[PATCH] hppa: allow max ram size upto 4Gb

[Igor Mammedov <imammedo@redhat.com>]

Previous patch drops silent ram_size fixup and makes
QEMU error out with:

 "RAM size more than 3840m is not supported"

when user specified -m X more than supported value.

User shouldn't be bothered with starting QEMU with valid CLI,
so for the sake of user convenience to allow using -m 4G vs -m 3840M.

Requested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
I dislike it but if you feel it's really necessary feel free to ack it.

should be applied on top of:
  "hppa: drop RAM size fixup"
---
 hw/hppa/machine.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/hw/hppa/machine.c b/hw/hppa/machine.c
index ebbf44f..7f8c92f 100644
--- a/hw/hppa/machine.c
+++ b/hw/hppa/machine.c
@@ -54,6 +54,7 @@ static uint64_t cpu_hppa_to_phys(void *opaque, uint64_t addr)
 
 static HPPACPU *cpu[HPPA_MAX_CPUS];
 static uint64_t firmware_entry;
+static ram_addr_t clamped_ram_size;
 
 static void machine_hppa_init(MachineState *machine)
 {
@@ -74,8 +75,6 @@ static void machine_hppa_init(MachineState *machine)
     long i;
     unsigned int smp_cpus = machine->smp.cpus;
 
-    ram_size = machine->ram_size;
-
     /* Create CPUs.  */
     for (i = 0; i < smp_cpus; i++) {
         char *name = g_strdup_printf("cpu%ld-io-eir", i);
@@ -90,10 +89,12 @@ static void machine_hppa_init(MachineState *machine)
     }
 
     /* Limit main memory. */
-    if (ram_size > FIRMWARE_START) {
-        error_report("RAM size more than %d is not supported", FIRMWARE_START);
+    if (machine->ram_size > 4 * GiB) {
+        error_report("RAM size more than 4Gb is not supported");
         exit(EXIT_FAILURE);
     }
+    clamped_ram_size = machine->ram_size > FIRMWARE_START ?
+        FIRMWARE_START : machine->ram_size;
 
     memory_region_add_subregion(addr_space, 0, machine->ram);
 
@@ -151,7 +152,7 @@ static void machine_hppa_init(MachineState *machine)
     qemu_log_mask(CPU_LOG_PAGE, "Firmware loaded at 0x%08" PRIx64
                   "-0x%08" PRIx64 ", entry at 0x%08" PRIx64 ".\n",
                   firmware_low, firmware_high, firmware_entry);
-    if (firmware_low < ram_size || firmware_high >= FIRMWARE_END) {
+    if (firmware_low < clamped_ram_size || firmware_high >= FIRMWARE_END) {
         error_report("Firmware overlaps with memory or IO space");
         exit(1);
     }
@@ -160,7 +161,8 @@ static void machine_hppa_init(MachineState *machine)
     rom_region = g_new(MemoryRegion, 1);
     memory_region_init_ram(rom_region, NULL, "firmware",
                            (FIRMWARE_END - FIRMWARE_START), &error_fatal);
-    memory_region_add_subregion(addr_space, FIRMWARE_START, rom_region);
+    memory_region_add_subregion_overlap(addr_space, FIRMWARE_START, rom_region,
+                                        1);
 
     /* Load kernel */
     if (kernel_filename) {
@@ -204,7 +206,7 @@ static void machine_hppa_init(MachineState *machine)
                (1) Due to sign-extension problems and PDC,
                put the initrd no higher than 1G.
                (2) Reserve 64k for stack.  */
-            initrd_base = MIN(ram_size, 1 * GiB);
+            initrd_base = MIN(clamped_ram_size, 1 * GiB);
             initrd_base = initrd_base - 64 * KiB;
             initrd_base = (initrd_base - initrd_size) & TARGET_PAGE_MASK;
 
@@ -232,7 +234,7 @@ static void machine_hppa_init(MachineState *machine)
      * various parameters in registers. After firmware initialization,
      * firmware will start the Linux kernel with ramdisk and cmdline.
      */
-    cpu[0]->env.gr[26] = ram_size;
+    cpu[0]->env.gr[26] = clamped_ram_size;
     cpu[0]->env.gr[25] = kernel_entry;
 
     /* tell firmware how many SMP CPUs to present in inventory table */
@@ -255,11 +257,11 @@ static void hppa_machine_reset(MachineState *ms)
     }
 
     /* already initialized by machine_hppa_init()? */
-    if (cpu[0]->env.gr[26] == ram_size) {
+    if (cpu[0]->env.gr[26] == clamped_ram_size) {
         return;
     }
 
-    cpu[0]->env.gr[26] = ram_size;
+    cpu[0]->env.gr[26] = clamped_ram_size;
     cpu[0]->env.gr[25] = 0; /* no firmware boot menu */
     cpu[0]->env.gr[24] = 'c';
     /* gr22/gr23 unused, no initrd while reboot. */
-- 
2.7.4