Revision 9d9a152ebaa86a9dede4624919566483c955d0a7 authored by Hans de Goede on 29 August 2018, 13:06:31 UTC, committed by Wolfram Sang on 30 August 2018, 21:02:13 UTC
On Bay Trail and Cherry Trail devices we set the pm_disabled flag for I2C busses which the OS shares with the PUNIT as these need special handling. Until now we called dev_pm_syscore_device(dev, true) for I2C controllers with this flag set to keep these I2C controllers always on. After commit 12864ff8545f ("ACPI / LPSS: Avoid PM quirks on suspend and resume from hibernation"), this no longer works. This commit modifies lpss_iosf_exit_d3_state() to only run if lpss_iosf_enter_d3_state() has ran before it, so that it does not run on a resume from hibernate (or from S3). On these systems the conditions for lpss_iosf_enter_d3_state() to run never become true, so lpss_iosf_exit_d3_state() never gets called and the 2 LPSS DMA controllers never get forced into D0 mode, instead they are left in their default automatic power-on when needed mode. The not forcing of D0 mode for the DMA controllers enables these systems to properly enter S0ix modes, which is a good thing. But after entering S0ix modes the I2C controller connected to the PMIC no longer works, leading to e.g. broken battery monitoring. The _PS3 method for this I2C controller looks like this: Method (_PS3, 0, NotSerialized) // _PS3: Power State 3 { If ((((PMID == 0x04) || (PMID == 0x05)) || (PMID == 0x06))) { Return (Zero) } PSAT |= 0x03 Local0 = PSAT /* \_SB_.I2C5.PSAT */ } Where PMID = 0x05, so we enter the Return (Zero) path on these systems. So even if we were to not call dev_pm_syscore_device(dev, true) the I2C controller will be left in D0 rather then be switched to D3. Yet on other Bay and Cherry Trail devices S0ix is not entered unless *all* I2C controllers are in D3 mode. This combined with the I2C controller no longer working now that we reach S0ix states on these systems leads to me believing that the PUNIT itself puts the I2C controller in D3 when all other conditions for entering S0ix states are true. Since now the I2C controller is put in D3 over a suspend/resume we must re-initialize it afterwards and that does indeed fix it no longer working. This commit implements this fix by: 1) Making the suspend_late callback a no-op if pm_disabled is set and making the resume_early callback skip the clock re-enable (since it now was not disabled) while still doing the necessary I2C controller re-init. 2) Removing the dev_pm_syscore_device(dev, true) call, so that the suspend and resume callbacks are actually called. Normally this would cause the ACPI pm code to call _PS3 putting the I2C controller in D3, wreaking havoc since it is shared with the PUNIT, but in this special case the _PS3 method is a no-op so we can safely allow a "fake" suspend / resume. Fixes: 12864ff8545f ("ACPI / LPSS: Avoid PM quirks on suspend and resume ...") Link: https://bugzilla.kernel.org/show_bug.cgi?id=200861 Cc: 4.15+ <stable@vger.kernel.org> # 4.15+ Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
1 parent 7fd6d98
swap_slots.c
// SPDX-License-Identifier: GPL-2.0
/*
* Manage cache of swap slots to be used for and returned from
* swap.
*
* Copyright(c) 2016 Intel Corporation.
*
* Author: Tim Chen <tim.c.chen@linux.intel.com>
*
* We allocate the swap slots from the global pool and put
* it into local per cpu caches. This has the advantage
* of no needing to acquire the swap_info lock every time
* we need a new slot.
*
* There is also opportunity to simply return the slot
* to local caches without needing to acquire swap_info
* lock. We do not reuse the returned slots directly but
* move them back to the global pool in a batch. This
* allows the slots to coaellesce and reduce fragmentation.
*
* The swap entry allocated is marked with SWAP_HAS_CACHE
* flag in map_count that prevents it from being allocated
* again from the global pool.
*
* The swap slots cache is protected by a mutex instead of
* a spin lock as when we search for slots with scan_swap_map,
* we can possibly sleep.
