From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Szyprowski Subject: Re: [RFC PATCH v4 1/8] iommu: provide early initialisation hook for IOMMU drivers Date: Tue, 18 Nov 2014 13:28:03 +0100 Message-ID: <546B3B53.6030202@samsung.com> References: <1415991397-9618-1-git-send-email-will.deacon@arm.com> <1415991397-9618-2-git-send-email-will.deacon@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <1415991397-9618-2-git-send-email-will.deacon-5wv7dgnIgG8@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Will Deacon , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Cc: jroedel-l3A5Bk7waGM@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org, Varun.Sethi-KZfg59tc24xl57MIdRCFDg@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org List-Id: iommu@lists.linux-foundation.org Hello, On 2014-11-14 19:56, Will Deacon wrote: > IOMMU drivers must be initialised before any of their upstream devices, > otherwise the relevant iommu_ops won't be configured for the bus in > question. To solve this, a number of IOMMU drivers use initcalls to > initialise the driver before anything has a chance to be probed. > > Whilst this solves the immediate problem, it leaves the job of probing > the IOMMU completely separate from the iommu_ops to configure the IOMMU, > which are called on a per-bus basis and require the driver to figure out > exactly which instance of the IOMMU is being requested. In particular, > the add_device callback simply passes a struct device to the driver, > which then has to parse firmware tables or probe buses to identify the > relevant IOMMU instance. > > This patch takes the first step in addressing this problem by adding an > early initialisation pass for IOMMU drivers, giving them the ability to > store some per-instance data in their iommu_ops structure and store that > in their of_node. This can later be used when parsing OF masters to > identify the IOMMU instance in question. > > Signed-off-by: Will Deacon > --- > drivers/iommu/of_iommu.c | 17 +++++++++++++++++ > include/asm-generic/vmlinux.lds.h | 2 ++ > include/linux/iommu.h | 2 ++ > include/linux/of_iommu.h | 25 +++++++++++++++++++++++++ > 4 files changed, 46 insertions(+) > > diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c > index e550ccb7634e..89b903406968 100644 > --- a/drivers/iommu/of_iommu.c > +++ b/drivers/iommu/of_iommu.c > @@ -22,6 +22,9 @@ > #include > #include > > +static const struct of_device_id __iommu_of_table_sentinel > + __used __section(__iommu_of_table_end); > + > /** > * of_get_dma_window - Parse *dma-window property and returns 0 if found. > * > @@ -89,3 +92,17 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index, > return 0; > } > EXPORT_SYMBOL_GPL(of_get_dma_window); > + > +void __init of_iommu_init(void) > +{ > + struct device_node *np; > + const struct of_device_id *match, *matches = &__iommu_of_table; > + > + for_each_matching_node_and_match(np, matches, &match) { > + const of_iommu_init_fn init_fn = match->data; > + > + if (init_fn(np)) > + pr_err("Failed to initialise IOMMU %s\n", > + of_node_full_name(np)); > + } > +} > diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h > index aa70cbda327c..bee5d683074d 100644 > --- a/include/asm-generic/vmlinux.lds.h > +++ b/include/asm-generic/vmlinux.lds.h > @@ -164,6 +164,7 @@ > #define CLKSRC_OF_TABLES() OF_TABLE(CONFIG_CLKSRC_OF, clksrc) > #define IRQCHIP_OF_MATCH_TABLE() OF_TABLE(CONFIG_IRQCHIP, irqchip) > #define CLK_OF_TABLES() OF_TABLE(CONFIG_COMMON_CLK, clk) > +#define IOMMU_OF_TABLES() OF_TABLE(CONFIG_OF_IOMMU, iommu) > #define RESERVEDMEM_OF_TABLES() OF_TABLE(CONFIG_OF_RESERVED_MEM, reservedmem) > #define CPU_METHOD_OF_TABLES() OF_TABLE(CONFIG_SMP, cpu_method) > #define EARLYCON_OF_TABLES() OF_TABLE(CONFIG_SERIAL_EARLYCON, earlycon) > @@ -497,6 +498,7 @@ > CLK_OF_TABLES() \ > RESERVEDMEM_OF_TABLES() \ > CLKSRC_OF_TABLES() \ > + IOMMU_OF_TABLES() \ > CPU_METHOD_OF_TABLES() \ > KERNEL_DTB() \ > IRQCHIP_OF_MATCH_TABLE() \ > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index e6a7c9ff72f2..7b83f9f8e11d 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -103,6 +103,7 @@ enum iommu_attr { > * @domain_get_attr: Query domain attributes > * @domain_set_attr: Change domain attributes > * @pgsize_bitmap: bitmap of supported page sizes > + * @priv: per-instance data private to the iommu driver > */ > struct iommu_ops { > bool (*capable)(enum iommu_cap); > @@ -133,6 +134,7 @@ struct iommu_ops { > u32 (*domain_get_windows)(struct iommu_domain *domain); > > unsigned long pgsize_bitmap; > + void *priv; > }; > > #define IOMMU_GROUP_NOTIFY_ADD_DEVICE 1 /* Device added */ > diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h > index 51a560f34bca..81447e0f68b5 100644 > --- a/include/linux/of_iommu.h > +++ b/include/linux/of_iommu.h > @@ -1,12 +1,17 @@ > #ifndef __OF_IOMMU_H > #define __OF_IOMMU_H > > +#include > +#include > + > #ifdef CONFIG_OF_IOMMU > > extern int of_get_dma_window(struct device_node *dn, const char *prefix, > int index, unsigned long *busno, dma_addr_t *addr, > size_t *size); > > +extern void of_iommu_init(void); > + > #else > > static inline int of_get_dma_window(struct device_node *dn, const char *prefix, > @@ -16,6 +21,26 @@ static inline int of_get_dma_window(struct device_node *dn, const char *prefix, > return -EINVAL; > } > > +static inline void of_iommu_init(void) { } > + > #endif /* CONFIG_OF_IOMMU */ > > +static inline void of_iommu_set_ops(struct device_node *np, > + struct iommu_ops *ops) I think it will be reasonable to change the second argument to "const struct iommu_ops *ops" to match other code that uses it. > +{ > + np->data = ops; The above change require adding a cast: np->data = (struct iommu_ops *)ops; > +} > + > +static inline struct iommu_ops *of_iommu_get_ops(struct device_node *np) > +{ > + return np->data; > +} > + > +extern struct of_device_id __iommu_of_table; > + > +typedef int (*of_iommu_init_fn)(struct device_node *); > + > +#define IOMMU_OF_DECLARE(name, compat, fn) \ > + _OF_DECLARE(iommu, name, compat, fn, of_iommu_init_fn) > + > #endif /* __OF_IOMMU_H */ Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland