[OpenBIOS] [PATCH] Enforce physical alignment based upon size for the SPARC32 romvec obp_dumb_memalloc() function.

[Mark Cave-Ayland]

It appears that Solaris assumes that the resulting memory is physically aligned based upon the
value of size. Make sure we also respect this alignment, so that memory allocated using this
interface can be correctly used for the Solaris IOMMU page tables.

Signed-off-by: Mark Cave-Ayland 
---
 openbios-devel/arch/sparc32/lib.c |   20 +++++++++++++++++++-
 1 files changed, 19 insertions(+), 1 deletions(-)

diff --git a/openbios-devel/arch/sparc32/lib.c b/openbios-devel/arch/sparc32/lib.c
index 5b41dff..59cd23b 100644
--- a/openbios-devel/arch/sparc32/lib.c
+++ b/openbios-devel/arch/sparc32/lib.c
@@ -351,9 +351,27 @@ char *obp_dumb_memalloc(char *va, unsigned int size)
 {
     phys_addr_t phys;
     ucell virt;
+    unsigned int align, i;
+    
+    /* Solaris seems to assume that the returned value is physically aligned to size. For
+       example, not having this here causes the Solaris 8 kernel to fault because the 
+       IOMMU page table base address is calculated incorrectly. */
+
+    /* Enforce a minimum alignment of CONFIG_OFMEM_MALLOC_ALIGN, and choose an alignment 
+       which is the next power of 2 higher than the specified size */
+    align = size;
+    if (align < CONFIG_OFMEM_MALLOC_ALIGN) {
+        align = CONFIG_OFMEM_MALLOC_ALIGN;
+    } else {
+        align--;
+        for (i = 1; i < sizeof(unsigned int) * 8; i<<=1) {
+            align = align | align >> i;
+        }
+        align++;
+    }

/* Claim physical memory */
-    phys = ofmem_claim_phys(-1, size, CONFIG_OFMEM_MALLOC_ALIGN);
+    phys = ofmem_claim_phys(-1, size, align);

/* Claim virtual memory */
     virt = ofmem_claim_virt(pointer2cell(va), size, 0);