*/
#include <linux/swap_slots.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/vmalloc.h>
#include <linux/mutex.h>
#include <linux/mm.h>
static DEFINE_PER_CPU(struct swap_slots_cache, swp_slots);
static bool swap_slot_cache_active;
bool swap_slot_cache_enabled;
static bool swap_slot_cache_initialized;
static DEFINE_MUTEX(swap_slots_cache_mutex);
/* Serialize swap slots cache enable/disable operations */
static DEFINE_MUTEX(swap_slots_cache_enable_mutex);
static void __drain_swap_slots_cache(unsigned int type);
static void deactivate_swap_slots_cache(void);
static void reactivate_swap_slots_cache(void);
#define use_swap_slot_cache (swap_slot_cache_active && \
swap_slot_cache_enabled && swap_slot_cache_initialized)
#define SLOTS_CACHE 0x1
#define SLOTS_CACHE_RET 0x2
static void deactivate_swap_slots_cache(void)
{
mutex_lock(&swap_slots_cache_mutex);
swap_slot_cache_active = false;
__drain_swap_slots_cache(SLOTS_CACHE|SLOTS_CACHE_RET);
mutex_unlock(&swap_slots_cache_mutex);
}
static void reactivate_swap_slots_cache(void)
{
mutex_lock(&swap_slots_cache_mutex);
swap_slot_cache_active = true;
mutex_unlock(&swap_slots_cache_mutex);
}
/* Must not be called with cpu hot plug lock */
void disable_swap_slots_cache_lock(void)
{
mutex_lock(&swap_slots_cache_enable_mutex);
swap_slot_cache_enabled = false;
if (swap_slot_cache_initialized) {
/* serialize with cpu hotplug operations */
get_online_cpus();
__drain_swap_slots_cache(SLOTS_CACHE|SLOTS_CACHE_RET);
put_online_cpus();
}
}
static void __reenable_swap_slots_cache(void)
{
swap_slot_cache_enabled = has_usable_swap();
}
void reenable_swap_slots_cache_unlock(void)
{
__reenable_swap_slots_cache();
mutex_unlock(&swap_slots_cache_enable_mutex);
}
static bool check_cache_active(void)
{
long pages;
if (!swap_slot_cache_enabled || !swap_slot_cache_initialized)
return false;
pages = get_nr_swap_pages();
if (!swap_slot_cache_active) {
if (pages > num_online_cpus() *
THRESHOLD_ACTIVATE_SWAP_SLOTS_CACHE)
reactivate_swap_slots_cache();
goto out;
}
/* if global pool of slot caches too low, deactivate cache */
if (pages < num_online_cpus() * THRESHOLD_DEACTIVATE_SWAP_SLOTS_CACHE)
deactivate_swap_slots_cache();
out:
return swap_slot_cache_active;
}
static int alloc_swap_slot_cache(unsigned int cpu)
{
struct swap_slots_cache *cache;
swp_entry_t *slots, *slots_ret;
/*
* Do allocation outside swap_slots_cache_mutex
* as kvzalloc could trigger reclaim and get_swap_page,
* which can lock swap_slots_cache_mutex.
*/
slots = kvcalloc(SWAP_SLOTS_CACHE_SIZE, sizeof(swp_entry_t),
GFP_KERNEL);
if (!slots)
return -ENOMEM;
slots_ret = kvcalloc(SWAP_SLOTS_CACHE_SIZE, sizeof(swp_entry_t),
GFP_KERNEL);
if (!slots_ret) {
kvfree(slots);
return -ENOMEM;
}
mutex_lock(&swap_slots_cache_mutex);
cache = &per_cpu(swp_slots, cpu);
if (cache->slots || cache->slots_ret)
/* cache already allocated */
goto out;
if (!cache->lock_initialized) {
mutex_init(&cache->alloc_lock);
spin_lock_init(&cache->free_lock);
cache->lock_initialized = true;
}
cache->nr = 0;
cache->cur = 0;
cache->n_ret = 0;
/*
* We initialized alloc_lock and free_lock earlier. We use
* !cache->slots or !cache->slots_ret to know if it is safe to acquire
* the corresponding lock and use the cache. Memory barrier below
* ensures the assumption.
*/
mb();
cache->slots = slots;
slots = NULL;
cache->slots_ret = slots_ret;
slots_ret = NULL;
out:
mutex_unlock(&swap_slots_cache_mutex);
if (slots)
kvfree(slots);
if (slots_ret)
kvfree(slots_ret);
return 0;
}
static void drain_slots_cache_cpu(unsigned int cpu, unsigned int type,
bool free_slots)
{
struct swap_slots_cache *cache;
swp_entry_t *slots = NULL;
cache = &per_cpu(swp_slots, cpu);
if ((type & SLOTS_CACHE) && cache->slots) {
mutex_lock(&cache->alloc_lock);
swapcache_free_entries(cache->slots + cache->cur, cache->nr);
cache->cur = 0;
cache->nr = 0;
if (free_slots && cache->slots) {
kvfree(cache->slots);
cache->slots = NULL;
}
mutex_unlock(&cache->alloc_lock);
}
if ((type & SLOTS_CACHE_RET) && cache->slots_ret) {
spin_lock_irq(&cache->free_lock);
swapcache_free_entries(cache->slots_ret, cache->n_ret);
cache->n_ret = 0;
if (free_slots && cache->slots_ret) {
slots = cache->slots_ret;
cache->slots_ret = NULL;
}
spin_unlock_irq(&cache->free_lock);
if (slots)
kvfree(slots);
}
}
static void __drain_swap_slots_cache(unsigned int type)
{
unsigned int cpu;
/*
* This function is called during
* 1) swapoff, when we have to make sure no
* left over slots are in cache when we remove
* a swap device;
* 2) disabling of swap slot cache, when we run low
* on swap slots when allocating memory and need
* to return swap slots to global pool.
