[PATCH 7/8] Allow for different IOMMU page sizes in cell IOMMU code

[Michael Ellerman]

Make some preliminary changes to cell_iommu_alloc_ptab() to allow it to
take the page size as a parameter rather than assuming IOMMU_PAGE_SIZE.

Signed-off-by: Michael Ellerman <[EMAIL PROTECTED]>
---
 arch/powerpc/platforms/cell/iommu.c |   28 ++++++++++++++++------------
 1 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/platforms/cell/iommu.c 
b/arch/powerpc/platforms/cell/iommu.c
index a7bbc0a..12db681 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -113,7 +113,7 @@
 
 /* IOMMU sizing */
 #define IO_SEGMENT_SHIFT       28
-#define IO_PAGENO_BITS         (IO_SEGMENT_SHIFT - IOMMU_PAGE_SHIFT)
+#define IO_PAGENO_BITS(shift)  (IO_SEGMENT_SHIFT - (shift))
 
 /* The high bit needs to be set on every DMA address */
 #define SPIDER_DMA_OFFSET      0x80000000ul
@@ -327,7 +327,8 @@ static void cell_iommu_setup_stab(struct cbe_iommu *iommu,
 }
 
 static unsigned long *cell_iommu_alloc_ptab(struct cbe_iommu *iommu,
-                                 unsigned long base, unsigned long size)
+                                 unsigned long base, unsigned long size,
+                                 unsigned long page_shift)
 {
        struct page *page;
        int i;
@@ -336,7 +337,10 @@ static unsigned long *cell_iommu_alloc_ptab(struct 
cbe_iommu *iommu,
 
        start_seg = base >> IO_SEGMENT_SHIFT;
        segments  = size >> IO_SEGMENT_SHIFT;
-       pages_per_segment = 1ull << IO_PAGENO_BITS;
+       pages_per_segment = 1ull << IO_PAGENO_BITS(page_shift);
+       /* PTEs for each segment must start on a 4K bounday */
+       pages_per_segment = max(pages_per_segment,
+                               (1 << 12) / sizeof(unsigned long));
 
        ptab_size = segments * pages_per_segment * sizeof(unsigned long);
        pr_debug("%s: iommu[%d]: ptab_size: %lu, order: %d\n", __FUNCTION__,
@@ -357,13 +361,12 @@ static unsigned long *cell_iommu_alloc_ptab(struct 
cbe_iommu *iommu,
        /* initialise the STEs */
        reg = IOSTE_V | ((n_pte_pages - 1) << 5);
 
-       if (IOMMU_PAGE_SIZE == 0x1000)
-               reg |= IOSTE_PS_4K;
-       else if (IOMMU_PAGE_SIZE == 0x10000)
-               reg |= IOSTE_PS_64K;
-       else {
-               extern void __unknown_page_size_error(void);
-               __unknown_page_size_error();
+       switch (page_shift) {
+       case 12: reg |= IOSTE_PS_4K;  break;
+       case 16: reg |= IOSTE_PS_64K; break;
+       case 20: reg |= IOSTE_PS_1M;  break;
+       case 24: reg |= IOSTE_PS_16M; break;
+       default: BUG();
        }
 
        pr_debug("Setting up IOMMU stab:\n");
@@ -421,7 +424,8 @@ static void cell_iommu_setup_hardware(struct cbe_iommu 
*iommu,
        unsigned long base, unsigned long size)
 {
        cell_iommu_setup_stab(iommu, base, size, 0, 0);
-       iommu->ptab = cell_iommu_alloc_ptab(iommu, base, size);
+       iommu->ptab = cell_iommu_alloc_ptab(iommu, base, size,
+                                           IOMMU_PAGE_SHIFT);
        cell_iommu_enable_hardware(iommu);
 }
 
@@ -878,7 +882,7 @@ static void cell_iommu_setup_fixed_ptab(struct cbe_iommu 
*iommu,
        int i;
        unsigned long base_pte, uaddr, *io_pte, *ptab;
 
-       ptab = cell_iommu_alloc_ptab(iommu, fbase, fsize);
+       ptab = cell_iommu_alloc_ptab(iommu, fbase, fsize, IOMMU_PAGE_SHIFT);
 
        dma_iommu_fixed_base = fbase;
 
-- 
1.5.2.rc1.1884.g59b20

_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev