Commit Graph

178 Commits

Author SHA1 Message Date
Miaoqian Lin
fa1ad9d4cc irqchip/gic-v3: Fix refcount leak in gic_populate_ppi_partitions
of_find_node_by_phandle() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
Add missing of_node_put() to avoid refcount leak.

Fixes: e3825ba1af ("irqchip/gic-v3: Add support for partitioned PPIs")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220601080930.31005-6-linmq006@gmail.com
2022-06-09 17:36:57 +01:00
Miaoqian Lin
ec8401a429 irqchip/gic-v3: Fix error handling in gic_populate_ppi_partitions
of_get_child_by_name() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
When kcalloc fails, it missing of_node_put() and results in refcount
leak. Fix this by goto out_put_node label.

Fixes: 52085d3f20 ("irqchip/gic-v3: Dynamically allocate PPI partition descriptors")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220601080930.31005-5-linmq006@gmail.com
2022-06-09 17:36:57 +01:00
Marc Zyngier
492449ae4f Merge branch irq/gic-v3-nmi-fixes-5.19 into irq/irqchip-next
* irq/gic-v3-nmi-fixes-5.19:
  : .
  : GICv3 pseudo-NMI fixes from Mark Rutland:
  :
  : "These patches fix a couple of issues with the way GICv3 pseudo-NMIs are
  : handled:
  :
  : * The first patch adds a barrier we missed from NMI handling due to an
  :   oversight.
  :
  : * The second patch refactors some logic around reads from ICC_IAR1_EL1
  :   and adds commentary to explain what's going on.
  :
  : * The third patch descends into madness, reworking gic_handle_irq() to
  :   consistently manage ICC_PMR_EL1 + DAIF and avoid cases where these can
  :   be left in an inconsistent state while softirqs are processed."
  : .
  irqchip/gic-v3: Fix priority mask handling
  irqchip/gic-v3: Refactor ISB + EOIR at ack time
  irqchip/gic-v3: Ensure pseudo-NMIs have an ISB between ack and handling

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-05-17 10:37:06 +01:00
Mark Rutland
614ab80c96 irqchip/gic-v3: Fix priority mask handling
When a kernel is built with CONFIG_ARM64_PSEUDO_NMI=y and pseudo-NMIs
are enabled at runtime, GICv3's gic_handle_irq() can leave DAIF and
ICC_PMR_EL1 in an unexpected state in some cases, breaking subsequent
usage of local_irq_enable() and resulting in softirqs being run with
IRQs erroneously masked (possibly resulting in deadlocks).

This can happen when an IRQ exception is taken from a context where
regular IRQs were unmasked, and either:

(1) ICC_IAR1_EL1 indicates a special INTID (e.g. as a result of an IRQ
    being withdrawn since the IRQ exception was taken).

(2) ICC_IAR1_EL1 and ICC_RPR_EL1 indicate an NMI was acknowledged.

When an NMI is taken from a context where regular IRQs were masked,
there is no problem.

When CONFIG_ARM64_DEBUG_PRIORITY_MASKING=y, this can be detected with
perf, e.g.

| # ./perf record -a -g -e cycles:k ls -alR / > /dev/null 2>&1
| ------------[ cut here ]------------
| WARNING: CPU: 0 PID: 14 at arch/arm64/include/asm/irqflags.h:32 arch_local_irq_enable+0x4c/0x6c
| Modules linked in:
| CPU: 0 PID: 14 Comm: ksoftirqd/0 Not tainted 5.18.0-rc5-00004-g876c38e3d20b #12
| Hardware name: linux,dummy-virt (DT)
| pstate: 204000c5 (nzCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : arch_local_irq_enable+0x4c/0x6c
| lr : __do_softirq+0x110/0x5d8
| sp : ffff8000080bbbc0
| pmr_save: 000000f0
| x29: ffff8000080bbbc0 x28: ffff316ac3a6ca40 x27: 0000000000000000
| x26: 0000000000000000 x25: ffffa04611c06008 x24: ffffa04611c06008
| x23: 0000000040400005 x22: 0000000000000200 x21: ffff8000080bbe20
| x20: ffffa0460fe10320 x19: 0000000000000009 x18: 0000000000000000
| x17: ffff91252dfa9000 x16: ffff800008004000 x15: 0000000000004000
| x14: 0000000000000028 x13: ffffa0460fe17578 x12: ffffa0460fed4294
| x11: ffffa0460fedc168 x10: ffffffffffffff80 x9 : ffffa0460fe10a70
| x8 : ffffa0460fedc168 x7 : 000000000000b762 x6 : 00000000057c3bdf
| x5 : ffff8000080bbb18 x4 : 0000000000000000 x3 : 0000000000000001
| x2 : ffff91252dfa9000 x1 : 0000000000000060 x0 : 00000000000000f0
| Call trace:
|  arch_local_irq_enable+0x4c/0x6c
|  __irq_exit_rcu+0x180/0x1ac
|  irq_exit_rcu+0x1c/0x44
|  el1_interrupt+0x4c/0xe4
|  el1h_64_irq_handler+0x18/0x24
|  el1h_64_irq+0x74/0x78
|  smpboot_thread_fn+0x68/0x2c0
|  kthread+0x124/0x130
|  ret_from_fork+0x10/0x20
| irq event stamp: 193241
| hardirqs last  enabled at (193240): [<ffffa0460fe10a9c>] __do_softirq+0x10c/0x5d8
| hardirqs last disabled at (193241): [<ffffa0461102ffe4>] el1_dbg+0x24/0x90
| softirqs last  enabled at (193234): [<ffffa0460fe10e00>] __do_softirq+0x470/0x5d8
| softirqs last disabled at (193239): [<ffffa0460fea9944>] __irq_exit_rcu+0x180/0x1ac
| ---[ end trace 0000000000000000 ]---

The necessary manipulation of DAIF and ICC_PMR_EL1 depends on the
interrupted context, but the structure of gic_handle_irq() makes this
also depend on whether the GIC reports an IRQ, NMI, or special INTID:

*  When the interrupted context had regular IRQs masked (and hence the
   interrupt must be an NMI), the entry code performs the NMI
   entry/exit and gic_handle_irq() should return with DAIF and
   ICC_PMR_EL1 unchanged.

   This is handled correctly today.

* When the interrupted context had regular IRQs unmasked, the entry code
  performs IRQ entry/exit, but expects gic_handle_irq() to always update
  ICC_PMR_EL1 and DAIF.IF to unmask NMIs (but not regular IRQs) prior to
  returning (which it must do prior to invoking any regular IRQ
  handler).

  This unbalanced calling convention is necessary because we don't know
  whether an NMI has been taken until acknowledged by a read from
  ICC_IAR1_EL1, and so we need to perform the read with NMI masked in
  case an NMI has been taken (and needs to be handled with NMIs masked).

  Unfortunately, this is not handled consistently:

  - When ICC_IAR1_EL1 reports a special INTID, gic_handle_irq() returns
    immediately without manipulating ICC_PMR_EL1 and DAIF.

  - When RPR_EL1 indicates an NMI, gic_handle_irq() calls
    gic_handle_nmi() to invoke the NMI handler, then returns without
    manipulating ICC_PMR_EL1 and DAIF.

  - For regular IRQs, gic_handle_irq() manipulates ICC_PMR_EL1 and DAIF
    prior to invoking the IRQ handler.

