From 2860af3c8f7ac9e2569378653c3948c422bd30c2 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Tue, 19 May 2015 15:20:31 +0200 Subject: [PATCH] iommu/exynos: Document internal structures Add a few words of comment to all internal structures used by the driver. Signed-off-by: Marek Szyprowski Tested-by: Javier Martinez Canillas Signed-off-by: Joerg Roedel --- drivers/iommu/exynos-iommu.c | 53 ++++++++++++++++++++++++------------ 1 file changed, 35 insertions(+), 18 deletions(-) diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c index 9d9fea2156cb..f6ed59cad90b 100644 --- a/drivers/iommu/exynos-iommu.c +++ b/drivers/iommu/exynos-iommu.c @@ -180,32 +180,49 @@ static char *sysmmu_fault_name[SYSMMU_FAULTS_NUM] = { "UNKNOWN FAULT" }; -/* attached to dev.archdata.iommu of the master device */ +/* + * This structure is attached to dev.archdata.iommu of the master device + * on device add, contains a list of SYSMMU controllers defined by device tree, + * which are bound to given master device. It is usually referenced by 'owner' + * pointer. +*/ struct exynos_iommu_owner { - struct device *sysmmu; + struct device *sysmmu; /* sysmmu controller for given master */ }; +/* + * This structure exynos specific generalization of struct iommu_domain. + * It contains list of SYSMMU controllers from all master devices, which has + * been attached to this domain and page tables of IO address space defined by + * it. It is usually referenced by 'domain' pointer. + */ struct exynos_iommu_domain { - struct list_head clients; /* list of sysmmu_drvdata.node */ - sysmmu_pte_t *pgtable; /* lv1 page table, 16KB */ - short *lv2entcnt; /* free lv2 entry counter for each section */ - spinlock_t lock; /* lock for this structure */ - spinlock_t pgtablelock; /* lock for modifying page table @ pgtable */ + struct list_head clients; /* list of sysmmu_drvdata.domain_node */ + sysmmu_pte_t *pgtable; /* lv1 page table, 16KB */ + short *lv2entcnt; /* free lv2 entry counter for each section */ + spinlock_t lock; /* lock for modyfying list of clients */ + spinlock_t pgtablelock; /* lock for modifying page table @ pgtable */ struct iommu_domain domain; /* generic domain data structure */ }; +/* + * This structure hold all data of a single SYSMMU controller, this includes + * hw resources like registers and clocks, pointers and list nodes to connect + * it to all other structures, internal state and parameters read from device + * tree. It is usually referenced by 'data' pointer. + */ struct sysmmu_drvdata { - struct device *sysmmu; /* System MMU's device descriptor */ - struct device *master; /* Owner of system MMU */ - void __iomem *sfrbase; - struct clk *clk; - struct clk *clk_master; - int activations; - spinlock_t lock; - struct exynos_iommu_domain *domain; - struct list_head domain_node; - phys_addr_t pgtable; - unsigned int version; + struct device *sysmmu; /* SYSMMU controller device */ + struct device *master; /* master device (owner) */ + void __iomem *sfrbase; /* our registers */ + struct clk *clk; /* SYSMMU's clock */ + struct clk *clk_master; /* master's device clock */ + int activations; /* number of calls to sysmmu_enable */ + spinlock_t lock; /* lock for modyfying state */ + struct exynos_iommu_domain *domain; /* domain we belong to */ + struct list_head domain_node; /* node for domain clients list */ + phys_addr_t pgtable; /* assigned page table structure */ + unsigned int version; /* our version */ }; static struct exynos_iommu_domain *to_exynos_domain(struct iommu_domain *dom) -- 2.20.1