Implement PAPR CRQ hypercalls

This patch implements the infrastructure and hypercalls necessary for the
PAPR specified CRQ (Command Request Queue) mechanism.  This general
request queueing system is used by many of the PAPR virtual IO devices,
including the virtual scsi adapter.

Signed-off-by: Ben Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 160 insertions, 0 deletions

diff --git a/hw/spapr_vio.c b/hw/spapr_vio.c
index 39d77ee28b..8f14fcc794 100644
--- a/hw/spapr_vio.c
+++ b/hw/spapr_vio.c
@@ -28,6 +28,7 @@
 #include "hw/sysbus.h"
 #include "kvm.h"
 #include "device_tree.h"
+#include "kvm_ppc.h"
 
 #include "hw/spapr.h"
 #include "hw/spapr_vio.h"
@@ -359,6 +360,159 @@ uint64_t ldq_tce(VIOsPAPRDevice *dev, uint64_t taddr)
     return tswap64(val);
 }
 
+/*
+ * CRQ handling
+ */
+static target_ulong h_reg_crq(CPUState *env, sPAPREnvironment *spapr,
+                              target_ulong opcode, target_ulong *args)
+{
+    target_ulong reg = args[0];
+    target_ulong queue_addr = args[1];
+    target_ulong queue_len = args[2];
+    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
+
+    if (!dev) {
+        hcall_dprintf("h_reg_crq on non-existent unit 0x"
+                      TARGET_FMT_lx "\n", reg);
+        return H_PARAMETER;
+    }
+
+    /* We can't grok a queue size bigger than 256M for now */
+    if (queue_len < 0x1000 || queue_len > 0x10000000) {
+        hcall_dprintf("h_reg_crq, queue size too small or too big (0x%llx)\n",
+                      (unsigned long long)queue_len);
+        return H_PARAMETER;
+    }
+
+    /* Check queue alignment */
+    if (queue_addr & 0xfff) {
+        hcall_dprintf("h_reg_crq, queue not aligned (0x%llx)\n",
+                      (unsigned long long)queue_addr);
+        return H_PARAMETER;
+    }
+
+    /* Check if device supports CRQs */
+    if (!dev->crq.SendFunc) {
+        return H_NOT_FOUND;
+    }
+
+
+    /* Already a queue ? */
+    if (dev->crq.qsize) {
+        return H_RESOURCE;
+    }
+    dev->crq.qladdr = queue_addr;
+    dev->crq.qsize = queue_len;
+    dev->crq.qnext = 0;
+
+    dprintf("CRQ for dev 0x" TARGET_FMT_lx " registered at 0x"
+            TARGET_FMT_lx "/0x" TARGET_FMT_lx "\n",
+            reg, queue_addr, queue_len);
+    return H_SUCCESS;
+}
+
+static target_ulong h_free_crq(CPUState *env, sPAPREnvironment *spapr,
+                               target_ulong opcode, target_ulong *args)
+{
+    target_ulong reg = args[0];
+    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
+
+    if (!dev) {
+        hcall_dprintf("h_free_crq on non-existent unit 0x"
+                      TARGET_FMT_lx "\n", reg);
+        return H_PARAMETER;
+    }
+
+    dev->crq.qladdr = 0;
+    dev->crq.qsize = 0;
+    dev->crq.qnext = 0;
+
+    dprintf("CRQ for dev 0x" TARGET_FMT_lx " freed\n", reg);
+
+    return H_SUCCESS;
+}
+
+static target_ulong h_send_crq(CPUState *env, sPAPREnvironment *spapr,
+                               target_ulong opcode, target_ulong *args)
+{
+    target_ulong reg = args[0];
+    target_ulong msg_hi = args[1];
+    target_ulong msg_lo = args[2];
+    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
+    uint64_t crq_mangle[2];
+
+    if (!dev) {
+        hcall_dprintf("h_send_crq on non-existent unit 0x"
+                      TARGET_FMT_lx "\n", reg);
+        return H_PARAMETER;
+    }
+    crq_mangle[0] = cpu_to_be64(msg_hi);
+    crq_mangle[1] = cpu_to_be64(msg_lo);
+
+    if (dev->crq.SendFunc) {
+        return dev->crq.SendFunc(dev, (uint8_t *)crq_mangle);
+    }
+
+    return H_HARDWARE;
+}
+
+static target_ulong h_enable_crq(CPUState *env, sPAPREnvironment *spapr,
+                                 target_ulong opcode, target_ulong *args)
+{
+    target_ulong reg = args[0];
+    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
+
+    if (!dev) {
+        hcall_dprintf("h_enable_crq on non-existent unit 0x"
+                      TARGET_FMT_lx "\n", reg);
+        return H_PARAMETER;
+    }
+
+    return 0;
+}
+
+/* Returns negative error, 0 success, or positive: queue full */
+int spapr_vio_send_crq(VIOsPAPRDevice *dev, uint8_t *crq)
+{
+    int rc;
+    uint8_t byte;
+
+    if (!dev->crq.qsize) {
+        fprintf(stderr, "spapr_vio_send_creq on uninitialized queue\n");
+        return -1;
+    }
+
+    /* Maybe do a fast path for KVM just writing to the pages */
+    rc = spapr_tce_dma_read(dev, dev->crq.qladdr + dev->crq.qnext, &byte, 1);
+    if (rc) {
+        return rc;
+    }
+    if (byte != 0) {
+        return 1;
+    }
+
+    rc = spapr_tce_dma_write(dev, dev->crq.qladdr + dev->crq.qnext + 8,
+                             &crq[8], 8);
+    if (rc) {
+        return rc;
+    }
+
+    kvmppc_eieio();
+
+    rc = spapr_tce_dma_write(dev, dev->crq.qladdr + dev->crq.qnext, crq, 8);
+    if (rc) {
+        return rc;
+    }
+
+    dev->crq.qnext = (dev->crq.qnext + 16) % dev->crq.qsize;
+
+    if (dev->signal_state & 1) {
+        qemu_irq_pulse(dev->qirq);
+    }
+
+    return 0;
+}
+
 static int spapr_vio_busdev_init(DeviceState *qdev, DeviceInfo *qinfo)
 {
     VIOsPAPRDeviceInfo *info = (VIOsPAPRDeviceInfo *)qinfo;
@@ -431,6 +585,12 @@ VIOsPAPRBus *spapr_vio_bus_init(void)
     /* hcall-tce */
     spapr_register_hypercall(H_PUT_TCE, h_put_tce);
 
+    /* hcall-crq */
+    spapr_register_hypercall(H_REG_CRQ, h_reg_crq);
+    spapr_register_hypercall(H_FREE_CRQ, h_free_crq);
+    spapr_register_hypercall(H_SEND_CRQ, h_send_crq);
+    spapr_register_hypercall(H_ENABLE_CRQ, h_enable_crq);
+
     for (qinfo = device_info_list; qinfo; qinfo = qinfo->next) {
         VIOsPAPRDeviceInfo *info = (VIOsPAPRDeviceInfo *)qinfo;