/nr_pages
> ==================================================================
> BUG: KASAN: slab-out-of-bounds in memchr+0x1e/0x40
> Read of size 1 at addr ffff8803ffcebcd1 by task sh/825
>
> CPU: 3 PID: 825 Comm: npktest.sh Tainted: G W 4.20.0-rc1+
> Call Trace:
> dump_stack+0x7c/0xc0
> print_address_description+0x6c/0x23c
> ? memchr+0x1e/0x40
> kasan_report.cold.5+0x241/0x308
> memchr+0x1e/0x40
> nr_pages_store+0x203/0xd00 [intel_th_msu]
Fix this by accounting for the comma character.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: ba82664c13
("intel_th: Add Memory Storage Unit driver")
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1523 lines
34 KiB
C
1523 lines
34 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Intel(R) Trace Hub Memory Storage Unit
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*
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* Copyright (C) 2014-2015 Intel Corporation.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/types.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/uaccess.h>
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#include <linux/sizes.h>
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#include <linux/printk.h>
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#include <linux/slab.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/io.h>
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#include <linux/dma-mapping.h>
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#ifdef CONFIG_X86
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#include <asm/set_memory.h>
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#endif
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#include "intel_th.h"
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#include "msu.h"
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#define msc_dev(x) (&(x)->thdev->dev)
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/**
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* struct msc_block - multiblock mode block descriptor
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* @bdesc: pointer to hardware descriptor (beginning of the block)
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* @addr: physical address of the block
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*/
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struct msc_block {
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struct msc_block_desc *bdesc;
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dma_addr_t addr;
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};
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/**
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* struct msc_window - multiblock mode window descriptor
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* @entry: window list linkage (msc::win_list)
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* @pgoff: page offset into the buffer that this window starts at
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* @nr_blocks: number of blocks (pages) in this window
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* @block: array of block descriptors
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*/
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struct msc_window {
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struct list_head entry;
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unsigned long pgoff;
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unsigned int nr_blocks;
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struct msc *msc;
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struct msc_block block[0];
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};
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/**
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* struct msc_iter - iterator for msc buffer
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* @entry: msc::iter_list linkage
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* @msc: pointer to the MSC device
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* @start_win: oldest window
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* @win: current window
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* @offset: current logical offset into the buffer
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* @start_block: oldest block in the window
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* @block: block number in the window
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* @block_off: offset into current block
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* @wrap_count: block wrapping handling
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* @eof: end of buffer reached
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*/
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struct msc_iter {
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struct list_head entry;
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struct msc *msc;
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struct msc_window *start_win;
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struct msc_window *win;
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unsigned long offset;
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int start_block;
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int block;
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unsigned int block_off;
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unsigned int wrap_count;
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unsigned int eof;
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};
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/**
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* struct msc - MSC device representation
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* @reg_base: register window base address
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* @thdev: intel_th_device pointer
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* @win_list: list of windows in multiblock mode
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* @nr_pages: total number of pages allocated for this buffer
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* @single_sz: amount of data in single mode
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* @single_wrap: single mode wrap occurred
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* @base: buffer's base pointer
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* @base_addr: buffer's base address
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* @user_count: number of users of the buffer
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* @mmap_count: number of mappings
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* @buf_mutex: mutex to serialize access to buffer-related bits
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* @enabled: MSC is enabled
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* @wrap: wrapping is enabled
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* @mode: MSC operating mode
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* @burst_len: write burst length
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* @index: number of this MSC in the MSU
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*/
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struct msc {
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void __iomem *reg_base;
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struct intel_th_device *thdev;
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struct list_head win_list;
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unsigned long nr_pages;
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unsigned long single_sz;
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unsigned int single_wrap : 1;
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void *base;
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dma_addr_t base_addr;
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/* <0: no buffer, 0: no users, >0: active users */
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atomic_t user_count;
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atomic_t mmap_count;
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struct mutex buf_mutex;
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struct list_head iter_list;
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/* config */
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unsigned int enabled : 1,
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wrap : 1;
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unsigned int mode;
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unsigned int burst_len;
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unsigned int index;
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};
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static inline bool msc_block_is_empty(struct msc_block_desc *bdesc)
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{
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/* header hasn't been written */
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if (!bdesc->valid_dw)
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return true;
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/* valid_dw includes the header */
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if (!msc_data_sz(bdesc))
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return true;
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return false;
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}
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/**
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* msc_oldest_window() - locate the window with oldest data
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* @msc: MSC device
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*
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* This should only be used in multiblock mode. Caller should hold the
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* msc::user_count reference.
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*
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* Return: the oldest window with valid data
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*/
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static struct msc_window *msc_oldest_window(struct msc *msc)
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{
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struct msc_window *win;
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u32 reg = ioread32(msc->reg_base + REG_MSU_MSC0NWSA);
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unsigned long win_addr = (unsigned long)reg << PAGE_SHIFT;
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unsigned int found = 0;
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if (list_empty(&msc->win_list))
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return NULL;
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/*
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* we might need a radix tree for this, depending on how
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* many windows a typical user would allocate; ideally it's
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* something like 2, in which case we're good
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*/
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list_for_each_entry(win, &msc->win_list, entry) {
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if (win->block[0].addr == win_addr)
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found++;
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/* skip the empty ones */
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if (msc_block_is_empty(win->block[0].bdesc))
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continue;
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if (found)
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return win;
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}
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return list_entry(msc->win_list.next, struct msc_window, entry);
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}
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/**
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* msc_win_oldest_block() - locate the oldest block in a given window
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* @win: window to look at
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*
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* Return: index of the block with the oldest data
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*/
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static unsigned int msc_win_oldest_block(struct msc_window *win)
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{
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unsigned int blk;
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struct msc_block_desc *bdesc = win->block[0].bdesc;
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/* without wrapping, first block is the oldest */
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if (!msc_block_wrapped(bdesc))
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return 0;
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/*
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* with wrapping, last written block contains both the newest and the
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* oldest data for this window.
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*/
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for (blk = 0; blk < win->nr_blocks; blk++) {
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bdesc = win->block[blk].bdesc;
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if (msc_block_last_written(bdesc))
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return blk;
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}
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return 0;
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}
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/**
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* msc_is_last_win() - check if a window is the last one for a given MSC
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* @win: window
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* Return: true if @win is the last window in MSC's multiblock buffer
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*/
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static inline bool msc_is_last_win(struct msc_window *win)
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{
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return win->entry.next == &win->msc->win_list;
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}
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/**
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* msc_next_window() - return next window in the multiblock buffer
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* @win: current window
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*
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* Return: window following the current one
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*/
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static struct msc_window *msc_next_window(struct msc_window *win)
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{
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if (msc_is_last_win(win))
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return list_entry(win->msc->win_list.next, struct msc_window,
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entry);
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return list_entry(win->entry.next, struct msc_window, entry);
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}
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static struct msc_block_desc *msc_iter_bdesc(struct msc_iter *iter)
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{
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return iter->win->block[iter->block].bdesc;
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}
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static void msc_iter_init(struct msc_iter *iter)
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{
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memset(iter, 0, sizeof(*iter));
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iter->start_block = -1;
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iter->block = -1;
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}
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static struct msc_iter *msc_iter_install(struct msc *msc)
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{
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struct msc_iter *iter;
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iter = kzalloc(sizeof(*iter), GFP_KERNEL);
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if (!iter)
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return ERR_PTR(-ENOMEM);
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mutex_lock(&msc->buf_mutex);
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/*
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* Reading and tracing are mutually exclusive; if msc is
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* enabled, open() will fail; otherwise existing readers
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* will prevent enabling the msc and the rest of fops don't
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* need to worry about it.
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*/
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if (msc->enabled) {
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kfree(iter);
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iter = ERR_PTR(-EBUSY);
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goto unlock;
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}
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msc_iter_init(iter);
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iter->msc = msc;
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list_add_tail(&iter->entry, &msc->iter_list);
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unlock:
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mutex_unlock(&msc->buf_mutex);
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return iter;
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}
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static void msc_iter_remove(struct msc_iter *iter, struct msc *msc)
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{
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mutex_lock(&msc->buf_mutex);
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list_del(&iter->entry);
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mutex_unlock(&msc->buf_mutex);
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kfree(iter);
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}
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static void msc_iter_block_start(struct msc_iter *iter)
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{
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if (iter->start_block != -1)
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return;
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iter->start_block = msc_win_oldest_block(iter->win);
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iter->block = iter->start_block;
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iter->wrap_count = 0;
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/*
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* start with the block with oldest data; if data has wrapped
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* in this window, it should be in this block
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*/
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if (msc_block_wrapped(msc_iter_bdesc(iter)))
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iter->wrap_count = 2;
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}
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static int msc_iter_win_start(struct msc_iter *iter, struct msc *msc)
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{
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/* already started, nothing to do */
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if (iter->start_win)
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return 0;
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iter->start_win = msc_oldest_window(msc);
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if (!iter->start_win)
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return -EINVAL;
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iter->win = iter->start_win;
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iter->start_block = -1;
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msc_iter_block_start(iter);
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return 0;
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}
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static int msc_iter_win_advance(struct msc_iter *iter)
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{
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iter->win = msc_next_window(iter->win);
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iter->start_block = -1;
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if (iter->win == iter->start_win) {
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iter->eof++;
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return 1;
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}
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msc_iter_block_start(iter);
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return 0;
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}
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static int msc_iter_block_advance(struct msc_iter *iter)
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{
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iter->block_off = 0;
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/* wrapping */
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if (iter->wrap_count && iter->block == iter->start_block) {
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iter->wrap_count--;
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if (!iter->wrap_count)
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/* copied newest data from the wrapped block */
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return msc_iter_win_advance(iter);
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}
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/* no wrapping, check for last written block */
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if (!iter->wrap_count && msc_block_last_written(msc_iter_bdesc(iter)))
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/* copied newest data for the window */
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return msc_iter_win_advance(iter);
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/* block advance */
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if (++iter->block == iter->win->nr_blocks)
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iter->block = 0;
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/* no wrapping, sanity check in case there is no last written block */
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if (!iter->wrap_count && iter->block == iter->start_block)
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return msc_iter_win_advance(iter);
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return 0;
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}
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/**
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* msc_buffer_iterate() - go through multiblock buffer's data
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* @iter: iterator structure
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* @size: amount of data to scan
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* @data: callback's private data
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* @fn: iterator callback
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*
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* This will start at the window which will be written to next (containing
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* the oldest data) and work its way to the current window, calling @fn
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* for each chunk of data as it goes.
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*
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* Caller should have msc::user_count reference to make sure the buffer
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* doesn't disappear from under us.
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*
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* Return: amount of data actually scanned.
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*/
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static ssize_t
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msc_buffer_iterate(struct msc_iter *iter, size_t size, void *data,
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unsigned long (*fn)(void *, void *, size_t))
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{
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struct msc *msc = iter->msc;
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size_t len = size;
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unsigned int advance;
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if (iter->eof)
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return 0;
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/* start with the oldest window */
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if (msc_iter_win_start(iter, msc))
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return 0;
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do {
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unsigned long data_bytes = msc_data_sz(msc_iter_bdesc(iter));
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void *src = (void *)msc_iter_bdesc(iter) + MSC_BDESC;
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size_t tocopy = data_bytes, copied = 0;
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size_t remaining = 0;
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advance = 1;
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/*
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* If block wrapping happened, we need to visit the last block
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* twice, because it contains both the oldest and the newest
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* data in this window.
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*
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* First time (wrap_count==2), in the very beginning, to collect
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* the oldest data, which is in the range
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* (data_bytes..DATA_IN_PAGE).
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*
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* Second time (wrap_count==1), it's just like any other block,
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* containing data in the range of [MSC_BDESC..data_bytes].
