* [patch 2/4] x86, ioapic: allocate ioapic_saved_data early
2011-05-16 18:56 [patch 1/4] x86, ioapic: fix potential resume deadlock Suresh Siddha
@ 2011-05-16 18:56 ` Suresh Siddha
2011-05-16 18:56 ` [patch 3/4] x86, ioapic: use ioapic_saved_data while enabling intr-remapping Suresh Siddha
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Suresh Siddha @ 2011-05-16 18:56 UTC (permalink / raw)
To: mingo, tglx, hpa; +Cc: linux-kernel, daniel.blueman, suresh.b.siddha
[-- Attachment #1: allocate_ioapic_saved_data_early.patch --]
[-- Type: text/plain, Size: 2093 bytes --]
This allows re-using this buffer for enabling interrupt-remapping during
boot and resume. And thus allow for conslidating the code between
ioapic suspend/resume and interrupt-remapping.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
---
arch/x86/kernel/apic/io_apic.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
Index: linux-2.6-tip/arch/x86/kernel/apic/io_apic.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-2.6-tip/arch/x86/kernel/apic/io_apic.c
@@ -100,6 +100,11 @@ int mp_irq_entries;
/* GSI interrupts */
static int nr_irqs_gsi = NR_IRQS_LEGACY;
+/*
+ * Saved I/O APIC state during suspend/resume.
+*/
+static struct IO_APIC_route_entry *ioapic_saved_data[MAX_IO_APICS];
+
#if defined (CONFIG_MCA) || defined (CONFIG_EISA)
int mp_bus_id_to_type[MAX_MP_BUSSES];
#endif
@@ -179,6 +184,14 @@ int __init arch_early_irq_init(void)
io_apic_irqs = ~0UL;
}
+ for (i = 0; i < nr_ioapics; i++) {
+ ioapic_saved_data[i] =
+ kzalloc(sizeof(struct IO_APIC_route_entry) *
+ nr_ioapic_registers[i], GFP_KERNEL);
+ if (!ioapic_saved_data[i])
+ pr_err("IOAPIC %d: suspend/resume impossible!\n", i);
+ }
+
cfg = irq_cfgx;
count = ARRAY_SIZE(irq_cfgx);
node = cpu_to_node(0);
@@ -2918,8 +2931,6 @@ static int __init io_apic_bug_finalize(v
late_initcall(io_apic_bug_finalize);
-static struct IO_APIC_route_entry *ioapic_saved_data[MAX_IO_APICS];
-
static void suspend_ioapic(int ioapic_id)
{
struct IO_APIC_route_entry *saved_data = ioapic_saved_data[ioapic_id];
@@ -2978,18 +2989,6 @@ static struct syscore_ops ioapic_syscore
static int __init ioapic_init_ops(void)
{
- int i;
-
- for (i = 0; i < nr_ioapics; i++) {
- unsigned int size;
-
- size = nr_ioapic_registers[i]
- * sizeof(struct IO_APIC_route_entry);
- ioapic_saved_data[i] = kzalloc(size, GFP_KERNEL);
- if (!ioapic_saved_data[i])
- pr_err("IOAPIC %d: suspend/resume impossible!\n", i);
- }
-
register_syscore_ops(&ioapic_syscore_ops);
return 0;
^ permalink raw reply [flat|nested] 6+ messages in thread* [patch 3/4] x86, ioapic: use ioapic_saved_data while enabling intr-remapping
2011-05-16 18:56 [patch 1/4] x86, ioapic: fix potential resume deadlock Suresh Siddha
2011-05-16 18:56 ` [patch 2/4] x86, ioapic: allocate ioapic_saved_data early Suresh Siddha
@ 2011-05-16 18:56 ` Suresh Siddha
2011-05-16 18:56 ` [patch 4/4] x86, ioapic: remove duplicate code for saving/restoring RTEs Suresh Siddha
2011-05-16 19:53 ` [patch 1/4] x86, ioapic: fix potential resume deadlock Daniel J Blueman
3 siblings, 0 replies; 6+ messages in thread
From: Suresh Siddha @ 2011-05-16 18:56 UTC (permalink / raw)
To: mingo, tglx, hpa; +Cc: linux-kernel, daniel.blueman, suresh.b.siddha
[-- Attachment #1: use_ioapic_saved_data_for_intremap.patch --]
[-- Type: text/plain, Size: 8508 bytes --]
Code flow for enabling interrupt-remapping was allocating/freeing buffers
for saving/restoring io-apic RTE's. ioapic suspend/resume code uses boot
time allocated ioapic_saved_data that is a perfect match for reuse here.
