Commit 45baee14 authored by Guilherme G. Piccoli's avatar Guilherme G. Piccoli Committed by Michael Ellerman

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
...@@ -89,6 +89,7 @@ void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level, ...@@ -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 pnv_iommu_bypass_disabled __read_mostly;
static bool pci_reset_phbs __read_mostly;
static int __init iommu_setup(char *str) static int __init iommu_setup(char *str)
{ {
...@@ -110,6 +111,14 @@ static int __init iommu_setup(char *str) ...@@ -110,6 +111,14 @@ static int __init iommu_setup(char *str)
} }
early_param("iommu", iommu_setup); 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) 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, ...@@ -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 * If we're running in kdump kernel, the previous kernel never
* shutdown PCI devices correctly. We already got IODA table * shutdown PCI devices correctly. We already got IODA table
* cleaned out. So we have to issue PHB reset to stop all PCI * 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"); pr_info(" Issue PHB reset ...\n");
pnv_eeh_phb_reset(hose, EEH_RESET_FUNDAMENTAL); pnv_eeh_phb_reset(hose, EEH_RESET_FUNDAMENTAL);
pnv_eeh_phb_reset(hose, EEH_RESET_DEACTIVATE); pnv_eeh_phb_reset(hose, EEH_RESET_DEACTIVATE);
......
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