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*/
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if (iter->block == iter->start_block && iter->wrap_count == 2) {
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tocopy = DATA_IN_PAGE - data_bytes;
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src += data_bytes;
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}
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if (!tocopy)
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goto next_block;
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tocopy -= iter->block_off;
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src += iter->block_off;
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if (len < tocopy) {
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tocopy = len;
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advance = 0;
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}
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remaining = fn(data, src, tocopy);
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if (remaining)
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advance = 0;
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copied = tocopy - remaining;
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len -= copied;
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iter->block_off += copied;
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iter->offset += copied;
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if (!advance)
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break;
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next_block:
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if (msc_iter_block_advance(iter))
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break;
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} while (len);
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return size - len;
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}
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/**
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* msc_buffer_clear_hw_header() - clear hw header for multiblock
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* @msc: MSC device
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*/
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static void msc_buffer_clear_hw_header(struct msc *msc)
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{
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struct msc_window *win;
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list_for_each_entry(win, &msc->win_list, entry) {
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unsigned int blk;
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size_t hw_sz = sizeof(struct msc_block_desc) -
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offsetof(struct msc_block_desc, hw_tag);
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for (blk = 0; blk < win->nr_blocks; blk++) {
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struct msc_block_desc *bdesc = win->block[blk].bdesc;
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memset(&bdesc->hw_tag, 0, hw_sz);
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}
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}
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}
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|
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/**
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* msc_configure() - set up MSC hardware
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|
* @msc: the MSC device to configure
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|
*
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* Program storage mode, wrapping, burst length and trace buffer address
|
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* into a given MSC. Then, enable tracing and set msc::enabled.
|
|
* The latter is serialized on msc::buf_mutex, so make sure to hold it.
|
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*/
|
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static int msc_configure(struct msc *msc)
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{
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u32 reg;
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|
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lockdep_assert_held(&msc->buf_mutex);
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|
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if (msc->mode > MSC_MODE_MULTI)
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return -ENOTSUPP;
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|
|
if (msc->mode == MSC_MODE_MULTI)
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msc_buffer_clear_hw_header(msc);
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|
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reg = msc->base_addr >> PAGE_SHIFT;
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iowrite32(reg, msc->reg_base + REG_MSU_MSC0BAR);
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|
|
if (msc->mode == MSC_MODE_SINGLE) {
|
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reg = msc->nr_pages;
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iowrite32(reg, msc->reg_base + REG_MSU_MSC0SIZE);
|
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}
|
|
|
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reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL);
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reg &= ~(MSC_MODE | MSC_WRAPEN | MSC_EN | MSC_RD_HDR_OVRD);
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|
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reg |= MSC_EN;
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reg |= msc->mode << __ffs(MSC_MODE);
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reg |= msc->burst_len << __ffs(MSC_LEN);
|
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|
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if (msc->wrap)
|
|
reg |= MSC_WRAPEN;
|
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|
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iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL);
|
|
|
|
msc->thdev->output.multiblock = msc->mode == MSC_MODE_MULTI;
|
|
intel_th_trace_enable(msc->thdev);
|
|
msc->enabled = 1;
|
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|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* msc_disable() - disable MSC hardware
|
|
* @msc: MSC device to disable
|
|
*
|
|
* If @msc is enabled, disable tracing on the switch and then disable MSC
|
|
* storage. Caller must hold msc::buf_mutex.
|
|
*/
|
|
static void msc_disable(struct msc *msc)
|
|
{
|
|
unsigned long count;
|
|
u32 reg;
|
|
|
|
lockdep_assert_held(&msc->buf_mutex);
|
|
|
|
intel_th_trace_disable(msc->thdev);
|
|
|
|
for (reg = 0, count = MSC_PLE_WAITLOOP_DEPTH;
|
|
count && !(reg & MSCSTS_PLE); count--) {
|
|
reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
|
|
cpu_relax();
|
|
}
|
|
|
|
if (!count)
|
|
dev_dbg(msc_dev(msc), "timeout waiting for MSC0 PLE\n");
|
|
|
|
if (msc->mode == MSC_MODE_SINGLE) {
|
|
msc->single_wrap = !!(reg & MSCSTS_WRAPSTAT);
|
|
|
|
reg = ioread32(msc->reg_base + REG_MSU_MSC0MWP);
|
|
msc->single_sz = reg & ((msc->nr_pages << PAGE_SHIFT) - 1);
|
|
dev_dbg(msc_dev(msc), "MSCnMWP: %08x/%08lx, wrap: %d\n",
|
|
reg, msc->single_sz, msc->single_wrap);
|
|
}
|
|
|
|
reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL);
|
|
reg &= ~MSC_EN;
|
|
iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL);
|
|
msc->enabled = 0;
|
|
|
|
iowrite32(0, msc->reg_base + REG_MSU_MSC0BAR);
|
|
iowrite32(0, msc->reg_base + REG_MSU_MSC0SIZE);
|
|
|
|
dev_dbg(msc_dev(msc), "MSCnNWSA: %08x\n",
|
|
ioread32(msc->reg_base + REG_MSU_MSC0NWSA));
|
|
|
|
reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
|
|
dev_dbg(msc_dev(msc), "MSCnSTS: %08x\n", reg);
|
|
}
|
|
|
|
static int intel_th_msc_activate(struct intel_th_device *thdev)
|
|
{
|
|
struct msc *msc = dev_get_drvdata(&thdev->dev);
|
|
int ret = -EBUSY;
|
|
|
|
if (!atomic_inc_unless_negative(&msc->user_count))
|
|
return -ENODEV;
|
|
|
|
mutex_lock(&msc->buf_mutex);
|
|
|
|
/* if there are readers, refuse */
|
|
if (list_empty(&msc->iter_list))
|
|
ret = msc_configure(msc);
|
|
|
|
mutex_unlock(&msc->buf_mutex);
|
|
|
|
if (ret)
|
|
atomic_dec(&msc->user_count);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void intel_th_msc_deactivate(struct intel_th_device *thdev)
|
|
{
|
|
struct msc *msc = dev_get_drvdata(&thdev->dev);
|
|
|
|
mutex_lock(&msc->buf_mutex);
|
|
if (msc->enabled) {
|
|
msc_disable(msc);
|
|
atomic_dec(&msc->user_count);
|
|
}
|
|
mutex_unlock(&msc->buf_mutex);
|
|
}
|
|
|
|
/**
|
|
* msc_buffer_contig_alloc() - allocate a contiguous buffer for SINGLE mode
|
|
* @msc: MSC device
|
|
* @size: allocation size in bytes
|
|
*
|
|
* This modifies msc::base, which requires msc::buf_mutex to serialize, so the
|
|
* caller is expected to hold it.
|
|
*
|
|
* Return: 0 on success, -errno otherwise.
|
|
*/
|
|
static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size)
|
|
{
|
|
unsigned int order = get_order(size);
|
|
struct page *page;
|
|
|
|
if (!size)
|
|
return 0;
|
|
|
|
page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
|
|
split_page(page, order);
|
|
msc->nr_pages = size >> PAGE_SHIFT;
|
|
msc->base = page_address(page);
|
|
msc->base_addr = page_to_phys(page);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* msc_buffer_contig_free() - free a contiguous buffer
|
|
* @msc: MSC configured in SINGLE mode
|
|
*/
|
|
static void msc_buffer_contig_free(struct msc *msc)
|
|
{
|
|
unsigned long off;
|
|
|
|
for (off = 0; off < msc->nr_pages << PAGE_SHIFT; off += PAGE_SIZE) {
|
|
struct page *page = virt_to_page(msc->base + off);
|
|
|
|
page->mapping = NULL;
|
|
__free_page(page);
|
|
}
|
|
|
|
msc->nr_pages = 0;
|
|
}
|
|
|
|
/**
|
|
* msc_buffer_contig_get_page() - find a page at a given offset
|
|
* @msc: MSC configured in SINGLE mode
|
|
* @pgoff: page offset
|
|
*
|
|
* Return: page, if @pgoff is within the range, NULL otherwise.
|
|
*/
|
|
static struct page *msc_buffer_contig_get_page(struct msc *msc,
|
|
unsigned long pgoff)
|
|
{
|
|
if (pgoff >= msc->nr_pages)
|
|
return NULL;
|
|
|
|
return virt_to_page(msc->base + (pgoff << PAGE_SHIFT));
|
|
}
|
|
|
|
/**
|
|
* msc_buffer_win_alloc() - alloc a window for a multiblock mode
|
|
* @msc: MSC device
|
|
* @nr_blocks: number of pages in this window
|
|
*
|
|
* This modifies msc::win_list and msc::base, which requires msc::buf_mutex
|
|
* to serialize, so the caller is expected to hold it.
|
|
*
|
|
* Return: 0 on success, -errno otherwise.
|
|
*/
|
|
static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks)
|
|
{
|
|
struct msc_window *win;
|
|
unsigned long size = PAGE_SIZE;
|
|
int i, ret = -ENOMEM;
|
|
|
|
if (!nr_blocks)
|
|
return 0;
|
|
|
|
win = kzalloc(offsetof(struct msc_window, block[nr_blocks]),
|
|
GFP_KERNEL);
|
|
if (!win)
|
|
return -ENOMEM;
|
|
|
|
if (!list_empty(&msc->win_list)) {
|
|
struct msc_window *prev = list_entry(msc->win_list.prev,
|
|
struct msc_window, entry);
|
|
|
|
win->pgoff = prev->pgoff + prev->nr_blocks;
|
|
}
|
|
|
|
for (i = 0; i < nr_blocks; i++) {
|
|
win->block[i].bdesc =
|
|
dma_alloc_coherent(msc_dev(msc)->parent->parent, size,
|
|
&win->block[i].addr, GFP_KERNEL);
|
|
|
|
if (!win->block[i].bdesc)
|
|
goto err_nomem;
|
|
|
|
#ifdef CONFIG_X86
|
|
/* Set the page as uncached */
|
|
set_memory_uc((unsigned long)win->block[i].bdesc, 1);
|
|
#endif
|
|
}
|
|
|
|
win->msc = msc;
|
|
win->nr_blocks = nr_blocks;
|
|
|
|
if (list_empty(&msc->win_list)) {
|
|
msc->base = win->block[0].bdesc;
|
|
msc->base_addr = win->block[0].addr;
|
|
}
|
|
|
|
list_add_tail(&win->entry, &msc->win_list);
|
|
msc->nr_pages += nr_blocks;
|
|
|
|
return 0;
|
|
|
|
err_nomem:
|
|
for (i--; i >= 0; i--) {
|
|
#ifdef CONFIG_X86
|
|
/* Reset the page to write-back before releasing */
|
|
set_memory_wb((unsigned long)win->block[i].bdesc, 1);
|
|
#endif
|
|
dma_free_coherent(msc_dev(msc)->parent->parent, size,
|
|
win->block[i].bdesc, win->block[i].addr);
|
|
}
|
|
kfree(win);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* msc_buffer_win_free() - free a window from MSC's window list
|
|
* @msc: MSC device
|
|
* @win: window to free
|
|
*
|
|
* This modifies msc::win_list and msc::base, which requires msc::buf_mutex
|
|
* to serialize, so the caller is expected to hold it.
|
|
*/
|
|
static void msc_buffer_win_free(struct msc *msc, struct msc_window *win)
|
|
{
|
|
int i;
|
|
|
|
msc->nr_pages -= win->nr_blocks;
|
|
|
|
list_del(&win->entry);
|
|
if (list_empty(&msc->win_list)) {
|
|
msc->base = NULL;
|
|
msc->base_addr = 0;
|
|
}
|
|
|
|
for (i = 0; i < win->nr_blocks; i++) {
|
|
struct page *page = virt_to_page(win->block[i].bdesc);
|
|
|
|
page->mapping = NULL;
|
|
#ifdef CONFIG_X86
|
|
/* Reset the page to write-back before releasing */
|
|
set_memory_wb((unsigned long)win->block[i].bdesc, 1);
|
|
#endif
|
|
dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE,
|
|
win->block[i].bdesc, win->block[i].addr);
|
|
}
|
|
|
|
kfree(win);
|
|
}
|
|
|
|
/**
|
|
* msc_buffer_relink() - set up block descriptors for multiblock mode
|
|
* @msc: MSC device
|
|
*
|
|
* This traverses msc::win_list, which requires msc::buf_mutex to serialize,
|
|
* so the caller is expected to hold it.
|
|
*/
|
|
static void msc_buffer_relink(struct msc *msc)
|
|
{
|
|
struct msc_window *win, *next_win;
|
|
|
|
/* call with msc::mutex locked */
|
|
list_for_each_entry(win, &msc->win_list, entry) {
|
|
unsigned int blk;
|
|
u32 sw_tag = 0;
|
|
|
|
/*
|
|
* Last window's next_win should point to the first window
|
|
* and MSC_SW_TAG_LASTWIN should be set.
|
|
*/
|
|
if (msc_is_last_win(win)) {
|
|
sw_tag |= MSC_SW_TAG_LASTWIN;
|
|
next_win = list_entry(msc->win_list.next,
|
|
struct msc_window, entry);
|
|
} else {
|
|
next_win = list_entry(win->entry.next,
|
|
struct msc_window, entry);
|
|
}
|
|
|
|
for (blk = 0; blk < win->nr_blocks; blk++) {
|
|
struct msc_block_desc *bdesc = win->block[blk].bdesc;
|
|
|
|
memset(bdesc, 0, sizeof(*bdesc));
|
|
|
|
bdesc->next_win = next_win->block[0].addr >> PAGE_SHIFT;
|
|
|
|
/*
|
|
* Similarly to last window, last block should point
|
|
* to the first one.
|
|
*/
|
|
if (blk == win->nr_blocks - 1) {
|
|
sw_tag |= MSC_SW_TAG_LASTBLK;
|
|
bdesc->next_blk =
|
|
win->block[0].addr >> PAGE_SHIFT;
|
|
} else {
|
|
bdesc->next_blk =
|
|
win->block[blk + 1].addr >> PAGE_SHIFT;
|
|
}
|
|
|
|
bdesc->sw_tag = sw_tag;
|
|
bdesc->block_sz = PAGE_SIZE / 64;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Make the above writes globally visible before tracing is
|
|
* enabled to make sure hardware sees them coherently.
|
|
*/
|
|
wmb();
|
|
}
|
|
|
|
static void msc_buffer_multi_free(struct msc *msc)
|
|
{
|
|
struct msc_window *win, *iter;
|
|
|
|
list_for_each_entry_safe(win, iter, &msc->win_list, entry)
|
|
msc_buffer_win_free(msc, win);
|
|
}
|
|
|
|
static int msc_buffer_multi_alloc(struct msc *msc, unsigned long *nr_pages,
|
|
unsigned int nr_wins)
|
|
{
|
|
int ret, i;
|
|
|
|
for (i = 0; i < nr_wins; i++) {
|
|
ret = msc_buffer_win_alloc(msc, nr_pages[i]);
|
|
if (ret) {
|
|
msc_buffer_multi_free(msc);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
msc_buffer_relink(msc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* msc_buffer_free() - free buffers for MSC
|
|
* @msc: MSC device
|
|
*
|
|
* Free MSC's storage buffers.
|
|
*
|
|
* This modifies msc::win_list and msc::base, which requires msc::buf_mutex to
|
|
* serialize, so the caller is expected to hold it.
|
|
*/
|
|
static void msc_buffer_free(struct msc *msc)
|
|
{
|
|
if (msc->mode == MSC_MODE_SINGLE)
|
|
msc_buffer_contig_free(msc);
|
|
else if (msc->mode == MSC_MODE_MULTI)
|
|
msc_buffer_multi_free(msc);
|
|
}
|
|
|
|
/**
|
|
* msc_buffer_alloc() - allocate a buffer for MSC
|
|
* @msc: MSC device
|
|
* @size: allocation size in bytes
|
|
*
|
|
* Allocate a storage buffer for MSC, depending on the msc::mode, it will be
|
|
* either done via msc_buffer_contig_alloc() for SINGLE operation mode or
|
|
* msc_buffer_win_alloc() for multiblock operation. The latter allocates one
|
|
* window per invocation, so in multiblock mode this can be called multiple
|
|
* times for the same MSC to allocate multiple windows.
|
|
*
|
|
* This modifies msc::win_list and msc::base, which requires msc::buf_mutex
|
|
* to serialize, so the caller is expected to hold it.
|
|
*
|
|
* Return: 0 on success, -errno otherwise.
|
|
*/
|
|
static int msc_buffer_alloc(struct msc *msc, unsigned long *nr_pages,
|
|
unsigned int nr_wins)
|
|
{
|
|
int ret;
|
|
|
|
/* -1: buffer not allocated */
|
|
if (atomic_read(&msc->user_count) != -1)
|
|
return -EBUSY;
|
|
|
|
if (msc->mode == MSC_MODE_SINGLE) {
|
|
if (nr_wins != 1)
|
|
return -EINVAL;
|
|
|
|
ret = msc_buffer_contig_alloc(msc, nr_pages[0] << PAGE_SHIFT);
|
|
} else if (msc->mode == MSC_MODE_MULTI) {
|
|
ret = msc_buffer_multi_alloc(msc, nr_pages, nr_wins);
|
|
} else {
|
|
ret = -ENOTSUPP;
|
|
}
|
|
|
|
if (!ret) {
|
|
/* allocation should be visible before the counter goes to 0 */
|
|
smp_mb__before_atomic();
|
|
|
|
if (WARN_ON_ONCE(atomic_cmpxchg(&msc->user_count, -1, 0) != -1))
|
|
return -EINVAL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* msc_buffer_unlocked_free_unless_used() - free a buffer unless it's in use
|
|
* @msc: MSC device
|
|
*
|
|
* This will free MSC buffer unless it is in use or there is no allocated
|
|
* buffer.
|
|
* Caller needs to hold msc::buf_mutex.
|
|
*
|
|
* Return: 0 on successful deallocation or if there was no buffer to
|
|
* deallocate, -EBUSY if there are active users.
|
|
*/
|
|
static int msc_buffer_unlocked_free_unless_used(struct msc *msc)
|
|
{
|
|
int count, ret = 0;
|
|
|
|
count = atomic_cmpxchg(&msc->user_count, 0, -1);
|
|
|
|
/* > 0: buffer is allocated and has users */
|
|
if (count > 0)
|
|
ret = -EBUSY;
|
|
/* 0: buffer is allocated, no users */
|
|
else if (!count)
|
|
msc_buffer_free(msc);
|
|
/* < 0: no buffer, nothing to do */
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* msc_buffer_free_unless_used() - free a buffer unless it's in use
|
|
* @msc: MSC device
|
|
*
|
|
* This is a locked version of msc_buffer_unlocked_free_unless_used().
|
|
*/
|
|
static int msc_buffer_free_unless_used(struct msc *msc)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&msc->buf_mutex);
|
|
ret = msc_buffer_unlocked_free_unless_used(msc);
|
|
mutex_unlock(&msc->buf_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* msc_buffer_get_page() - get MSC buffer page at a given offset
|
|
* @msc: MSC device
|
|
* @pgoff: page offset into the storage buffer
|
|
*
|
|
* This traverses msc::win_list, so holding msc::buf_mutex is expected from
|
|
* the caller.
|
|
*
|
|
* Return: page if @pgoff corresponds to a valid buffer page or NULL.
|
|
*/
|
|
static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff)
|
|
{
|
|
struct msc_window *win;
|
|
|
|
if (msc->mode == MSC_MODE_SINGLE)
|
|
return msc_buffer_contig_get_page(msc, pgoff);
|
|
|
|
list_for_each_entry(win, &msc->win_list, entry)
|
|
if (pgoff >= win->pgoff && pgoff < win->pgoff + win->nr_blocks)
|
|
goto found;
|
|
|
|
return NULL;
|
|
|
|
found:
|
|
pgoff -= win->pgoff;
|
|
return virt_to_page(win->block[pgoff].bdesc);
|
|
}
|
|
|
|
/**
|
|
* struct msc_win_to_user_struct - data for copy_to_user() callback
|
|
* @buf: userspace buffer to copy data to
|
|
* @offset: running offset
|
|
*/
|
|
struct msc_win_to_user_struct {
|
|
char __user *buf;
|
|
unsigned long offset;
|
|
};
|
|
|
|
/**
|
|
* msc_win_to_user() - iterator for msc_buffer_iterate() to copy data to user
|
|
* @data: callback's private data
|
|
* @src: source buffer
|
|
* @len: amount of data to copy from the source buffer
|
|
*/
|
|
static unsigned long msc_win_to_user(void *data, void *src, size_t len)
|
|
{
|
|
struct msc_win_to_user_struct *u = data;
|
|
unsigned long ret;
|
|
|
|
ret = copy_to_user(u->buf + u->offset, src, len);
|
|
u->offset += len - ret;
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
/*
|
|
* file operations' callbacks
|
|
*/
|
|
|
|
static int intel_th_msc_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct intel_th_device *thdev = file->private_data;
|
|
struct msc *msc = dev_get_drvdata(&thdev->dev);
|
|
struct msc_iter *iter;
|
|
|
|
if (!capable(CAP_SYS_RAWIO))
|
|
return -EPERM;
|
|
|
|
iter = msc_iter_install(msc);
|
|
if (IS_ERR(iter))
|
|
return PTR_ERR(iter);
|
|
|
|
file->private_data = iter;
|
|
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
static int intel_th_msc_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct msc_iter *iter = file->private_data;
|
|
struct msc *msc = iter->msc;
|
|
|
|
msc_iter_remove(iter, msc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t
|
|
msc_single_to_user(struct msc *msc, char __user *buf, loff_t off, size_t len)
|
|
{
|
|
unsigned long size = msc->nr_pages << PAGE_SHIFT, rem = len;
|
|
unsigned long start = off, tocopy = 0;
|
|
|
|
if (msc->single_wrap) {
|
|
start += msc->single_sz;
|
|
if (start < size) {
|
|
tocopy = min(rem, size - start);
|
|
if (copy_to_user(buf, msc->base + start, tocopy))
|
|
return -EFAULT;
|
|
|
|
buf += tocopy;
|
|
rem -= tocopy;
|
|
start += tocopy;
|
|
}
|
|
|
|
start &= size - 1;
|
|
if (rem) {
|
|
tocopy = min(rem, msc->single_sz - start);
|
|
if (copy_to_user(buf, msc->base + start, tocopy))
|
|
return -EFAULT;
|
|
|
|
rem -= tocopy;
|
|
}
|
|
|
|
return len - rem;
|
|
}
|
|
|
|
if (copy_to_user(buf, msc->base + start, rem))
|
|
return -EFAULT;
|
|
|
|
return len;
|
|
}
|
|
|
|
static ssize_t intel_th_msc_read(struct file *file, char __user *buf,
|
|
size_t len, loff_t *ppos)
|
|
{
|
|
struct msc_iter *iter = file->private_data;
|
|
struct msc *msc = iter->msc;
|
|
size_t size;
|
|
loff_t off = *ppos;
|
|
ssize_t ret = 0;
|
|
|
|
if (!atomic_inc_unless_negative(&msc->user_count))
|
|
return 0;
|
|
|
|
if (msc->mode == MSC_MODE_SINGLE && !msc->single_wrap)
|
|
size = msc->single_sz;
|
|
else
|
|
size = msc->nr_pages << PAGE_SHIFT;
|
|
|
|
if (!size)
|
|
goto put_count;
|
|
|
|
if (off >= size)
|
|
goto put_count;
|
|
|
|
if (off + len >= size)
|
|
len = size - off;
|
|
|
|
if (msc->mode == MSC_MODE_SINGLE) {
|
|
ret = msc_single_to_user(msc, buf, off, len);
|
|
if (ret >= 0)
|
|
*ppos += ret;
|
|
} else if (msc->mode == MSC_MODE_MULTI) {
|
|
struct msc_win_to_user_struct u = {
|
|
.buf = buf,
|
|
.offset = 0,
|
|
};
|
|
|
|
ret = msc_buffer_iterate(iter, len, &u, msc_win_to_user);
|
|
if (ret >= 0)
|
|
*ppos = iter->offset;
|
|
} else {
|
|
ret = -ENOTSUPP;
|
|
}
|
|
|
|
put_count:
|
|
atomic_dec(&msc->user_count);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* vm operations callbacks (vm_ops)
|
|
*/
|
|
|
|
static void msc_mmap_open(struct vm_area_struct *vma)
|
|
{
|
|
struct msc_iter *iter = vma->vm_file->private_data;
|
|
struct msc *msc = iter->msc;
|
|
|
|
atomic_inc(&msc->mmap_count);
|
|
}
|
|
|
|
static void msc_mmap_close(struct vm_area_struct *vma)
|
|
{
|
|
struct msc_iter *iter = vma->vm_file->private_data;
|
|
struct msc *msc = iter->msc;
|
|
unsigned long pg;
|
|
|
|
if (!atomic_dec_and_mutex_lock(&msc->mmap_count, &msc->buf_mutex))
|
|
return;
|
|
|
|
/* drop page _refcounts */
|
|
for (pg = 0; pg < msc->nr_pages; pg++) {
|
|
struct page *page = msc_buffer_get_page(msc, pg);
|
|
|
|
if (WARN_ON_ONCE(!page))
|
|
continue;
|
|
|
|
if (page->mapping)
|
|
page->mapping = NULL;
|
|
}
|
|
|
|
/* last mapping -- drop user_count */
|
|
atomic_dec(&msc->user_count);
|
|
mutex_unlock(&msc->buf_mutex);
|
|
}
|
|
|
|
static vm_fault_t msc_mmap_fault(struct vm_fault *vmf)
|
|
{
|
|
struct msc_iter *iter = vmf->vma->vm_file->private_data;
|
|
struct msc *msc = iter->msc;
|
|
|
|
vmf->page = msc_buffer_get_page(msc, vmf->pgoff);
|
|
if (!vmf->page)
|
|
return VM_FAULT_SIGBUS;
|
|
|
|
get_page(vmf->page);
|
|
vmf->page->mapping = vmf->vma->vm_file->f_mapping;
|
|
vmf->page->index = vmf->pgoff;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct vm_operations_struct msc_mmap_ops = {
|
|
.open = msc_mmap_open,
|
|
.close = msc_mmap_close,
|
|
.fault = msc_mmap_fault,
|
|
};
|
|
|
|
static int intel_th_msc_mmap(struct file *file, struct vm_area_struct *vma)
|
|
{
|
|
unsigned long size = vma->vm_end - vma->vm_start;
|
|
struct msc_iter *iter = vma->vm_file->private_data;
|
|
struct msc *msc = iter->msc;
|
|
int ret = -EINVAL;
|
|
|
|
if (!size || offset_in_page(size))
|
|
return -EINVAL;
|
|
|
|
if (vma->vm_pgoff)
|
|
return -EINVAL;
|
|
|
|
/* grab user_count once per mmap; drop in msc_mmap_close() */
|
|
if (!atomic_inc_unless_negative(&msc->user_count))
|
|
return -EINVAL;
|
|
|
|
if (msc->mode != MSC_MODE_SINGLE &&
|
|
msc->mode != MSC_MODE_MULTI)
|
|
goto out;
|
|
|
|
if (size >> PAGE_SHIFT != msc->nr_pages)
|
|
goto out;
|
|
|
|
atomic_set(&msc->mmap_count, 1);
|
|
ret = 0;
|
|
|
|
out:
|
|
if (ret)
|
|
atomic_dec(&msc->user_count);
|
|
|
|
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
|
|
vma->vm_flags |= VM_DONTEXPAND | VM_DONTCOPY;
|
|
vma->vm_ops = &msc_mmap_ops;
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations intel_th_msc_fops = {
|
|
.open = intel_th_msc_open,
|
|
.release = intel_th_msc_release,
|
|
.read = intel_th_msc_read,
|
|
.mmap = intel_th_msc_mmap,
|
|
.llseek = no_llseek,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int intel_th_msc_init(struct msc *msc)
|
|
{
|
|
atomic_set(&msc->user_count, -1);
|
|
|
|
msc->mode = MSC_MODE_MULTI;
|
|
mutex_init(&msc->buf_mutex);
|
|
INIT_LIST_HEAD(&msc->win_list);
|
|
INIT_LIST_HEAD(&msc->iter_list);
|
|
|
|
msc->burst_len =
|
|
(ioread32(msc->reg_base + REG_MSU_MSC0CTL) & MSC_LEN) >>
|
|
__ffs(MSC_LEN);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const char * const msc_mode[] = {
|
|
[MSC_MODE_SINGLE] = "single",
|
|
[MSC_MODE_MULTI] = "multi",
|
|
[MSC_MODE_EXI] = "ExI",
|
|
[MSC_MODE_DEBUG] = "debug",
|
|
};
|
|
|
|
static ssize_t
|
|
wrap_show(struct device *dev, struct device_attribute *attr, char *buf)
|
|
{
|
|
struct msc *msc = dev_get_drvdata(dev);
|
|
|
|
return scnprintf(buf, PAGE_SIZE, "%d\n", msc->wrap);
|
|
}
|
|
|
|
static ssize_t
|
|
wrap_store(struct device *dev, struct device_attribute *attr, const char *buf,
|
|
size_t size)
|
|
{
|
|
struct msc *msc = dev_get_drvdata(dev);
|
|
unsigned long val;
|
|
int ret;
|
|
|
|
ret = kstrtoul(buf, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
|
|
msc->wrap = !!val;
|
|
|
|
return size;
|
|
}
|
|
|
|
static DEVICE_ATTR_RW(wrap);
|
|
|
|
static ssize_t
|
|
mode_show(struct device *dev, struct device_attribute *attr, char *buf)
|
|
{
|
|
struct msc *msc = dev_get_drvdata(dev);
|
|
|
|
return scnprintf(buf, PAGE_SIZE, "%s\n", msc_mode[msc->mode]);
|
|
}
|
|
|
|
static ssize_t
|
|
mode_store(struct device *dev, struct device_attribute *attr, const char *buf,
|
|
size_t size)
|
|
{
|
|
struct msc *msc = dev_get_drvdata(dev);
|
|
size_t len = size;
|
|
char *cp;
|
|
int i, ret;
|
|
|
|
if (!capable(CAP_SYS_RAWIO))
|
|
return -EPERM;
|
|
|
|
cp = memchr(buf, '\n', len);
|
|
if (cp)
|
|
len = cp - buf;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(msc_mode); i++)
|
|
if (!strncmp(msc_mode[i], buf, len))
|
|
goto found;
|
|
|
|
return -EINVAL;
|
|
|
|
found:
|
|
mutex_lock(&msc->buf_mutex);
|
|
ret = msc_buffer_unlocked_free_unless_used(msc);
