| /* |
| * QEMU educational PCI device |
| * |
| * Copyright (c) 2012-2015 Jiri Slaby |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
| * DEALINGS IN THE SOFTWARE. |
| */ |
| |
| #include "hw/pci/pci.h" |
| #include "qemu/timer.h" |
| #include "qemu/main-loop.h" /* iothread mutex */ |
| #include "qapi/visitor.h" |
| |
| #define EDU(obj) OBJECT_CHECK(EduState, obj, "edu") |
| |
| #define FACT_IRQ 0x00000001 |
| #define DMA_IRQ 0x00000100 |
| |
| #define DMA_START 0x40000 |
| #define DMA_SIZE 4096 |
| |
| typedef struct { |
| PCIDevice pdev; |
| MemoryRegion mmio; |
| |
| QemuThread thread; |
| QemuMutex thr_mutex; |
| QemuCond thr_cond; |
| bool stopping; |
| |
| uint32_t addr4; |
| uint32_t fact; |
| #define EDU_STATUS_COMPUTING 0x01 |
| #define EDU_STATUS_IRQFACT 0x80 |
| uint32_t status; |
| |
| uint32_t irq_status; |
| |
| #define EDU_DMA_RUN 0x1 |
| #define EDU_DMA_DIR(cmd) (((cmd) & 0x2) >> 1) |
| # define EDU_DMA_FROM_PCI 0 |
| # define EDU_DMA_TO_PCI 1 |
| #define EDU_DMA_IRQ 0x4 |
| struct dma_state { |
| dma_addr_t src; |
| dma_addr_t dst; |
| dma_addr_t cnt; |
| dma_addr_t cmd; |
| } dma; |
| QEMUTimer dma_timer; |
| char dma_buf[DMA_SIZE]; |
| uint64_t dma_mask; |
| } EduState; |
| |
| static void edu_raise_irq(EduState *edu, uint32_t val) |
| { |
| edu->irq_status |= val; |
| if (edu->irq_status) { |
| pci_set_irq(&edu->pdev, 1); |
| } |
| } |
| |
| static void edu_lower_irq(EduState *edu, uint32_t val) |
| { |
| edu->irq_status &= ~val; |
| |
| if (!edu->irq_status) { |
| pci_set_irq(&edu->pdev, 0); |
| } |
| } |
| |
| static bool within(uint32_t addr, uint32_t start, uint32_t end) |
| { |
| return start <= addr && addr < end; |
| } |
| |
| static void edu_check_range(uint32_t addr, uint32_t size1, uint32_t start, |
| uint32_t size2) |
| { |
| uint32_t end1 = addr + size1; |
| uint32_t end2 = start + size2; |
| |
| if (within(addr, start, end2) && |
| end1 > addr && within(end1, start, end2)) { |
| return; |
| } |
| |
| hw_error("EDU: DMA range 0x%.8x-0x%.8x out of bounds (0x%.8x-0x%.8x)!", |
| addr, end1 - 1, start, end2 - 1); |
| } |
| |
| static dma_addr_t edu_clamp_addr(const EduState *edu, dma_addr_t addr) |
| { |
| dma_addr_t res = addr & edu->dma_mask; |
| |
| if (addr != res) { |
| printf("EDU: clamping DMA %#.16"PRIx64" to %#.16"PRIx64"!\n", addr, res); |
| } |
| |
| return res; |
| } |
| |
| static void edu_dma_timer(void *opaque) |
| { |
| EduState *edu = opaque; |
| bool raise_irq = false; |
| |
| if (!(edu->dma.cmd & EDU_DMA_RUN)) { |
| return; |
| } |
| |
| if (EDU_DMA_DIR(edu->dma.cmd) == EDU_DMA_FROM_PCI) { |
| uint32_t dst = edu->dma.dst; |
| edu_check_range(dst, edu->dma.cnt, DMA_START, DMA_SIZE); |
| dst -= DMA_START; |
| pci_dma_read(&edu->pdev, edu_clamp_addr(edu, edu->dma.src), |
| edu->dma_buf + dst, edu->dma.cnt); |
| } else { |
| uint32_t src = edu->dma.src; |
| edu_check_range(src, edu->dma.cnt, DMA_START, DMA_SIZE); |
| src -= DMA_START; |
| pci_dma_write(&edu->pdev, edu_clamp_addr(edu, edu->dma.dst), |
| edu->dma_buf + src, edu->dma.cnt); |
| } |
| |
| edu->dma.cmd &= ~EDU_DMA_RUN; |
| if (edu->dma.cmd & EDU_DMA_IRQ) { |
| raise_irq = true; |
| } |
| |
| if (raise_irq) { |
| edu_raise_irq(edu, DMA_IRQ); |
| } |
| } |
| |
| static void dma_rw(EduState *edu, bool write, dma_addr_t *val, dma_addr_t *dma, |
| bool timer) |
| { |
| if (write && (edu->dma.cmd & EDU_DMA_RUN)) { |
| return; |
| } |
| |
| if (write) { |
| *dma = *val; |
| } else { |
| *val = *dma; |
| } |
| |
| if (timer) { |
| timer_mod(&edu->dma_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 100); |
| } |
| } |
| |
| static uint64_t edu_mmio_read(void *opaque, hwaddr addr, unsigned size) |
| { |
| EduState *edu = opaque; |
| uint64_t val = ~0ULL; |
| |
| if (size != 4) { |
| return val; |
| } |
| |
| switch (addr) { |
| case 0x00: |
| val = 0x010000edu; |
| break; |
| case 0x04: |
| val = edu->addr4; |
| break; |
| case 0x08: |
| qemu_mutex_lock(&edu->thr_mutex); |
| val = edu->fact; |
| qemu_mutex_unlock(&edu->thr_mutex); |
| break; |
| case 0x20: |
| val = atomic_read(&edu->status); |
| break; |
| case 0x24: |
| val = edu->irq_status; |
| break; |
| case 0x80: |
| dma_rw(edu, false, &val, &edu->dma.src, false); |
| break; |
| case 0x88: |
| dma_rw(edu, false, &val, &edu->dma.dst, false); |
| break; |
| case 0x90: |
| dma_rw(edu, false, &val, &edu->dma.cnt, false); |
| break; |
| case 0x98: |
| dma_rw(edu, false, &val, &edu->dma.cmd, false); |
| break; |
| } |
| |
| return val; |
| } |
| |
| static void edu_mmio_write(void *opaque, hwaddr addr, uint64_t val, |
| unsigned size) |
| { |
| EduState *edu = opaque; |
| |
| if (addr < 0x80 && size != 4) { |
| return; |
| } |
| |
| if (addr >= 0x80 && size != 4 && size != 8) { |
| return; |
| } |
| |
| switch (addr) { |
| case 0x04: |
| edu->addr4 = ~val; |
| break; |
| case 0x08: |
| if (atomic_read(&edu->status) & EDU_STATUS_COMPUTING) { |
| break; |
| } |
| /* EDU_STATUS_COMPUTING cannot go 0->1 concurrently, because it is only |
| * set in this function and it is under the iothread mutex. |
| */ |
| qemu_mutex_lock(&edu->thr_mutex); |
| edu->fact = val; |
| atomic_or(&edu->status, EDU_STATUS_COMPUTING); |
| qemu_cond_signal(&edu->thr_cond); |
| qemu_mutex_unlock(&edu->thr_mutex); |
| break; |
| case 0x20: |
| if (val & EDU_STATUS_IRQFACT) { |
| atomic_or(&edu->status, EDU_STATUS_IRQFACT); |
| } else { |
| atomic_and(&edu->status, ~EDU_STATUS_IRQFACT); |
| } |
| break; |
| case 0x60: |
| edu_raise_irq(edu, val); |
| break; |
| case 0x64: |
| edu_lower_irq(edu, val); |
| break; |
| case 0x80: |
| dma_rw(edu, true, &val, &edu->dma.src, false); |
| break; |
| case 0x88: |
| dma_rw(edu, true, &val, &edu->dma.dst, false); |
| break; |
| case 0x90: |
| dma_rw(edu, true, &val, &edu->dma.cnt, false); |
| break; |
| case 0x98: |
| if (!(val & EDU_DMA_RUN)) { |
| break; |
| } |
| dma_rw(edu, true, &val, &edu->dma.cmd, true); |
| break; |
| } |
| } |
| |
| static const MemoryRegionOps edu_mmio_ops = { |
| .read = edu_mmio_read, |
| .write = edu_mmio_write, |
| .endianness = DEVICE_NATIVE_ENDIAN, |
| }; |
| |
| /* |
| * We purposely use a thread, so that users are forced to wait for the status |
| * register. |
| */ |
| static void *edu_fact_thread(void *opaque) |
| { |
| EduState *edu = opaque; |
| |
| while (1) { |
| uint32_t val, ret = 1; |
| |
| qemu_mutex_lock(&edu->thr_mutex); |
| while ((atomic_read(&edu->status) & EDU_STATUS_COMPUTING) == 0 && |
| !edu->stopping) { |
| qemu_cond_wait(&edu->thr_cond, &edu->thr_mutex); |
| } |
| |
| if (edu->stopping) { |
| qemu_mutex_unlock(&edu->thr_mutex); |
| break; |
| } |
| |
| val = edu->fact; |
| qemu_mutex_unlock(&edu->thr_mutex); |
| |
| while (val > 0) { |
| ret *= val--; |
| } |
| |
| /* |
| * We should sleep for a random period here, so that students are |
| * forced to check the status properly. |
| */ |
| |
| qemu_mutex_lock(&edu->thr_mutex); |
| edu->fact = ret; |
| qemu_mutex_unlock(&edu->thr_mutex); |
| atomic_and(&edu->status, ~EDU_STATUS_COMPUTING); |
| |
| if (atomic_read(&edu->status) & EDU_STATUS_IRQFACT) { |
| qemu_mutex_lock_iothread(); |
| edu_raise_irq(edu, FACT_IRQ); |
| qemu_mutex_unlock_iothread(); |
| } |
| } |
| |
| return NULL; |
| } |
| |
| static int pci_edu_init(PCIDevice *pdev) |
| { |
| EduState *edu = DO_UPCAST(EduState, pdev, pdev); |
| uint8_t *pci_conf = pdev->config; |
| |
| timer_init_ms(&edu->dma_timer, QEMU_CLOCK_VIRTUAL, edu_dma_timer, edu); |
| |
| qemu_mutex_init(&edu->thr_mutex); |
| qemu_cond_init(&edu->thr_cond); |
| qemu_thread_create(&edu->thread, "edu", edu_fact_thread, |
| edu, QEMU_THREAD_JOINABLE); |
| |
| pci_config_set_interrupt_pin(pci_conf, 1); |
| |
| memory_region_init_io(&edu->mmio, OBJECT(edu), &edu_mmio_ops, edu, |
| "edu-mmio", 1 << 20); |
| pci_register_bar(pdev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY, &edu->mmio); |
| |
| return 0; |
| } |
| |
| static void pci_edu_uninit(PCIDevice *pdev) |
| { |
| EduState *edu = DO_UPCAST(EduState, pdev, pdev); |
| |
| qemu_mutex_lock(&edu->thr_mutex); |
| edu->stopping = true; |
| qemu_mutex_unlock(&edu->thr_mutex); |
| qemu_cond_signal(&edu->thr_cond); |
| qemu_thread_join(&edu->thread); |
| |
| qemu_cond_destroy(&edu->thr_cond); |
| qemu_mutex_destroy(&edu->thr_mutex); |
| |
| timer_del(&edu->dma_timer); |
| } |
| |
| static void edu_obj_uint64(Object *obj, struct Visitor *v, void *opaque, |
| const char *name, Error **errp) |
| { |
| uint64_t *val = opaque; |
| |
| visit_type_uint64(v, val, name, errp); |
| } |
| |
| static void edu_instance_init(Object *obj) |
| { |
| EduState *edu = EDU(obj); |
| |
| edu->dma_mask = (1UL << 28) - 1; |
| object_property_add(obj, "dma_mask", "uint64", edu_obj_uint64, |
| edu_obj_uint64, NULL, &edu->dma_mask, NULL); |
| } |
| |
| static void edu_class_init(ObjectClass *class, void *data) |
| { |
| PCIDeviceClass *k = PCI_DEVICE_CLASS(class); |
| |
| k->init = pci_edu_init; |
| k->exit = pci_edu_uninit; |
| k->vendor_id = PCI_VENDOR_ID_QEMU; |
| k->device_id = 0x11e8; |
| k->revision = 0x10; |
| k->class_id = PCI_CLASS_OTHERS; |
| } |
| |
| static void pci_edu_register_types(void) |
| { |
| static const TypeInfo edu_info = { |
| .name = "edu", |
| .parent = TYPE_PCI_DEVICE, |
| .instance_size = sizeof(EduState), |
| .instance_init = edu_instance_init, |
| .class_init = edu_class_init, |
| }; |
| |
| type_register_static(&edu_info); |
| } |
| type_init(pci_edu_register_types) |