From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chintan Pandya Subject: Re: [PATCH] of: add early boot allocation of of_find_node_by_phandle() cache Date: Fri, 16 Feb 2018 14:37:55 +0530 Message-ID: <25deaf48-6590-4ca2-e0db-adaef1f49c5d@codeaurora.org> References: <1518655465-10759-1-git-send-email-frowand.list@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1518655465-10759-1-git-send-email-frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Content-Language: en-US Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Rob Herring Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On 2/15/2018 6:14 AM, frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org wrote: > From: Frank Rowand > > The initial implementation of the of_find_node_by_phandle() cache > allocates the cache using kcalloc(). Add an early boot allocation > of the cache so it will be usable during early boot. Switch over > to the kcalloc() based cache once normal memory allocation > becomes available. > > Signed-off-by: Frank Rowand > --- > > This patch is optional, to be added at Rob's discretion. The > extra complexity is not as much as I had feared, but the boot > speed up is also likely small. > > drivers/of/base.c | 33 +++++++++++++++++++++++++++++++++ > drivers/of/fdt.c | 2 ++ > drivers/of/of_private.h | 2 ++ > 3 files changed, 37 insertions(+) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index ab545dfa9173..d7b1ff1209e8 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -16,9 +16,11 @@ > > #define pr_fmt(fmt) "OF: " fmt > > +#include > #include > #include > #include > +#include > #include > #include > #include > @@ -131,6 +133,29 @@ static void of_populate_phandle_cache(void) > raw_spin_unlock_irqrestore(&devtree_lock, flags); > } > > +void __init of_populate_phandle_cache_early(void) > +{ > + u32 cache_entries; > + struct device_node *np; > + u32 phandles = 0; > + size_t size; > + > + for_each_of_allnodes(np) > + if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL) > + phandles++; > + > + cache_entries = roundup_pow_of_two(phandles); > + phandle_cache_mask = cache_entries - 1; > + > + size = cache_entries * sizeof(*phandle_cache); > + phandle_cache = memblock_virt_alloc(size, 4); > + memset(phandle_cache, 0, size); > + > + for_each_of_allnodes(np) > + if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL) > + phandle_cache[np->phandle & phandle_cache_mask] = np; > +} There is a lot of code duplication in this function with of_populate_phandle_cache. Would you think of taking out common code or differ the function with extra bool parameter to say 'early' or 'not early'. > + > #ifndef CONFIG_MODULES > static int __init of_free_phandle_cache(void) > { > @@ -150,7 +175,15 @@ static int __init of_free_phandle_cache(void) > > void __init of_core_init(void) > { > + unsigned long flags; > struct device_node *np; > + phys_addr_t size; > + > + raw_spin_lock_irqsave(&devtree_lock, flags); > + size = (phandle_cache_mask + 1) * sizeof(*phandle_cache); > + memblock_free(__pa(phandle_cache), size); > + phandle_cache = NULL; > + raw_spin_unlock_irqrestore(&devtree_lock, flags); > > of_populate_phandle_cache(); > > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index 84aa9d676375..cb320df23f26 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -1264,6 +1264,8 @@ void __init unflatten_device_tree(void) > of_alias_scan(early_init_dt_alloc_memory_arch); > > unittest_unflatten_overlay_base(); > + > + of_populate_phandle_cache_early(); > } > > /** > diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h > index fa70650136b4..6720448c84cc 100644 > --- a/drivers/of/of_private.h > +++ b/drivers/of/of_private.h > @@ -134,6 +134,8 @@ extern void __of_sysfs_remove_bin_file(struct device_node *np, > /* illegal phandle value (set when unresolved) */ > #define OF_PHANDLE_ILLEGAL 0xdeadbeef > > +extern void __init of_populate_phandle_cache_early(void); > + > /* iterators for transactions, used for overlays */ > /* forward iterator */ > #define for_each_transaction_entry(_oft, _te) \ > Chintan -- Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html