This will remove the unnecessary allocation/free of the temporary buffers
during suspend/resume of interrupt-remapping enabled platforms aswell
as paving the way for further code consolidation.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
---
arch/x86/include/asm/io_apic.h | 20 +++-------
arch/x86/kernel/apic/apic.c | 48 ++++++------------------
arch/x86/kernel/apic/io_apic.c | 80 +++++++++--------------------------------
3 files changed, 37 insertions(+), 111 deletions(-)
Index: linux-2.6-tip/arch/x86/kernel/apic/io_apic.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-2.6-tip/arch/x86/kernel/apic/io_apic.c
@@ -101,7 +101,7 @@ int mp_irq_entries;
static int nr_irqs_gsi = NR_IRQS_LEGACY;
/*
- * Saved I/O APIC state during suspend/resume.
+ * Saved I/O APIC state during suspend/resume, or while enabling intr-remap.
*/
static struct IO_APIC_route_entry *ioapic_saved_data[MAX_IO_APICS];
@@ -628,74 +628,43 @@ static int __init ioapic_pirq_setup(char
__setup("pirq=", ioapic_pirq_setup);
#endif /* CONFIG_X86_32 */
-struct IO_APIC_route_entry **alloc_ioapic_entries(void)
-{
- int apic;
- struct IO_APIC_route_entry **ioapic_entries;
-
- ioapic_entries = kzalloc(sizeof(*ioapic_entries) * nr_ioapics,
- GFP_ATOMIC);
- if (!ioapic_entries)
- return 0;
-
- for (apic = 0; apic < nr_ioapics; apic++) {
- ioapic_entries[apic] =
- kzalloc(sizeof(struct IO_APIC_route_entry) *
- nr_ioapic_registers[apic], GFP_ATOMIC);
- if (!ioapic_entries[apic])
- goto nomem;
- }
-
- return ioapic_entries;
-
-nomem:
- while (--apic >= 0)
- kfree(ioapic_entries[apic]);
- kfree(ioapic_entries);
-
- return 0;
-}
-
/*
* Saves all the IO-APIC RTE's
*/
-int save_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
+int save_ioapic_entries(void)
{
int apic, pin;
-
- if (!ioapic_entries)
- return -ENOMEM;
+ int err = 0;
for (apic = 0; apic < nr_ioapics; apic++) {
- if (!ioapic_entries[apic])
- return -ENOMEM;
+ if (!ioapic_saved_data[apic]) {
+ err = -ENOMEM;
+ continue;
+ }
for (pin = 0; pin < nr_ioapic_registers[apic]; pin++)
- ioapic_entries[apic][pin] =
+ ioapic_saved_data[apic][pin] =
ioapic_read_entry(apic, pin);
}
- return 0;
+ return err;
}
/*
* Mask all IO APIC entries.
*/
-void mask_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
+void mask_ioapic_entries(void)
{
int apic, pin;
- if (!ioapic_entries)
- return;
-
for (apic = 0; apic < nr_ioapics; apic++) {
- if (!ioapic_entries[apic])
- break;
+ if (!ioapic_saved_data[apic])
+ continue;
for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
struct IO_APIC_route_entry entry;
- entry = ioapic_entries[apic][pin];
+ entry = ioapic_saved_data[apic][pin];
if (!entry.mask) {
entry.mask = 1;
ioapic_write_entry(apic, pin, entry);
@@ -705,36 +674,23 @@ void mask_IO_APIC_setup(struct IO_APIC_r
}
/*
- * Restore IO APIC entries which was saved in ioapic_entries.
+ * Restore IO APIC entries which was saved in ioapic_saved_data
*/
-int restore_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
+int restore_ioapic_entries(void)
{
int apic, pin;
- if (!ioapic_entries)
- return -ENOMEM;
-
for (apic = 0; apic < nr_ioapics; apic++) {
- if (!ioapic_entries[apic])
- return -ENOMEM;
+ if (!ioapic_saved_data[apic])
+ continue;
for (pin = 0; pin < nr_ioapic_registers[apic]; pin++)
ioapic_write_entry(apic, pin,
- ioapic_entries[apic][pin]);
+ ioapic_saved_data[apic][pin]);
}
return 0;
}
-void free_ioapic_entries(struct IO_APIC_route_entry **ioapic_entries)
-{
- int apic;
-
- for (apic = 0; apic < nr_ioapics; apic++)
- kfree(ioapic_entries[apic]);
-
- kfree(ioapic_entries);
-}
-
/*
* Find the IRQ entry number of a certain pin.
