Add a driver for the Intel CBDMA device. This driver is based on and named after the Linux driver for this device (drivers/dma/ioat/) and also based on previous work from Peter Shier pshier@google.com.
The driver aims to be as simple as possible. It uses a single descriptor to issue DMA operations, and only supports the copy operation. For "DMA storms", the driver kicks off the maximum number of maximum-sized DMA operations. On Skylake server parts, this was 2^16-1 copies of size 2M and lasts about 15 seconds.
Create symlinks to drivers/dma/ioat/{hw.h,registers.h} to get access to various macros (e.g. IOAT_CHANCMD_RESET) and struct ioat_dma_descriptor.
Cc: Dave Jiang dave.jiang@intel.com Cc: Dan Williams dan.j.williams@intel.com Signed-off-by: David Matlack dmatlack@google.com --- .../selftests/vfio/lib/drivers/ioat/hw.h | 1 + .../selftests/vfio/lib/drivers/ioat/ioat.c | 235 ++++++++++++++++++ .../vfio/lib/drivers/ioat/registers.h | 1 + tools/testing/selftests/vfio/lib/libvfio.mk | 7 + .../selftests/vfio/lib/vfio_pci_driver.c | 10 +- 5 files changed, 253 insertions(+), 1 deletion(-) create mode 120000 tools/testing/selftests/vfio/lib/drivers/ioat/hw.h create mode 100644 tools/testing/selftests/vfio/lib/drivers/ioat/ioat.c create mode 120000 tools/testing/selftests/vfio/lib/drivers/ioat/registers.h
diff --git a/tools/testing/selftests/vfio/lib/drivers/ioat/hw.h b/tools/testing/selftests/vfio/lib/drivers/ioat/hw.h new file mode 120000 index 000000000000..8ab52ddd4458 --- /dev/null +++ b/tools/testing/selftests/vfio/lib/drivers/ioat/hw.h @@ -0,0 +1 @@ +../../../../../../../drivers/dma/ioat/hw.h \ No newline at end of file diff --git a/tools/testing/selftests/vfio/lib/drivers/ioat/ioat.c b/tools/testing/selftests/vfio/lib/drivers/ioat/ioat.c new file mode 100644 index 000000000000..c3b91d9b1f59 --- /dev/null +++ b/tools/testing/selftests/vfio/lib/drivers/ioat/ioat.c @@ -0,0 +1,235 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <stdint.h> +#include <unistd.h> + +#include <linux/errno.h> +#include <linux/io.h> +#include <linux/pci_ids.h> +#include <linux/sizes.h> + +#include <vfio_util.h> + +#include "hw.h" +#include "registers.h" + +#define IOAT_DMACOUNT_MAX UINT16_MAX + +struct ioat_state { + /* Single descriptor used to issue DMA memcpy operations */ + struct ioat_dma_descriptor desc; + + /* Copy buffers used by ioat_send_msi() to generate an interrupt. */ + u64 send_msi_src; + u64 send_msi_dst; +}; + +static inline struct ioat_state *to_ioat_state(struct vfio_pci_device *device) +{ + return device->driver.region.vaddr; +} + +static inline void *ioat_channel_registers(struct vfio_pci_device *device) +{ + return device->bars[0].vaddr + IOAT_CHANNEL_MMIO_SIZE; +} + +static int ioat_probe(struct vfio_pci_device *device) +{ + u8 version; + int r; + + if (!vfio_pci_device_match(device, PCI_VENDOR_ID_INTEL, + PCI_DEVICE_ID_INTEL_IOAT_SKX)) + return -EINVAL; + + VFIO_ASSERT_NOT_NULL(device->bars[0].vaddr); + + version = readb(device->bars[0].vaddr + IOAT_VER_OFFSET); + switch (version) { + case IOAT_VER_3_2: + case IOAT_VER_3_3: + r = 0; + break; + default: + printf("ioat: Unsupported version: 0x%x\n", version); + r = -EINVAL; + } + return