[OpenBIOS] [PATCH 4/6] ppc: fix stack usage in mmu_claim, mem_claim

[Cormac O'Brien]

The 'phys' argument to mem_claim() and 'virt' argument to mmu_claim() are now
only popped from the stack if the 'align' argument is provided. Exception
throws have been removed to simplify crossing C <-> Forth boundaries and to
maintain consistency with other architectures.

This patch also fixes two stack diagrams with 'phys' arguments instead of
'virt' ones.

Signed-off-by: Cormac O'Brien 
---
 arch/ppc/qemu/methods.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/arch/ppc/qemu/methods.c b/arch/ppc/qemu/methods.c
index fd993da..cb72bc1 100644
--- a/arch/ppc/qemu/methods.c
+++ b/arch/ppc/qemu/methods.c
@@ -164,21 +164,21 @@ DECLARE_UNNAMED_NODE( mmu, INSTALL_OPEN, 0 );
 DECLARE_NODE( mmu_ciface, 0, 0, "+/openprom/client-services" );

-/* ( phys size align --- base ) */
+/* ( [phys] size align --- base ) */
 static void
 mem_claim( void )
 {
    ucell align = POP();
    ucell size = POP();
-	ucell phys = POP();
-	ucell ret = ofmem_claim_phys( phys, size, align );
+	phys_addr_t phys = -1;

-	if( ret == -1 ) {
-		printk("MEM: claim failure\n");
-		throw( -13 );
-		return;
+	if (!align) {
+		phys = POP();
    }
-	PUSH( ret );
+
+	phys = ofmem_claim_phys(phys, size, align);
+
+	PUSH(phys);
 }

/* ( phys size --- ) */
@@ -188,24 +188,24 @@ mem_release( void )
    POP(); POP();
 }

-/* ( phys size align --- base ) */
+/* ( [virt] size align --- base ) */
 static void
 mmu_claim( void )
 {
    ucell align = POP();
    ucell size = POP();
-	ucell phys = POP();
-	ucell ret = ofmem_claim_virt( phys, size, align );
+	ucell virt = -1;

-	if( ret == -1 ) {
-		printk("MMU: CLAIM failure\n");
-		throw( -13 );
-		return;
+	if (!align) {
+		virt = POP();
    }
-	PUSH( ret );
+
+	virt = ofmem_claim_virt(virt, size, align);
+
+	PUSH(virt);
 }

-/* ( phys size --- ) */
+/* ( virt size --- ) */
 static void
 mmu_release( void )
 {