This patch adds debug interfaces for SMMUv3 driver in sysfs. It adds debug related files under /sys/kernel/debug/iommu/smmuv3.
User should firstly set device and pasid to pci_dev and pasid by: (currently only support PCI device) echo <domain>:<bus>:<dev>.<fun> > /sys/kernel/debug/iommu/smmuv3/pci_dev echo <pasid> > /sys/kernel/debug/iommu/smmuv3/pasid Then value in cd and ste can be got by: cat /sys/kernel/debug/iommu/smmuv3/ste cat /sys/kernel/debug/iommu/smmuv3/cd S1 and S2 page tables can be got by: cat /sys/kernel/debug/iommu/smmuv3/pt_dump_s1 cat /sys/kernel/debug/iommu/smmuv3/pt_dump_s2 For ste, cd and page table, related device and pasid are set in pci_dev and pasid files as above. Signed-off-by: Zhou Wang <wangzh...@hisilicon.com> --- drivers/iommu/Kconfig | 11 + drivers/iommu/arm/arm-smmu-v3/Makefile | 1 + drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 3 + drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 8 + drivers/iommu/arm/arm-smmu-v3/debugfs.c | 398 ++++++++++++++++++++++++++++ 5 files changed, 421 insertions(+) create mode 100644 drivers/iommu/arm/arm-smmu-v3/debugfs.c diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 192ef8f..4822c88 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -325,6 +325,17 @@ config ARM_SMMU_V3_SVA Say Y here if your system supports SVA extensions such as PCIe PASID and PRI. +config ARM_SMMU_V3_DEBUGFS + bool "Export ARM SMMUv3 internals in Debugfs" + depends on ARM_SMMU_V3 && IOMMU_DEBUGFS + help + DO NOT ENABLE THIS OPTION UNLESS YOU REALLY KNOW WHAT YOU ARE DOING! + + Expose ARM SMMUv3 internals in Debugfs. + + This option is -NOT- intended for production environments, and should + only be enabled for debugging ARM SMMUv3. + config S390_IOMMU def_bool y if S390 && PCI depends on S390 && PCI diff --git a/drivers/iommu/arm/arm-smmu-v3/Makefile b/drivers/iommu/arm/arm-smmu-v3/Makefile index 54feb1ec..55b411a 100644 --- a/drivers/iommu/arm/arm-smmu-v3/Makefile +++ b/drivers/iommu/arm/arm-smmu-v3/Makefile @@ -3,3 +3,4 @@ obj-$(CONFIG_ARM_SMMU_V3) += arm_smmu_v3.o arm_smmu_v3-objs-y += arm-smmu-v3.o arm_smmu_v3-objs-$(CONFIG_ARM_SMMU_V3_SVA) += arm-smmu-v3-sva.o arm_smmu_v3-objs := $(arm_smmu_v3-objs-y) +obj-$(CONFIG_ARM_SMMU_V3_DEBUGFS) += debugfs.o diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index b65f63e2..aac7fdb 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -3602,6 +3602,8 @@ static int arm_smmu_device_probe(struct platform_device *pdev) return ret; } + arm_smmu_debugfs_init(); + return arm_smmu_set_bus_ops(&arm_smmu_ops); } @@ -3610,6 +3612,7 @@ static int arm_smmu_device_remove(struct platform_device *pdev) struct arm_smmu_device *smmu = platform_get_drvdata(pdev); arm_smmu_set_bus_ops(NULL); + arm_smmu_debugfs_uninit(); iommu_device_unregister(&smmu->iommu); iommu_device_sysfs_remove(&smmu->iommu); arm_smmu_device_disable(smmu); diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h index 3e7af39..31c4580 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -752,4 +752,12 @@ static inline u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle) static inline void arm_smmu_sva_notifier_synchronize(void) {} #endif /* CONFIG_ARM_SMMU_V3_SVA */ + +#ifdef CONFIG_ARM_SMMU_V3_DEBUGFS +void arm_smmu_debugfs_init(void); +void arm_smmu_debugfs_uninit(void); +#else +static inline void arm_smmu_debugfs_init(void) {} +static inline void arm_smmu_debugfs_uninit(void) {} +#endif /* CONFIG_ARM_SMMU_V3_DEBUGFS */ #endif /* _ARM_SMMU_V3_H */ diff --git a/drivers/iommu/arm/arm-smmu-v3/debugfs.c b/drivers/iommu/arm/arm-smmu-v3/debugfs.c new file mode 100644 index 0000000..1af219a --- /dev/null +++ b/drivers/iommu/arm/arm-smmu-v3/debugfs.c @@ -0,0 +1,398 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/debugfs.h> +#include <linux/iommu.h> +#include <linux/io-pgtable.h> +#include <linux/pci.h> +#include "arm-smmu-v3.h" +#include "../../io-pgtable-arm.h" + +#undef pr_fmt +#define pr_fmt(fmt) "SMMUv3 debug: " fmt + +#define NAME_BUF_LEN 32 + +static struct dentry *arm_smmu_debug; +static char dump_pci_dev[NAME_BUF_LEN]; +static u32 pasid; +static struct mutex lock; + +static ssize_t master_pdev_read(struct file *filp, char __user *buf, + size_t count, loff_t *pos) +{ + char pdev_name[NAME_BUF_LEN]; + char name[NAME_BUF_LEN]; + int ret; + + mutex_lock(&lock); + strncpy(pdev_name, dump_pci_dev, NAME_BUF_LEN); + mutex_unlock(&lock); + + if (!strlen(pdev_name)) { + pr_err("Please set pci_dev firstly\n"); + return 0; + } + + ret = scnprintf(name, NAME_BUF_LEN, "%s\n", pdev_name); + return simple_read_from_buffer(buf, count, pos, name, ret); +} + +static ssize_t master_pdev_write(struct file *filp, const char __user *buf, + size_t count, loff_t *pos) +{ + char name[NAME_BUF_LEN]; + struct device *dev; + int len; + + if (*pos != 0) + return 0; + + if (count >= NAME_BUF_LEN) + return -ENOSPC; + + len = simple_write_to_buffer(name, NAME_BUF_LEN - 1, pos, buf, count); + if (len < 0) + return len; + name[len] = '\0'; + + dev = bus_find_device_by_name(&pci_bus_type, NULL, name); + if (!dev) { + pr_err("Failed to find device\n"); + return -EINVAL; + } + + mutex_lock(&lock); + strncpy(dump_pci_dev, dev_name(dev), NAME_BUF_LEN); + mutex_unlock(&lock); + + put_device(dev); + + return count; +} + +static const struct file_operations master_pdev_fops = { + .owner = THIS_MODULE, + .open = simple_open, + .read = master_pdev_read, + .write = master_pdev_write, +}; + +static struct arm_smmu_master *arm_smmu_get_master(struct device *dev) +{ + struct arm_smmu_master *master; + + if (!dev->iommu) { + pr_err("master device driver may not be loaded!\n"); + return NULL; + } + + master = dev_iommu_priv_get(dev); + if (!master) { + pr_err("Failed to find master dev\n"); + return NULL; + } + + return master; +} + +static void ste_dump(struct seq_file *m, struct device *dev, __le64 *ste) +{ + int i; + + seq_printf(m, "SMMUv3 STE values for device: %s\n", dev_name(dev)); + for (i = 0; i < STRTAB_STE_DWORDS; i++) { + seq_printf(m, "0x%016llx\n", *ste); + ste++; + } +} + +static int ste_show(struct seq_file *m, void *unused) +{ + struct arm_smmu_master *master; + struct arm_smmu_device *smmu; + struct device *dev; + __le64 *ste; + + mutex_lock(&lock); + + dev = bus_find_device_by_name(&pci_bus_type, NULL, dump_pci_dev); + if (!dev) { + mutex_unlock(&lock); + pr_err("Failed to find device\n"); + return -EINVAL; + } + + master = arm_smmu_get_master(dev); + if (!master) { + put_device(dev); + mutex_unlock(&lock); + return -ENODEV; + } + smmu = master->smmu; + + /* currently only support one master one sid */ + ste = arm_smmu_get_step_for_sid(smmu, master->sids[0]); + ste_dump(m, dev, ste); + + put_device(dev); + mutex_unlock(&lock); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(ste); + +static void cd_dump(struct seq_file *m, struct device *dev, __le64 *cd) +{ + int i; + + seq_printf(m, "SMMUv3 CD values for device: %s, ssid: 0x%x\n", + dev_name(dev), pasid); + for (i = 0; i < CTXDESC_CD_DWORDS; i++) { + seq_printf(m, "0x%016llx\n", *cd); + cd++; + } +} + +static int cd_show(struct seq_file *m, void *unused) +{ + struct arm_smmu_master *master; + struct arm_smmu_domain *domain; + struct device *dev; + __le64 *cd; + int ret; + + mutex_lock(&lock); + + dev = bus_find_device_by_name(&pci_bus_type, NULL, dump_pci_dev); + if (!dev) { + mutex_unlock(&lock); + pr_err("Failed to find device\n"); + return -EINVAL; + } + + master = arm_smmu_get_master(dev); + if (!master) { + ret = -ENODEV; + goto err_out; + } + domain = master->domain; + + cd = arm_smmu_get_cd_ptr(domain, pasid); + if (!cd) { + ret = -EINVAL; + pr_err("Failed to find cd(ssid: %u)\n", pasid); + goto err_out; + } + cd_dump(m, dev, cd); + + put_device(dev); + mutex_unlock(&lock); + + return 0; + +err_out: + put_device(dev); + mutex_unlock(&lock); + return ret; +} +DEFINE_SHOW_ATTRIBUTE(cd); + +static void __ptdump(arm_lpae_iopte *ptep, int lvl, u64 va, + struct arm_lpae_io_pgtable *data, struct seq_file *m) +{ + arm_lpae_iopte pte, *ptep_next; + u64 i, tmp_va = 0; + int entry_num; + + entry_num = 1 << (data->bits_per_level + ARM_LPAE_PGD_IDX(lvl, data)); + + for (i = 0; i < entry_num; i++) { + pte = READ_ONCE(*(ptep + i)); + if (!pte) + continue; + + tmp_va = va | (i << ARM_LPAE_LVL_SHIFT(lvl, data)); + + if (iopte_leaf(pte, lvl, data->iop.fmt)) { + /* To do: print prot */ + seq_printf(m, "va: %llx -> pa: %llx\n", tmp_va, + iopte_to_paddr(pte, data)); + continue; + } + + ptep_next = iopte_deref(pte, data); + __ptdump(ptep_next, lvl + 1, tmp_va, data, m); + } +} + +static void ptdump(struct seq_file *m, struct arm_smmu_domain *domain, + void *pgd, int stage) +{ + struct arm_lpae_io_pgtable *data, data_sva; + int levels, va_bits, bits_per_level; + struct io_pgtable_ops *ops; + arm_lpae_iopte *ptep = pgd; + + if (stage == 1 && !pasid) { + ops = domain->pgtbl_ops; + data = io_pgtable_ops_to_data(ops); + } else { + va_bits = VA_BITS - PAGE_SHIFT; + bits_per_level = PAGE_SHIFT - ilog2(sizeof(arm_lpae_iopte)); + levels = DIV_ROUND_UP(va_bits, bits_per_level); + + data_sva.start_level = ARM_LPAE_MAX_LEVELS - levels; + data_sva.pgd_bits = va_bits - (bits_per_level * (levels - 1)); + data_sva.bits_per_level = bits_per_level; + data_sva.pgd = pgd; + + data = &data_sva; + } + + __ptdump(ptep, data->start_level, 0, data, m); +} + +static int pt_dump_s1_show(struct seq_file *m, void *unused) +{ + struct arm_smmu_master *master; + struct arm_smmu_domain *domain; + struct device *dev; + __le64 *cd; + void *pgd; + u64 ttbr; + int ret; + + mutex_lock(&lock); + + dev = bus_find_device_by_name(&pci_bus_type, NULL, dump_pci_dev); + if (!dev) { + mutex_unlock(&lock); + pr_err("Failed to find device\n"); + return -EINVAL; + } + + master = arm_smmu_get_master(dev); + if (!master) { + ret = -ENODEV; + goto err_out; + } + domain = master->domain; + + cd = arm_smmu_get_cd_ptr(domain, pasid); + if (!cd || !