ipmi: Split out KCS-specific code from ISA KCS code

Get ready for PCI and other KCS interfaces.

No functional changes, just split the code into the generic KCS code
and the ISA-specific code.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
diff --git a/hw/ipmi/ipmi_kcs.c b/hw/ipmi/ipmi_kcs.c
new file mode 100644
index 0000000..dab1af8
--- /dev/null
+++ b/hw/ipmi/ipmi_kcs.c
@@ -0,0 +1,408 @@
+/*
+ * QEMU IPMI KCS emulation
+ *
+ * Copyright (c) 2015,2017 Corey Minyard, MontaVista Software, LLC
+ *
+ * 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 "qemu/osdep.h"
+#include "migration/vmstate.h"
+#include "qemu/log.h"
+#include "qapi/error.h"
+#include "hw/ipmi/ipmi_kcs.h"
+
+#define IPMI_KCS_OBF_BIT        0
+#define IPMI_KCS_IBF_BIT        1
+#define IPMI_KCS_SMS_ATN_BIT    2
+#define IPMI_KCS_CD_BIT         3
+
+#define IPMI_KCS_OBF_MASK          (1 << IPMI_KCS_OBF_BIT)
+#define IPMI_KCS_GET_OBF(d)        (((d) >> IPMI_KCS_OBF_BIT) & 0x1)
+#define IPMI_KCS_SET_OBF(d, v)     (d) = (((d) & ~IPMI_KCS_OBF_MASK) | \
+                                       (((v) & 1) << IPMI_KCS_OBF_BIT))
+#define IPMI_KCS_IBF_MASK          (1 << IPMI_KCS_IBF_BIT)
+#define IPMI_KCS_GET_IBF(d)        (((d) >> IPMI_KCS_IBF_BIT) & 0x1)
+#define IPMI_KCS_SET_IBF(d, v)     (d) = (((d) & ~IPMI_KCS_IBF_MASK) | \
+                                       (((v) & 1) << IPMI_KCS_IBF_BIT))
+#define IPMI_KCS_SMS_ATN_MASK      (1 << IPMI_KCS_SMS_ATN_BIT)
+#define IPMI_KCS_GET_SMS_ATN(d)    (((d) >> IPMI_KCS_SMS_ATN_BIT) & 0x1)
+#define IPMI_KCS_SET_SMS_ATN(d, v) (d) = (((d) & ~IPMI_KCS_SMS_ATN_MASK) | \
+                                       (((v) & 1) << IPMI_KCS_SMS_ATN_BIT))
+#define IPMI_KCS_CD_MASK           (1 << IPMI_KCS_CD_BIT)
+#define IPMI_KCS_GET_CD(d)         (((d) >> IPMI_KCS_CD_BIT) & 0x1)
+#define IPMI_KCS_SET_CD(d, v)      (d) = (((d) & ~IPMI_KCS_CD_MASK) | \
+                                       (((v) & 1) << IPMI_KCS_CD_BIT))
+
+#define IPMI_KCS_IDLE_STATE        0
+#define IPMI_KCS_READ_STATE        1
+#define IPMI_KCS_WRITE_STATE       2
+#define IPMI_KCS_ERROR_STATE       3
+
+#define IPMI_KCS_GET_STATE(d)    (((d) >> 6) & 0x3)
+#define IPMI_KCS_SET_STATE(d, v) ((d) = ((d) & ~0xc0) | (((v) & 0x3) << 6))
+
+#define IPMI_KCS_ABORT_STATUS_CMD       0x60
+#define IPMI_KCS_WRITE_START_CMD        0x61
+#define IPMI_KCS_WRITE_END_CMD          0x62
+#define IPMI_KCS_READ_CMD               0x68
+
+#define IPMI_KCS_STATUS_NO_ERR          0x00
+#define IPMI_KCS_STATUS_ABORTED_ERR     0x01
+#define IPMI_KCS_STATUS_BAD_CC_ERR      0x02
+#define IPMI_KCS_STATUS_LENGTH_ERR      0x06
+
+static void ipmi_kcs_raise_irq(IPMIKCS *ik)
+{
+    if (ik->use_irq && ik->irqs_enabled && ik->raise_irq) {
+        ik->raise_irq(ik);
+    }
+}
+
+static void ipmi_kcs_lower_irq(IPMIKCS *ik)
+{
+    if (ik->lower_irq) {
+        ik->lower_irq(ik);
+    }
+}
+
+#define SET_OBF() \
+    do {                                                                      \
+        IPMI_KCS_SET_OBF(ik->status_reg, 1);                                  \
+        if (!ik->obf_irq_set) {                                               \
+            ik->obf_irq_set = 1;                                              \
+            if (!ik->atn_irq_set) {                                           \
+                ipmi_kcs_raise_irq(ik);                                  \
+            }                                                                 \
+        }                                                                     \
+    } while (0)
+
+static void ipmi_kcs_signal(IPMIKCS *ik, IPMIInterface *ii)
+{
+    IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
+
+    ik->do_wake = 1;
+    while (ik->do_wake) {
+        ik->do_wake = 0;
+        iic->handle_if_event(ii);
+    }
+}
+
+static void ipmi_kcs_handle_event(IPMIInterface *ii)
+{
+    IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
+    IPMIKCS *ik = iic->get_backend_data(ii);
+
+    if (ik->cmd_reg == IPMI_KCS_ABORT_STATUS_CMD) {
+        if (IPMI_KCS_GET_STATE(ik->status_reg) != IPMI_KCS_ERROR_STATE) {
+            ik->waiting_rsp++; /* Invalidate the message */
+            ik->outmsg[0] = IPMI_KCS_STATUS_ABORTED_ERR;
+            ik->outlen = 1;
+            ik->outpos = 0;
+            IPMI_KCS_SET_STATE(ik->status_reg, IPMI_KCS_ERROR_STATE);
+            SET_OBF();
+        }
+        goto out;
+    }
+
+    switch (IPMI_KCS_GET_STATE(ik->status_reg)) {
+    case IPMI_KCS_IDLE_STATE:
+        if (ik->cmd_reg == IPMI_KCS_WRITE_START_CMD) {
+            IPMI_KCS_SET_STATE(ik->status_reg, IPMI_KCS_WRITE_STATE);
+            ik->cmd_reg = -1;
+            ik->write_end = 0;
+            ik->inlen = 0;
+            SET_OBF();
+        }
+        break;
+
+    case IPMI_KCS_READ_STATE:
+    handle_read:
+        if (ik->outpos >= ik->outlen) {
+            IPMI_KCS_SET_STATE(ik->status_reg, IPMI_KCS_IDLE_STATE);
+            SET_OBF();
+        } else if (ik->data_in_reg == IPMI_KCS_READ_CMD) {
+            ik->data_out_reg = ik->outmsg[ik->outpos];
+            ik->outpos++;
+            SET_OBF();
+        } else {
+            ik->outmsg[0] = IPMI_KCS_STATUS_BAD_CC_ERR;
+            ik->outlen = 1;
+            ik->outpos = 0;
+            IPMI_KCS_SET_STATE(ik->status_reg, IPMI_KCS_ERROR_STATE);
+            SET_OBF();
+            goto out;
+        }
+        break;
+
+    case IPMI_KCS_WRITE_STATE:
+        if (ik->data_in_reg != -1) {
+            /*
+             * Don't worry about input overrun here, that will be
+             * handled in the BMC.
