--- /dev/null
+/*
+ * 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)
Code Review / kvmfornfv.git / blobdiff