r; +} + +static u64 ioat_channel_status(void *bar) +{ + return readq(bar + IOAT_CHANSTS_OFFSET) & IOAT_CHANSTS_STATUS; +} + +static void ioat_clear_errors(struct vfio_pci_device *device) +{ + void *registers = ioat_channel_registers(device); + u32 errors; + + errors = vfio_pci_config_readl(device, IOAT_PCI_CHANERR_INT_OFFSET); + vfio_pci_config_writel(device, IOAT_PCI_CHANERR_INT_OFFSET, errors); + + errors = vfio_pci_config_readl(device, IOAT_PCI_DMAUNCERRSTS_OFFSET); + vfio_pci_config_writel(device, IOAT_PCI_CHANERR_INT_OFFSET, errors); + + errors = readl(registers + IOAT_CHANERR_OFFSET); + writel(errors, registers + IOAT_CHANERR_OFFSET); +} + +static void ioat_reset(struct vfio_pci_device *device) +{ + void *registers = ioat_channel_registers(device); + u32 sleep_ms = 1, attempts = 5000 / sleep_ms; + u8 chancmd; + + ioat_clear_errors(device); + + writeb(IOAT_CHANCMD_RESET, registers + IOAT2_CHANCMD_OFFSET); + + for (;;) { + chancmd = readb(registers + IOAT2_CHANCMD_OFFSET); + if (!(chancmd & IOAT_CHANCMD_RESET)) + break; + + VFIO_ASSERT_GT(--attempts, 0); + usleep(sleep_ms * 1000); + } + + VFIO_ASSERT_EQ(ioat_channel_status(registers), IOAT_CHANSTS_HALTED); +} + +static void ioat_init(struct vfio_pci_device *device) +{ + struct ioat_state *ioat = to_ioat_state(device); + u8 intrctrl; + + VFIO_ASSERT_GE(device->driver.region.size, sizeof(*ioat)); + + vfio_pci_config_writew(device, PCI_COMMAND, + PCI_COMMAND_MEMORY | + PCI_COMMAND_MASTER | + PCI_COMMAND_INTX_DISABLE); + + ioat_reset(device); + + /* Enable the use of MXI-x interrupts for channel interrupts. */ + intrctrl = IOAT_INTRCTRL_MSIX_VECTOR_CONTROL; + writeb(intrctrl, device->bars[0].vaddr + IOAT_INTRCTRL_OFFSET); + + vfio_pci_msix_enable(device, 0, device->msix_info.count); + + device->driver.msi = 0; + device->driver.max_memcpy_size = + 1UL << readb(device->bars[0].vaddr + IOAT_XFERCAP_OFFSET); + device->driver.max_memcpy_count = IOAT_DMACOUNT_MAX; +} + +static void ioat_remove(struct vfio_pci_device *device) +{ + ioat_reset(device); + vfio_pci_msix_disable(device); +} + +static void ioat_handle_error(struct vfio_pci_device *device) +{ + void *registers = ioat_channel_registers(device); + + printf("Error detected during memcpy operation!\n" + " CHANERR: 0x%x\n" + " CHANERR_INT: 0x%x\n" + " DMAUNCERRSTS: 0x%x\n", + readl(registers + IOAT_CHANERR_OFFSET), + vfio_pci_config_readl(device, IOAT_PCI_CHANERR_INT_OFFSET), + vfio_pci_config_readl(device, IOAT_PCI_DMAUNCERRSTS_OFFSET)); + + ioat_reset(device); +} + +static int ioat_memcpy_wait(struct vfio_pci_device *device) +{ + void *registers = ioat_channel_registers(device); + u64 status; + int r = 0; + + /* Wait until all operations complete. */ + for (;;) { + status = ioat_channel_status(registers); + if (status == IOAT_CHANSTS_DONE) + break; + + if (status == IOAT_CHANSTS_HALTED) { + ioat_handle_error(device); + return -1; + } + } + + /* Put the channel into the SUSPENDED state. */ + writeb(IOAT_CHANCMD_SUSPEND, registers + IOAT2_CHANCMD_OFFSET); + for (;;) { + status = ioat_channel_status(registers); + if (status == IOAT_CHANSTS_SUSPENDED) + break; + } + + return r; +} + +static void __ioat_memcpy_start(struct vfio_pci_device *device, + iova_t