linux-user: Implement /proc/cpuinfo for ppc cpus

Mimic the entries for /proc/cpuinfo to what can be seen on two debian
porterboxes (ppc64 and ppc64le), which are running via KVM/QEMU.

The "timebase" value in /proc/cpuinfo is used by glibc on power, but only if
the __kernel_get_tbfreq vdso call isn't implemented. So switch
cpu_ppc_load_tbl() for linux-user to get_clock(), as suggested by Richard, and
report timebase = 1GHz in /proc/cpuinfo, which will make the vdso
implementation simple too.

v4: change timebase to 1GHz and use get_clock()
v3: drop another colon, indenting fixes
v2: drop colon, add clock output, refine pvr calculation

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Helge Deller <deller@gmx.de>

linux-user/ppc/cpu_loop.c

@@ -26,7 +26,7 @@
 
 static inline uint64_t cpu_ppc_get_tb(CPUPPCState *env)
 {
-    return cpu_get_host_ticks();
+    return get_clock();
 }
 
 uint64_t cpu_ppc_load_tbl(CPUPPCState *env)

linux-user/ppc/target_proc.h

@@ -1 +1,90 @@
-/* No target-specific /proc support */
+/*
+ * ppc specific proc functions for linux-user
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#ifndef PPC_TARGET_PROC_H
+#define PPC_TARGET_PROC_H
+
+#include <time.h>
+
+#define PVR_VER(pvr)    (((pvr) >>  16) & 0xFFFF)      /* Version field */
+#define PVR_REV(pvr)    (((pvr) >>   0) & 0xFFFF)      /* Revison field */
+#define PVR_MAJ(pvr)    (((pvr) >>  4) & 0xF)   /* Major revision field */
+#define PVR_MIN(pvr)    (((pvr) >>  0) & 0xF)   /* Minor revision field */
+
+static int open_cpuinfo(CPUArchState *cpu_env, int fd)
+{
+    struct timespec res;
+    double freq_mhz;
+    int i, num_cpus;
+    unsigned int maj, min, pvr;
+
+    PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(env_cpu(cpu_env));
+    DeviceClass *dc = DEVICE_CLASS(ppc_cpu_get_family_class(pcc));
+
+    pvr = pcc->pvr;
+
+    /* Taken from Linux kernel: */
+    /* If we are a Freescale core do a simple check so
+     * we don't have to keep adding cases in the future */
+    if (PVR_VER(pvr) & 0x8000) {
+        switch (PVR_VER(pvr)) {
+        case 0x8000: /* 7441/7450/7451, Voyager */
+        case 0x8001: /* 7445/7455, Apollo 6 */
+        case 0x8002: /* 7447/7457, Apollo 7 */
+        case 0x8003: /* 7447A, Apollo 7 PM */
+        case 0x8004: /* 7448, Apollo 8 */
+        case 0x800c: /* 7410, Nitro */
+            maj = ((pvr >> 8) & 0xF);
+            min = PVR_MIN(pvr);
+            break;
+        default:     /* e500/book-e */
+            maj = PVR_MAJ(pvr);
+            min = PVR_MIN(pvr);
+            break;
+        }
+    } else {
+        switch (PVR_VER(pvr)) {
+        case 0x1008: /* 740P/750P ?? */
+            maj = ((pvr >> 8) & 0xFF) - 1;
+            min = pvr & 0xFF;
+            break;
+        case 0x004e: /* POWER9 bits 12-15 give chip type */
+        case 0x0080: /* POWER10 bit 12 gives SMT8/4 */
+            maj = (pvr >> 8) & 0x0F;
+            min = pvr & 0xFF;
+            break;
+        default:
+            maj = (pvr >> 8) & 0xFF;
+            min = pvr & 0xFF;
+            break;
+        }
+    }
+
+    if (clock_getres(CLOCK_REALTIME, &res) == -1) {
+        res.tv_nsec = 1;
+    }
+    freq_mhz = 1000.0 / res.tv_nsec;
+
+    num_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+    for (i = 0; i < num_cpus; i++) {
+        dprintf(fd, "processor\t: %d\n", i);
+        dprintf(fd, "cpu\t\t: %s%s\n",
+                    dc->desc,
+                    pcc->insns_flags & PPC_ALTIVEC ? ", altivec supported":"");
+        dprintf(fd, "clock\t\t: %.3fMHz\n", freq_mhz);
+        dprintf(fd, "revision\t: %d.%d (pvr %04x %04x)\n\n",
+                    maj, min, PVR_VER(pvr), PVR_REV(pvr));
+    }
+
+    dprintf(fd, "timebase\t: 1000000000\n");
+    dprintf(fd, "platform\t: pSeries\n");
+    dprintf(fd, "model\t\t: IBM pSeries (QEMU user v" QEMU_VERSION ")\n");
+    dprintf(fd, "machine\t\t: CHRP IBM pSeries\n");
+
+    return 0;
+}
+#define HAVE_ARCH_PROC_CPUINFO
+
+#endif /* PPC_TARGET_PROC_H */