[POWERPC] Add support to cell_iommu_setup_page_tables() for multiple windows

Add support to cell_iommu_setup_page_tables() for handling two windows,
the dynamic window and the fixed window.  A fixed window size of 0
indicates that there is no fixed window at all.

Currently there are no callers who pass a non-zero fixed window, but the
upcoming fixed IOMMU mapping patch will change that.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 10 insertions, 5 deletions

diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index a6e6bc1b020f..950d4327b41e 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -307,14 +307,19 @@ static int cell_iommu_find_ioc(int nid, unsigned long *base)
 }
 
 static void cell_iommu_setup_page_tables(struct cbe_iommu *iommu,
-                                         unsigned long base, unsigned long size)
+                                unsigned long dbase, unsigned long dsize,
+                                unsigned long fbase, unsigned long fsize)
 {
         struct page *page;
         int i;
         unsigned long reg, segments, pages_per_segment, ptab_size, stab_size,
-                      n_pte_pages;
+                      n_pte_pages, base;
 
-        segments = size >> IO_SEGMENT_SHIFT;
+        base = dbase;
+        if (fsize != 0)
+                base = min(fbase, dbase);
+
+        segments = max(dbase + dsize, fbase + fsize) >> IO_SEGMENT_SHIFT;
         pages_per_segment = 1ull << IO_PAGENO_BITS;
 
         pr_debug("%s: iommu[%d]: segments: %lu, pages per segment: %lu\n",
@@ -366,7 +371,7 @@ static void cell_iommu_setup_page_tables(struct cbe_iommu *iommu,
         }
 
         pr_debug("Setting up IOMMU stab:\n");
-        for (i = 0; i * (1ul << IO_SEGMENT_SHIFT) < size; i++) {
+        for (i = base >> IO_SEGMENT_SHIFT; i < segments; i++) {
                 iommu->stab[i] = reg |
                         (__pa(iommu->ptab) + n_pte_pages * IOMMU_PAGE_SIZE * i);
                 pr_debug("\t[%d] 0x%016lx\n", i, iommu->stab[i]);
@@ -417,7 +422,7 @@ static void cell_iommu_enable_hardware(struct cbe_iommu *iommu)
 static void cell_iommu_setup_hardware(struct cbe_iommu *iommu,
         unsigned long base, unsigned long size)
 {
-        cell_iommu_setup_page_tables(iommu, base, size);
+        cell_iommu_setup_page_tables(iommu, base, size, 0, 0);
         cell_iommu_enable_hardware(iommu);
 }