ppc/pegasos2: Implement some RTAS functions with VOF

Linux uses RTAS functions to access PCI devices so we need to provide
these with VOF. Implement some of the most important functions to
allow booting Linux with VOF. With this the board is now usable
without a binary ROM image and we can enable it by default as other
boards.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Message-Id: <20210708215113.B3F747456E3@zero.eik.bme.hu>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 137 insertions, 0 deletions

diff --git a/hw/ppc/pegasos2.c b/hw/ppc/pegasos2.c
index cf1dc53..9a6ae86 100644
--- a/hw/ppc/pegasos2.c
+++ b/hw/ppc/pegasos2.c
@@ -43,6 +43,7 @@
 #define PROM_SIZE     0x80000
 
 #define KVMPPC_HCALL_BASE    0xf000
+#define KVMPPC_H_RTAS        (KVMPPC_HCALL_BASE + 0x0)
 #define KVMPPC_H_VOF_CLIENT  (KVMPPC_HCALL_BASE + 0x5)
 
 #define H_SUCCESS     0
@@ -195,6 +196,30 @@ static void pegasos2_init(MachineState *machine)
     }
 }
 
+static uint32_t pegasos2_pci_config_read(AddressSpace *as, int bus,
+                                         uint32_t addr, uint32_t len)
+{
+    hwaddr pcicfg = (bus ? 0xf1000c78 : 0xf1000cf8);
+    uint32_t val = 0xffffffff;
+
+    stl_le_phys(as, pcicfg, addr | BIT(31));
+    switch (len) {
+    case 4:
+        val = ldl_le_phys(as, pcicfg + 4);
+        break;
+    case 2:
+        val = lduw_le_phys(as, pcicfg + 4);
+        break;
+    case 1:
+        val = ldub_phys(as, pcicfg + 4);
+        break;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid length\n", __func__);
+        break;
+    }
+    return val;
+}
+
 static void pegasos2_pci_config_write(AddressSpace *as, int bus, uint32_t addr,
                                       uint32_t len, uint32_t val)
 {
@@ -304,6 +329,87 @@ static void pegasos2_machine_reset(MachineState *machine)
     pm->cpu->vhyp = PPC_VIRTUAL_HYPERVISOR(machine);
 }
 