(le64_to_cpu(cd[0]) & CTXDESC_CD_0_V)) { + ret = -EINVAL; + pr_err("Failed to find valid cd(ssid: %u)\n", pasid); + goto err_out; + } + + /* CD0 and other CDx are all using ttbr0 */ + ttbr = le64_to_cpu(cd[1]) & CTXDESC_CD_1_TTB0_MASK; + pgd = phys_to_virt(ttbr); + + if (ttbr) { + seq_printf(m, "SMMUv3 dump page table for device %s, stage 1, ssid 0x%x:\n", + dev_name(dev), pasid); + ptdump(m, domain, pgd, 1); + } + + put_device(dev); + mutex_unlock(&lock); + + return 0; + +err_out: + put_device(dev); + mutex_unlock(&lock); + return ret; +} +DEFINE_SHOW_ATTRIBUTE(pt_dump_s1); + +static int pt_dump_s2_show(struct seq_file *m, void *unused) +{ + struct arm_smmu_master *master; + struct arm_smmu_device *smmu; + struct device *dev; + __le64 *ste; + u64 vttbr; + void *pgd; + int ret; + + mutex_lock(&lock); + + dev = bus_find_device_by_name(&pci_bus_type, NULL, dump_pci_dev); + if (!dev) { + mutex_unlock(&lock); + pr_err("Failed to find device\n"); + return -EINVAL; + } + + master = arm_smmu_get_master(dev); + if (!master) { + ret = -ENODEV; + goto err_out; + } + smmu = master->smmu; + + /* currently only support one master one sid */ + ste = arm_smmu_get_step_for_sid(smmu, master->sids[0]); + if (!(le64_to_cpu(ste[0]) & (1UL << 2))) { + ret = -EINVAL; + pr_err("Stage 2 translation is not valid\n"); + goto err_out; + } + + vttbr = le64_to_cpu(ste[3]) & STRTAB_STE_3_S2TTB_MASK; + pgd = phys_to_virt(vttbr); + + if (vttbr) { + seq_printf(m, "SMMUv3 dump page table for device %s, stage 2:\n", + dev_name(dev)); + ptdump(m, 0, pgd, 2); + } + + put_device(dev); + mutex_unlock(&lock); + + return 0; + +err_out: + put_device(dev); + mutex_unlock(&lock); + return ret; +} +DEFINE_SHOW_ATTRIBUTE(pt_dump_s2); + +void arm_smmu_debugfs_init(void) +{ + mutex_init(&lock); + + arm_smmu_debug = debugfs_create_dir("smmuv3", iommu_debugfs_dir); + + debugfs_create_file("pci_dev", 0644, arm_smmu_debug, NULL, + &master_pdev_fops); + /* + * Problem here is we need to know dump which cd, currently my idea + * is we can get related pasid by smmu_bond_get trace point or by + * debug interface of master device specific driver, then here we + * use pasid to dump related cd. + * + * Or there is no need to dump page table about s1(pasid != 0) and s2 + * as they can be got by /proc/<pid>/pagemap. + */ + debugfs_create_u32("pasid", 0644, arm_smmu_debug, &pasid); + + debugfs_create_file("ste", 0444, arm_smmu_debug, NULL, &ste_fops); + + debugfs_create_file("cd", 0444, arm_smmu_debug, NULL, &cd_fops); + + debugfs_create_file("pt_dump_s1", 0444, arm_smmu_debug, NULL, + &pt_dump_s1_fops); + + debugfs_create_file("pt_dump_s2", 0444, arm_smmu_debug, NULL, + &pt_dump_s2_fops); +} + +void arm_smmu_debugfs_uninit(void) +{ + debugfs_remove_recursive(arm_smmu_debug); + mutex_destroy(&lock); +} -- 2.8.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu