[Qemu-devel] [PATCH 02/13] pseries: Split device tree construction from device tree load

From: David Gibson <david@gibson.dropbear.id.au>
To: aik@ozlabs.ru, mdroth@linux.vnet.ibm.com, groug@kaod.org
Cc: agraf@suse.de, lvivier@redhat.com, thuth@redhat.com,
	qemu-ppc@nongnu.org, qemu-devel@nongnu.org,
	David Gibson <david@gibson.dropbear.id.au>
Subject: [Qemu-devel] [PATCH 02/13] pseries: Split device tree construction from device tree load
Date: Thu, 20 Oct 2016 16:11:59 +1100	[thread overview]
Message-ID: <1476940330-27705-3-git-send-email-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <1476940330-27705-1-git-send-email-david@gibson.dropbear.id.au>

spapr_finalize_fdt() both finishes building the device tree for the guest
and loads it into guest memory.  For future cleanups, it's going to be
more convenient to do these two things separately.  The loading portion is
pretty trivial, so we move it inline into the caller, ppc_spapr_reset().

We also rename spapr_finalize_fdt(), because the current name is going to
become inaccurate.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/ppc/spapr.c | 41 ++++++++++++++++++++++-------------------
 1 file changed, 22 insertions(+), 19 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index ddb7438..7ff3590 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -900,10 +900,9 @@ int spapr_h_cas_compose_response(sPAPRMachineState *spapr,
     return 0;
 }
 
-static void spapr_finalize_fdt(sPAPRMachineState *spapr,
-                               hwaddr fdt_addr,
-                               hwaddr rtas_addr,
-                               hwaddr rtas_size)
+static void *spapr_build_fdt(sPAPRMachineState *spapr,
+                             hwaddr rtas_addr,
+                             hwaddr rtas_size)
 {
     MachineState *machine = MACHINE(qdev_get_machine());
     MachineClass *mc = MACHINE_GET_CLASS(machine);
@@ -999,19 +998,8 @@ static void spapr_finalize_fdt(sPAPRMachineState *spapr,
         }
     }
 
-    _FDT((fdt_pack(fdt)));
-
-    if (fdt_totalsize(fdt) > FDT_MAX_SIZE) {
-        error_report("FDT too big ! 0x%x bytes (max is 0x%x)",
-                     fdt_totalsize(fdt), FDT_MAX_SIZE);
-        exit(1);
-    }
-
-    qemu_fdt_dumpdtb(fdt, fdt_totalsize(fdt));
-    cpu_physical_memory_write(fdt_addr, fdt, fdt_totalsize(fdt));
-
     g_free(bootlist);
-    g_free(fdt);
+    return fdt;
 }
 
 static uint64_t translate_kernel_address(void *opaque, uint64_t addr)
@@ -1147,6 +1135,8 @@ static void ppc_spapr_reset(void)
     sPAPRMachineState *spapr = SPAPR_MACHINE(machine);
     PowerPCCPU *first_ppc_cpu;
     uint32_t rtas_limit;
+    void *fdt;
+    int rc;
 
     /* Check for unknown sysbus devices */
     foreach_dynamic_sysbus_device(find_unknown_sysbus_device, NULL);
@@ -1173,14 +1163,27 @@ static void ppc_spapr_reset(void)
     spapr->rtas_addr = rtas_limit - RTAS_MAX_SIZE;
     spapr->fdt_addr = spapr->rtas_addr - FDT_MAX_SIZE;
 
-    /* Load the fdt */
-    spapr_finalize_fdt(spapr, spapr->fdt_addr, spapr->rtas_addr,
-                       spapr->rtas_size);
+    fdt = spapr_build_fdt(spapr, spapr->rtas_addr, spapr->rtas_size);
 
     /* Copy RTAS over */
     cpu_physical_memory_write(spapr->rtas_addr, spapr->rtas_blob,
                               spapr->rtas_size);
 
+    rc = fdt_pack(fdt);
+
+    /* Should only fail if we've built a corrupted tree */
+    assert(rc == 0);
+
+    if (fdt_totalsize(fdt) > FDT_MAX_SIZE) {
+        error_report("FDT too big ! 0x%x bytes (max is 0x%x)",
+                     fdt_totalsize(fdt), FDT_MAX_SIZE);
+        exit(1);
+    }
+
+    /* Load the fdt */
+    qemu_fdt_dumpdtb(fdt, fdt_totalsize(fdt));
+    cpu_physical_memory_write(spapr->fdt_addr, fdt, fdt_totalsize(fdt));
+
     /* Set up the entry state */
     first_ppc_cpu = POWERPC_CPU(first_cpu);
     first_ppc_cpu->env.gpr[3] = spapr->fdt_addr;
-- 
2.7.4
