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Commit 45baee14 authored by Guilherme G. Piccoli's avatar Guilherme G. Piccoli Committed by Michael Ellerman
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powerpc/powernv: Add ppc_pci_reset_phbs parameter to issue a PHB reset 



During a kdump kernel boot in PowerPC, we request a reset of the PHBs
to the FW. It makes sense, since if we are booting a kdump kernel it
means we had some trouble before and we cannot rely in the adapters'
health; they could be in a bad state, hence the reset is needed.

But this reset is useful not only in kdump - there are situations,
specially when debugging drivers, that we could break an adapter in
a way it requires such reset. One can tell to just go ahead and
reboot the machine, but happens that many times doing kexec is much
faster, and so preferable than a full power cycle.

This patch adds the ppc_pci_reset_phbs parameter to perform such reset.

Signed-off-by: default avatarGuilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 7339390d

arch/powerpc/platforms/powernv/pci-ioda.c

+12 −2
Original line number Diff line number Diff line
@@ -89,6 +89,7 @@ void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level, 
}



static bool pnv_iommu_bypass_disabled __read_mostly;

static bool pci_reset_phbs __read_mostly;



static int __init iommu_setup(char *str)

{
@@ -110,6 +111,14 @@ static int __init iommu_setup(char *str) 
}

early_param("iommu", iommu_setup);



static int __init pci_reset_phbs_setup(char *str)

{

	pci_reset_phbs = true;

	return 0;

}



early_param("ppc_pci_reset_phbs", pci_reset_phbs_setup);



static inline bool pnv_pci_is_m64(struct pnv_phb *phb, struct resource *r)

{

	/*
@@ -4033,9 +4042,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np, 
	 * If we're running in kdump kernel, the previous kernel never

	 * shutdown PCI devices correctly. We already got IODA table

	 * cleaned out. So we have to issue PHB reset to stop all PCI

	 * transactions from previous kernel.

	 * transactions from previous kernel. The ppc_pci_reset_phbs

	 * kernel parameter will force this reset too.

	 */

	if (is_kdump_kernel()) {

	if (is_kdump_kernel() || pci_reset_phbs) {

		pr_info("  Issue PHB reset ...\n");

		pnv_eeh_phb_reset(hose, EEH_RESET_FUNDAMENTAL);

		pnv_eeh_phb_reset(hose, EEH_RESET_DEACTIVATE);