There were related problems with special INTID handling in the past,
where if an exception was taken from a context with regular IRQs masked
and ICC_IAR_EL1 reported a special INTID, gic_handle_irq() would
erroneously unmask NMIs in NMI context permitted an unexpected nested
NMI. That case specifically was fixed by commit:

  a97709f563 ("irqchip/gic-v3: Do not enable irqs when handling spurious interrups")

... but unfortunately that commit added an inverse problem, where if an
exception was taken from a context with regular IRQs *unmasked* and
ICC_IAR_EL1 reported a special INTID, gic_handle_irq() would erroneously
fail to  unmask NMIs (and consequently regular IRQs could not be
unmasked during softirq processing). Before and after that commit, if an
NMI was taken from a context with regular IRQs unmasked gic_handle_irq()
would not unmask NMIs prior to returning, leading to the same problem
with softirq handling.

This patch fixes this by restructuring gic_handle_irq(), splitting it
into separate irqson/irqsoff helper functions which consistently perform
the DAIF + ICC_PMR1_EL1 manipulation based upon the interrupted context,
regardless of the event indicated by ICC_IAR1_EL1.

The special INTID handling is moved into the low-level IRQ/NMI handler
invocation helper functions, so that early returns don't prevent the
required manipulation of DAIF + ICC_PMR_EL1.

Fixes: f32c926651 ("irqchip/gic-v3: Handle pseudo-NMIs")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220513133038.226182-4-mark.rutland@arm.com
2022-05-15 16:47:31 +01:00
Mark Rutland
6efb509237 irqchip/gic-v3: Refactor ISB + EOIR at ack time
There are cases where a context synchronization event is necessary
between an IRQ being raised and being handled, and there are races such
that we cannot rely upon the exception entry being subsequent to the
interrupt being raised. To fix this, we place an ISB between a read of
IAR and the subsequent invocation of an IRQ handler.

When EOI mode 1 is in use, we need to EOI an interrupt prior to invoking
its handler, and we have a write to EOIR for this. As this write to EOIR
requires an ISB, and this is provided by the gic_write_eoir() helper, we
omit the usual ISB in this case, with the logic being:

|	if (static_branch_likely(&supports_deactivate_key))
|		gic_write_eoir(irqnr);
|	else
|		isb();

This is somewhat opaque, and it would be a little clearer if there were
an unconditional ISB, with only the write to EOIR being conditional,
e.g.

|	if (static_branch_likely(&supports_deactivate_key))
|		write_gicreg(irqnr, ICC_EOIR1_EL1);
|
|	isb();

This patch rewrites the code that way, with this logic factored into a
new helper function with comments explaining what the ISB is for, as
were originally laid out in commit:

  39a06b67c2 ("irqchip/gic: Ensure we have an ISB between ack and ->handle_irq")

Note that since then, we removed the IAR polling in commit:

  342677d70a ("irqchip/gic-v3: Remove acknowledge loop")

... which removed one of the two race conditions.

For consistency, other portions of the driver are made to manipulate
EOIR using write_gicreg() and explcit ISBs, and the gic_write_eoir()
helper function is removed.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220513133038.226182-3-mark.rutland@arm.com
2022-05-15 16:38:25 +01:00
Mark Rutland
adf14453d2 irqchip/gic-v3: Ensure pseudo-NMIs have an ISB between ack and handling
There are cases where a context synchronization event is necessary
between an IRQ being raised and being handled, and there are races such
that we cannot rely upon the exception entry being subsequent to the
interrupt being raised.

We identified and fixes this for regular IRQs in commit:

  39a06b67c2 ("irqchip/gic: Ensure we have an ISB between ack and ->handle_irq")

Unfortunately, we forgot to do the same for psuedo-NMIs when support for
those was added in commit:

  f32c926651 ("irqchip/gic-v3: Handle pseudo-NMIs")

Which means that when pseudo-NMIs are used for PMU support, we'll hit
the same problem.

Apply the same fix as for regular IRQs. Note that when EOI mode 1 is in
use, the call to gic_write_eoir() will provide an ISB.

Fixes: f32c926651 ("irqchip/gic-v3: Handle pseudo-NMIs")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220513133038.226182-2-mark.rutland@arm.com
2022-05-15 16:38:18 +01:00
Robin Murphy
2b2cd74a06 irqchip/gic-v3: Claim iomem resources
As a simple quality-of-life tweak, claim our MMIO regions when mapping
them, such that the GIC shows up in /proc/iomem. No effort is spent on
trying to release them, since frankly if the GIC fails to probe then
it's never getting a second try anyway.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/c534c2a458a3bf94ccdae8abc6edc3d45a689c30.1649777295.git.robin.murphy@arm.com
2022-05-04 15:46:03 +01:00
Marc Zyngier
63f13483f0 irqchip/gic-v3: Relax polling of GIC{R,D}_CTLR.RWP
Recent work on the KVM GIC emulation has revealed that the GICv3
driver is a bit RWP-happy, as it polls this bit for each and
every write MMIO access involving a single interrupt.

As it turns out, polling RWP is only required when:
- Disabling an SGI, PPI or SPI
- Disabling LPIs at the redistributor level
- Disabling groups
- Enabling ARE
- Dealing with DPG*

Simplify the driver by removing all the other instances of RWP
polling, and add the one that was missing when enabling the distributor
(as that's where we set ARE).

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220405183857.205960-4-maz@kernel.org
2022-05-04 15:38:55 +01:00
Marc Zyngier
a837ed362e irqchip/gic-v3: Detect LPI invalidation MMIO registers
Since GICv4.1, an implementation can offer the same MMIO-based
implementation as DirectLPI, only with an ITS. Given that this
can be hugely beneficial for workloads that are very LPI masking
heavy (although these workloads are admitedly a bit odd).

Interestingly, this is independent of RVPEI, which only *implies*
the functionnality.

So let's detect whether the implementation has GICR_CTLR.IR set,
and propagate this as DirectLPI to the ITS driver.

While we're at it, repaint the GICv3 banner so that we advertise
the various capabilities at boot time to be slightly less invasive.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220405183857.205960-3-maz@kernel.org
2022-05-04 15:38:55 +01:00
Andre Przywara
544808f7e2 irqchip/gic, gic-v3: Prevent GSI to SGI translations
At the moment the GIC IRQ domain translation routine happily converts
ACPI table GSI numbers below 16 to GIC SGIs (Software Generated
Interrupts aka IPIs). On the Devicetree side we explicitly forbid this
translation, actually the function will never return HWIRQs below 16 when
using a DT based domain translation.

We expect SGIs to be handled in the first part of the function, and any
further occurrence should be treated as a firmware bug, so add a check
and print to report this explicitly and avoid lengthy debug sessions.

Fixes: 64b499d8df ("irqchip/gic-v3: Configure SGIs as standard interrupts")
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220404110842.2882446-1-andre.przywara@arm.com
2022-04-05 16:33:47 +01:00
Marc Zyngier
0df6664531 irqchip/gic-v3: Fix GICR_CTLR.RWP polling
It turns out that our polling of RWP is totally wrong when checking
for it in the redistributors, as we test the *distributor* bit index,
whereas it is a different bit number in the RDs... Oopsie boo.

This is embarassing. Not only because it is wrong, but also because
it took *8 years* to notice the blunder...

Just fix the damn thing.

Fixes: 021f653791 ("irqchip: gic-v3: Initial support for GICv3")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Link: https://lore.kernel.org/r/20220315165034.794482-2-maz@kernel.org
2022-04-05 16:33:13 +01:00
Barry Song
80e4e1f472 irqchip/gic-v3: Use dsb(ishst) to order writes with ICC_SGI1R_EL1 accesses
A dsb(ishst) barrier should be enough to order previous writes with
the system register generating the SGI, as we only need to guarantee
the visibility of data to other CPUs in the inner shareable domain
before we send the SGI.

A micro-benchmark is written to verify the performance impact on
kunpeng920 machine with 2 sockets, each socket has 2 dies, and
each die has 24 CPUs, so totally the system has 2 * 2 * 24 = 96
CPUs. ~2% performance improvement can be seen by this benchmark.

The code of benchmark module:

 #include <linux/module.h>
 #include <linux/timekeeping.h>

 volatile int data0 ____cacheline_aligned;
 volatile int data1 ____cacheline_aligned;
 volatile int data2 ____cacheline_aligned;
 volatile int data3 ____cacheline_aligned;
 volatile int data4 ____cacheline_aligned;
 volatile int data5 ____cacheline_aligned;
 volatile int data6 ____cacheline_aligned;

 static void ipi_latency_func(void *val)
 {
 }

 static int __init ipi_latency_init(void)
 {
 	ktime_t stime, etime, delta;
 	int cpu, i;
 	int start = smp_processor_id();

 	stime = ktime_get();
 	for ( i = 0; i < 1000; i++)
 		for (cpu = 0; cpu < 96; cpu++) {
 			data0 = data1 = data2 = data3 = data4 = data5 = data6 = cpu;
 			smp_call_function_single(cpu, ipi_latency_func, NULL, 1);
 		}
 	etime = ktime_get();

 	delta = ktime_sub(etime, stime);

 	printk("%s ipi from cpu%d to cpu0-95 delta of 1000times:%lld\n",
 			__func__, start, delta);

 	return 0;
 }
 module_init(ipi_latency_init);

 static void ipi_latency_exit(void)
 {
 }
 module_exit(ipi_latency_exit);

 MODULE_DESCRIPTION("IPI benchmark");
 MODULE_LICENSE("GPL");

run the below commands 10 times on both Vanilla and the kernel with this
patch:
 # taskset -c 0 insmod test.ko
 # rmmod test

The result on vanilla:
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:126757449
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:126784249
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:126177703
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:127022281
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:126184883
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:127374585
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:125778089
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:126974441
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:127357625
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:126228184

The result on the kernel with this patch:
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:124467401
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:123474209
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:123558497
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:122993951
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:122984223
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:123323609
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:124507583
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:123386963
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:123340664
 ipi_latency_init ipi from cpu0 to cpu0-95 delta of 1000times:123285324

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
[maz: tidied up commit message]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220220061910.6155-1-21cnbao@gmail.com
2022-02-21 16:17:02 +00:00
Marc Zyngier
cd448b24c6 Merge branch irq/misc-5.17 into irq/irqchip-next
* irq/misc-5.17:
  : .
  : Misc irqchip fixes:
  :
  : - Disable GICv4.1 RD's VPE table at boot time to avoid RAS errors
  : - Fix Ingenic TCU's u32/unsigned long abuse
  : - Some GICv2m constifying
  : - Mark imx_gpcv2_instance as __ro_after_init
  : - Enable a few missing IRQs on Spear
  : - Conversion to platform_get_irq_optional() for the Renesas irqchips
  : .
  irqchip/renesas-intc-irqpin: Use platform_get_irq_optional() to get the interrupt
  irqchip/renesas-irqc: Use platform_get_irq_optional() to get the interrupt
  irqchip/gic-v4: Disable redistributors' view of the VPE table at boot time
  irqchip/ingenic-tcu: Use correctly sized arguments for bit field
  irqchip/gic-v2m: Add const to of_device_id
  irqchip/imx-gpcv2: Mark imx_gpcv2_instance with __ro_after_init
  irqchip/spear-shirq: Add support for IRQ 0..6

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-12-20 14:00:47 +00:00
Marc Zyngier
79a7f77b9b irqchip/gic-v4: Disable redistributors' view of the VPE table at boot time
Jay Chen reported that using a kdump kernel on a GICv4.1 system
results in a RAS error being delivered when the secondary kernel
configures the ITS's view of the new VPE table.

As it turns out, that's because each RD still has a pointer to
the previous instance of the VPE table, and that particular
implementation is very upset by seeing two bits of the HW that
should point to the same table with different values.

To solve this, let's invalidate any reference that any RD has to
the VPE table when discovering the RDs. The ITS can then be
programmed as expected.

Reported-by: Jay Chen <jkchen@linux.alibaba.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Link: https://lore.kernel.org/r/20211214064716.21407-1-jkchen@linux.alibaba.com
Link: https://lore.kernel.org/r/20211216144804.1578566-1-maz@kernel.org
2021-12-16 15:19:52 +00:00
Valentin Schneider
d23bc2bc1d irqchip/gic-v3-its: Postpone LPI pending table freeing and memreserve
Memory used by the LPI tables have to be made persistent for kexec to have
a chance to work, as explained in [1]. If they have been made persistent
and we are booting into a kexec'd kernel, we also need to free the pages
that were preemptively allocated by the new kernel for those tables.

Both of those operations currently happen during its_cpu_init(), which
happens in a _STARTING (IOW atomic) cpuhp callback for secondary
CPUs. efi_mem_reserve_iomem() issues a GFP_ATOMIC allocation, which
unfortunately doesn't work under PREEMPT_RT (this ends up grabbing a
non-raw spinlock, which can sleep under PREEMPT_RT). Similarly, freeing the
pages ends up grabbing a sleepable spinlock.

Since the memreserve is only required by kexec, it doesn't have to be done
so early in the secondary boot process. Issue the reservation in a new
CPUHP_AP_ONLINE_DYN cpuhp callback, and piggy-back the page freeing on top
of it. A CPU gets to run the body of this new callback exactly once.

As kexec issues a machine_shutdown() prior to machine_kexec(), it will be
serialized vs a CPU being plugged to life by the hotplug machinery - either
the CPU will have been brought up and have had its redistributor's pending
table memreserved, or it never went online and will have its table
allocated by the new kernel.

[1]: https://lore.kernel.org/lkml/20180921195954.21574-1-marc.zyngier@arm.com/

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211027151506.2085066-3-valentin.schneider@arm.com
2021-12-16 13:21:11 +00:00
Mark Rutland
0953fb2637 irq: remove handle_domain_{irq,nmi}()
Now that entry code handles IRQ entry (including setting the IRQ regs)
before calling irqchip code, irqchip code can safely call
generic_handle_domain_irq(), and there's no functional reason for it to
call handle_domain_irq().

Let's cement this split of responsibility and remove handle_domain_irq()
entirely, updating irqchip drivers to call generic_handle_domain_irq().

For consistency, handle_domain_nmi() is similarly removed and replaced
with a generic_handle_domain_nmi() function which also does not perform
any entry logic.

Previously handle_domain_{irq,nmi}() had a WARN_ON() which would fire
when they were called in an inappropriate context. So that we can
identify similar issues going forward, similar WARN_ON_ONCE() logic is
added to the generic_handle_*() functions, and comments are updated for
clarity and consistency.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2021-10-26 10:13:31 +01:00
Marc Zyngier
acdcfd94ef Merge branch irq/misc-5.15 into irq/irqchip-next
* irq/misc-5.15:
  : .
  : Various irqchip fixes:
  :
  : - Fix edge interrupt support on loongson systems
  : - Advertise lack of wake-up logic on mtk-sysirq
  : - Fix mask tracking on the Apple AIC
  : - Correct priority reading of arm64 pseudo-NMI when SCR_EL3.FIQ==0
  : .
  irqchip/gic-v3: Fix priority comparison when non-secure priorities are used
  irqchip/apple-aic: Fix irq_disable from within irq handlers

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20 15:03:40 +01:00
Chen-Yu Tsai
8d474deaba irqchip/gic-v3: Fix priority comparison when non-secure priorities are used
When non-secure priorities are used, compared to the raw priority set,
the value read back from RPR is also right-shifted by one and the
highest bit set.

Add a macro to do the modifications to the raw priority when doing the
comparison against the RPR value. This corrects the pseudo-NMI behavior
when non-secure priorities in the GIC are used. Tested on 5.10 with
the "IPI as pseudo-NMI" series [1] applied on MT8195.

[1] https://lore.kernel.org/linux-arm-kernel/1604317487-14543-1-git-send-email-sumit.garg@linaro.org/

Fixes: 3367805909 ("irqchip/gic-v3: Support pseudo-NMIs when SCR_EL3.FIQ == 0")
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
[maz: Added comment contributed by Alex]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210811171505.1502090-1-wenst@chromium.org
2021-08-20 15:03:01 +01:00
James Morse
d753f849bf irqchip/gic-v3: Fix selection of partition domain for EPPIs
commit 5f51f80382 ("irqchip/gic-v3: Add EPPI range support") added
GIC_IRQ_TYPE_PARTITION support for EPPI to gic_irq_domain_translate(),
and commit 52085d3f20 ("irqchip/gic-v3: Dynamically allocate PPI
partition descriptors") made the gic_data.ppi_descs array big enough for
EPPI, but neither gic_irq_domain_select() nor partition_domain_translate()
were updated.

This means partitions are created by partition_create_desc() for the
EPPI range, but can't be registered as they will always match the root
domain and map to the summary interrupt.

Update gic_irq_domain_select() to match PPI and EPPI. The fwspec for
PPI and EPPI both start from 0. Use gic_irq_domain_translate() to find
the hwirq from the fwspec, then convert this to a ppi index.

Reported-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210729172748.28841-3-james.morse@arm.com
2021-08-12 08:11:03 +01:00
James Morse
bfa80ee9ce irqchip/gic-v3: Add __gic_get_ppi_index() to find the PPI number from hwirq
gic_get_ppi_index() is a useful concept for ppi partitions, as the GIC
has two PPI ranges but needs mapping to a single range when used as an
index in the gic_data.ppi_descs[] array.

Add a double-underscore version which takes just the intid. This will
be used in the partition domain select and translate helpers to enable
partition support for the EPPI range.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210729172748.28841-2-james.morse@arm.com
2021-08-12 08:11:03 +01:00
Linus Torvalds
36824f198c ARM:
- Add MTE support in guests, complete with tag save/restore interface
 
 - Reduce the impact of CMOs by moving them in the page-table code
 
 - Allow device block mappings at stage-2
 
 - Reduce the footprint of the vmemmap in protected mode
 
 - Support the vGIC on dumb systems such as the Apple M1
 
 - Add selftest infrastructure to support multiple configuration
   and apply that to PMU/non-PMU setups
 
 - Add selftests for the debug architecture
 
 - The usual crop of PMU fixes
 
 PPC:
 
 - Support for the H_RPT_INVALIDATE hypercall
 
 - Conversion of Book3S entry/exit to C
 
 - Bug fixes
 
 S390:
 
 - new HW facilities for guests
 
 - make inline assembly more robust with KASAN and co
 
 x86:
 
 - Allow userspace to handle emulation errors (unknown instructions)
 
 - Lazy allocation of the rmap (host physical -> guest physical address)
 
 - Support for virtualizing TSC scaling on VMX machines
 
 - Optimizations to avoid shattering huge pages at the beginning of live migration
 
 - Support for initializing the PDPTRs without loading them from memory
 
 - Many TLB flushing cleanups
 
 - Refuse to load if two-stage paging is available but NX is not (this has
   been a requirement in practice for over a year)
 
 - A large series that separates the MMU mode (WP/SMAP/SMEP etc.) from
   CR0/CR4/EFER, using the MMU mode everywhere once it is computed
   from the CPU registers
 
 - Use PM notifier to notify the guest about host suspend or hibernate
 
 - Support for passing arguments to Hyper-V hypercalls using XMM registers
 
 - Support for Hyper-V TLB flush hypercalls and enlightened MSR bitmap on
   AMD processors
 
 - Hide Hyper-V hypercalls that are not included in the guest CPUID
 
 - Fixes for live migration of virtual machines that use the Hyper-V
   "enlightened VMCS" optimization of nested virtualization
 
 - Bugfixes (not many)
 
 Generic:
 
 - Support for retrieving statistics without debugfs
 
 - Cleanups for the KVM selftests API
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "This covers all architectures (except MIPS) so I don't expect any
  other feature pull requests this merge window.

  ARM:

   - Add MTE support in guests, complete with tag save/restore interface

   - Reduce the impact of CMOs by moving them in the page-table code

   - Allow device block mappings at stage-2

   - Reduce the footprint of the vmemmap in protected mode

   - Support the vGIC on dumb systems such as the Apple M1

   - Add selftest infrastructure to support multiple configuration and
     apply that to PMU/non-PMU setups

   - Add selftests for the debug architecture

   - The usual crop of PMU fixes

  PPC:

   - Support for the H_RPT_INVALIDATE hypercall

   - Conversion of Book3S entry/exit to C

   - Bug fixes

  S390:

   - new HW facilities for guests

   - make inline assembly more robust with KASAN and co

  x86:

   - Allow userspace to handle emulation errors (unknown instructions)

   - Lazy allocation of the rmap (host physical -> guest physical
     address)

   - Support for virtualizing TSC scaling on VMX machines

   - Optimizations to avoid shattering huge pages at the beginning of
     live migration

   - Support for initializing the PDPTRs without loading them from
     memory

   - Many TLB flushing cleanups

   - Refuse to load if two-stage paging is available but NX is not (this
     has been a requirement in practice for over a year)

   - A large series that separates the MMU mode (WP/SMAP/SMEP etc.) from
     CR0/CR4/EFER, using the MMU mode everywhere once it is computed
     from the CPU registers

   - Use PM notifier to notify the guest about host suspend or hibernate

   - Support for passing arguments to Hyper-V hypercalls using XMM
     registers

   - Support for Hyper-V TLB flush hypercalls and enlightened MSR bitmap
     on AMD processors

   - Hide Hyper-V hypercalls that are not included in the guest CPUID

   - Fixes for live migration of virtual machines that use the Hyper-V
     "enlightened VMCS" optimization of nested virtualization

   - Bugfixes (not many)

  Generic:

   - Support for retrieving statistics without debugfs

   - Cleanups for the KVM selftests API"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (314 commits)
  KVM: x86: rename apic_access_page_done to apic_access_memslot_enabled
  kvm: x86: disable the narrow guest module parameter on unload
  selftests: kvm: Allows userspace to handle emulation errors.
  kvm: x86: Allow userspace to handle emulation errors
  KVM: x86/mmu: Let guest use GBPAGES if supported in hardware and TDP is on
  KVM: x86/mmu: Get CR4.SMEP from MMU, not vCPU, in shadow page fault
  KVM: x86/mmu: Get CR0.WP from MMU, not vCPU, in shadow page fault
  KVM: x86/mmu: Drop redundant rsvd bits reset for nested NPT
  KVM: x86/mmu: Optimize and clean up so called "last nonleaf level" logic
  KVM: x86: Enhance comments for MMU roles and nested transition trickiness
  KVM: x86/mmu: WARN on any reserved SPTE value when making a valid SPTE
  KVM: x86/mmu: Add helpers to do full reserved SPTE checks w/ generic MMU
  KVM: x86/mmu: Use MMU's role to determine PTTYPE
  KVM: x86/mmu: Collapse 32-bit PAE and 64-bit statements for helpers
  KVM: x86/mmu: Add a helper to calculate root from role_regs
  KVM: x86/mmu: Add helper to update paging metadata
  KVM: x86/mmu: Don't update nested guest's paging bitmasks if CR0.PG=0
  KVM: x86/mmu: Consolidate reset_rsvds_bits_mask() calls
  KVM: x86/mmu: Use MMU role_regs to get LA57, and drop vCPU LA57 helper
  KVM: x86/mmu: Get nested MMU's root level from the MMU's role
  ...
2021-06-28 15:40:51 -07:00
Marc Zyngier
382e6e177b irqchip/gic-v3: Workaround inconsistent PMR setting on NMI entry
The arm64 entry code suffers from an annoying issue on taking
a NMI, as it sets PMR to a value that actually allows IRQs
to be acknowledged. This is done for consistency with other parts
of the code, and is in the process of being fixed. This shouldn't
be a problem, as we are not enabling interrupts whilst in NMI
context.

However, in the infortunate scenario that we took a spurious NMI
(retired before the read of IAR) *and* that there is an IRQ pending
at the same time, we'll ack the IRQ in NMI context. Too bad.

In order to avoid deadlocks while running something like perf,
teach the GICv3 driver about this situation: if we were in
a context where no interrupt should have fired, transiently
set PMR to a value that only allows NMIs before acking the pending
interrupt, and restore the original value after that.

This papers over the core issue for the time being, and makes
NMIs great again. Sort of.

Fixes: 4d6a38da8e ("arm64: entry: always set GIC_PRIO_PSR_I_SET during entry")
Co-developed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/lkml/20210610145731.1350460-1-maz@kernel.org
2021-06-10 17:54:34 +01:00
Marc Zyngier
0e5cb77706 irqchip/gic: Split vGIC probing information from the GIC code
The vGIC advertising code is unsurprisingly very much tied to
the GIC implementations. However, we are about to extend the
support to lesser implementations.

Let's dissociate the vgic registration from the GIC code and
move it into KVM, where it makes a bit more sense. This also
allows us to mark the gic_kvm_info structures as __initdata.

Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-01 10:45:58 +01:00
Thomas Gleixner
765822e156 irqchip updates for Linux 5.13
New HW support:
 
 - New driver for the Nuvoton WPCM450 interrupt controller
 - New driver for the IDT 79rc3243x interrupt controller
 - Add support for interrupt trigger configuration to the MStar irqchip
 - Add more external interrupt support to the STM32 irqchip
 - Add new compatible strings for QCOM SC7280 to the qcom-pdc binding
 
 Fixes and cleanups:
 
 - Drop irq_create_strict_mappings() and irq_create_identity_mapping()
   from the irqdomain API, with cleanups in a couple of drivers
 - Fix nested NMI issue with spurious interrupts on GICv3
 - Don't allow GICv4.1 vSGIs when the CPU doesn't support them
 - Various cleanups and minor fixes
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Merge tag 'irqchip-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip and irqdomain updates from Marc Zyngier:

 New HW support:

  - New driver for the Nuvoton WPCM450 interrupt controller
  - New driver for the IDT 79rc3243x interrupt controller
  - Add support for interrupt trigger configuration to the MStar irqchip
  - Add more external interrupt support to the STM32 irqchip
  - Add new compatible strings for QCOM SC7280 to the qcom-pdc binding

 Fixes and cleanups:

  - Drop irq_create_strict_mappings() and irq_create_identity_mapping()
    from the irqdomain API, with cleanups in a couple of drivers
  - Fix nested NMI issue with spurious interrupts on GICv3
  - Don't allow GICv4.1 vSGIs when the CPU doesn't support them
  - Various cleanups and minor fixes

Link: https://lore.kernel.org/r/20210424094640.1731920-1-maz@kernel.org
2021-04-24 21:18:44 +02:00
He Ying
a97709f563 irqchip/gic-v3: Do not enable irqs when handling spurious interrups
We triggered the following error while running our 4.19 kernel
with the pseudo-NMI patches backported to it:

[   14.816231] ------------[ cut here ]------------
[   14.816231] kernel BUG at irq.c:99!
[   14.816232] Internal error: Oops - BUG: 0 [#1] SMP
[   14.816232] Process swapper/0 (pid: 0, stack limit = 0x(____ptrval____))
[   14.816233] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G           O      4.19.95.aarch64 #14
[   14.816233] Hardware name: evb (DT)
[   14.816234] pstate: 80400085 (Nzcv daIf +PAN -UAO)
[   14.816234] pc : asm_nmi_enter+0x94/0x98
[   14.816235] lr : asm_nmi_enter+0x18/0x98
[   14.816235] sp : ffff000008003c50
[   14.816235] pmr_save: 00000070
[   14.816237] x29: ffff000008003c50 x28: ffff0000095f56c0
[   14.816238] x27: 0000000000000000 x26: ffff000008004000
[   14.816239] x25: 00000000015e0000 x24: ffff8008fb916000
[   14.816240] x23: 0000000020400005 x22: ffff0000080817cc
[   14.816241] x21: ffff000008003da0 x20: 0000000000000060
[   14.816242] x19: 00000000000003ff x18: ffffffffffffffff
[   14.816243] x17: 0000000000000008 x16: 003d090000000000
[   14.816244] x15: ffff0000095ea6c8 x14: ffff8008fff5ab40
[   14.816244] x13: ffff8008fff58b9d x12: 0000000000000000
[   14.816245] x11: ffff000008c8a200 x10: 000000008e31fca5
[   14.816246] x9 : ffff000008c8a208 x8 : 000000000000000f
[   14.816247] x7 : 0000000000000004 x6 : ffff8008fff58b9e
[   14.816248] x5 : 0000000000000000 x4 : 0000000080000000
[   14.816249] x3 : 0000000000000000 x2 : 0000000080000000
[   14.816250] x1 : 0000000000120000 x0 : ffff0000095f56c0
[   14.816251] Call trace:
[   14.816251]  asm_nmi_enter+0x94/0x98
[   14.816251]  el1_irq+0x8c/0x180                    (IRQ C)
[   14.816252]  gic_handle_irq+0xbc/0x2e4
[   14.816252]  el1_irq+0xcc/0x180                    (IRQ B)
[   14.816253]  arch_timer_handler_virt+0x38/0x58
[   14.816253]  handle_percpu_devid_irq+0x90/0x240
[   14.816253]  generic_handle_irq+0x34/0x50
[   14.816254]  __handle_domain_irq+0x68/0xc0
[   14.816254]  gic_handle_irq+0xf8/0x2e4
[   14.816255]  el1_irq+0xcc/0x180                    (IRQ A)
[   14.816255]  arch_cpu_idle+0x34/0x1c8
[   14.816255]  default_idle_call+0x24/0x44
[   14.816256]  do_idle+0x1d0/0x2c8
[   14.816256]  cpu_startup_entry+0x28/0x30
[   14.816256]  rest_init+0xb8/0xc8
[   14.816257]  start_kernel+0x4c8/0x4f4
[   14.816257] Code: 940587f1 d5384100 b9401001 36a7fd01 (d4210000)
[   14.816258] Modules linked in: start_dp(O) smeth(O)
[   15.103092] ---[ end trace 701753956cb14aa8 ]---
[   15.103093] Kernel panic - not syncing: Fatal exception in interrupt
[   15.103099] SMP: stopping secondary CPUs
[   15.103100] Kernel Offset: disabled
[   15.103100] CPU features: 0x36,a2400218
[   15.103100] Memory Limit: none

which is cause by a 'BUG_ON(in_nmi())' in nmi_enter().

From the call trace, we can find three interrupts (noted A, B, C above):
interrupt (A) is preempted by (B), which is further interrupted by (C).

Subsequent investigations show that (B) results in nmi_enter() being
called, but that it actually is a spurious interrupt. Furthermore,
interrupts are reenabled in the context of (B), and (C) fires with
NMI priority. We end-up with a nested NMI situation, something
we definitely do not want to (and cannot) handle.

The bug here is that spurious interrupts should never result in any
state change, and we should just return to the interrupted context.
Moving the handling of spurious interrupts as early as possible in
the GICv3 handler fixes this issue.

Fixes: 3f1f3234bc ("irqchip/gic-v3: Switch to PMR masking before calling IRQ handler")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: He Ying <heying24@huawei.com>
[maz: rewrote commit message, corrected Fixes: tag]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210423083516.170111-1-heying24@huawei.com
Cc: stable@vger.kernel.org
2021-04-23 13:19:08 +01:00
Ingo Molnar
a359f75796 irq: Fix typos in comments
Fix ~36 single-word typos in the IRQ, irqchip and irqdomain code comments.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-03-22 04:23:14 +01:00
Lorenzo Pieralisi
d40341145a irqchip/gic-v3: Fix typos in PMR/RPR SCR_EL3.FIQ handling explanation
The GICv3 driver explanation related to PMR/RPR and SCR_EL3.FIQ
secure/non-secure priority handling contains a couple of typos.

Fix them.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210121182252.29320-1-lorenzo.pieralisi@arm.com
2021-01-21 20:21:49 +00:00
Valentin Schneider
6abbd69889 irqchip/gic, gic-v3: Make SGIs use handle_percpu_devid_irq()
handle_percpu_devid_fasteoi_ipi() states:

 * The biggest difference with the IRQ version is that the interrupt is
 * EOIed early, as the IPI could result in a context switch, and we need to
 * make sure the IPI can fire again

All that can actually happen scheduler-wise within the handling of an IPI
is the raising of TIF_NEED_RESCHED (and / or folding thereof into
preempt_count); see scheduler_ipi() or sched_ttwu_pending() for instance.

Said flag / preempt_count is evaluated some time later before returning to
whatever context was interrupted, and this gates a call to
preempt_schedule_irq() (arm64_preempt_schedule_irq() in arm64).

Per the above, SGI's do not need a different handler than PPI's, so make
them use the same (handle_percpu_devid_irq).

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201109094121.29975-2-valentin.schneider@arm.com
2020-12-11 14:47:49 +00:00
Marc Zyngier
eff65bd439 Merge remote-tracking branch 'origin/irq/gic-retrigger' into irq/irqchip-next
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-09-17 16:50:02 +01:00
Marc Zyngier
7e62dd911a Merge remote-tracking branch 'origin/irq/ipi-as-irq' into irq/irqchip-next
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-09-17 16:47:27 +01:00
Marc Zyngier
64b499d8df irqchip/gic-v3: Configure SGIs as standard interrupts
Change the way we deal with GICv3 SGIs by turning them into proper
IRQs, and calling into the arch code to register the interrupt range
instead of a callback.

Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-09-17 16:37:26 +01:00
Alexandru Elisei
3367805909 irqchip/gic-v3: Support pseudo-NMIs when SCR_EL3.FIQ == 0
The GIC's internal view of the priority mask register and the assigned
interrupt priorities are based on whether GIC security is enabled and
whether firmware routes Group 0 interrupts to EL3. At the moment, we
support priority masking when ICC_PMR_EL1 and interrupt priorities are
either both modified by the GIC, or both left unchanged.

Trusted Firmware-A's default interrupt routing model allows Group 0
interrupts to be delivered to the non-secure world (SCR_EL3.FIQ == 0).
Unfortunately, this is precisely the case that the GIC driver doesn't
support: ICC_PMR_EL1 remains unchanged, but the GIC's view of interrupt
priorities is different from the software programmed values.

Support pseudo-NMIs when SCR_EL3.FIQ == 0 by using a different value to
mask regular interrupts. All the other values remain the same.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200912153707.667731-3-alexandru.elisei@arm.com
2020-09-13 17:52:04 +01:00
Alexandru Elisei
4e594ad106 irqchip/gic-v3: Spell out when pseudo-NMIs are enabled
When NMIs cannot be enabled, the driver prints a message stating that
unambiguously. When they are enabled, the only feedback we get is a message
regarding the use of synchronization for ICC_PMR_EL1 writes, which is not
as useful for a user who is not intimately familiar with how NMIs are
implemented.

Let's make it obvious that pseudo-NMIs are enabled. Keep the message about
using a barrier for ICC_PMR_EL1 writes, because it has a non-negligible
impact on performance.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200912153707.667731-2-alexandru.elisei@arm.com
2020-09-13 17:51:35 +01:00
Marc Zyngier
70a29c32cf irqchip/gic-v3: Describe the SGI range
As we are about to start making use of SGIs in a more conventional
way, let's describe it is the GICv3 list of interrupt types.

Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-09-13 17:05:39 +01:00
Valentin Schneider
1b57d91b96 irqchip/gic-v2, v3: Prevent SW resends entirely
The GIC irqchips can now use a HW resend when a retrigger is invoked by
check_irq_resend(). However, should the HW resend fail, check_irq_resend()
will still attempt to trigger a SW resend, which is still a bad idea for
the GICs.

Prevent this from happening by setting IRQD_HANDLE_ENFORCE_IRQCTX on all
GIC IRQs. Technically per-cpu IRQs do not need this, as their flow handlers
never set IRQS_PENDING, but this aligns all IRQs wrt context enforcement:
this also forces all GIC IRQ handling to happen in IRQ context (as defined
by in_irq()).

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200730170321.31228-3-valentin.schneider@arm.com
2020-09-06 18:26:13 +01:00
Valentin Schneider
17f644e949 irqchip/gic-v2, v3: Implement irq_chip->irq_retrigger()
While digging around IRQCHIP_EOI_IF_HANDLED and irq/resend.c, it has come
to my attention that the IRQ resend situation seems a bit precarious for
the GIC(s).

When marking an IRQ with IRQS_PENDING, handle_fasteoi_irq() will bail out
and issue an irq_eoi(). Should the IRQ in question be re-enabled,
check_irq_resend() will trigger a SW resend, which will go through the flow
handler again and issue *another* irq_eoi() on the *same* IRQ
activation. This is something the GIC spec clearly describes as a bad idea:
any EOI must match a previous ACK.

Implement irq_chip.irq_retrigger() for the GIC chips by setting the GIC
pending bit of the relevant IRQ. After being called by check_irq_resend(),
this will eventually trigger a *new* interrupt which we will handle as usual.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200730170321.31228-2-valentin.schneider@arm.com
2020-09-06 18:26:13 +01:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Oscar Carter
aba3c7ed3f drivers/irqchip: Use new macro ACPI_DECLARE_SUBTABLE_PROBE_ENTRY
In an effort to enable -Wcast-function-type in the top-level Makefile to
support Control Flow Integrity builds, there are the need to remove all
the function callback casts.

To do this, modify the IRQCHIP_ACPI_DECLARE macro to use the new defined
macro ACPI_DECLARE_SUBTABLE_PROBE_ENTRY instead of the macro
ACPI_DECLARE_PROBE_ENTRY. This is necessary to be able to initialize the
the acpi_probe_entry struct using the probe_subtbl field instead of the
probe_table field and avoid function cast mismatches.

Also, modify the prototype of the functions used by the invocation of the
IRQCHIP_ACPI_DECLARE macro to match all the parameters.

Co-developed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Oscar Carter <oscar.carter@gmx.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20200530143430.5203-3-oscar.carter@gmx.com
2020-06-27 11:55:52 +01:00
Valentin Schneider
cc86432aa8 irqchip/gic-v2, v3: Drop extra IRQ_NOAUTOEN setting for (E)PPIs
(E)PPIs are per-CPU interrupts, so we want each CPU to go and enable them
via enable_percpu_irq(); this also means we want IRQ_NOAUTOEN for them as
the autoenable would lead to calling irq_enable() instead of the more
appropriate irq_percpu_enable().

Calling irq_set_percpu_devid() is enough to get just that since it trickles
down to irq_set_percpu_devid_flags(), which gives us IRQ_NOAUTOEN (and a
few others). Setting IRQ_NOAUTOEN *again* right after this call is just
redundant, so don't do it.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200521223500.834-1-valentin.schneider@arm.com
2020-05-25 10:32:51 +01:00
Ingo Rohloff
8a94c1ab34 irqchip/gic-v3: Fix missing "__init" for gic_smp_init()
With an SMP configuration, gic_smp_init() calls set_smp_cross_call().
set_smp_cross_call() is marked with "__init".
So gic_smp_init() should also be marked with "__init".
gic_smp_init() is only called from gic_init_bases().
gic_init_bases() is also marked with "__init";
So marking gic_smp_init() with "__init" is fine.

Signed-off-by: Ingo Rohloff <ingo.rohloff@lauterbach.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200422112857.4300-1-ingo.rohloff@lauterbach.com
2020-05-18 10:28:30 +01:00
Marc Zyngier
96806229ca irqchip/gic-v4.1: Add support for VPENDBASER's Dirty+Valid signaling
When a vPE is made resident, the GIC starts parsing the virtual pending
table to deliver pending interrupts. This takes place asynchronously,
and can at times take a long while. Long enough that the vcpu enters
the guest and hits WFI before any interrupt has been signaled yet.
The vcpu then exits, blocks, and now gets a doorbell. Rince, repeat.

In order to avoid the above, a (optional on GICv4, mandatory on v4.1)
feature allows the GIC to feedback to the hypervisor whether it is
done parsing the VPT by clearing the GICR_VPENDBASER.Dirty bit.
The hypervisor can then wait until the GIC is ready before actually
running the vPE.

Plug the detection code as well as polling on vPE schedule. While
at it, tidy-up the kernel message that displays the GICv4 optional
features.

Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-04-16 10:28:12 +01:00
Linus Torvalds
2d385336af Updates for the interrupt subsystem:
Treewide:
 
     - Cleanup of setup_irq() which is not longer required because the
       memory allocator is available early. Most cleanup changes come
       through the various maintainer trees, so the final removal of
       setup_irq() is postponed towards the end of the merge window.
 
   Core:
 
     - Protection against unsafe invocation of interrupt handlers and unsafe
       interrupt injection including a fixup of the offending PCI/AER error
       injection mechanism.
 
       Invoking interrupt handlers from arbitrary contexts, i.e. outside of
       an actual interrupt, can cause inconsistent state on the fragile
       x86 interrupt affinity changing hardware trainwreck.
 
   Drivers:
 
     - Second wave of support for the new ARM GICv4.1
     - Multi-instance support for Xilinx and PLIC interrupt controllers
     - CPU-Hotplug support for PLIC
     - The obligatory new driver for X1000 TCU
     - Enhancements, cleanups and fixes all over the place
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Merge tag 'irq-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "Updates for the interrupt subsystem:

  Treewide:

    - Cleanup of setup_irq() which is not longer required because the
      memory allocator is available early.

      Most cleanup changes come through the various maintainer trees, so
      the final removal of setup_irq() is postponed towards the end of
      the merge window.

  Core:

    - Protection against unsafe invocation of interrupt handlers and
      unsafe interrupt injection including a fixup of the offending
      PCI/AER error injection mechanism.

      Invoking interrupt handlers from arbitrary contexts, i.e. outside
      of an actual interrupt, can cause inconsistent state on the
      fragile x86 interrupt affinity changing hardware trainwreck.

  Drivers:

    - Second wave of support for the new ARM GICv4.1

    - Multi-instance support for Xilinx and PLIC interrupt controllers

    - CPU-Hotplug support for PLIC

    - The obligatory new driver for X1000 TCU

    - Enhancements, cleanups and fixes all over the place"

* tag 'irq-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits)
  unicore32: Replace setup_irq() by request_irq()
  sh: Replace setup_irq() by request_irq()
  hexagon: Replace setup_irq() by request_irq()
  c6x: Replace setup_irq() by request_irq()
  alpha: Replace setup_irq() by request_irq()
  irqchip/gic-v4.1: Eagerly vmap vPEs
  irqchip/gic-v4.1: Add VSGI property setup
  irqchip/gic-v4.1: Add VSGI allocation/teardown
  irqchip/gic-v4.1: Move doorbell management to the GICv4 abstraction layer
  irqchip/gic-v4.1: Plumb set_vcpu_affinity SGI callbacks
  irqchip/gic-v4.1: Plumb get/set_irqchip_state SGI callbacks
  irqchip/gic-v4.1: Plumb mask/unmask SGI callbacks
  irqchip/gic-v4.1: Add initial SGI configuration
  irqchip/gic-v4.1: Plumb skeletal VSGI irqchip
  irqchip/stm32: Retrigger both in eoi and unmask callbacks
  irqchip/gic-v3: Move irq_domain_update_bus_token to after checking for NULL domain
  irqchip/xilinx: Do not call irq_set_default_host()
  irqchip/xilinx: Enable generic irq multi handler
  irqchip/xilinx: Fill error code when irq domain registration fails
  irqchip/xilinx: Add support for multiple instances
  ...
2020-03-30 17:35:14 -07:00
Marc Zyngier
771df8cf0b Merge branch 'irq/gic-v4.1' into irq/irqchip-next
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-03-24 12:43:47 +00:00
luanshi
eeaa4b24e5 irqchip/gic-v3: Move irq_domain_update_bus_token to after checking for NULL domain
irq_domain_update_bus_token should be called after checking for NULL
domain.

Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1583983255-44115-1-git-send-email-zhangliguang@linux.alibaba.com
2020-03-22 11:52:53 +00:00
Marc Zyngier
3c40706d05 irqchip/gic-v4.1: Advertise support v4.1 to KVM
Tell KVM that we support v4.1. Nothing uses this information so far.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20200304203330.4967-7-maz@kernel.org
2020-03-20 17:48:38 +00:00
Marc Zyngier
9058a4e980 irqchip/gic-v4.1: Ensure mutual exclusion betwen invalidations on the same RD
The GICv4.1 spec says that it is CONTRAINED UNPREDICTABLE to write to
any of the GICR_INV{LPI,ALL}R registers if GICR_SYNCR.Busy == 1.

To deal with it, we must ensure that only a single invalidation can
happen at a time for a given redistributor. Add a per-RD lock to that
effect and take it around the invalidation/syncr-read to deal with this.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20200304203330.4967-6-maz@kernel.org
2020-03-20 17:48:21 +00:00
Marc Zyngier
0b04758b00 irqchip/gic-v3: Use SGIs without active state if offered
To allow the direct injection of SGIs into a guest, the GICv4.1
architecture has to sacrifice the Active state so that SGIs look
a lot like LPIs (they are injected by the same mechanism).

In order not to break existing software, the architecture gives
offers guests OSs the choice: SGIs with or without an active
state. It is the hypervisors duty to honor the guest's choice.

For this, the architecture offers a discovery bit indicating whether
the GIC supports GICv4.1 SGIs (GICD_TYPER2.nASSGIcap), and another
bit indicating whether the guest wants Active-less SGIs or not
(controlled by GICD_CTLR.nASSGIreq).

A hypervisor not supporting GICv4.1 SGIs would leave nASSGIcap
clear, and a guest not knowing about GICv4.1 SGIs (or definitely
wanting an Active state) would leave nASSGIreq clear (both being
thankfully backward compatible with older revisions of the GIC).

Since Linux is perfectly happy without an active state on SGIs,
inform the hypervisor that we'll use that if offered.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20200304203330.4967-2-maz@kernel.org
2020-03-19 11:11:21 +00:00
Marc Zyngier
d01fd161e8 irqchip/gic-v3: Workaround Cavium erratum 38539 when reading GICD_TYPER2
Despite the architecture spec requiring that reserved registers in the GIC
distributor memory map are RES0 (and thus are not allowed to generate
an exception), the Cavium ThunderX (aka TX1) SoC explodes as such:

[    0.000000] GICv3: GIC: Using split EOI/Deactivate mode
[    0.000000] GICv3: 128 SPIs implemented
[    0.000000] GICv3: 0 Extended SPIs implemented
[    0.000000] Internal error: synchronous external abort: 96000210 [#1] SMP
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc4-00035-g3cf6a3d5725f #7956
[    0.000000] Hardware name: cavium,thunder-88xx (DT)
[    0.000000] pstate: 60000085 (nZCv daIf -PAN -UAO)
[    0.000000] pc : __raw_readl+0x0/0x8
[    0.000000] lr : gic_init_bases+0x110/0x560
[    0.000000] sp : ffff800011243d90
[    0.000000] x29: ffff800011243d90 x28: 0000000000000000
[    0.000000] x27: 0000000000000018 x26: 0000000000000002
[    0.000000] x25: ffff8000116f0000 x24: ffff000fbe6a2c80
[    0.000000] x23: 0000000000000000 x22: ffff010fdc322b68
[    0.000000] x21: ffff800010a7a208 x20: 00000000009b0404
[    0.000000] x19: ffff80001124dad0 x18: 0000000000000010
[    0.000000] x17: 000000004d8d492b x16: 00000000f67eb9af
[    0.000000] x15: ffffffffffffffff x14: ffff800011249908
[    0.000000] x13: ffff800091243ae7 x12: ffff800011243af4
[    0.000000] x11: ffff80001126e000 x10: ffff800011243a70
[    0.000000] x9 : 00000000ffffffd0 x8 : ffff80001069c828
[    0.000000] x7 : 0000000000000059 x6 : ffff8000113fb4d1
[    0.000000] x5 : 0000000000000001 x4 : 0000000000000000
[    0.000000] x3 : 0000000000000000 x2 : 0000000000000000
[    0.000000] x1 : 0000000000000000 x0 : ffff8000116f000c
[    0.000000] Call trace:
[    0.000000]  __raw_readl+0x0/0x8
[    0.000000]  gic_of_init+0x188/0x224
[    0.000000]  of_irq_init+0x200/0x3cc
[    0.000000]  irqchip_init+0x1c/0x40
[    0.000000]  init_IRQ+0x160/0x1d0
[    0.000000]  start_kernel+0x2ec/0x4b8
[    0.000000] Code: a8c47bfd d65f03c0 d538d080 d65f03c0 (b9400000)

when reading the GICv4.1 GICD_TYPER2 register, which is unexpected...

Work around it by adding a new quirk for the following variants:

 ThunderX: CN88xx
 OCTEON TX: CN83xx, CN81xx
 OCTEON TX2: CN93xx, CN96xx, CN98xx, CNF95xx*

and use this flag to avoid accessing GICD_TYPER2. Note that all
reserved registers (including redistributors and ITS) are impacted
by this erratum, but that only GICD_TYPER2 has to be worked around
so far.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Robert Richter <rrichter@marvell.com>
Tested-by: Mark Salter <msalter@redhat.com>
Tested-by: Tim Harvey <tharvey@gateworks.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Robert Richter <rrichter@marvell.com>
Link: https://lore.kernel.org/r/20191027144234.8395-11-maz@kernel.org
Link: https://lore.kernel.org/r/20200311115649.26060-1-maz@kernel.org
2020-03-14 10:15:19 +00:00
Marc Zyngier
926b5dfa6b irqchip/gic-v3: Only provision redistributors that are enabled in ACPI
We currently allocate redistributor region structures for
individual redistributors when ACPI doesn't present us with
compact MMIO regions covering multiple redistributors.

It turns out that we allocate these structures even when
the redistributor is flagged as disabled by ACPI. It works
fine until someone actually tries to tarse one of these
structures, and access the corresponding MMIO region.

Instead, track the number of enabled redistributors, and
only allocate what is required. This makes sure that there
is no invalid data to misuse.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reported-by: Heyi Guo <guoheyi@huawei.com>
Tested-by: Heyi Guo <guoheyi@huawei.com>
Link: https://lore.kernel.org/r/20191216062745.63397-1-guoheyi@huawei.com
2020-01-28 13:17:46 +00:00
Marc Zyngier
f2d834092e irqchip/gic-v3: Add GICv4.1 VPEID size discovery
While GICv4.0 mandates 16 bit worth of VPEIDs, GICv4.1 allows smaller
implementations to be built. Add the required glue to dynamically
compute the limit.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20191224111055.11836-3-maz@kernel.org
2020-01-22 14:22:19 +00:00