hw/riscv: virt: Add optional ACLINT support to virt machine

We extend virt machine to emulate ACLINT devices only when "aclint=on"
parameter is passed along with machine name in QEMU command-line.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Message-id: 20210831110603.338681-5-anup.patel@wdc.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
diff --git a/docs/system/riscv/virt.rst b/docs/system/riscv/virt.rst
index 321d77e..fa01658 100644
--- a/docs/system/riscv/virt.rst
+++ b/docs/system/riscv/virt.rst
@@ -53,6 +53,16 @@
 the recommended RISC-V bootflow: U-Boot SPL (M-mode) loads OpenSBI fw_dynamic
 firmware and U-Boot proper (S-mode), using the standard -bios functionality.
 
+Machine-specific options
+------------------------
+
+The following machine-specific options are supported:
+
+- aclint=[on|off]
+
+  When this option is "on", ACLINT devices will be emulated instead of
+  SiFive CLINT. When not specified, this option is assumed to be "off".
+
 Running Linux kernel
 --------------------
 
diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
index 7f71690..ec0cb69 100644
--- a/hw/riscv/virt.c
+++ b/hw/riscv/virt.c
@@ -48,6 +48,7 @@
     [VIRT_TEST] =        {   0x100000,        0x1000 },
     [VIRT_RTC] =         {   0x101000,        0x1000 },
     [VIRT_CLINT] =       {  0x2000000,       0x10000 },
+    [VIRT_ACLINT_SSWI] = {  0x2F00000,        0x4000 },
     [VIRT_PCIE_PIO] =    {  0x3000000,       0x10000 },
     [VIRT_PLIC] =        {  0xc000000, VIRT_PLIC_SIZE(VIRT_CPUS_MAX * 2) },
     [VIRT_UART0] =       { 0x10000000,         0x100 },
@@ -281,6 +282,82 @@
     g_free(clint_cells);
 }
 
+static void create_fdt_socket_aclint(RISCVVirtState *s,
+                                     const MemMapEntry *memmap, int socket,
+                                     uint32_t *intc_phandles)
+{
+    int cpu;
+    char *name;
+    unsigned long addr;
+    uint32_t aclint_cells_size;
+    uint32_t *aclint_mswi_cells;
+    uint32_t *aclint_sswi_cells;
+    uint32_t *aclint_mtimer_cells;
+    MachineState *mc = MACHINE(s);
+
+    aclint_mswi_cells = g_new0(uint32_t, s->soc[socket].num_harts * 2);
+    aclint_mtimer_cells = g_new0(uint32_t, s->soc[socket].num_harts * 2);
+    aclint_sswi_cells = g_new0(uint32_t, s->soc[socket].num_harts * 2);
+
+    for (cpu = 0; cpu < s->soc[socket].num_harts; cpu++) {
+        aclint_mswi_cells[cpu * 2 + 0] = cpu_to_be32(intc_phandles[cpu]);
+        aclint_mswi_cells[cpu * 2 + 1] = cpu_to_be32(IRQ_M_SOFT);
+        aclint_mtimer_cells[cpu * 2 + 0] = cpu_to_be32(intc_phandles[cpu]);
+        aclint_mtimer_cells[cpu * 2 + 1] = cpu_to_be32(IRQ_M_TIMER);
+        aclint_sswi_cells[cpu * 2 + 0] = cpu_to_be32(intc_phandles[cpu]);
+        aclint_sswi_cells[cpu * 2 + 1] = cpu_to_be32(IRQ_S_SOFT);
+    }
+    aclint_cells_size = s->soc[socket].num_harts * sizeof(uint32_t) * 2;
+
+    addr = memmap[VIRT_CLINT].base + (memmap[VIRT_CLINT].size * socket);
+    name = g_strdup_printf("/soc/mswi@%lx", addr);
+    qemu_fdt_add_subnode(mc->fdt, name);
+    qemu_fdt_setprop_string(mc->fdt, name, "compatible", "riscv,aclint-mswi");
+    qemu_fdt_setprop_cells(mc->fdt, name, "reg",
+        0x0, addr, 0x0, RISCV_ACLINT_SWI_SIZE);
+    qemu_fdt_setprop(mc->fdt, name, "interrupts-extended",
+        aclint_mswi_cells, aclint_cells_size);
+    qemu_fdt_setprop(mc->fdt, name, "interrupt-controller", NULL, 0);
+    qemu_fdt_setprop_cell(mc->fdt, name, "#interrupt-cells", 0);
+    riscv_socket_fdt_write_id(mc, mc->fdt, name, socket);
+    g_free(name);
+
+    addr = memmap[VIRT_CLINT].base + RISCV_ACLINT_SWI_SIZE +
+        (memmap[VIRT_CLINT].size * socket);
+    name = g_strdup_printf("/soc/mtimer@%lx", addr);
+    qemu_fdt_add_subnode(mc->fdt, name);
+    qemu_fdt_setprop_string(mc->fdt, name, "compatible",
+        "riscv,aclint-mtimer");
+    qemu_fdt_setprop_cells(mc->fdt, name, "reg",
+        0x0, addr + RISCV_ACLINT_DEFAULT_MTIME,
+        0x0, memmap[VIRT_CLINT].size - RISCV_ACLINT_SWI_SIZE -
+             RISCV_ACLINT_DEFAULT_MTIME,
+        0x0, addr + RISCV_ACLINT_DEFAULT_MTIMECMP,
+        0x0, RISCV_ACLINT_DEFAULT_MTIME);
+    qemu_fdt_setprop(mc->fdt, name, "interrupts-extended",
+        aclint_mtimer_cells, aclint_cells_size);
+    riscv_socket_fdt_write_id(mc, mc->fdt, name, socket);
+    g_free(name);
+
+    addr = memmap[VIRT_ACLINT_SSWI].base +
+        (memmap[VIRT_ACLINT_SSWI].size * socket);
+    name = g_strdup_printf("/soc/sswi@%lx", addr);
+    qemu_fdt_add_subnode(mc->fdt, name);
+    qemu_fdt_setprop_string(mc->fdt, name, "compatible", "riscv,aclint-sswi");
+    qemu_fdt_setprop_cells(mc->fdt, name, "reg",
+        0x0, addr, 0x0, memmap[VIRT_ACLINT_SSWI].size);
+    qemu_fdt_setprop(mc->fdt, name, "interrupts-extended",
+        aclint_sswi_cells, aclint_cells_size);
+    qemu_fdt_setprop(mc->fdt, name, "interrupt-controller", NULL, 0);
+    qemu_fdt_setprop_cell(mc->fdt, name, "#interrupt-cells", 0);
+    riscv_socket_fdt_write_id(mc, mc->fdt, name, socket);
+    g_free(name);
+
+    g_free(aclint_mswi_cells);
+    g_free(aclint_mtimer_cells);
+    g_free(aclint_sswi_cells);
+}
+
 static void create_fdt_socket_plic(RISCVVirtState *s,
                                    const MemMapEntry *memmap, int socket,
                                    uint32_t *phandle, uint32_t *intc_phandles,
@@ -359,7 +436,11 @@
 
