On Wed, 2019-03-20 at 13:58 +1100, Sam Bobroff wrote:
> The EEH address cache is currently initialized and populated by a
> single function: eeh_addr_cache_build(). While the initial population
> of the cache can only be done once resources are allocated,
> initialization (just setting up a spinlock) could be done much
> earlier.
>
> So move the initialization step into a separate function and call it
> from a core_initcall (rather than a subsys initcall).
>
> This will allow future work to make use of the cache during boot time
> PCI scanning.
What's the idea there? Checking for overlaps in the BAR assignments?
> Signed-off-by: Sam Bobroff <sbobr...@linux.ibm.com>
> ---
> arch/powerpc/include/asm/eeh.h | 3 +++
> arch/powerpc/kernel/eeh.c | 2 ++
> arch/powerpc/kernel/eeh_cache.c | 13 +++++++++++--
> 3 files changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
> index e217ccda55d0..791b9e6fcc45 100644
> --- a/arch/powerpc/include/asm/eeh.h
> +++ b/arch/powerpc/include/asm/eeh.h
> @@ -295,6 +295,7 @@ int __init eeh_ops_register(struct eeh_ops *ops);
> int __exit eeh_ops_unregister(const char *name);
> int eeh_check_failure(const volatile void __iomem *token);
> int eeh_dev_check_failure(struct eeh_dev *edev);
> +void eeh_addr_cache_init(void);
> void eeh_addr_cache_build(void);
> void eeh_add_device_early(struct pci_dn *);
> void eeh_add_device_tree_early(struct pci_dn *);
> @@ -362,6 +363,8 @@ static inline int eeh_check_failure(const volatile void
> __iomem *token)
>
> #define eeh_dev_check_failure(x) (0)
>
> +static inline void eeh_addr_cache_init(void) { }
> +
> static inline void eeh_addr_cache_build(void) { }
>
> static inline void eeh_add_device_early(struct pci_dn *pdn) { }
> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
> index 3dcff29cb9b3..7a406d58d2c0 100644
> --- a/arch/powerpc/kernel/eeh.c
> +++ b/arch/powerpc/kernel/eeh.c
> @@ -1219,6 +1219,8 @@ static int eeh_init(void)
> list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
> eeh_dev_phb_init_dynamic(hose);
>
> + eeh_addr_cache_init();
> +
> /* Initialize EEH event */
> return eeh_event_init();
> }
> diff --git a/arch/powerpc/kernel/eeh_cache.c b/arch/powerpc/kernel/eeh_cache.c
> index 9c68f0837385..f93dd5cf6a39 100644
> --- a/arch/powerpc/kernel/eeh_cache.c
> +++ b/arch/powerpc/kernel/eeh_cache.c
> @@ -267,6 +267,17 @@ void eeh_addr_cache_rmv_dev(struct pci_dev *dev)
> spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags);
> }
>
> +/**
> + * eeh_addr_cache_init - Initialize a cache of I/O addresses
> + *
> + * Initialize a cache of pci i/o addresses. This cache will be used to
> + * find the pci device that corresponds to a given address.
> + */
> +void eeh_addr_cache_init(void)
> +{
> + spin_lock_init(&pci_io_addr_cache_root.piar_lock);
> +}
You could move this out of the pci_io_addr_cache structure and use
DEFINE_SPINLOCK() too. We might even be able to get rid of the hand-
rolled interval tree in eeh_cache.c in favour of the generic
implementation (see mm/interval_tree.c). I'm pretty sure the generic
one is a drop-in replacement, but I haven't had a chance to have a
detailed look to see if there's any differences in behaviour.
> +
> /**
> * eeh_addr_cache_build - Build a cache of I/O addresses
> *
> @@ -282,8 +293,6 @@ void eeh_addr_cache_build(void)
> struct eeh_dev *edev;
> struct pci_dev *dev = NULL;
>
> - spin_lock_init(&pci_io_addr_cache_root.piar_lock);
> -
> for_each_pci_dev(dev) {
> pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
> if (!pdn)
