Re: [PATCH kernel] powerpc/ioda/npu2: Call hot reset skiboot hook when disabling NPU

Hi Alexey,

On Wednesday, 11 July 2018 7:45:10 PM AEST Alexey Kardashevskiy wrote:

On Thu,  7 Jun 2018 17:06:07 +1000
Alexey Kardashevskiy [off-list ref] wrote:

quoted

This brings NPU2 in a safe mode when it does not throw HMI if GPU
coherent memory is gone.

It might be helpful if you you could describe the problem and what you are
trying to solve in a bit more depth. Assuming the memory was online how are you
offlining it? If the memory has been online merely fencing/hot-resetting the
NVLink is likely not sufficient as you also need to flush caches prior to taking
the links down.

- Alistair

quoted

Signed-off-by: Alexey Kardashevskiy <redacted>

Anyone, ping?

quoted

---

The main aim for this is nvlink2 pass through, helps a lot.


---
 arch/powerpc/platforms/powernv/pci-ioda.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 66c2804..29f798c 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c

@@ -3797,6 +3797,16 @@ static void pnv_pci_release_device(struct pci_dev *pdev)
 		pnv_ioda_release_pe(pe);
 }
 
+void pnv_npu_disable_device(struct pci_dev *pdev)
+{
+	struct eeh_dev *edev = pci_dev_to_eeh_dev(pdev);
+	struct eeh_pe *eehpe = edev ? edev->pe : NULL;
+
+	if (eehpe && eeh_ops && eeh_ops->reset) {
+		eeh_ops->reset(eehpe, EEH_RESET_HOT);
+	}
+}
+
 static void pnv_pci_ioda_shutdown(struct pci_controller *hose)
 {
 	struct pnv_phb *phb = hose->private_data;

@@ -3841,6 +3851,7 @@ static const struct pci_controller_ops pnv_npu_ioda_controller_ops = {
 	.reset_secondary_bus	= pnv_pci_reset_secondary_bus,
 	.dma_set_mask		= pnv_npu_dma_set_mask,
 	.shutdown		= pnv_pci_ioda_shutdown,
+	.disable_device		= pnv_npu_disable_device,
 };
 
 static const struct pci_controller_ops pnv_npu_ocapi_ioda_controller_ops = {

--
Alexey