         create_fdt_socket_memory(s, memmap, socket);
 
-        create_fdt_socket_clint(s, memmap, socket, intc_phandles);
+        if (s->have_aclint) {
+            create_fdt_socket_aclint(s, memmap, socket, intc_phandles);
+        } else {
+            create_fdt_socket_clint(s, memmap, socket, intc_phandles);
+        }
 
         create_fdt_socket_plic(s, memmap, socket, phandle,
             intc_phandles, xplic_phandles);
@@ -750,6 +831,14 @@
             RISCV_ACLINT_DEFAULT_MTIMECMP, RISCV_ACLINT_DEFAULT_MTIME,
             RISCV_ACLINT_DEFAULT_TIMEBASE_FREQ, true);
 
+        /* Per-socket ACLINT SSWI */
+        if (s->have_aclint) {
+            riscv_aclint_swi_create(
+                memmap[VIRT_ACLINT_SSWI].base +
+                    i * memmap[VIRT_ACLINT_SSWI].size,
+                base_hartid, hart_count, true);
+        }
+
         /* Per-socket PLIC hart topology configuration string */
         plic_hart_config = plic_hart_config_string(hart_count);
 
@@ -914,6 +1003,22 @@
 {
 }
 
+static bool virt_get_aclint(Object *obj, Error **errp)
+{
+    MachineState *ms = MACHINE(obj);
+    RISCVVirtState *s = RISCV_VIRT_MACHINE(ms);
+
+    return s->have_aclint;
+}
+
+static void virt_set_aclint(Object *obj, bool value, Error **errp)
+{
+    MachineState *ms = MACHINE(obj);
+    RISCVVirtState *s = RISCV_VIRT_MACHINE(ms);
+
+    s->have_aclint = value;
+}
+
 static void virt_machine_class_init(ObjectClass *oc, void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
@@ -929,6 +1034,12 @@
     mc->numa_mem_supported = true;
 
     machine_class_allow_dynamic_sysbus_dev(mc, TYPE_RAMFB_DEVICE);
+
+    object_class_property_add_bool(oc, "aclint", virt_get_aclint,
+                                   virt_set_aclint);
+    object_class_property_set_description(oc, "aclint",
+                                          "Set on/off to enable/disable "
+                                          "emulating ACLINT devices");
 }
 
 static const TypeInfo virt_machine_typeinfo = {
diff --git a/include/hw/riscv/virt.h b/include/hw/riscv/virt.h
index 349fee1..d9105c1 100644
--- a/include/hw/riscv/virt.h
+++ b/include/hw/riscv/virt.h
@@ -43,6 +43,7 @@
     FWCfgState *fw_cfg;
 
     int fdt_size;
+    bool have_aclint;
 };
 
 enum {
@@ -51,6 +52,7 @@
     VIRT_TEST,
     VIRT_RTC,
     VIRT_CLINT,
+    VIRT_ACLINT_SSWI,
     VIRT_PLIC,
     VIRT_UART0,
     VIRT_VIRTIO,