|
|
if (!ret)
|
|
msc->mode = i;
|
|
mutex_unlock(&msc->buf_mutex);
|
|
|
|
return ret ? ret : size;
|
|
}
|
|
|
|
static DEVICE_ATTR_RW(mode);
|
|
|
|
static ssize_t
|
|
nr_pages_show(struct device *dev, struct device_attribute *attr, char *buf)
|
|
{
|
|
struct msc *msc = dev_get_drvdata(dev);
|
|
struct msc_window *win;
|
|
size_t count = 0;
|
|
|
|
mutex_lock(&msc->buf_mutex);
|
|
|
|
if (msc->mode == MSC_MODE_SINGLE)
|
|
count = scnprintf(buf, PAGE_SIZE, "%ld\n", msc->nr_pages);
|
|
else if (msc->mode == MSC_MODE_MULTI) {
|
|
list_for_each_entry(win, &msc->win_list, entry) {
|
|
count += scnprintf(buf + count, PAGE_SIZE - count,
|
|
"%d%c", win->nr_blocks,
|
|
msc_is_last_win(win) ? '\n' : ',');
|
|
}
|
|
} else {
|
|
count = scnprintf(buf, PAGE_SIZE, "unsupported\n");
|
|
}
|
|
|
|
mutex_unlock(&msc->buf_mutex);
|
|
|
|
return count;
|
|
}
|
|
|
|
static ssize_t
|
|
nr_pages_store(struct device *dev, struct device_attribute *attr,
|
|
const char *buf, size_t size)
|
|
{
|
|
struct msc *msc = dev_get_drvdata(dev);
|
|
unsigned long val, *win = NULL, *rewin;
|
|
size_t len = size;
|
|
const char *p = buf;
|
|
char *end, *s;
|
|
int ret, nr_wins = 0;
|
|
|
|
if (!capable(CAP_SYS_RAWIO))
|
|
return -EPERM;
|
|
|
|
ret = msc_buffer_free_unless_used(msc);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* scan the comma-separated list of allocation sizes */
|
|
end = memchr(buf, '\n', len);
|
|
if (end)
|
|
len = end - buf;
|
|
|
|
do {
|
|
end = memchr(p, ',', len);
|
|
s = kstrndup(p, end ? end - p : len, GFP_KERNEL);
|
|
if (!s) {
|
|
ret = -ENOMEM;
|
|
goto free_win;
|
|
}
|
|
|
|
ret = kstrtoul(s, 10, &val);
|
|
kfree(s);
|
|
|
|
if (ret || !val)
|
|
goto free_win;
|
|
|
|
if (nr_wins && msc->mode == MSC_MODE_SINGLE) {
|
|
ret = -EINVAL;
|
|
goto free_win;
|
|
}
|
|
|
|
nr_wins++;
|
|
rewin = krealloc(win, sizeof(*win) * nr_wins, GFP_KERNEL);
|
|
if (!rewin) {
|
|
kfree(win);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
win = rewin;
|
|
win[nr_wins - 1] = val;
|
|
|
|
if (!end)
|
|
break;
|
|
|
|
/* consume the number and the following comma, hence +1 */
|
|
len -= end - p + 1;
|
|
p = end + 1;
|
|
} while (len);
|
|
|
|
mutex_lock(&msc->buf_mutex);
|
|
ret = msc_buffer_alloc(msc, win, nr_wins);
|
|
mutex_unlock(&msc->buf_mutex);
|
|
|
|
free_win:
|
|
kfree(win);
|
|
|
|
return ret ? ret : size;
|
|
}
|
|
|
|
static DEVICE_ATTR_RW(nr_pages);
|
|
|
|
static struct attribute *msc_output_attrs[] = {
|
|
&dev_attr_wrap.attr,
|
|
&dev_attr_mode.attr,
|
|
&dev_attr_nr_pages.attr,
|
|
NULL,
|
|
};
|
|
|
|
static struct attribute_group msc_output_group = {
|
|
.attrs = msc_output_attrs,
|
|
};
|
|
|
|
static int intel_th_msc_probe(struct intel_th_device *thdev)
|
|
{
|
|
struct device *dev = &thdev->dev;
|
|
struct resource *res;
|
|
struct msc *msc;
|
|
void __iomem *base;
|
|
int err;
|
|
|
|
res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 0);
|
|
if (!res)
|
|
return -ENODEV;
|
|
|
|
base = devm_ioremap(dev, res->start, resource_size(res));
|
|
if (!base)
|
|
return -ENOMEM;
|
|
|
|
msc = devm_kzalloc(dev, sizeof(*msc), GFP_KERNEL);
|
|
if (!msc)
|
|
return -ENOMEM;
|
|
|
|
msc->index = thdev->id;
|
|
|
|
msc->thdev = thdev;
|
|
msc->reg_base = base + msc->index * 0x100;
|
|
|
|
err = intel_th_msc_init(msc);
|
|
if (err)
|
|
return err;
|
|
|
|
dev_set_drvdata(dev, msc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void intel_th_msc_remove(struct intel_th_device *thdev)
|
|
{
|
|
struct msc *msc = dev_get_drvdata(&thdev->dev);
|
|
int ret;
|
|
|
|
intel_th_msc_deactivate(thdev);
|
|
|
|
/*
|
|
* Buffers should not be used at this point except if the
|
|
* output character device is still open and the parent
|
|
* device gets detached from its bus, which is a FIXME.
|
|
*/
|
|
ret = msc_buffer_free_unless_used(msc);
|
|
WARN_ON_ONCE(ret);
|
|
}
|
|
|
|
static struct intel_th_driver intel_th_msc_driver = {
|
|
.probe = intel_th_msc_probe,
|
|
.remove = intel_th_msc_remove,
|
|
.activate = intel_th_msc_activate,
|
|
.deactivate = intel_th_msc_deactivate,
|
|
.fops = &intel_th_msc_fops,
|
|
.attr_group = &msc_output_group,
|
|
.driver = {
|
|
.name = "msc",
|
|
.owner = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
module_driver(intel_th_msc_driver,
|
|
intel_th_driver_register,
|
|
intel_th_driver_unregister);
|
|
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_DESCRIPTION("Intel(R) Trace Hub Memory Storage Unit driver");
|
|
MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");
|