6.6-stable review patch. If anyone has any objections, please let me know.
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From: Nianyao Tang tangnianyao@huawei.com
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 --- drivers/irqchip/irq-gic-v3-its.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
--- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -786,6 +786,7 @@ static struct its_vpe *its_build_vmapp_c 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; @@ -798,6 +799,11 @@ static struct its_vpe *its_build_vmapp_c 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; @@ -832,7 +838,7 @@ static struct its_vpe *its_build_vmapp_c 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,