+enum pegasos2_rtas_tokens {
+    RTAS_RESTART_RTAS = 0,
+    RTAS_NVRAM_FETCH = 1,
+    RTAS_NVRAM_STORE = 2,
+    RTAS_GET_TIME_OF_DAY = 3,
+    RTAS_SET_TIME_OF_DAY = 4,
+    RTAS_EVENT_SCAN = 6,
+    RTAS_CHECK_EXCEPTION = 7,
+    RTAS_READ_PCI_CONFIG = 8,
+    RTAS_WRITE_PCI_CONFIG = 9,
+    RTAS_DISPLAY_CHARACTER = 10,
+    RTAS_SET_INDICATOR = 11,
+    RTAS_POWER_OFF = 17,
+    RTAS_SUSPEND = 18,
+    RTAS_HIBERNATE = 19,
+    RTAS_SYSTEM_REBOOT = 20,
+};
+
+static target_ulong pegasos2_rtas(PowerPCCPU *cpu, Pegasos2MachineState *pm,
+                                  target_ulong args_real)
+{
+    AddressSpace *as = CPU(cpu)->as;
+    uint32_t token = ldl_be_phys(as, args_real);
+    uint32_t nargs = ldl_be_phys(as, args_real + 4);
+    uint32_t nrets = ldl_be_phys(as, args_real + 8);
+    uint32_t args = args_real + 12;
+    uint32_t rets = args_real + 12 + nargs * 4;
+
+    if (nrets < 1) {
+        qemu_log_mask(LOG_GUEST_ERROR, "Too few return values in RTAS call\n");
+        return H_PARAMETER;
+    }
+    switch (token) {
+    case RTAS_READ_PCI_CONFIG:
+    {
+        uint32_t addr, len, val;
+
+        if (nargs != 2 || nrets != 2) {
+            stl_be_phys(as, rets, -1);
+            return H_PARAMETER;
+        }
+        addr = ldl_be_phys(as, args);
+        len = ldl_be_phys(as, args + 4);
+        val = pegasos2_pci_config_read(as, !(addr >> 24),
+                                       addr & 0x0fffffff, len);
+        stl_be_phys(as, rets, 0);
+        stl_be_phys(as, rets + 4, val);
+        return H_SUCCESS;
+    }
+    case RTAS_WRITE_PCI_CONFIG:
+    {
+        uint32_t addr, len, val;
+
+        if (nargs != 3 || nrets != 1) {
+            stl_be_phys(as, rets, -1);
+            return H_PARAMETER;
+        }
+        addr = ldl_be_phys(as, args);
+        len = ldl_be_phys(as, args + 4);
+        val = ldl_be_phys(as, args + 8);
+        pegasos2_pci_config_write(as, !(addr >> 24),
+                                  addr & 0x0fffffff, len, val);
+        stl_be_phys(as, rets, 0);
+        return H_SUCCESS;
+    }
+    case RTAS_DISPLAY_CHARACTER:
+        if (nargs != 1 || nrets != 1) {
+            stl_be_phys(as, rets, -1);
+            return H_PARAMETER;
+        }
+        qemu_log_mask(LOG_UNIMP, "%c", ldl_be_phys(as, args));
+        stl_be_phys(as, rets, 0);
+        return H_SUCCESS;
+    default:
+        qemu_log_mask(LOG_UNIMP, "Unknown RTAS token %u (args=%u, rets=%u)\n",
+                      token, nargs, nrets);
+        stl_be_phys(as, rets, 0);
+        return H_SUCCESS;
+    }
+}
+
 static void pegasos2_hypercall(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu)
 {
     Pegasos2MachineState *pm = PEGASOS2_MACHINE(vhyp);
@@ -315,6 +421,8 @@ static void pegasos2_hypercall(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu)
     if (msr_pr) {
         qemu_log_mask(LOG_GUEST_ERROR, "Hypercall made with MSR[PR]=1\n");
         env->gpr[3] = H_PRIVILEGE;
+    } else if (env->gpr[3] == KVMPPC_H_RTAS) {
+        env->gpr[3] = pegasos2_rtas(cpu, pm, env->gpr[4]);
     } else if (env->gpr[3] == KVMPPC_H_VOF_CLIENT) {
         int ret = vof_client_call(MACHINE(pm), pm->vof, pm->fdt_blob,
                                   env->gpr[4]);
@@ -687,6 +795,35 @@ static void *build_fdt(MachineState *machine, int *fdt_size)
     qemu_fdt_setprop_string(fdt, "/failsafe", "device_type", "serial");
     qemu_fdt_setprop_string(fdt, "/failsafe", "name", "failsafe");
 
+    qemu_fdt_add_subnode(fdt, "/rtas");
+    qemu_fdt_setprop_cell(fdt, "/rtas", "system-reboot", RTAS_SYSTEM_REBOOT);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "hibernate", RTAS_HIBERNATE);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "suspend", RTAS_SUSPEND);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "power-off", RTAS_POWER_OFF);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "set-indicator", RTAS_SET_INDICATOR);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "display-character",
+                          RTAS_DISPLAY_CHARACTER);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "write-pci-config",
+                          RTAS_WRITE_PCI_CONFIG);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "read-pci-config",
+                          RTAS_READ_PCI_CONFIG);
+    /* Pegasos2 firmware misspells check-exception and guests use that */
+    qemu_fdt_setprop_cell(fdt, "/rtas", "check-execption",
+                          RTAS_CHECK_EXCEPTION);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "event-scan", RTAS_EVENT_SCAN);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "set-time-of-day",
+                          RTAS_SET_TIME_OF_DAY);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "get-time-of-day",
+                          RTAS_GET_TIME_OF_DAY);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "nvram-store", RTAS_NVRAM_STORE);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "nvram-fetch", RTAS_NVRAM_FETCH);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "restart-rtas", RTAS_RESTART_RTAS);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "rtas-error-log-max", 0);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "rtas-event-scan-rate", 0);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "rtas-display-device", 0);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "rtas-size", 20);
+    qemu_fdt_setprop_cell(fdt, "/rtas", "rtas-version", 1);
+
     /* cpus */
     qemu_fdt_add_subnode(fdt, "/cpus");
     qemu_fdt_setprop_cell(fdt, "/cpus", "#cpus", 1);