*/
Index: linux-2.6-tip/arch/x86/include/asm/io_apic.h
===================================================================
--- linux-2.6-tip.orig/arch/x86/include/asm/io_apic.h
+++ linux-2.6-tip/arch/x86/include/asm/io_apic.h
@@ -152,11 +152,9 @@ extern void ioapic_insert_resources(void
int io_apic_setup_irq_pin_once(unsigned int irq, int node, struct io_apic_irq_attr *attr);
-extern struct IO_APIC_route_entry **alloc_ioapic_entries(void);
-extern void free_ioapic_entries(struct IO_APIC_route_entry **ioapic_entries);
-extern int save_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries);
-extern void mask_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries);
-extern int restore_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries);
+extern int save_ioapic_entries(void);
+extern void mask_ioapic_entries(void);
+extern int restore_ioapic_entries(void);
extern int get_nr_irqs_gsi(void);
@@ -192,19 +190,13 @@ struct io_apic_irq_attr;
static inline int io_apic_set_pci_routing(struct device *dev, int irq,
struct io_apic_irq_attr *irq_attr) { return 0; }
-static inline struct IO_APIC_route_entry **alloc_ioapic_entries(void)
-{
- return NULL;
-}
-
-static inline void free_ioapic_entries(struct IO_APIC_route_entry **ent) { }
-static inline int save_IO_APIC_setup(struct IO_APIC_route_entry **ent)
+static inline int save_ioapic_entries(void)
{
return -ENOMEM;
}
-static inline void mask_IO_APIC_setup(struct IO_APIC_route_entry **ent) { }
-static inline int restore_IO_APIC_setup(struct IO_APIC_route_entry **ent)
+static inline void mask_ioapic_entries(void) { }
+static inline int restore_ioapic_entries(void)
{
return -ENOMEM;
}
Index: linux-2.6-tip/arch/x86/kernel/apic/apic.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/apic.c
+++ linux-2.6-tip/arch/x86/kernel/apic/apic.c
@@ -1461,7 +1461,6 @@ int __init enable_IR(void)
void __init enable_IR_x2apic(void)
{
unsigned long flags;
- struct IO_APIC_route_entry **ioapic_entries;
int ret, x2apic_enabled = 0;
int dmar_table_init_ret;
@@ -1469,13 +1468,7 @@ void __init enable_IR_x2apic(void)
if (dmar_table_init_ret && !x2apic_supported())
return;
- ioapic_entries = alloc_ioapic_entries();
- if (!ioapic_entries) {
- pr_err("Allocate ioapic_entries failed\n");
- goto out;
- }
-
- ret = save_IO_APIC_setup(ioapic_entries);
+ ret = save_ioapic_entries();
if (ret) {
pr_info("Saving IO-APIC state failed: %d\n", ret);
goto out;
@@ -1483,7 +1476,7 @@ void __init enable_IR_x2apic(void)
local_irq_save(flags);
legacy_pic->mask_all();
- mask_IO_APIC_setup(ioapic_entries);
+ mask_ioapic_entries();
if (dmar_table_init_ret)
ret = 0;
@@ -1514,14 +1507,11 @@ void __init enable_IR_x2apic(void)
nox2apic:
if (!ret) /* IR enabling failed */
- restore_IO_APIC_setup(ioapic_entries);
+ restore_ioapic_entries();
legacy_pic->restore_mask();
local_irq_restore(flags);
out:
- if (ioapic_entries)
- free_ioapic_entries(ioapic_entries);
-
if (x2apic_enabled)
return;
@@ -2095,28 +2085,20 @@ static void lapic_resume(void)
{
unsigned int l, h;
unsigned long flags;
- int maxlvt, ret;
- struct IO_APIC_route_entry **ioapic_entries = NULL;
+ int maxlvt;
if (!apic_pm_state.active)
return;
local_irq_save(flags);
if (intr_remapping_enabled) {
- ioapic_entries = alloc_ioapic_entries();
- if (!ioapic_entries) {
- WARN(1, "Alloc ioapic_entries in lapic resume failed.");
- goto restore;
- }
-
- ret = save_IO_APIC_setup(ioapic_entries);
- if (ret) {
- WARN(1, "Saving IO-APIC state failed: %d\n", ret);
- free_ioapic_entries(ioapic_entries);
- goto restore;
- }
-
- mask_IO_APIC_setup(ioapic_entries);
+ /*
+ * IO-APIC and PIC have their own resume routines.
+ * We just mask them here to make sure the interrupt
+ * subsystem is completely quiet while we enable x2apic
+ * and interrupt-remapping.
+ */
+ mask_ioapic_entries();
legacy_pic->mask_all();
}
@@ -2159,13 +2141,9 @@ static void lapic_resume(void)
apic_write(APIC_ESR, 0);
apic_read(APIC_ESR);
- if (intr_remapping_enabled) {
+ if (intr_remapping_enabled)
reenable_intr_remapping(x2apic_mode);
- legacy_pic->restore_mask();
- restore_IO_APIC_setup(ioapic_entries);
- free_ioapic_entries(ioapic_entries);
- }
-restore:
+
local_irq_restore(flags);
}
^ permalink raw reply [flat|nested] 6+ messages in thread* [patch 4/4] x86, ioapic: remove duplicate code for saving/restoring RTEs
2011-05-16 18:56 [patch 1/4] x86, ioapic: fix potential resume deadlock Suresh Siddha
2011-05-16 18:56 ` [patch 2/4] x86, ioapic: allocate ioapic_saved_data early Suresh Siddha
2011-05-16 18:56 ` [patch 3/4] x86, ioapic: use ioapic_saved_data while enabling intr-remapping Suresh Siddha
@ 2011-05-16 18:56 ` Suresh Siddha
2011-05-17 9:08 ` Ingo Molnar
2011-05-16 19:53 ` [patch 1/4] x86, ioapic: fix potential resume deadlock Daniel J Blueman
3 siblings, 1 reply; 6+ messages in thread
From: Suresh Siddha @ 2011-05-16 18:56 UTC (permalink / raw)
To: mingo, tglx, hpa; +Cc: linux-kernel, daniel.blueman, suresh.b.siddha
[-- Attachment #1: use_saved_ioapic_for_suspend.patch --]
[-- Type: text/plain, Size: 2185 bytes --]
Code flow for enabling interrupt-remapping has its own routines for saving and
restoring io-apic RTE's. ioapic suspend/resume code flow also has similar
routines. Remove the duplicate code.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
---
arch/x86/kernel/apic/io_apic.c | 36 +++++-------------------------------
1 file changed, 5 insertions(+), 31 deletions(-)
Index: linux-2.6-tip/arch/x86/kernel/apic/io_apic.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-2.6-tip/arch/x86/kernel/apic/io_apic.c
@@ -2887,37 +2887,11 @@ static int __init io_apic_bug_finalize(v
late_initcall(io_apic_bug_finalize);
-static void suspend_ioapic(int ioapic_id)
+static void resume_ioapic_id(int ioapic_id)
{
- struct IO_APIC_route_entry *saved_data = ioapic_saved_data[ioapic_id];
- int i;
-
- if (!saved_data)
- return;
-
- for (i = 0; i < nr_ioapic_registers[ioapic_id]; i++)
- saved_data[i] = ioapic_read_entry(ioapic_id, i);
-}
-
-static int ioapic_suspend(void)
-{
- int ioapic_id;
-
- for (ioapic_id = 0; ioapic_id < nr_ioapics; ioapic_id++)
- suspend_ioapic(ioapic_id);
-
- return 0;
-}
-
-static void resume_ioapic(int ioapic_id)
-{
- struct IO_APIC_route_entry *saved_data = ioapic_saved_data[ioapic_id];
unsigned long flags;
union IO_APIC_reg_00 reg_00;
- int i;
- if (!saved_data)
- return;
raw_spin_lock_irqsave(&ioapic_lock, flags);
reg_00.raw = io_apic_read(ioapic_id, 0);
@@ -2926,8 +2900,6 @@ static void resume_ioapic(int ioapic_id)
io_apic_write(ioapic_id, 0, reg_00.raw);
}
raw_spin_unlock_irqrestore(&ioapic_lock, flags);
- for (i = 0; i < nr_ioapic_registers[ioapic_id]; i++)
- ioapic_write_entry(ioapic_id, i, saved_data[i]);
}
static void ioapic_resume(void)
@@ -2935,11 +2907,13 @@ static void ioapic_resume(void)
int ioapic_id;
for (ioapic_id = nr_ioapics - 1; ioapic_id >= 0; ioapic_id--)
- resume_ioapic(ioapic_id);
+ resume_ioapic_id(ioapic_id);
+
+ restore_ioapic_entries();
}
static struct syscore_ops ioapic_syscore_ops = {
- .suspend = ioapic_suspend,
+ .suspend = save_ioapic_entries,
.resume = ioapic_resume,
};
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [patch 4/4] x86, ioapic: remove duplicate code for saving/restoring RTEs
2011-05-16 18:56 ` [patch 4/4] x86, ioapic: remove duplicate code for saving/restoring RTEs Suresh Siddha
@ 2011-05-17 9:08 ` Ingo Molnar
0 siblings, 0 replies; 6+ messages in thread
From: Ingo Molnar @ 2011-05-17 9:08 UTC (permalink / raw)
To: Suresh Siddha; +Cc: tglx, hpa, linux-kernel, daniel.blueman
ok, this series looks better, but as this bug has demonstrated it we need to do
better to keep the ioapic code clean.
Firstly, please introduce a 'struct ioapic' structure that starts out with a
nr_registers field, and add an ioapics[] array and consolidate
nr_ioapic_registers into this.
The consolidate other ioapic driver state as well:
- add a *saved_registers field and consolidate ioapic_saved_data into it
- add a 'struct mpc_ioapic mp_config' entry and consolidate mp_ioapics[]
- add a 'struct mp_ioapic_gsi gsi_config' entry and consolidate mp_gsi_routing[]
- add a 'int pin_programmed' field and consolidate mp_ioapic_routing[] into it
ioapics[] itself should be static to io_apic.c.
Please create a separate patch for each change: that way it's bisectable and
reviewable.
These changes alone will make the IO-APIC code a *lot* more readable, more
extensible - and hopefully much less prone to suspend/resume bugs as well.
Feel free to do this on top of your current queue to keep your patch-shuffling
overhead low.
Thanks,
Ingo
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [patch 1/4] x86, ioapic: fix potential resume deadlock
2011-05-16 18:56 [patch 1/4] x86, ioapic: fix potential resume deadlock Suresh Siddha
` (2 preceding siblings ...)
2011-05-16 18:56 ` [patch 4/4] x86, ioapic: remove duplicate code for saving/restoring RTEs Suresh Siddha
@ 2011-05-16 19:53 ` Daniel J Blueman
3 siblings, 0 replies; 6+ messages in thread
From: Daniel J Blueman @ 2011-05-16 19:53 UTC (permalink / raw)
To: Suresh Siddha; +Cc: mingo, tglx, hpa, linux-kernel, stable
On 16 May 2011 19:56, Suresh Siddha <suresh.b.siddha@intel.com> wrote:
> From: Daniel J Blueman <daniel.blueman@gmail.com>
> Subject: x86, ioapic: fix potential resume deadlock
>
> Fix a potential deadlock when resuming; here the calling function
> has disabled interrupts, so we cannot sleep.
>
> Change the memory allocation flag from GFP_KERNEL to GFP_ATOMIC.
>
> TODO: We can do away with this memory allocation during resume by
> reusing the ioapic suspend/resume code that uses boot time allocated
> buffers.
>
> Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
> Cc: stable@kernel.org [v2.6.39]
> ---
> arch/x86/kernel/apic/io_apic.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> Index: linux-2.6-tip/arch/x86/kernel/apic/io_apic.c
> ===================================================================
> --- linux-2.6-tip.orig/arch/x86/kernel/apic/io_apic.c
> +++ linux-2.6-tip/arch/x86/kernel/apic/io_apic.c
> @@ -621,14 +621,14 @@ struct IO_APIC_route_entry **alloc_ioapi
> struct IO_APIC_route_entry **ioapic_entries;
>
> ioapic_entries = kzalloc(sizeof(*ioapic_entries) * nr_ioapics,
> - GFP_KERNEL);
> + GFP_ATOMIC);
> if (!ioapic_entries)
> return 0;
>
> for (apic = 0; apic < nr_ioapics; apic++) {
> ioapic_entries[apic] =
> kzalloc(sizeof(struct IO_APIC_route_entry) *
> - nr_ioapic_registers[apic], GFP_KERNEL);
> + nr_ioapic_registers[apic], GFP_ATOMIC);
> if (!ioapic_entries[apic])
> goto nomem;
> }
I just tested this patch series (1-3) and it does addresses the resume
allocation failures I was consistently seeing (triggering your
warning); it passes nicely with full lock, allocation etc debugging,
so looks all good. Tested-by: Daniel J Blueman
<daniel.blueman@gmail.com>
Thanks, Suresh!
Daniel
--
Daniel J Blueman
^ permalink raw reply [flat|nested] 6+ messages in thread