This patch dumps all active mapping entries from pagetable to a debugfs directory named "mappings". Attaching an example: SWGROUP: hc as->id: 0 as->attr: R|W|N as->pd_dma: 0x0000000080c03000 { [index: 1023] 0xf0080c3e (count: 2) { PTE RANGE | ATTR | PHYS | IOVA | SIZE [#1022, #1023] | 0x5 | 0x000000010bbf1000 | 0x00000000ffffe000 | 0x2000 } } Total PDE count: 1 Total PTE count: 2 Signed-off-by: Nicolin Chen <nicoleotsuka@xxxxxxxxx> --- drivers/iommu/tegra-smmu.c | 145 +++++++++++++++++++++++++++++++++++++ 1 file changed, 145 insertions(+) diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c index 68c34a4a0ecc..aac977e181f6 100644 --- a/drivers/iommu/tegra-smmu.c +++ b/drivers/iommu/tegra-smmu.c @@ -46,6 +46,7 @@ struct tegra_smmu { struct list_head list; struct dentry *debugfs; + struct dentry *debugfs_mappings; struct iommu_device iommu; /* IOMMU Core code handle */ }; @@ -153,6 +154,9 @@ static inline u32 smmu_readl(struct tegra_smmu *smmu, unsigned long offset) #define SMMU_PDE_ATTR (SMMU_PDE_READABLE | SMMU_PDE_WRITABLE | \ SMMU_PDE_NONSECURE) +#define SMMU_PTE_ATTR (SMMU_PTE_READABLE | SMMU_PTE_WRITABLE | \ + SMMU_PTE_NONSECURE) +#define SMMU_PTE_ATTR_SHIFT 29 static unsigned int iova_pd_index(unsigned long iova) { @@ -164,6 +168,12 @@ static unsigned int iova_pt_index(unsigned long iova) return (iova >> SMMU_PTE_SHIFT) & (SMMU_NUM_PTE - 1); } +static unsigned long pd_pt_index_iova(unsigned int pd_index, unsigned int pt_index) +{ + return ((dma_addr_t)pd_index & (SMMU_NUM_PDE - 1)) << SMMU_PDE_SHIFT | + ((dma_addr_t)pt_index & (SMMU_NUM_PTE - 1)) << SMMU_PTE_SHIFT; +} + static bool smmu_dma_addr_valid(struct tegra_smmu *smmu, dma_addr_t addr) { addr >>= 12; @@ -496,6 +506,8 @@ static void tegra_smmu_as_unprepare(struct tegra_smmu *smmu, mutex_unlock(&smmu->lock); } +static const struct file_operations tegra_smmu_debugfs_mappings_fops; + static void tegra_smmu_attach_as(struct tegra_smmu *smmu, struct tegra_smmu_as *as, unsigned int swgroup) @@ -517,6 +529,12 @@ static void tegra_smmu_attach_as(struct tegra_smmu *smmu, dev_warn(smmu->dev, "overwriting group->as for swgroup: %s\n", swgrp->name); group->as = as; + + if (smmu->debugfs_mappings) + debugfs_create_file(group->swgrp->name, 0444, + smmu->debugfs_mappings, group, + &tegra_smmu_debugfs_mappings_fops); + break; } @@ -541,6 +559,12 @@ static void tegra_smmu_detach_as(struct tegra_smmu *smmu, if (group->swgrp != swgrp) continue; group->as = NULL; + + if (smmu->debugfs_mappings) { + d = debugfs_lookup(group->swgrp->name, smmu->debugfs_mappings); + debugfs_remove(d); + } + break; } @@ -1124,6 +1148,125 @@ static int tegra_smmu_clients_show(struct seq_file *s, void *data) DEFINE_SHOW_ATTRIBUTE(tegra_smmu_clients); +static int tegra_smmu_debugfs_mappings_show(struct seq_file *s, void *data) +{ + struct tegra_smmu_group *group = s->private; + const struct tegra_smmu_swgroup *swgrp; + struct tegra_smmu_as *as; + struct tegra_smmu *smmu; + unsigned int pd_index; + unsigned int pt_index; + unsigned long flags; + u64 pte_count = 0; + u32 pde_count = 0; + u32 *pd, val; + + if (!group || !group->as || !group->swgrp) + return 0; + + swgrp = group->swgrp; + smmu = group->smmu; + as = group->as; + + mutex_lock(&smmu->lock); + + val = smmu_readl(smmu, swgrp->reg) & SMMU_ASID_ENABLE; + if (!val) + goto unlock; + + pd = page_address(as->pd); + if (!pd) + goto unlock; + + seq_printf(s, "\nSWGROUP: %s\n", swgrp->name); + seq_printf(s, "as->id: %d\nas->attr: %c|%c|%s\nas->pd_dma: %pad\n", as->id, + as->attr & SMMU_PD_READABLE ? 'R' : '-', + as->attr & SMMU_PD_WRITABLE ? 'W' : '-', + as->attr & SMMU_PD_NONSECURE ? "NS" : "S", + &as->pd_dma); + seq_puts(s, "{\n"); + + spin_lock_irqsave(&as->lock, flags); + + for (pd_index = 0; pd_index < SMMU_NUM_PDE; pd_index++) { + struct page *pt_page; + unsigned int i; + u32 *addr; + + /* An empty PDE should not have a pte use count */ + WARN_ON_ONCE(!pd[pd_index] ^ !as->count[pd_index]); + + /* Skip this empty PDE */ + if (!pd[pd_index]) + continue; + + pde_count++; + pte_count += as->count[pd_index]; + seq_printf(s, "\t[index: %u] 0x%x (count: %d)\n", + pd_index, pd[pd_index], as->count[pd_index]); + pt_page = as->pts[pd_index]; + addr = page_address(pt_page); + + seq_puts(s, "\t{\n"); + seq_printf(s, "\t\t%-14s | %-4s | %-10s%s | %-10s%s | %-11s\n", + "PTE RANGE", "ATTR", + "PHYS", sizeof(phys_addr_t) > 4 ? " " : "", + "IOVA", sizeof(dma_addr_t) > 4 ? " " : "", + "SIZE"); + for (pt_index = 0; pt_index < SMMU_NUM_PTE; pt_index += i) { + size_t size = SMMU_SIZE_PT; + dma_addr_t iova; + phys_addr_t pa; + + i = 1; + + if (!addr[pt_index]) + continue; + + iova = pd_pt_index_iova(pd_index, pt_index); + pa = SMMU_PFN_PHYS(addr[pt_index] & ~SMMU_PTE_ATTR); + + /* Check contiguous mappings and increase size */ + while (pt_index + i < SMMU_NUM_PTE) { + dma_addr_t next_iova; + phys_addr_t next_pa; + + if (!addr[pt_index + i]) + break; + + next_iova = pd_pt_index_iova(pd_index, pt_index + i); + next_pa = SMMU_PFN_PHYS(addr[pt_index + i] & ~SMMU_PTE_ATTR); + + /* Break at the end of a linear mapping */ + if ((next_iova - iova != SMMU_SIZE_PT * i) || + (next_pa - pa != SMMU_SIZE_PT * i)) + break; + + i++; + } + + seq_printf(s, "\t\t[#%-4u, #%-4u] | 0x%-2x | %pa | %pad | 0x%-9zx\n", + pt_index, pt_index + i - 1, + addr[pt_index] >> SMMU_PTE_ATTR_SHIFT, + &pa, &iova, size * i); + } + seq_puts(s, "\t}\n"); + } + + spin_unlock_irqrestore(&as->lock, flags); + + seq_puts(s, "}\n"); + seq_printf(s, "Total PDE count: %u\n", pde_count); + seq_printf(s, "Total PTE count: %llu\n", pte_count); + +unlock: + mutex_unlock(&smmu->lock); + + return 0; +} + +DEFINE_SHOW_ATTRIBUTE(tegra_smmu_debugfs_mappings); + static void tegra_smmu_debugfs_init(struct tegra_smmu *smmu) { smmu->debugfs = debugfs_create_dir("smmu", NULL); @@ -1134,6 +1277,8 @@ static void tegra_smmu_debugfs_init(struct tegra_smmu *smmu) &tegra_smmu_swgroups_fops); debugfs_create_file("clients", S_IRUGO, smmu->debugfs, smmu, &tegra_smmu_clients_fops); + + smmu->debugfs_mappings = debugfs_create_dir("mappings", smmu->debugfs); } static void tegra_smmu_debugfs_exit(struct tegra_smmu *smmu) -- 2.17.1