+             */
+            if (ik->inlen < sizeof(ik->inmsg)) {
+                ik->inmsg[ik->inlen] = ik->data_in_reg;
+            }
+            ik->inlen++;
+        }
+        if (ik->write_end) {
+            IPMIBmcClass *bk = IPMI_BMC_GET_CLASS(ik->bmc);
+            ik->outlen = 0;
+            ik->write_end = 0;
+            ik->outpos = 0;
+            bk->handle_command(ik->bmc, ik->inmsg, ik->inlen, sizeof(ik->inmsg),
+                               ik->waiting_rsp);
+            goto out_noibf;
+        } else if (ik->cmd_reg == IPMI_KCS_WRITE_END_CMD) {
+            ik->cmd_reg = -1;
+            ik->write_end = 1;
+        }
+        SET_OBF();
+        break;
+
+    case IPMI_KCS_ERROR_STATE:
+        if (ik->data_in_reg != -1) {
+            IPMI_KCS_SET_STATE(ik->status_reg, IPMI_KCS_READ_STATE);
+            ik->data_in_reg = IPMI_KCS_READ_CMD;
+            goto handle_read;
+        }
+        break;
+    }
+
+    if (ik->cmd_reg != -1) {
+        /* Got an invalid command */
+        ik->outmsg[0] = IPMI_KCS_STATUS_BAD_CC_ERR;
+        ik->outlen = 1;
+        ik->outpos = 0;
+        IPMI_KCS_SET_STATE(ik->status_reg, IPMI_KCS_ERROR_STATE);
+    }
+
+ out:
+    ik->cmd_reg = -1;
+    ik->data_in_reg = -1;
+    IPMI_KCS_SET_IBF(ik->status_reg, 0);
+ out_noibf:
+    return;
+}
+
+static void ipmi_kcs_handle_rsp(IPMIInterface *ii, uint8_t msg_id,
+                                unsigned char *rsp, unsigned int rsp_len)
+{
+    IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
+    IPMIKCS *ik = iic->get_backend_data(ii);
+
+    if (ik->waiting_rsp == msg_id) {
+        ik->waiting_rsp++;
+        if (rsp_len > sizeof(ik->outmsg)) {
+            ik->outmsg[0] = rsp[0];
+            ik->outmsg[1] = rsp[1];
+            ik->outmsg[2] = IPMI_CC_CANNOT_RETURN_REQ_NUM_BYTES;
+            ik->outlen = 3;
+        } else {
+            memcpy(ik->outmsg, rsp, rsp_len);
+            ik->outlen = rsp_len;
+        }
+        IPMI_KCS_SET_STATE(ik->status_reg, IPMI_KCS_READ_STATE);
+        ik->data_in_reg = IPMI_KCS_READ_CMD;
+        ipmi_kcs_signal(ik, ii);
+    }
+}
+
+
+static uint64_t ipmi_kcs_ioport_read(void *opaque, hwaddr addr, unsigned size)
+{
+    IPMIInterface *ii = opaque;
+    IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
+    IPMIKCS *ik = iic->get_backend_data(ii);
+    uint32_t ret;
+
+    switch (addr & 1) {
+    case 0:
+        ret = ik->data_out_reg;
+        IPMI_KCS_SET_OBF(ik->status_reg, 0);
+        if (ik->obf_irq_set) {
+            ik->obf_irq_set = 0;
+            if (!ik->atn_irq_set) {
+                ipmi_kcs_lower_irq(ik);
+            }
+        }
+        break;
+    case 1:
+        ret = ik->status_reg;
+        if (ik->atn_irq_set) {
+            ik->atn_irq_set = 0;
+            if (!ik->obf_irq_set) {
+                ipmi_kcs_lower_irq(ik);
+            }
+        }
+        break;
+    }
+    return ret;
+}
+
+static void ipmi_kcs_ioport_write(void *opaque, hwaddr addr, uint64_t val,
+                                  unsigned size)
+{
+    IPMIInterface *ii = opaque;
+    IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
+    IPMIKCS *ik = iic->get_backend_data(ii);
+
+    if (IPMI_KCS_GET_IBF(ik->status_reg)) {
+        return;
+    }
+
+    switch (addr & 1) {
+    case 0:
+        ik->data_in_reg = val;
+        break;
+
+    case 1:
+        ik->cmd_reg = val;
+        break;
+    }
+    IPMI_KCS_SET_IBF(ik->status_reg, 1);
+    ipmi_kcs_signal(ik, ii);
+}
+
+const MemoryRegionOps ipmi_kcs_io_ops = {
+    .read = ipmi_kcs_ioport_read,
+    .write = ipmi_kcs_ioport_write,
+    .impl = {
+        .min_access_size = 1,
+        .max_access_size = 1,
+    },
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static void ipmi_kcs_set_atn(IPMIInterface *ii, int val, int irq)
+{
+    IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
+    IPMIKCS *ik = iic->get_backend_data(ii);
+
+    IPMI_KCS_SET_SMS_ATN(ik->status_reg, val);
+    if (val) {
+        if (irq && !ik->atn_irq_set) {
+            ik->atn_irq_set = 1;
+            if (!ik->obf_irq_set) {
+                ipmi_kcs_raise_irq(ik);
+            }
+        }
+    } else {
+        if (ik->atn_irq_set) {
+            ik->atn_irq_set = 0;
+            if (!ik->obf_irq_set) {
+                ipmi_kcs_lower_irq(ik);
+            }
+        }
+    }
+}
+
+static void ipmi_kcs_set_irq_enable(IPMIInterface *ii, int val)
+{
+    IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
+    IPMIKCS *ik = iic->get_backend_data(ii);
+
+    ik->irqs_enabled = val;
+}
+
+static void ipmi_kcs_init(IPMIInterface *ii, Error **errp)
+{
+    IPMIInterfaceClass *iic = IPMI_INTERFACE_GET_CLASS(ii);
+    IPMIKCS *ik = iic->get_backend_data(ii);
+
+    ik->io_length = 2;
+    memory_region_init_io(&ik->io, NULL, &ipmi_kcs_io_ops, ii, "ipmi-kcs", 2);
+}
+
+int ipmi_kcs_vmstate_post_load(void *opaque, int version)
+{
+    IPMIKCS *ik = opaque;
+
+    /* Make sure all the values are sane. */
+    if (ik->outpos >= MAX_IPMI_MSG_SIZE || ik->outlen >= MAX_IPMI_MSG_SIZE ||
+        ik->outpos >= ik->outlen) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "ipmi:kcs: vmstate transfer received bad out values: %d %d\n",
+                      ik->outpos, ik->outlen);
+        ik->outpos = 0;
+        ik->outlen = 0;
+    }
+
+    if (ik->inlen >= MAX_IPMI_MSG_SIZE) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "ipmi:kcs: vmstate transfer received bad in value: %d\n",
+                      ik->inlen);
+        ik->inlen = 0;
+    }
+
+    return 0;
+}
+
+static bool vmstate_kcs_before_version2(void *opaque, int version)
+{
+    return version <= 1;
+}
+
+const VMStateDescription vmstate_IPMIKCS = {
+    .name = TYPE_IPMI_INTERFACE_PREFIX "kcs",
+    .version_id = 2,
+    .minimum_version_id = 1,
+    .post_load = ipmi_kcs_vmstate_post_load,
+    .fields      = (VMStateField[]) {
+        VMSTATE_BOOL(obf_irq_set, IPMIKCS),
+        VMSTATE_BOOL(atn_irq_set, IPMIKCS),
+        VMSTATE_UNUSED_TEST(vmstate_kcs_before_version2, 1), /* Was use_irq */
+        VMSTATE_BOOL(irqs_enabled, IPMIKCS),
+        VMSTATE_UINT32(outpos, IPMIKCS),
+        VMSTATE_UINT32_V(outlen, IPMIKCS, 2),
+        VMSTATE_UINT8_ARRAY(outmsg, IPMIKCS, MAX_IPMI_MSG_SIZE),
+        VMSTATE_UINT32_V(inlen, IPMIKCS, 2),
+        VMSTATE_UINT8_ARRAY(inmsg, IPMIKCS, MAX_IPMI_MSG_SIZE),
+        VMSTATE_BOOL(write_end, IPMIKCS),
+        VMSTATE_UINT8(status_reg, IPMIKCS),
+        VMSTATE_UINT8(data_out_reg, IPMIKCS),
+        VMSTATE_INT16(data_in_reg, IPMIKCS),
+        VMSTATE_INT16(cmd_reg, IPMIKCS),
+        VMSTATE_UINT8(waiting_rsp, IPMIKCS),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+void ipmi_kcs_get_fwinfo(IPMIKCS *ik, IPMIFwInfo *info)
+{
+    info->interface_name = "kcs";
+    info->interface_type = IPMI_SMBIOS_KCS;
+    info->ipmi_spec_major_revision = 2;
+    info->ipmi_spec_minor_revision = 0;
+    info->base_address = ik->io_base;
+    info->i2c_slave_address = ik->bmc->slave_addr;
+    info->register_length = ik->io_length;
+    info->register_spacing = 1;
+    info->memspace = IPMI_MEMSPACE_IO;
+    info->irq_type = IPMI_LEVEL_IRQ;
+}
+
+void ipmi_kcs_class_init(IPMIInterfaceClass *iic)
+{
+    iic->init = ipmi_kcs_init;
+    iic->set_atn = ipmi_kcs_set_atn;
+    iic->handle_rsp = ipmi_kcs_handle_rsp;
+    iic->handle_if_event = ipmi_kcs_handle_event;
+    iic->set_irq_enable = ipmi_kcs_set_irq_enable;
+}