From 274c2218b8b29ea2e0404f97d52040deb16d42dd Mon Sep 17 00:00:00 2001 From: Vasant Hegde Date: Wed, 28 Jun 2023 05:16:24 +0000 Subject: [PATCH] iommu/amd: Handle PPR log overflow Some ATS-capable peripherals can issue requests to the processor to service peripheral page requests using PCIe PRI (the Page Request Interface). IOMMU supports PRI using PPR log buffer. IOMMU writes PRI request to PPR log buffer and sends PPR interrupt to host. When there is no space in the PPR log buffer (PPR log overflow) it will set PprOverflow bit in 'MMIO Offset 2020h IOMMU Status Register'. When this happens PPR log needs to be restarted as specified in IOMMU spec [1] section 2.6.2. When handling the event it just resumes the PPR log without resizing (similar to the way event and GA log overflow is handled). Failing to handle PPR overflow means device may not work properly as IOMMU stops processing new PPR events from device. [1] https://www.amd.com/system/files/TechDocs/48882_3.07_PUB.pdf Reviewed-by: Jerry Snitselaar Reviewed-by: Suravee Suthikulpanit Reviewed-by: Joao Martins Signed-off-by: Vasant Hegde Link: https://lore.kernel.org/r/20230628051624.5792-3-vasant.hegde@amd.com Signed-off-by: Joerg Roedel --- drivers/iommu/amd/amd_iommu.h | 1 + drivers/iommu/amd/amd_iommu_types.h | 2 ++ drivers/iommu/amd/init.c | 11 +++++++++++ drivers/iommu/amd/iommu.c | 9 ++++++++- 4 files changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h index 0c35018239cec..8c61c19dabc4f 100644 --- a/drivers/iommu/amd/amd_iommu.h +++ b/drivers/iommu/amd/amd_iommu.h @@ -16,6 +16,7 @@ irqreturn_t amd_iommu_int_handler(int irq, void *data); void amd_iommu_apply_erratum_63(struct amd_iommu *iommu, u16 devid); void amd_iommu_restart_event_logging(struct amd_iommu *iommu); void amd_iommu_restart_ga_log(struct amd_iommu *iommu); +void amd_iommu_restart_ppr_log(struct amd_iommu *iommu); int amd_iommu_init_devices(void); void amd_iommu_uninit_devices(void); void amd_iommu_init_notifier(void); diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h index 7c436ba2a0a23..c8150eaf5c0e2 100644 --- a/drivers/iommu/amd/amd_iommu_types.h +++ b/drivers/iommu/amd/amd_iommu_types.h @@ -124,7 +124,9 @@ #define MMIO_STATUS_EVT_INT_MASK BIT(1) #define MMIO_STATUS_COM_WAIT_INT_MASK BIT(2) #define MMIO_STATUS_EVT_RUN_MASK BIT(3) +#define MMIO_STATUS_PPR_OVERFLOW_MASK BIT(5) #define MMIO_STATUS_PPR_INT_MASK BIT(6) +#define MMIO_STATUS_PPR_RUN_MASK BIT(7) #define MMIO_STATUS_GALOG_RUN_MASK BIT(8) #define MMIO_STATUS_GALOG_OVERFLOW_MASK BIT(9) #define MMIO_STATUS_GALOG_INT_MASK BIT(10) diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index 7fab6ecb62958..e78d7c4f41bd4 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -799,6 +799,17 @@ void amd_iommu_restart_ga_log(struct amd_iommu *iommu) MMIO_STATUS_GALOG_OVERFLOW_MASK); } +/* + * This function restarts ppr logging in case the IOMMU experienced + * PPR log overflow. + */ +void amd_iommu_restart_ppr_log(struct amd_iommu *iommu) +{ + amd_iommu_restart_log(iommu, "PPR", CONTROL_PPRINT_EN, + CONTROL_PPRLOG_EN, MMIO_STATUS_PPR_RUN_MASK, + MMIO_STATUS_PPR_OVERFLOW_MASK); +} + /* * This function resets the command buffer if the IOMMU stopped fetching * commands from it. diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 86c0ae34373b5..f8316901a1780 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -844,6 +844,7 @@ amd_iommu_set_pci_msi_domain(struct device *dev, struct amd_iommu *iommu) { } #define AMD_IOMMU_INT_MASK \ (MMIO_STATUS_EVT_OVERFLOW_MASK | \ MMIO_STATUS_EVT_INT_MASK | \ + MMIO_STATUS_PPR_OVERFLOW_MASK | \ MMIO_STATUS_PPR_INT_MASK | \ MMIO_STATUS_GALOG_OVERFLOW_MASK | \ MMIO_STATUS_GALOG_INT_MASK) @@ -863,11 +864,17 @@ irqreturn_t amd_iommu_int_thread(int irq, void *data) iommu_poll_events(iommu); } - if (status & MMIO_STATUS_PPR_INT_MASK) { + if (status & (MMIO_STATUS_PPR_INT_MASK | + MMIO_STATUS_PPR_OVERFLOW_MASK)) { pr_devel("Processing IOMMU PPR Log\n"); iommu_poll_ppr_log(iommu); } + if (status & MMIO_STATUS_PPR_OVERFLOW_MASK) { + pr_info_ratelimited("IOMMU PPR log overflow\n"); + amd_iommu_restart_ppr_log(iommu); + } + #ifdef CONFIG_IRQ_REMAP if (status & (MMIO_STATUS_GALOG_INT_MASK | MMIO_STATUS_GALOG_OVERFLOW_MASK)) { -- 2.30.2