ppc/spapr: Add hotremovable flag on DIMM LMBs on drmem_v2

On reboot, all memory that was previously added using object_add and
device_add is placed in this DIMM area.

The new SPAPR_LMB_FLAGS_HOTREMOVABLE flag helps Linux to put this memory in
the correct memory zone, so no unmovable allocations are made there,
allowing the object to be easily hot-removed by device_del and
object_del.

This new flag was accepted in Power Architecture documentation.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Reviewed-by: Bharata B Rao <bharata@linux.ibm.com>
Message-Id: <20200511200201.58537-1-leobras.c@gmail.com>
[dwg: Fixed syntax error spotted by Cédric Le Goater]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/ppc/pnv.c

@@ -1984,15 +1984,15 @@ static void pnv_cpu_do_nmi_on_cpu(CPUState *cs, run_on_cpu_data arg)
 
     cpu_synchronize_state(cs);
     ppc_cpu_do_system_reset(cs);
-    if (env->spr[SPR_SRR1] & PPC_BITMASK(46, 47)) {
+    if (env->spr[SPR_SRR1] & SRR1_WAKESTATE) {
         /*
          * Power-save wakeups, as indicated by non-zero SRR1[46:47] put the
          * wakeup reason in SRR1[42:45], system reset is indicated with 0b0100
          * (PPC_BIT(43)).
          */
-        if (!(env->spr[SPR_SRR1] & PPC_BIT(43))) {
+        if (!(env->spr[SPR_SRR1] & SRR1_WAKERESET)) {
             warn_report("ppc_cpu_do_system_reset does not set system reset wakeup reason");
-            env->spr[SPR_SRR1] |= PPC_BIT(43);
+            env->spr[SPR_SRR1] |= SRR1_WAKERESET;
         }
     } else {
         /*
@@ -2002,7 +2002,7 @@ static void pnv_cpu_do_nmi_on_cpu(CPUState *cs, run_on_cpu_data arg)
          * another CPU requesting a NMI IPI) system reset exception should be
          * 0b0010 (PPC_BIT(44)).
          */
-        env->spr[SPR_SRR1] |= PPC_BIT(44);
+        env->spr[SPR_SRR1] |= SRR1_WAKESCOM;
     }
 }
 

hw/ppc/spapr.c

@@ -445,7 +445,8 @@ static int spapr_dt_dynamic_memory_v2(SpaprMachineState *spapr, void *fdt,
         g_assert(drc);
         elem = spapr_get_drconf_cell(size / lmb_size, addr,
                                      spapr_drc_index(drc), node,
-                                     SPAPR_LMB_FLAGS_ASSIGNED);
+                                     (SPAPR_LMB_FLAGS_ASSIGNED |
+                                      SPAPR_LMB_FLAGS_HOTREMOVABLE));
         QSIMPLEQ_INSERT_TAIL(&drconf_queue, elem, entry);
         nr_entries++;
         cur_addr = addr + size;

include/hw/ppc/spapr.h

@@ -886,6 +886,7 @@ int spapr_rtc_import_offset(SpaprRtcState *rtc, int64_t legacy_offset);
 #define SPAPR_LMB_FLAGS_ASSIGNED 0x00000008
 #define SPAPR_LMB_FLAGS_DRC_INVALID 0x00000020
 #define SPAPR_LMB_FLAGS_RESERVED 0x00000080
+#define SPAPR_LMB_FLAGS_HOTREMOVABLE 0x00000100
 
 void spapr_do_system_reset_on_cpu(CPUState *cs, run_on_cpu_data arg);
 

target/ppc/cpu.h

@@ -476,6 +476,27 @@ typedef struct ppc_v3_pate_t {
 #define SRR1_PROTFAULT           DSISR_PROTFAULT
 #define SRR1_IAMR                DSISR_AMR
 
+/* SRR1[42:45] wakeup fields for System Reset Interrupt */
+
+#define SRR1_WAKEMASK           0x003c0000 /* reason for wakeup */
+
+#define SRR1_WAKEHMI            0x00280000 /* Hypervisor maintenance */
+#define SRR1_WAKEHVI            0x00240000 /* Hypervisor Virt. Interrupt (P9) */
+#define SRR1_WAKEEE             0x00200000 /* External interrupt */
+#define SRR1_WAKEDEC            0x00180000 /* Decrementer interrupt */
+#define SRR1_WAKEDBELL          0x00140000 /* Privileged doorbell */
+#define SRR1_WAKERESET          0x00100000 /* System reset */
+#define SRR1_WAKEHDBELL         0x000c0000 /* Hypervisor doorbell */
+#define SRR1_WAKESCOM           0x00080000 /* SCOM not in power-saving mode */
+
+/* SRR1[46:47] power-saving exit mode */
+
+#define SRR1_WAKESTATE          0x00030000 /* Powersave exit mask */
+
+#define SRR1_WS_HVLOSS          0x00030000 /* HV resources not maintained */
+#define SRR1_WS_GPRLOSS         0x00020000 /* GPRs not maintained */
+#define SRR1_WS_NOLOSS          0x00010000 /* All resources maintained */
+
 /* Facility Status and Control (FSCR) bits */
 #define FSCR_EBB        (63 - 56) /* Event-Based Branch Facility */
 #define FSCR_TAR        (63 - 55) /* Target Address Register */

target/ppc/excp_helper.c

@@ -101,7 +101,7 @@ static int powerpc_reset_wakeup(CPUState *cs, CPUPPCState *env, int excp,
     env->resume_as_sreset = false;
 
     /* Pretend to be returning from doze always as we don't lose state */
-    *msr |= (0x1ull << (63 - 47));
+    *msr |= SRR1_WS_NOLOSS;
 
     /* Machine checks are sent normally */
     if (excp == POWERPC_EXCP_MCHECK) {
@@ -109,25 +109,25 @@ static int powerpc_reset_wakeup(CPUState *cs, CPUPPCState *env, int excp,
     }
     switch (excp) {
     case POWERPC_EXCP_RESET:
-        *msr |= 0x4ull << (63 - 45);
+        *msr |= SRR1_WAKERESET;
         break;
     case POWERPC_EXCP_EXTERNAL:
-        *msr |= 0x8ull << (63 - 45);
+        *msr |= SRR1_WAKEEE;
         break;
     case POWERPC_EXCP_DECR:
-        *msr |= 0x6ull << (63 - 45);
+        *msr |= SRR1_WAKEDEC;
         break;
     case POWERPC_EXCP_SDOOR:
-        *msr |= 0x5ull << (63 - 45);
+        *msr |= SRR1_WAKEDBELL;
         break;
     case POWERPC_EXCP_SDOOR_HV:
-        *msr |= 0x3ull << (63 - 45);
+        *msr |= SRR1_WAKEHDBELL;
         break;
     case POWERPC_EXCP_HV_MAINT:
-        *msr |= 0xaull << (63 - 45);
+        *msr |= SRR1_WAKEHMI;
         break;
     case POWERPC_EXCP_HVIRT:
-        *msr |= 0x9ull << (63 - 45);
+        *msr |= SRR1_WAKEHVI;
         break;
     default:
         cpu_abort(cs, "Unsupported exception %d in Power Save mode\n",