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authorBjorn Helgaas <bhelgaas@google.com>2019-03-06 15:30:12 -0600
committerBjorn Helgaas <bhelgaas@google.com>2019-03-06 15:30:12 -0600
commit58a79db4818296a609f4ab8335f707fa5e60787e (patch)
tree7ad8ad7883a4e40b575270e1eb895215296c5208 /drivers/pci
parent5d130e3dd8b6995e93aeb7a740709a46e7acf5df (diff)
parent2a727f6091372231281efaa8a5f56ee79509fd83 (diff)
downloadlinux-58a79db4818296a609f4ab8335f707fa5e60787e.tar.bz2
Merge branch 'pci/hotplug'
- Reorder pciehp cached state/hardware state updates to avoid missed interrupts (Mika Westerberg) - Turn ibmphp semaphores into completions or mutexes (Arnd Bergmann) * pci/hotplug: PCI: ibmphp: Turn semaphores into completions or mutexes PCI: pciehp: Assign ctrl->slot_ctrl before writing it to hardware
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/hotplug/ibmphp.h1
-rw-r--r--drivers/pci/hotplug/ibmphp_core.c2
-rw-r--r--drivers/pci/hotplug/ibmphp_hpc.c47
-rw-r--r--drivers/pci/hotplug/pciehp_hpc.c2
4 files changed, 15 insertions, 37 deletions
diff --git a/drivers/pci/hotplug/ibmphp.h b/drivers/pci/hotplug/ibmphp.h
index b89f850c3a4e..e90a4ebf6550 100644
--- a/drivers/pci/hotplug/ibmphp.h
+++ b/drivers/pci/hotplug/ibmphp.h
@@ -378,7 +378,6 @@ int ibmphp_add_pfmem_from_mem(struct resource_node *);
struct bus_node *ibmphp_find_res_bus(u8);
void ibmphp_print_test(void); /* for debugging purposes */
-void ibmphp_hpc_initvars(void);
int ibmphp_hpc_readslot(struct slot *, u8, u8 *);
int ibmphp_hpc_writeslot(struct slot *, u8);
void ibmphp_lock_operations(void);
diff --git a/drivers/pci/hotplug/ibmphp_core.c b/drivers/pci/hotplug/ibmphp_core.c
index 08a58e911fc2..17124254d897 100644
--- a/drivers/pci/hotplug/ibmphp_core.c
+++ b/drivers/pci/hotplug/ibmphp_core.c
@@ -1277,8 +1277,6 @@ static int __init ibmphp_init(void)
ibmphp_debug = debug;
- ibmphp_hpc_initvars();
-
for (i = 0; i < 16; i++)
irqs[i] = 0;
diff --git a/drivers/pci/hotplug/ibmphp_hpc.c b/drivers/pci/hotplug/ibmphp_hpc.c
index 752c384cbd4c..508a62a6b5f9 100644
--- a/drivers/pci/hotplug/ibmphp_hpc.c
+++ b/drivers/pci/hotplug/ibmphp_hpc.c
@@ -15,13 +15,13 @@
#include <linux/wait.h>
#include <linux/time.h>
+#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/sched.h>
-#include <linux/semaphore.h>
#include <linux/kthread.h>
#include "ibmphp.h"
@@ -88,10 +88,10 @@ static int to_debug = 0;
//----------------------------------------------------------------------------
// global variables
//----------------------------------------------------------------------------
-static struct mutex sem_hpcaccess; // lock access to HPC
-static struct semaphore semOperations; // lock all operations and
+static DEFINE_MUTEX(sem_hpcaccess); // lock access to HPC
+static DEFINE_MUTEX(operations_mutex); // lock all operations and
// access to data structures
-static struct semaphore sem_exit; // make sure polling thread goes away
+static DECLARE_COMPLETION(exit_complete); // make sure polling thread goes away
static struct task_struct *ibmphp_poll_thread;
//----------------------------------------------------------------------------
// local function prototypes
@@ -110,23 +110,6 @@ static int hpc_wait_ctlr_notworking(int, struct controller *, void __iomem *, u8
/*----------------------------------------------------------------------
-* Name: ibmphp_hpc_initvars
-*
-* Action: initialize semaphores and variables
-*---------------------------------------------------------------------*/
-void __init ibmphp_hpc_initvars(void)
-{
- debug("%s - Entry\n", __func__);
-
- mutex_init(&sem_hpcaccess);
- sema_init(&semOperations, 1);
- sema_init(&sem_exit, 0);
- to_debug = 0;
-
- debug("%s - Exit\n", __func__);
-}
-
-/*----------------------------------------------------------------------
* Name: i2c_ctrl_read
*
* Action: read from HPC over I2C
@@ -780,7 +763,7 @@ void free_hpc_access(void)
*---------------------------------------------------------------------*/
void ibmphp_lock_operations(void)
{
- down(&semOperations);
+ mutex_lock(&operations_mutex);
to_debug = 1;
}
@@ -790,7 +773,7 @@ void ibmphp_lock_operations(void)
void ibmphp_unlock_operations(void)
{
debug("%s - Entry\n", __func__);
- up(&semOperations);
+ mutex_unlock(&operations_mutex);
to_debug = 0;
debug("%s - Exit\n", __func__);
}
@@ -816,7 +799,7 @@ static int poll_hpc(void *data)
while (!kthread_should_stop()) {
/* try to get the lock to do some kind of hardware access */
- down(&semOperations);
+ mutex_lock(&operations_mutex);
switch (poll_state) {
case POLL_LATCH_REGISTER:
@@ -871,13 +854,13 @@ static int poll_hpc(void *data)
break;
case POLL_SLEEP:
/* don't sleep with a lock on the hardware */
- up(&semOperations);
+ mutex_unlock(&operations_mutex);
msleep(POLL_INTERVAL_SEC * 1000);
if (kthread_should_stop())
goto out_sleep;
- down(&semOperations);
+ mutex_lock(&operations_mutex);
if (poll_count >= POLL_LATCH_CNT) {
poll_count = 0;
@@ -887,12 +870,12 @@ static int poll_hpc(void *data)
break;
}
/* give up the hardware semaphore */
- up(&semOperations);
+ mutex_unlock(&operations_mutex);
/* sleep for a short time just for good measure */
out_sleep:
msleep(100);
}
- up(&sem_exit);
+ complete(&exit_complete);
debug("%s - Exit\n", __func__);
return 0;
}
@@ -1060,9 +1043,9 @@ void __exit ibmphp_hpc_stop_poll_thread(void)
debug("after locking operations\n");
// wait for poll thread to exit
- debug("before sem_exit down\n");
- down(&sem_exit);
- debug("after sem_exit down\n");
+ debug("before exit_complete down\n");
+ wait_for_completion(&exit_complete);
+ debug("after exit_completion down\n");
// cleanup
debug("before free_hpc_access\n");
@@ -1070,8 +1053,6 @@ void __exit ibmphp_hpc_stop_poll_thread(void)
debug("after free_hpc_access\n");
ibmphp_unlock_operations();
debug("after unlock operations\n");
- up(&sem_exit);
- debug("after sem exit up\n");
debug("%s - Exit\n", __func__);
}
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 7dd443aea5a5..cd9eae650aa5 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -156,9 +156,9 @@ static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd,
slot_ctrl |= (cmd & mask);
ctrl->cmd_busy = 1;
smp_mb();
+ ctrl->slot_ctrl = slot_ctrl;
pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, slot_ctrl);
ctrl->cmd_started = jiffies;
- ctrl->slot_ctrl = slot_ctrl;
/*
* Controllers with the Intel CF118 and similar errata advertise