If a PCIe RC use gic-v2m or gic-v3-its as a msi domain but doesn't have iommu support, we don't need to do iommu_dma_map_msi_msg to get mapped iommu address as all we need is the physical address. Otherwise we see the oops shown below as we can't get a iommu_group for a device without iommu capable.
Unable to handle kernel NULL pointer dereference at virtual address 000000d0 [00000000000000d0] user address but active_mm is swapper Internal error: Oops: 96000004 [#1] PREEMPT SMP Modules linked in: CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.13.0-rc5-next-20170815-00001-g0744890-dirty #53 Hardware name: Firefly-RK3399 Board (DT) task: ffff80007bc70000 task.stack: ffff80007bc6c000 PC is at iommu_get_domain_for_dev+0x38/0x50 LR is at iommu_dma_map_msi_msg+0x3c/0x1b8 pc : [<ffff000008569210>] lr : [<ffff00000856c1e4>] pstate: a0000045 ... [<ffff000008569210>] iommu_get_domain_for_dev+0x38/0x50 [<ffff00000856c1e4>] iommu_dma_map_msi_msg+0x3c/0x1b8 [<ffff0000083d4d8c>] its_irq_compose_msi_msg+0x44/0x50 [<ffff00000811be50>] irq_chip_compose_msi_msg+0x40/0x58 [<ffff000008120e34>] msi_domain_activate+0x1c/0x48 [<ffff00000811d9f8>] __irq_domain_activate_irq+0x40/0x58 [<ffff00000811f724>] irq_domain_activate_irq+0x24/0x40 [<ffff00000812139c>] msi_domain_alloc_irqs+0x104/0x190 [<ffff000008445abc>] pci_msi_setup_msi_irqs+0x3c/0x48 [<ffff00000844658c>] __pci_enable_msi_range+0x21c/0x408 [<ffff0000084468a4>] pci_alloc_irq_vectors_affinity+0x104/0x168 [<ffff00000843cd98>] pcie_port_device_register+0x200/0x488 [<ffff00000843d2ac>] pcie_portdrv_probe+0x34/0xd0 [<ffff00000842e2cc>] local_pci_probe+0x3c/0xb8 [<ffff00000842f5f8>] pci_device_probe+0x138/0x170 [<ffff00000857d964>] driver_probe_device+0x21c/0x2d8 [<ffff00000857db6c>] __device_attach_driver+0x9c/0xf8 [<ffff00000857bbfc>] bus_for_each_drv+0x5c/0x98 [<ffff00000857d61c>] __device_attach+0xc4/0x138 [<ffff00000857d6a0>] device_attach+0x10/0x18 [<ffff00000842395c>] pci_bus_add_device+0x4c/0xa8 [<ffff0000084239fc>] pci_bus_add_devices+0x44/0x90 [<ffff000008451e88>] rockchip_pcie_probe+0xc70/0xcc8 [<ffff00000857f738>] platform_drv_probe+0x58/0xc0 [<ffff00000857d964>] driver_probe_device+0x21c/0x2d8 [<ffff00000857dacc>] __driver_attach+0xac/0xb0 [<ffff00000857bb3c>] bus_for_each_dev+0x64/0xa0 [<ffff00000857d258>] driver_attach+0x20/0x28 [<ffff00000857cd08>] bus_add_driver+0x110/0x230 [<ffff00000857e468>] driver_register+0x60/0xf8 [<ffff00000857f690>] __platform_driver_register+0x40/0x48 [<ffff000008dd6dc0>] rockchip_pcie_driver_init+0x18/0x20 [<ffff000008083970>] do_one_initcall+0xb0/0x120 [<ffff000008db0cfc>] kernel_init_freeable+0x184/0x224 [<ffff00000896fce8>] kernel_init+0x10/0x100 [<ffff000008084ad0>] ret_from_fork+0x10/0x18 This patch is to fix the problem exposed by the commit mentioned below. Before this commit, iommu has a work around method to fix this but now it doesn't. So we could fix this in gic code but maybe still need a fixes tag here. Fixes: 05f80300dc8b ("iommu: Finish making iommu_group support mandatory") Signed-off-by: Shawn Lin <shawn....@rock-chips.com> --- drivers/irqchip/irq-gic-common.c | 10 ++++++++++ drivers/irqchip/irq-gic-common.h | 2 +- drivers/irqchip/irq-gic-v2m.c | 6 +++++- drivers/irqchip/irq-gic-v3-its.c | 4 +++- 4 files changed, 19 insertions(+), 3 deletions(-) diff --git a/drivers/irqchip/irq-gic-common.c b/drivers/irqchip/irq-gic-common.c index 9ae7180..c340d70 100644 --- a/drivers/irqchip/irq-gic-common.c +++ b/drivers/irqchip/irq-gic-common.c @@ -14,6 +14,7 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <linux/device.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/irq.h> @@ -146,3 +147,12 @@ void gic_cpu_config(void __iomem *base, void (*sync_access)(void)) if (sync_access) sync_access(); } + +bool gic_check_iommu_capable(struct device *dev) +{ + struct device_node *np = dev->of_node; + int ret; + + ret = of_count_phandle_with_args(np, "iommus", "#iommu-cells"); + return (ret > 0); +} diff --git a/drivers/irqchip/irq-gic-common.h b/drivers/irqchip/irq-gic-common.h index 205e5fd..61c5db3 100644 --- a/drivers/irqchip/irq-gic-common.h +++ b/drivers/irqchip/irq-gic-common.h @@ -37,5 +37,5 @@ void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks, void *data); void gic_set_kvm_info(const struct gic_kvm_info *info); - +bool gic_check_iommu_capable(struct device *dev); #endif /* _IRQ_GIC_COMMON_H */ diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c index 993a842..87235d6 100644 --- a/drivers/irqchip/irq-gic-v2m.c +++ b/drivers/irqchip/irq-gic-v2m.c @@ -27,6 +27,8 @@ #include <linux/spinlock.h> #include <linux/irqchip/arm-gic.h> +#include "irq-gic-common.h" + /* * MSI_TYPER: * [31:26] Reserved @@ -101,6 +103,7 @@ static void gicv2m_unmask_msi_irq(struct irq_data *d) static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) { struct v2m_data *v2m = irq_data_get_irq_chip_data(data); + struct device *dev = msi_desc_to_dev(irq_get_msi_desc(data->irq)); phys_addr_t addr = v2m->res.start + V2M_MSI_SETSPI_NS; msg->address_hi = upper_32_bits(addr); @@ -110,7 +113,8 @@ static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) if (v2m->flags & GICV2M_NEEDS_SPI_OFFSET) msg->data -= v2m->spi_offset; - iommu_dma_map_msi_msg(data->irq, msg); + if (gic_check_iommu_capable(dev)) + iommu_dma_map_msi_msg(data->irq, msg); } static struct irq_chip gicv2m_irq_chip = { diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 6893287..843d56a 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -658,6 +658,7 @@ static void its_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg) { struct its_device *its_dev = irq_data_get_irq_chip_data(d); struct its_node *its; + struct device *dev = msi_desc_to_dev(irq_get_msi_desc(d->irq)); u64 addr; its = its_dev->its; @@ -667,7 +668,8 @@ static void its_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg) msg->address_hi = upper_32_bits(addr); msg->data = its_get_event_id(d); - iommu_dma_map_msi_msg(d->irq, msg); + if (gic_check_iommu_capable(dev)) + iommu_dma_map_msi_msg(d->irq, msg); } static struct irq_chip its_irq_chip = { -- 1.9.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu