// SPDX-License-Identifier: GPL-2.0
/*
* Intel(R) Trace Hub Memory Storage Unit
*
* Copyright (C) 2014-2015 Intel Corporation.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/types.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/uaccess.h>
#include <linux/sizes.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/workqueue.h>
#include <linux/dma-mapping.h>
#ifdef CONFIG_X86
#include <asm/set_memory.h>
#endif
#include <linux/intel_th.h>
#include "intel_th.h"
#include "msu.h"
#define msc_dev(x) (&(x)->thdev->dev)
/*
* Lockout state transitions:
* READY -> INUSE -+-> LOCKED -+-> READY -> etc.
* \-----------/
* WIN_READY: window can be used by HW
* WIN_INUSE: window is in use
* WIN_LOCKED: window is filled up and is being processed by the buffer
* handling code
*
* All state transitions happen automatically, except for the LOCKED->READY,
* which needs to be signalled by the buffer code by calling
* intel_th_msc_window_unlock().
*
* When the interrupt handler has to switch to the next window, it checks
* whether it's READY, and if it is, it performs the switch and tracing
* continues. If it's LOCKED, it stops the trace.
*/
enum lockout_state {
WIN_READY = 0,
WIN_INUSE,
WIN_LOCKED
};
/**
* struct msc_window - multiblock mode window descriptor
* @entry: window list linkage (msc::win_list)
* @pgoff: page offset into the buffer that this window starts at
* @lockout: lockout state, see comment below
* @lo_lock: lockout state serialization
* @nr_blocks: number of blocks (pages) in this window
* @nr_segs: number of segments in this window (<= @nr_blocks)
* @msc: pointer to the MSC device
* @_sgt: array of block descriptors
* @sgt: array of block descriptors
*/
struct msc_window {
struct list_head entry;
unsigned long pgoff;
enum lockout_state lockout;
spinlock_t lo_lock;
unsigned int nr_blocks;
unsigned int nr_segs;
struct msc *msc;
struct sg_table _sgt;
struct sg_table *sgt;
};
/**
* struct msc_iter - iterator for msc buffer
* @entry: msc::iter_list linkage
* @msc: pointer to the MSC device
* @start_win: oldest window
* @win: current window
* @offset: current logical offset into the buffer
* @start_block: oldest block in the window
* @block: block number in the window
* @block_off: offset into current block
* @wrap_count: block wrapping handling
* @eof: end of buffer reached
*/
struct msc_iter {
struct list_head entry;
struct msc *msc;
struct msc_window *start_win;
struct msc_window *win;
unsigned long offset;
struct scatterlist *start_block;
struct scatterlist *block;
unsigned int block_off;
unsigned int wrap_count;
unsigned int eof;
};
/**
* struct msc - MSC device representation
* @reg_base: register window base address
* @thdev: intel_th_device pointer
* @mbuf: MSU buffer, if assigned
* @mbuf_priv MSU buffer's private data, if @mbuf
* @win_list: list of windows in multiblock mode
* @single_sgt: single mode buffer
* @cur_win: current window
* @nr_pages: total number of pages allocated for this buffer
* @single_sz: amount of data in single mode
* @single_wrap: single mode wrap occurred
* @base: buffer's base pointer
* @base_addr: buffer's base address
* @user_count: number of users of the buffer
* @mmap_count: number of mappings
* @buf_mutex: mutex to serialize access to buffer-related bits
* @enabled: MSC is enabled
* @wrap: wrapping is enabled
* @mode: MSC operating mode
* @burst_len: write burst length
* @index: number of this MSC in the MSU
*/
struct msc {
void __iomem *reg_base;
void __iomem *msu_base;
struct intel_th_device *thdev;
const struct msu_buffer *mbuf;
void *mbuf_priv;
struct work_struct work;
struct list_head win_list;
struct sg_table single_sgt;
struct msc_window *cur_win;
struct msc_window *switch_on_unlock;
unsigned long nr_pages;
unsigned long single_sz;
unsigned int single_wrap : 1;
void *base;
dma_addr_t base_addr;
u32 orig_addr;
u32 orig_sz;
/* <0: no buffer, 0: no users, >0: active users */
atomic_t user_count;
atomic_t mmap_count;
struct mutex buf_mutex;
struct list_head iter_list;
bool stop_on_full;
