powerpc/powernv: Rework TCE level allocation

This moves actual pages allocation to a separate function which is going
to be reused later in on-demand TCE allocation.

While we are at it, remove unnecessary level size round up as the caller
does this already.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/platforms/powernv/pci-ioda-tce.c b/arch/powerpc/platforms/powernv/pci-ioda-tce.c
index 88cecc1..123c499 100644 (file)
--- a/arch/powerpc/platforms/powernv/pci-ioda-tce.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda-tce.c
@@ -31,6 +31,23 @@ void pnv_pci_setup_iommu_table(struct iommu_table *tbl,
        tbl->it_type = TCE_PCI;
 }
 
+static __be64 *pnv_alloc_tce_level(int nid, unsigned int shift)
+{
+       struct page *tce_mem = NULL;
+       __be64 *addr;
+
+       tce_mem = alloc_pages_node(nid, GFP_KERNEL, shift - PAGE_SHIFT);
+       if (!tce_mem) {
+               pr_err("Failed to allocate a TCE memory, level shift=%d\n",
+                               shift);
+               return NULL;
+       }
+       addr = page_address(tce_mem);
+       memset(addr, 0, 1UL << shift);
+
+       return addr;
+}
+
 static __be64 *pnv_tce(struct iommu_table *tbl, bool user, long idx)
 {
        __be64 *tmp = user ? tbl->it_userspace : (__be64 *) tbl->it_base;
@@ -165,21 +182,12 @@ static __be64 *pnv_pci_ioda2_table_do_alloc_pages(int nid, unsigned int shift,
                unsigned int levels, unsigned long limit,
                unsigned long *current_offset, unsigned long *total_allocated)
 {
-       struct page *tce_mem = NULL;
        __be64 *addr, *tmp;
-       unsigned int order = max_t(unsigned int, shift, PAGE_SHIFT) -
-                       PAGE_SHIFT;
-       unsigned long allocated = 1UL << (order + PAGE_SHIFT);
+       unsigned long allocated = 1UL << shift;
        unsigned int entries = 1UL << (shift - 3);
        long i;
 
-       tce_mem = alloc_pages_node(nid, GFP_KERNEL, order);
-       if (!tce_mem) {
-               pr_err("Failed to allocate a TCE memory, order=%d\n", order);
-               return NULL;
-       }
-       addr = page_address(tce_mem);
-       memset(addr, 0, allocated);
+       addr = pnv_alloc_tce_level(nid, shift);
        *total_allocated += allocated;
 
        --levels;