src, iova_t dst, u64 size, + u16 count, bool interrupt) +{ + void *registers = ioat_channel_registers(device); + struct ioat_state *ioat = to_ioat_state(device); + u64 desc_iova; + u16 chanctrl; + + desc_iova = to_iova(device, &ioat->desc); + ioat->desc = (struct ioat_dma_descriptor) { + .ctl_f.op = IOAT_OP_COPY, + .ctl_f.int_en = interrupt, + .src_addr = src, + .dst_addr = dst, + .size = size, + .next = desc_iova, + }; + + /* Tell the device the address of the descriptor. */ + writeq(desc_iova, registers + IOAT2_CHAINADDR_OFFSET); + + /* (Re)Enable the channel interrupt and abort on any errors */ + chanctrl = IOAT_CHANCTRL_INT_REARM | IOAT_CHANCTRL_ANY_ERR_ABORT_EN; + writew(chanctrl, registers + IOAT_CHANCTRL_OFFSET); + + /* Kick off @count DMA copy operation(s). */ + writew(count, registers + IOAT_CHAN_DMACOUNT_OFFSET); +} + +static void ioat_memcpy_start(struct vfio_pci_device *device, + iova_t src, iova_t dst, u64 size, + u64 count) +{ + __ioat_memcpy_start(device, src, dst, size, count, false); +} + +static void ioat_send_msi(struct vfio_pci_device *device) +{ + struct ioat_state *ioat = to_ioat_state(device); + + __ioat_memcpy_start(device, + to_iova(device, &ioat->send_msi_src), + to_iova(device, &ioat->send_msi_dst), + sizeof(ioat->send_msi_src), 1, true); + + VFIO_ASSERT_EQ(ioat_memcpy_wait(device), 0); +} + +const struct vfio_pci_driver_ops ioat_ops = { + .name = "ioat", + .probe = ioat_probe, + .init = ioat_init, + .remove = ioat_remove, + .memcpy_start = ioat_memcpy_start, + .memcpy_wait = ioat_memcpy_wait, + .send_msi = ioat_send_msi, +}; diff --git a/tools/testing/selftests/vfio/lib/drivers/ioat/registers.h b/tools/testing/selftests/vfio/lib/drivers/ioat/registers.h new file mode 120000 index 000000000000..0b809cfd8fe6 --- /dev/null +++ b/tools/testing/selftests/vfio/lib/drivers/ioat/registers.h @@ -0,0 +1 @@ +../../../../../../../drivers/dma/ioat/registers.h \ No newline at end of file diff --git a/tools/testing/selftests/vfio/lib/libvfio.mk b/tools/testing/selftests/vfio/lib/libvfio.mk index a3c3bc9a7c00..624dc267a879 100644 --- a/tools/testing/selftests/vfio/lib/libvfio.mk +++ b/tools/testing/selftests/vfio/lib/libvfio.mk @@ -1,8 +1,15 @@ +include $(top_srcdir)/scripts/subarch.include +ARCH ?= $(SUBARCH) + VFIO_DIR := $(selfdir)/vfio
LIBVFIO_C := lib/vfio_pci_device.c LIBVFIO_C += lib/vfio_pci_driver.c
+ifeq ($(ARCH:x86_64=x86),x86) +LIBVFIO_C += lib/drivers/ioat/ioat.c +endif + LIBVFIO_O := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBVFIO_C))
LIBVFIO_O_DIRS := $(shell dirname $(LIBVFIO_O) | uniq) diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_driver.c b/tools/testing/selftests/vfio/lib/vfio_pci_driver.c index c98bd2d31d8a..aa47360e47a9 100644 --- a/tools/testing/selftests/vfio/lib/vfio_pci_driver.c +++ b/tools/testing/selftests/vfio/lib/vfio_pci_driver.c @@ -4,7 +4,15 @@ #include "../../../kselftest.h" #include <vfio_util.h>
-static struct vfio_pci_driver_ops *driver_ops[] = {}; +#ifdef __x86_64__ +extern struct vfio_pci_driver_ops ioat_ops; +#endif + +static struct vfio_pci_driver_ops *driver_ops[] = { +#ifdef __x86_64__ + &ioat_ops, +#endif +};
void vfio_pci_driver_probe(struct vfio_pci_device *device) {