Hi Greg,
sorry to bother you but I missed that the smp_cpu_get_cpu_address() address used here was only added with the commit 42d211a1ae3b77 ("s390/cpuinfo: show processor physical address") which landed in v5.7-rc1. This would therefore break if ever called (luckily it would not be called on any shipped hardware) and also causes a missing declaration warning as reported by Naresh Kamboju thanks! Since this is as of now just a spec fix, as on all known hardware the Linux CPU Id always matches the CPU Address, I would recommend to simply revert the commit. Thanks in advance!
Best regards, Niklas Schnelle
On 12/10/20 3:26 PM, Greg Kroah-Hartman wrote:
From: Alexander Gordeev agordeev@linux.ibm.com
commit a2bd4097b3ec242f4de4924db463a9c94530e03a upstream.
The directed MSIs are delivered to CPUs whose address is written to the MSI message address. The current code assumes that a CPU logical number (as it is seen by the kernel) is also the CPU address.
The above assumption is not correct, as the CPU address is rather the value returned by STAP instruction. That value does not necessarily match the kernel logical CPU number.
Fixes: e979ce7bced2 ("s390/pci: provide support for CPU directed interrupts") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Alexander Gordeev agordeev@linux.ibm.com Reviewed-by: Halil Pasic pasic@linux.ibm.com Reviewed-by: Niklas Schnelle schnelle@linux.ibm.com Signed-off-by: Niklas Schnelle schnelle@linux.ibm.com Signed-off-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
arch/s390/pci/pci_irq.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
--- a/arch/s390/pci/pci_irq.c +++ b/arch/s390/pci/pci_irq.c @@ -103,9 +103,10 @@ static int zpci_set_irq_affinity(struct { struct msi_desc *entry = irq_get_msi_desc(data->irq); struct msi_msg msg = entry->msg;
- int cpu_addr = smp_cpu_get_cpu_address(cpumask_first(dest));
msg.address_lo &= 0xff0000ff;
- msg.address_lo |= (cpumask_first(dest) << 8);
- msg.address_lo |= (cpu_addr << 8); pci_write_msi_msg(data->irq, &msg);
return IRQ_SET_MASK_OK; @@ -238,6 +239,7 @@ int arch_setup_msi_irqs(struct pci_dev * unsigned long bit; struct msi_desc *msi; struct msi_msg msg;
- int cpu_addr; int rc, irq;
zdev->aisb = -1UL; @@ -287,9 +289,15 @@ int arch_setup_msi_irqs(struct pci_dev * handle_percpu_irq); msg.data = hwirq - bit; if (irq_delivery == DIRECTED) {
if (msi->affinity)cpu = cpumask_first(&msi->affinity->mask);elsecpu = 0;cpu_addr = smp_cpu_get_cpu_address(cpu);msg.address_lo = zdev->msi_addr & 0xff0000ff;
msg.address_lo |= msi->affinity ?(cpumask_first(&msi->affinity->mask) << 8) : 0;
msg.address_lo |= (cpu_addr << 8);for_each_possible_cpu(cpu) { airq_iv_set_data(zpci_ibv[cpu], hwirq, irq); }