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irqchip/gic-v3-its: Fix VSYNC referencing an unmapped VPE on GIC v4.1

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commit 80e9963fb3b5509dfcabe9652d56bf4b35542055 upstream.

As per the GICv4.1 spec (Arm IHI 0069H, 5.3.19):

 "A VMAPP with {V, Alloc}=={0, x} is self-synchronizing, This means the ITS
  command queue does not show the command as consumed until all of its
  effects are completed."

Furthermore, VSYNC is allowed to deliver an SError when referencing a
non existent VPE.

By these definitions, a VMAPP followed by a VSYNC is a bug, as the
later references a VPE that has been unmapped by the former.

Fix it by eliding the VSYNC in this scenario.

Fixes: 64edfaa9a234 ("irqchip/gic-v4.1: Implement the v4.1 flavour of VMAPP")
Signed-off-by: Nianyao Tang <tangnianyao@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20240406022737.3898763-1-tangnianyao@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Nianyao Tang 2024-04-06 02:27:37 +00:00 • committed by Ksawlii
parent f93e3153c5
commit c25cfe7ca9
1 changed files with 7 additions and 1 deletions
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8
drivers/irqchip/irq-gic-v3-its.c
View file

@ -779,6 +779,7 @@ static struct its_vpe *its_build_vmapp_cmd(struct its_node *its,
struct its_cmd_block *cmd,
struct its_cmd_desc *desc)
{
struct its_vpe *vpe = valid_vpe(its, desc->its_vmapp_cmd.vpe);
unsigned long vpt_addr, vconf_addr;
u64 target;
bool alloc;
@ -791,6 +792,11 @@ static struct its_vpe *its_build_vmapp_cmd(struct its_node *its,
if (is_v4_1(its)) {
alloc = !atomic_dec_return(&desc->its_vmapp_cmd.vpe->vmapp_count);
its_encode_alloc(cmd, alloc);
/*
* Unmapping a VPE is self-synchronizing on GICv4.1,
* no need to issue a VSYNC.
*/
vpe = NULL;
}
goto out;
@ -820,7 +826,7 @@ static struct its_vpe *its_build_vmapp_cmd(struct its_node *its,
out:
its_fixup_cmd(cmd);
return valid_vpe(its, desc->its_vmapp_cmd.vpe);
return vpe;
}
static struct its_vpe *its_build_vmapti_cmd(struct its_node *its,