*
* We cannot acquire cpu hot plug lock here as
* this function can be invoked in the cpu
* hot plug path:
* cpu_up -> lock cpu_hotplug -> cpu hotplug state callback
* -> memory allocation -> direct reclaim -> get_swap_page
* -> drain_swap_slots_cache
*
* Hence the loop over current online cpu below could miss cpu that
* is being brought online but not yet marked as online.
* That is okay as we do not schedule and run anything on a
* cpu before it has been marked online. Hence, we will not
* fill any swap slots in slots cache of such cpu.
* There are no slots on such cpu that need to be drained.
*/
for_each_online_cpu(cpu)
drain_slots_cache_cpu(cpu, type, false);
}
static int free_slot_cache(unsigned int cpu)
{
mutex_lock(&swap_slots_cache_mutex);
drain_slots_cache_cpu(cpu, SLOTS_CACHE | SLOTS_CACHE_RET, true);
mutex_unlock(&swap_slots_cache_mutex);
return 0;
}
int enable_swap_slots_cache(void)
{
int ret = 0;
mutex_lock(&swap_slots_cache_enable_mutex);
if (swap_slot_cache_initialized) {
__reenable_swap_slots_cache();
goto out_unlock;
}
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "swap_slots_cache",
alloc_swap_slot_cache, free_slot_cache);
if (WARN_ONCE(ret < 0, "Cache allocation failed (%s), operating "
"without swap slots cache.\n", __func__))
goto out_unlock;
swap_slot_cache_initialized = true;
__reenable_swap_slots_cache();
out_unlock:
mutex_unlock(&swap_slots_cache_enable_mutex);
return 0;
}
/* called with swap slot cache's alloc lock held */
static int refill_swap_slots_cache(struct swap_slots_cache *cache)
{
if (!use_swap_slot_cache || cache->nr)
return 0;
cache->cur = 0;
if (swap_slot_cache_active)
cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE,
cache->slots, 1);
return cache->nr;
}
int free_swap_slot(swp_entry_t entry)
{
struct swap_slots_cache *cache;
cache = raw_cpu_ptr(&swp_slots);
if (likely(use_swap_slot_cache && cache->slots_ret)) {
spin_lock_irq(&cache->free_lock);
/* Swap slots cache may be deactivated before acquiring lock */
if (!use_swap_slot_cache || !cache->slots_ret) {
spin_unlock_irq(&cache->free_lock);
goto direct_free;
}
if (cache->n_ret >= SWAP_SLOTS_CACHE_SIZE) {
/*
* Return slots to global pool.
* The current swap_map value is SWAP_HAS_CACHE.
* Set it to 0 to indicate it is available for
* allocation in global pool
*/
swapcache_free_entries(cache->slots_ret, cache->n_ret);
cache->n_ret = 0;
}
cache->slots_ret[cache->n_ret++] = entry;
spin_unlock_irq(&cache->free_lock);
} else {
direct_free:
swapcache_free_entries(&entry, 1);
}
return 0;
}
swp_entry_t get_swap_page(struct page *page)
{
swp_entry_t entry, *pentry;
struct swap_slots_cache *cache;
entry.val = 0;
if (PageTransHuge(page)) {
if (IS_ENABLED(CONFIG_THP_SWAP))
get_swap_pages(1, &entry, HPAGE_PMD_NR);
goto out;
}
/*
* Preemption is allowed here, because we may sleep
* in refill_swap_slots_cache(). But it is safe, because
* accesses to the per-CPU data structure are protected by the
* mutex cache->alloc_lock.
*
* The alloc path here does not touch cache->slots_ret
* so cache->free_lock is not taken.
*/
cache = raw_cpu_ptr(&swp_slots);
if (likely(check_cache_active() && cache->slots)) {
mutex_lock(&cache->alloc_lock);
if (cache->slots) {
repeat:
if (cache->nr) {
pentry = &cache->slots[cache->cur++];
entry = *pentry;
pentry->val = 0;
cache->nr--;
} else {
if (refill_swap_slots_cache(cache))
goto repeat;
}
}
mutex_unlock(&cache->alloc_lock);
if (entry.val)
goto out;
}
get_swap_pages(1, &entry, 1);
out:
if (mem_cgroup_try_charge_swap(page, entry)) {
put_swap_page(page, entry);
entry.val = 0;
}
return entry;
}
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