[PATCH 4/4] iommu/exynos: decode the v7 fault transaction info
Markuss Broks via B4 Relay <[email protected]>
| Newsgroups | dev.linux.lists.iommu,org.infradead.lists.linux-arm-kernel,org.kernel.feeds.b4-sent,org.kernel.vger.linux-kernel,org.kernel.vger.linux-samsung-soc |
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| Message-ID | <[email protected]> |
From: Markuss Broks <[email protected]> The v7+ fault registers carry a transaction-info word alongside the faulting address, but it is only used to derive the read/write direction and then thrown away. Keep it and print it: AxID identifies which port inside the master issued the faulting transaction, which is the only way to tell apart the several DMA engines a single block can contain, and the remaining bits of the raw word are implementation defined and worth having in a fault report. Define the known fields of the word instead of open-coding the masks; this also names the direction bit the driver was already testing as a bare BIT(20). Gate the print on the variant having a fault_info register, so older SysMMUs are unaffected. Signed-off-by: Markuss Broks <[email protected]> --- drivers/iommu/exynos-iommu.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c index 29b27c7e400a..0bca3662fdc2 100644 --- a/drivers/iommu/exynos-iommu.c +++ b/drivers/iommu/exynos-iommu.c @@ -8,6 +8,7 @@ #define DEBUG #endif +#include <linux/bitfield.h> #include <linux/clk.h> #include <linux/dma-mapping.h> #include <linux/err.h> @@ -144,6 +145,9 @@ static u32 lv2ent_offset(sysmmu_iova_t iova) #define CAPA0_CAPA1_EXIST BIT(11) #define CAPA1_VCR_ENABLED BIT(14) #define CAPA1_NO_BLOCK_MODE BIT(15) +#define FAULT_INFO_AXID GENMASK(15, 0) +#define FAULT_INFO_AXLEN GENMASK(19, 16) +#define FAULT_INFO_WRITE BIT(20) /* common registers */ #define REG_MMU_CTRL 0x000 @@ -194,6 +198,7 @@ struct sysmmu_fault { sysmmu_iova_t addr; /* IOVA address that caused fault */ const char *name; /* human readable fault name */ unsigned int type; /* fault type for report_iommu_fault() */ + u32 info; /* raw transaction info (v7+ only) */ }; struct sysmmu_v1_fault_info { @@ -360,7 +365,8 @@ static int exynos_sysmmu_v7_get_fault_info(struct sysmmu_drvdata *data, fault->addr = readl(SYSMMU_REG(data, fault_va)); fault->name = sysmmu_v7_fault_names[itype % 4]; - fault->type = (info & BIT(20)) ? IOMMU_FAULT_WRITE : IOMMU_FAULT_READ; + fault->type = (info & FAULT_INFO_WRITE) ? IOMMU_FAULT_WRITE : IOMMU_FAULT_READ; + fault->info = info; return 0; } @@ -558,6 +564,12 @@ static void show_fault_information(struct sysmmu_drvdata *data, dev_name(data->master), fault->type == IOMMU_FAULT_READ ? "READ" : "WRITE", fault->name, fault->addr); + /* AxID identifies the issuing port inside the master */ + if (data->variant->fault_info) + dev_err(data->sysmmu, "transaction info %#010x: AxID %#lx, AxLEN %lu\n", + fault->info, + FIELD_GET(FAULT_INFO_AXID, fault->info), + FIELD_GET(FAULT_INFO_AXLEN, fault->info)); dev_dbg(data->sysmmu, "Page table base: %pa\n", &data->pgtable); ent = section_entry(phys_to_virt(data->pgtable), fault->addr); dev_dbg(data->sysmmu, "\tLv1 entry: %#x\n", *ent); -- 2.55.0