/* config */
unsigned int enabled : 1,
wrap : 1,
do_irq : 1,
multi_is_broken : 1;
unsigned int mode;
unsigned int burst_len;
unsigned int index;
};
static LIST_HEAD(msu_buffer_list);
static DEFINE_MUTEX(msu_buffer_mutex);
/**
* struct msu_buffer_entry - internal MSU buffer bookkeeping
* @entry: link to msu_buffer_list
* @mbuf: MSU buffer object
* @owner: module that provides this MSU buffer
*/
struct msu_buffer_entry {
struct list_head entry;
const struct msu_buffer *mbuf;
struct module *owner;
};
static struct msu_buffer_entry *__msu_buffer_entry_find(const char *name)
{
struct msu_buffer_entry *mbe;
lockdep_assert_held(&msu_buffer_mutex);
list_for_each_entry(mbe, &msu_buffer_list, entry) {
if (!strcmp(mbe->mbuf->name, name))
return mbe;
}
return NULL;
}
static const struct msu_buffer *
msu_buffer_get(const char *name)
{
struct msu_buffer_entry *mbe;
mutex_lock(&msu_buffer_mutex);
mbe = __msu_buffer_entry_find(name);
if (mbe && !try_module_get(mbe->owner))
mbe = NULL;
mutex_unlock(&msu_buffer_mutex);
return mbe ? mbe->mbuf : NULL;
}
static void msu_buffer_put(const struct msu_buffer *mbuf)
{
struct msu_buffer_entry *mbe;
mutex_lock(&msu_buffer_mutex);
mbe = __msu_buffer_entry_find(mbuf->name);
if (mbe)
module_put(mbe->owner);
mutex_unlock(&msu_buffer_mutex);
}
int intel_th_msu_buffer_register(const struct msu_buffer *mbuf,
struct module *owner)
{
struct msu_buffer_entry *mbe;
int ret = 0;
mbe = kzalloc(sizeof(*mbe), GFP_KERNEL);
if (!mbe)
return -ENOMEM;
mutex_lock(&msu_buffer_mutex);
if (__msu_buffer_entry_find(mbuf->name)) {
ret = -EEXIST;
kfree(mbe);
goto unlock;
}
mbe->mbuf = mbuf;
mbe->owner = owner;
list_add_tail(&mbe->entry, &msu_buffer_list);
unlock:
mutex_unlock(&msu_buffer_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(intel_th_msu_buffer_register);
void intel_th_msu_buffer_unregister(const struct msu_buffer *mbuf)
{
struct msu_buffer_entry *mbe;
mutex_lock(&msu_buffer_mutex);
mbe = __msu_buffer_entry_find(mbuf->name);
if (mbe) {
list_del(&mbe->entry);
kfree(mbe);
}
mutex_unlock(&msu_buffer_mutex);
}
EXPORT_SYMBOL_GPL(intel_th_msu_buffer_unregister);
static inline bool msc_block_is_empty(struct msc_block_desc *bdesc)
{
/* header hasn't been written */
if (!bdesc->valid_dw)
return true;
/* valid_dw includes the header */
if (!msc_data_sz(bdesc))
return true;
return false;
}
static inline struct scatterlist *msc_win_base_sg(struct msc_window *win)
{
return win->sgt->sgl;
}
static inline struct msc_block_desc *msc_win_base(struct msc_window *win)
{
return sg_virt(msc_win_base_sg(win));
}
static inline dma_addr_t msc_win_base_dma(struct msc_window *win)
{
return sg_dma_address(msc_win_base_sg(win));
}
static inline unsigned long
msc_win_base_pfn(struct msc_window *win)
{
return PFN_DOWN(msc_win_base_dma(win));
}
/**
* msc_is_last_win() - check if a window is the last one for a given MSC
* @win: window
* Return: true if @win is the last window in MSC's multiblock buffer
*/
static inline bool msc_is_last_win(struct msc_window *win)
{
return win->entry.next == &win->msc->win_list;
}
/**
* msc_next_window() - return next window in the multiblock buffer
* @win: current window
*
* Return: window following the current one
*/
static struct msc_window *msc_next_window(struct msc_window *win)
{
if (msc_is_last_win(win))
return list_first_entry(&win->msc->win_list, struct msc_window,
entry);
return list_next_entry(win, entry);
}
static size_t msc_win_total_sz(struct msc_window *win)
{
struct scatterlist *sg;
unsigned int blk;
size_t size = 0;
for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
struct msc_block_desc *bdesc = sg_virt(sg);
if (msc_block_wrapped(bdesc))
return (size_t)win->nr_blocks << PAGE_SHIFT;
size += msc_total_sz(bdesc);
if (msc_block_last_written(bdesc))
break;
}
return size;
}
/**
* msc_find_window() - find a window matching a given sg_table
* @msc: MSC device
* @sgt: SG table of the window
* @nonempty: skip over empty windows
*
* Return: MSC window structure pointer or NULL if the window
* could not be found.
*/
static struct msc_window *
msc_find_window(struct msc *msc, struct sg_table *sgt, bool nonempty)
{
struct msc_window *win;
unsigned int found = 0;
if (list_empty(&msc->win_list))
return NULL;
/*
* we might need a radix tree for this, depending on how
* many windows a typical user would allocate; ideally it's
* something like 2, in which case we're good
*/
list_for_each_entry(win, &msc->win_list, entry) {
if (win->sgt == sgt)
found++;
/* skip the empty ones */
if (nonempty && msc_block_is_empty(msc_win_base(win)))
continue;
if (found)
return win;
}
return NULL;
}
/**
* msc_oldest_window() - locate the window with oldest data
* @msc: MSC device
*
* This should only be used in multiblock mode. Caller should hold the
* msc::user_count reference.
*
* Return: the oldest window with valid data
*/
static struct msc_window *msc_oldest_window(struct msc *msc)
{
struct msc_window *win;
if (list_empty(&msc->win_list))
return NULL;
win = msc_find_window(msc, msc_next_window(msc->cur_win)->sgt, true);
if (win)
return win;
return list_first_entry(&msc->win_list, struct msc_window, entry);
}
/**
* msc_win_oldest_sg() - locate the oldest block in a given window
* @win: window to look at
*
* Return: index of the block with the oldest data
*/
static struct scatterlist *msc_win_oldest_sg(struct msc_window *win)
{
unsigned int blk;
struct scatterlist *sg;
struct msc_block_desc *bdesc = msc_win_base(win);
/* without wrapping, first block is the oldest */
if (!msc_block_wrapped(bdesc))
return msc_win_base_sg(win);
/*
* with wrapping, last written block contains both the newest and the
* oldest data for this window.
*/
for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
struct msc_block_desc *bdesc = sg_virt(sg);
if (msc_block_last_written(bdesc))
return sg;
}
return msc_win_base_sg(win);
}
static struct msc_block_desc *msc_iter_bdesc(struct msc_iter *iter)
{
return sg_virt(iter->block);
}
static struct msc_iter *msc_iter_install(struct msc *msc)
{
struct msc_iter *iter;
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
if (!iter)
return ERR_PTR(-ENOMEM);
mutex_lock(&msc->buf_mutex);
/*
* Reading and tracing are mutually exclusive; if msc is
* enabled, open() will fail; otherwise existing readers
* will prevent enabling the msc and the rest of fops don't
* need to worry about it.
*/
if (msc->enabled) {
kfree(iter);
iter = ERR_PTR(-EBUSY);
goto unlock;
}
iter->msc = msc;
list_add_tail(&iter->entry, &msc->iter_list);
unlock:
mutex_unlock(&msc->buf_mutex);
return iter;
}
static void msc_iter_remove(struct msc_iter *iter, struct msc *msc)
{
mutex_lock(&msc->buf_mutex);
list_del(&iter->entry);
mutex_unlock(&msc->buf_mutex);
kfree(iter);
}
static void msc_iter_block_start(struct msc_iter *iter)
{
if (iter->start_block)
return;
iter->start_block = msc_win_oldest_sg(iter->win);
iter->block = iter->start_block;
iter->wrap_count = 0;
/*
* start with the block with oldest data; if data has wrapped
* in this window, it should be in this block
*/
if (msc_block_wrapped(msc_iter_bdesc(iter)))
iter->wrap_count = 2;
}
static int msc_iter_win_start(struct msc_iter *iter, struct msc *msc)
{
/* already started, nothing to do */
if (iter->start_win)
return 0;
iter->start_win = msc_oldest_window(msc);
if (!iter->start_win)
return -EINVAL;
iter->win = iter->start_win;
iter->start_block = NULL;
msc_iter_block_start(iter);
return 0;
}
static int msc_iter_win_advance(struct msc_iter *iter)
{
iter->win = msc_next_window(iter->win);
iter->start_block = NULL;
if (iter->win == iter->start_win) {
iter->eof++;
return 1;
}
msc_iter_block_start(iter);
return 0;
}
static int msc_iter_block_advance(struct msc_iter *iter)
{
iter->block_off = 0;
/* wrapping */
if (iter->wrap_count && iter->block == iter->start_block) {
iter->wrap_count--;
if (!iter->wrap_count)
/* copied newest data from the wrapped block */
return msc_iter_win_advance(iter);
}
/* no wrapping, check for last written block */
if (!iter->wrap_count && msc_block_last_written(msc_iter_bdesc(iter)))
/* copied newest data for the window */
return msc_iter_win_advance(iter);
/* block advance */
if (sg_is_last(iter->block))
iter->block = msc_win_base_sg(iter->win);
else
iter->block = sg_next(iter->block);
/* no wrapping, sanity check in case there is no last written block */
if (!iter->wrap_count && iter->block == iter->start_block)
return msc_iter_win_advance(iter);
return 0;
}
/**
* msc_buffer_iterate() - go through multiblock buffer's data
* @iter: iterator structure
* @size: amount of data to scan
* @data: callback's private data
* @fn: iterator callback
*
* This will start at the window which will be written to next (containing
* the oldest data) and work its way to the current window, calling @fn
* for each chunk of data as it goes.
*
* Caller should have msc::user_count reference to make sure the buffer
* doesn't disappear from under us.
*
* Return: amount of data actually scanned.
*/
static ssize_t
msc_buffer_iterate(struct msc_iter *iter, size_t size, void *data,
unsigned long (*fn)(void *, void *, size_t))
{
struct msc *msc = iter->msc;
size_t len = size;
unsigned int advance;
if (iter->eof)
return 0;
/* start with the oldest window */
if (msc_iter_win_start(iter, msc))
return 0;
do {
unsigned long data_bytes = msc_data_sz(msc_iter_bdesc(iter));
void *src = (void *)msc_iter_bdesc(iter) + MSC_BDESC;
size_t tocopy = data_bytes, copied = 0;
size_t remaining = 0;
advance = 1;
/*
* If block wrapping happened, we need to visit the last block
* twice, because it contains both the oldest and the newest
* data in this window.
*
* First time (wrap_count==2), in the very beginning, to collect
* the oldest data, which is in the range
* (data_bytes..DATA_IN_PAGE).
*
* Second time (wrap_count==1), it's just like any other block,
* containing data in the range of [MSC_BDESC..data_bytes].
*/
if (iter->block == iter->start_block && iter->wrap_count == 2) {
tocopy = DATA_IN_PAGE - data_bytes;
src += data_bytes;
}
if (!tocopy)
goto next_block;
tocopy -= iter->block_off;
src += iter->block_off;
if (len < tocopy) {
tocopy = len;
advance = 0;
}
remaining = fn(data, src, tocopy);
if (remaining)
advance = 0;
copied = tocopy - remaining;
len -= copied;
iter->block_off += copied;
iter->offset += copied;
if (!advance)
break;
next_block:
if (msc_iter_block_advance(iter))
break;
} while (len);
return size - len;
}
/**
* msc_buffer_clear_hw_header() - clear hw header for multiblock
* @msc: MSC device
*/
static void msc_buffer_clear_hw_header(struct msc *msc)
{
struct msc_window *win;
struct scatterlist *sg;
list_for_each_entry(win, &msc->win_list, entry) {
unsigned int blk;
for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
struct msc_block_desc *bdesc = sg_virt(sg);
memset_startat(bdesc, 0, hw_tag);
}
}
}
static int intel_th_msu_init(struct msc *msc)
{
u32 mintctl, msusts;
if (!msc->do_irq)
return 0;
if (!msc->mbuf)
return 0;
mintctl = ioread32(msc->msu_base + REG_MSU_MINTCTL);
mintctl |= msc->index ? M1BLIE : M0BLIE;
iowrite32(mintctl, msc->msu_base + REG_MSU_MINTCTL);
if (mintctl != ioread32(msc->msu_base + REG_MSU_MINTCTL)) {
dev_info(msc_dev(msc), "MINTCTL ignores writes: no usable interrupts\n");
msc->do_irq = 0;
return 0;
}
msusts = ioread32(msc->msu_base + REG_MSU_MSUSTS);
iowrite32(msusts, msc->msu_base + REG_MSU_MSUSTS);
return 0;
}
static void intel_th_msu_deinit(struct msc *msc)
{
u32 mintctl;
if (!msc->do_irq)
return;
mintctl = ioread32(msc->msu_base + REG_MSU_MINTCTL);
mintctl &= msc->index ? ~M1BLIE : ~M0BLIE;
iowrite32(mintctl, msc->msu_base + REG_MSU_MINTCTL);
}
static int msc_win_set_lockout(struct msc_window *win,
enum lockout_state expect,
enum lockout_state new)
{
enum lockout_state old;
unsigned long flags;
int ret = 0;
if (!win->msc->mbuf)
return 0;
spin_lock_irqsave(&win->lo_lock, flags);
old = win->lockout;
if (old != expect) {
ret = -EINVAL;
goto unlock;
}
win->lockout = new;
if (old == expect && new == WIN_LOCKED)
atomic_inc(&win->msc->user_count);
else if (old == expect && old == WIN_LOCKED)
atomic_dec(&win->msc->user_count);
unlock:
spin_unlock_irqrestore(&win->lo_lock, flags);
if (ret) {
if (expect == WIN_READY && old == WIN_LOCKED)
return -EBUSY;
/* from intel_th_msc_window_unlock(), don't warn if not locked */
if (expect == WIN_LOCKED && old == new)
return 0;
dev_warn_ratelimited(msc_dev(win->msc),
"expected lockout state %d, got %d\n",
expect, old);
}
return ret;
}
/**
* msc_configure() - set up MSC hardware
* @msc: the MSC device to configure
*
* Program storage mode, wrapping, burst length and trace buffer address
* 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.
*
* Return: %0 for success or a negative error code otherwise.
*/
static int msc_configure(struct msc *msc)
{
u32 reg;
lockdep_assert_held(&msc->buf_mutex);
if (msc->mode > MSC_MODE_MULTI)
return -EINVAL;
if (msc->mode == MSC_MODE_MULTI) {
if (msc_win_set_lockout(msc->cur_win, WIN_READY, WIN_INUSE))
return -EBUSY;
msc_buffer_clear_hw_header(msc);
}
msc->orig_addr = ioread32(msc->reg_base + REG_MSU_MSC0BAR);
msc->orig_sz = ioread32(msc->reg_base + REG_MSU_MSC0SIZE);
reg = msc->base_addr >> PAGE_SHIFT;
iowrite32(reg, msc->reg_base + REG_MSU_MSC0BAR);
if (msc->mode == MSC_MODE_SINGLE) {
reg = msc->nr_pages;
iowrite32(reg, msc->reg_base + REG_MSU_MSC0SIZE);
}
reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL);
reg &= ~(MSC_MODE | MSC_WRAPEN | MSC_EN | MSC_RD_HDR_OVRD);
reg |= MSC_EN;
reg |= msc->mode << __ffs(MSC_MODE);
reg |= msc->burst_len << __ffs(MSC_LEN);
if (msc->wrap)
reg |= MSC_WRAPEN;
iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL);
intel_th_msu_init(msc);
msc->thdev->output.multiblock = msc->mode == MSC_MODE_MULTI;
intel_th_trace_enable(msc->thdev);
msc->enabled = 1;
if (msc->mbuf && msc->mbuf->activate)
msc->mbuf->activate(msc->mbuf_priv);
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)
{
struct msc_window *win = msc->cur_win;
u32 reg;
lockdep_assert_held(&msc->buf_mutex);
if (msc->mode == MSC_MODE_MULTI)
msc_win_set_lockout(win, WIN_INUSE, WIN_LOCKED);
if (msc->mbuf && msc->mbuf->deactivate)
msc->mbuf->deactivate(msc->mbuf_priv);
intel_th_msu_deinit(msc);
intel_th_trace_disable(msc->thdev);
if (msc->mode == MSC_MODE_SINGLE) {
reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
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);
if (msc->mbuf && msc->mbuf->ready)
msc->mbuf->ready(msc->mbuf_priv, win->sgt,
msc_win_total_sz(win));
msc->enabled = 0;
iowrite32(msc->orig_addr, msc->reg_base + REG_MSU_MSC0BAR);
iowrite32(msc->orig_sz, 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);
reg = ioread32(msc->reg_base + REG_MSU_MSUSTS);
reg &= msc->index ? MSUSTS_MSC1BLAST : MSUSTS_MSC0BLAST;
iowrite32(reg, msc->reg_base + REG_MSU_MSUSTS);
}
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 long nr_pages = size >> PAGE_SHIFT;
unsigned int order = get_order(size);
struct page *page;
int ret;
if (!size)
return 0;
ret = sg_alloc_table(&msc->single_sgt, 1, GFP_KERNEL);
if (ret)
goto err_out;
ret = -ENOMEM;
page = alloc_pages(GFP_KERNEL | __GFP_ZERO | GFP_DMA32, order);
if (!page)
goto err_free_sgt;
split_page(page, order);
sg_set_buf(msc->single_sgt.sgl, page_address(page), size);
ret = dma_map_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl, 1,
DMA_FROM_DEVICE);
if (ret < 0)
goto err_free_pages;
msc->nr_pages = nr_pages;
msc->base = page_address(page);
msc->base_addr = sg_dma_address(msc->single_sgt.sgl);
return 0;
err_free_pages:
__free_pages(page, order);
err_free_sgt:
sg_free_table(&msc->single_sgt);
err_out:
return ret;
}
/**
* 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;
dma_unmap_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl,
1, DMA_FROM_DEVICE);
sg_free_table(&msc->single_sgt);
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));
}
static int __msc_buffer_win_alloc(struct msc_window *win,
unsigned int nr_segs)
{
struct scatterlist *sg_ptr;
void *block;
int i, ret;
ret = sg_alloc_table(win->sgt, nr_segs, GFP_KERNEL);
if (ret)
return -ENOMEM;
for_each_sg(win->sgt->sgl, sg_ptr, nr_segs, i) {
block = dma_alloc_coherent(msc_dev(win->msc)->parent->parent,
PAGE_SIZE, &sg_dma_address(sg_ptr),
GFP_KERNEL);
if (!block)
goto err_nomem;
sg_set_buf(sg_ptr, block, PAGE_SIZE);
}
return nr_segs;
err_nomem:
for_each_sg(win->sgt->sgl, sg_ptr, i, ret)
dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE,
sg_virt(sg_ptr), sg_dma_address(sg_ptr));
sg_free_table(win->sgt);
return -ENOMEM;
}
#ifdef CONFIG_X86
static void msc_buffer_set_uc(struct msc *msc)
{
struct scatterlist *sg_ptr;
struct msc_window *win;
int i;
if (msc->mode == MSC_MODE_SINGLE) {
set_memory_uc((unsigned long)msc->base, msc->nr_pages);
return;
}
list_for_each_entry(win, &msc->win_list, entry) {
for_each_sg(win->sgt->sgl, sg_ptr, win->nr_segs, i) {
/* Set the page as uncached */
set_memory_uc((unsigned long)sg_virt(sg_ptr),
PFN_DOWN(sg_ptr->length));
}
}
}
static void msc_buffer_set_wb(struct msc *msc)
{
struct scatterlist *sg_ptr;
struct msc_window *win;
int i;
if (msc->mode == MSC_MODE_SINGLE) {
set_memory_wb((unsigned long)msc->base, msc->nr_pages);
return;
}
list_for_each_entry(win, &msc->win_list, entry) {
for_each_sg(win->sgt->sgl, sg_ptr, win->nr_segs, i) {
/* Reset the page to write-back */
set_memory_wb((unsigned long)sg_virt(sg_ptr),
PFN_DOWN(sg_ptr->length));
}
}
}
#else /* !X86 */
static inline void
msc_buffer_set_uc(struct msc *msc) {}
static inline void msc_buffer_set_wb(struct msc *msc) {}
#endif /* CONFIG_X86 */
static struct page *msc_sg_page(struct scatterlist *sg)
{
void *addr = sg_virt(sg);
if (is_vmalloc_addr(addr))
return vmalloc_to_page(addr);
return sg_page(sg);
}
/**
* 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;
int ret = -ENOMEM;
if (!nr_blocks)
return 0;
win = kzalloc(sizeof(*win), GFP_KERNEL);
if (!win)
return -ENOMEM;
win->msc = msc;
win->sgt = &win->_sgt;
win->lockout = WIN_READY;
spin_lock_init(&win->lo_lock);
if (!list_empty(&msc->win_list)) {
struct msc_window *prev = list_last_entry(&msc->win_list,
struct msc_window,
entry);
win->pgoff = prev->pgoff + prev->nr_blocks;
}
if (msc->mbuf && msc->mbuf->alloc_window)
ret = msc->mbuf->alloc_window(msc->mbuf_priv, &win->sgt,
nr_blocks << PAGE_SHIFT);
else
ret = __msc_buffer_win_alloc(win, nr_blocks);
if (ret <= 0)
goto err_nomem;
win->nr_segs = ret;
win->nr_blocks = nr_blocks;
if (list_empty(&msc->win_list)) {
msc->base = msc_win_base(win);
msc->base_addr = msc_win_base_dma(win);
msc->cur_win = win;
}
list_add_tail(&win->entry, &msc->win_list);
msc->nr_pages += nr_blocks;
return 0;
err_nomem:
kfree(win);
return ret;
}
static void __msc_buffer_win_free(struct msc *msc, struct msc_window *win)
{
struct scatterlist *sg;
int i;
for_each_sg(win->sgt->sgl, sg, win->nr_segs, i) {
struct page *page = msc_sg_page(sg);
page->mapping = NULL;
dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE,
sg_virt(sg), sg_dma_address(sg));
}
sg_free_table(win->sgt);
}
/**
* 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)
{
msc->nr_pages -= win->nr_blocks;
list_del(&win->entry);
if (list_empty(&msc->win_list)) {
msc->base = NULL;
msc->base_addr = 0;
}
if (msc->mbuf && msc->mbuf->free_window)
msc->mbuf->free_window(msc->mbuf_priv, win->sgt);
else
__msc_buffer_win_free(msc, win);
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) {
struct scatterlist *sg;
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_first_entry(&msc->win_list,
struct msc_window, entry);
} else {
next_win = list_next_entry(win, entry);
}
for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
struct msc_block_desc *bdesc = sg_virt(sg);
memset(bdesc, 0, sizeof(*bdesc));
bdesc->next_win = msc_win_base_pfn(next_win);
/*
* Similarly to last window, last block should point
* to the first one.
*/
if (blk == win->nr_segs - 1) {
sw_tag |= MSC_SW_TAG_LASTBLK;
bdesc->next_blk = msc_win_base_pfn(win);
} else {
dma_addr_t addr = sg_dma_address(sg_next(sg));
bdesc->next_blk = PFN_DOWN(addr);
}
bdesc->sw_tag = sw_tag;
bdesc->block_sz = sg->length / 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)
{
msc_buffer_set_wb(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
* @nr_pages: number of pages for each window
* @nr_wins: number of windows
*
* 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 = -EINVAL;
}
if (!ret) {
msc_buffer_set_uc(msc);
/* 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().
*
* Return: 0 on successful deallocation or if there was no buffer to
* deallocate, -EBUSY if there are active users.
*/
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;
struct scatterlist *sg;
unsigned int blk;
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;
for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
struct page *page = msc_sg_page(sg);
size_t pgsz = PFN_DOWN(sg->length);
if (pgoff < pgsz)
return page + pgoff;
pgoff -= pgsz;
}
return NULL;
}
/**
* 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
*
* Return: >= %0 for success or -errno for error.
*/
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 = -EINVAL;
}
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);
vm_flags_set(vma, 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,
.owner = THIS_MODULE,
};
static void intel_th_msc_wait_empty(struct intel_th_device *thdev)
{
struct msc *msc = dev_get_drvdata(&thdev->dev);
unsigned long count;
u32 reg;
for (reg = 0, count = MSC_PLE_WAITLOOP_DEPTH;
count && !(reg & MSCSTS_PLE); count--) {
reg = __raw_readl(msc->reg_base + REG_MSU_MSC0STS);
cpu_relax();
}
if (!count)
dev_dbg(msc_dev(msc), "timeout waiting for MSC0 PLE\n");
}
static int intel_th_msc_init(struct msc *msc)
{
atomic_set(&msc->user_count, -1);
msc->mode = msc->multi_is_broken ? MSC_MODE_SINGLE : 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 int msc_win_switch(struct msc *msc)
{
struct msc_window *first;
if (list_empty(&msc->win_list))
return -EINVAL;
first = list_first_entry(&msc->win_list, struct msc_window, entry);
if (msc_is_last_win(msc->cur_win))
msc->cur_win = first;
else
msc->cur_win = list_next_entry(msc->cur_win, entry);
msc->base = msc_win_base(msc->cur_win);
msc->base_addr = msc_win_base_dma(msc->cur_win);
intel_th_trace_switch(msc->thdev);
return 0;
}
/**
* intel_th_msc_window_unlock - put the window back in rotation
* @dev: MSC device to which this relates
* @sgt: buffer's sg_table for the window, does nothing if NULL
*/
void intel_th_msc_window_unlock(struct device *dev, struct sg_table *sgt)
{
struct msc *msc = dev_get_drvdata(dev);
struct msc_window *win;
if (!sgt)
return;
win = msc_find_window(msc, sgt, false);
if (!win)
return;
msc_win_set_lockout(win, WIN_LOCKED, WIN_READY);
if (msc->switch_on_unlock == win) {
msc->switch_on_unlock = NULL;
msc_win_switch(msc);
}
}
EXPORT_SYMBOL_GPL(intel_th_msc_window_unlock);
static void msc_work(struct work_struct *work)
{
struct msc *msc = container_of(work, struct msc, work);
intel_th_msc_deactivate(msc->thdev);
}
static irqreturn_t intel_th_msc_interrupt(struct intel_th_device *thdev)
{
struct msc *msc = dev_get_drvdata(&thdev->dev);
u32 msusts = ioread32(msc->msu_base + REG_MSU_MSUSTS);
u32 mask = msc->index ? MSUSTS_MSC1BLAST : MSUSTS_MSC0BLAST;
struct msc_window *win, *next_win;
if (!msc->do_irq || !msc->mbuf)
return IRQ_NONE;
msusts &= mask;
if (!msusts)
return msc->enabled ? IRQ_HANDLED : IRQ_NONE;
iowrite32(msusts, msc->msu_base + REG_MSU_MSUSTS);
if (!msc->enabled)
return IRQ_NONE;
/* grab the window before we do the switch */
win = msc->cur_win;
if (!win)
return IRQ_HANDLED;
next_win = msc_next_window(win);
if (!next_win)
return IRQ_HANDLED;
/* next window: if READY, proceed, if LOCKED, stop the trace */
if (msc_win_set_lockout(next_win, WIN_READY, WIN_INUSE)) {
if (msc->stop_on_full)
schedule_work(&msc->work);
else
msc->switch_on_unlock = next_win;
return IRQ_HANDLED;
}
/* current window: INUSE -> LOCKED */
msc_win_set_lockout(win, WIN_INUSE, WIN_LOCKED);
msc_win_switch(msc);
if (msc->mbuf && msc->mbuf->ready)
msc->mbuf->ready(msc->mbuf_priv, win->sgt,
msc_win_total_sz(win));
return IRQ_HANDLED;
}
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 void msc_buffer_unassign(struct msc *msc)
{
lockdep_assert_held(&msc->buf_mutex);
if (!msc->mbuf)
return;
msc->mbuf->unassign(msc->mbuf_priv);
msu_buffer_put(msc->mbuf);
msc->mbuf_priv = NULL;
msc->mbuf = NULL;
}
static ssize_t
mode_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct msc *msc = dev_get_drvdata(dev);
const char *mode = msc_mode[msc->mode];
ssize_t ret;
mutex_lock(&msc->buf_mutex);
if (msc->mbuf)
mode = msc->mbuf->name;
ret = scnprintf(buf, PAGE_SIZE, "%s\n", mode);
mutex_unlock(&msc->buf_mutex);
return ret;
}
static ssize_t
mode_store(struct device *dev, struct device_attribute *attr, const char *buf,
size_t size)
{
const struct msu_buffer *mbuf = NULL;
struct msc *msc = dev_get_drvdata(dev);
size_t len = size;
char *cp, *mode;
int i, ret;
if (!capable(CAP_SYS_RAWIO))
return -EPERM;
cp = memchr(buf, '\n', len);
if (cp)
len = cp - buf;
mode = kstrndup(buf, len, GFP_KERNEL);
if (!mode)
return -ENOMEM;
i = match_string(msc_mode, ARRAY_SIZE(msc_mode), mode);
if (i >= 0) {
kfree(mode);
goto found;
}
/* Buffer sinks only work with a usable IRQ */
if (!msc->do_irq) {
kfree(mode);
return -EINVAL;
}
mbuf = msu_buffer_get(mode);
kfree(mode);
if (mbuf)
goto found;
return -EINVAL;
found:
if (i == MSC_MODE_MULTI && msc->multi_is_broken)
return -EOPNOTSUPP;
mutex_lock(&msc->buf_mutex);
ret = 0;
/* Same buffer: do nothing */
if (mbuf && mbuf == msc->mbuf) {
/* put the extra reference we just got */
msu_buffer_put(mbuf);
goto unlock;
}
ret = msc_buffer_unlocked_free_unless_used(msc);
if (ret)
goto unlock;
if (mbuf) {
void *mbuf_priv = mbuf->assign(dev, &i);
if (!mbuf_priv) {
ret = -ENOMEM;
goto unlock;
}
msc_buffer_unassign(msc);
msc->mbuf_priv = mbuf_priv;
msc->mbuf = mbuf;
} else {
msc_buffer_unassign(msc);
}
msc->mode = i;
unlock:
if (ret && mbuf)
msu_buffer_put(mbuf);
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_array(win, nr_wins, sizeof(*win), 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 ssize_t
win_switch_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;
if (val != 1)
return -EINVAL;
ret = -EINVAL;
mutex_lock(&msc->buf_mutex);
/*
* Window switch can only happen in the "multi" mode.
* If a external buffer is engaged, they have the full
* control over window switching.
*/
if (msc->mode == MSC_MODE_MULTI && !msc->mbuf)
ret = msc_win_switch(msc);
mutex_unlock(&msc->buf_mutex);
return ret ? ret : size;
}
static DEVICE_ATTR_WO(win_switch);
static ssize_t stop_on_full_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct msc *msc = dev_get_drvdata(dev);
return sprintf(buf, "%d\n", msc->stop_on_full);
}
static ssize_t stop_on_full_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
struct msc *msc = dev_get_drvdata(dev);
int ret;
ret = kstrtobool(buf, &msc->stop_on_full);
if (ret)
return ret;
return size;
}
static DEVICE_ATTR_RW(stop_on_full);
static struct attribute *msc_output_attrs[] = {
&dev_attr_wrap.attr,
&dev_attr_mode.attr,
&dev_attr_nr_pages.attr,
&dev_attr_win_switch.attr,
&dev_attr_stop_on_full.attr,
NULL,
};
static const 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;
res = intel_th_device_get_resource(thdev, IORESOURCE_IRQ, 1);
if (!res)
msc->do_irq = 1;
if (INTEL_TH_CAP(to_intel_th(thdev), multi_is_broken))
msc->multi_is_broken = 1;
msc->index = thdev->id;
msc->thdev = thdev;
msc->reg_base = base + msc->index * 0x100;
msc->msu_base = base;
INIT_WORK(&msc->work, msc_work);
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,
.irq = intel_th_msc_interrupt,
.wait_empty = intel_th_msc_wait_empty,
.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 <[email protected]>");
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