Mediatek extend bit9 in the lvl1 and lvl2 pgtable descriptor of the
Short-descriptor as the 4GB mode in which the dram size will be
over 4GB.

We add a special quirk for this MTK-4GB mode, And in the standard
spec, Bit9 in the lvl1 is "IMPLEMENTATION DEFINED", while it's AP[2]
in the lvl2, therefore if this quirk is enabled, NO_PERMS is also
expected.

Signed-off-by: Yong Wu <yong...@mediatek.com>
---
In arm_v7s_init_pte, We add bit9 if the 4GB mode is enabled no matter
the current pa is over 4GB or not.

 drivers/iommu/io-pgtable-arm-v7s.c | 14 +++++++++++++-
 drivers/iommu/io-pgtable.h         |  6 ++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c 
b/drivers/iommu/io-pgtable-arm-v7s.c
index 9fcceb1..bf6a6f0 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -121,6 +121,8 @@
 #define ARM_V7S_TEX_MASK               0x7
 #define ARM_V7S_ATTR_TEX(val)          (((val) & ARM_V7S_TEX_MASK) << 
ARM_V7S_TEX_SHIFT)
 
+#define ARM_V7S_ATTR_MTK_4GB           BIT(9) /* MTK extend it for 4GB mode */
+
 /* *well, except for TEX on level 2 large pages, of course :( */
 #define ARM_V7S_CONT_PAGE_TEX_SHIFT    6
 #define ARM_V7S_CONT_PAGE_TEX_MASK     (ARM_V7S_TEX_MASK << 
ARM_V7S_CONT_PAGE_TEX_SHIFT)
@@ -364,6 +366,9 @@ static int arm_v7s_init_pte(struct arm_v7s_io_pgtable *data,
        if (lvl == 1 && (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS))
                pte |= ARM_V7S_ATTR_NS_SECTION;
 
+       if (cfg->quirks & IO_PGTABLE_QUIRK_MTK_4GB_EXT)
+               pte |= ARM_V7S_ATTR_MTK_4GB;
+
        if (num_entries > 1)
                pte = arm_v7s_pte_to_cont(pte, lvl);
 
@@ -625,9 +630,16 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct 
io_pgtable_cfg *cfg,
 
        if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS |
                            IO_PGTABLE_QUIRK_NO_PERMS |
-                           IO_PGTABLE_QUIRK_TLBI_ON_MAP))
+                           IO_PGTABLE_QUIRK_TLBI_ON_MAP |
+                           IO_PGTABLE_QUIRK_MTK_4GB_EXT))
                return NULL;
 
+       /* If MTK_4GB_EXT is enabled, the NO_PERMS is also expected. */
+       if (cfg->quirks & IO_PGTABLE_QUIRK_MTK_4GB_EXT) {
+               if (!(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS))
+                       return NULL;
+       }
+
        data = kmalloc(sizeof(*data), GFP_KERNEL);
        if (!data)
                return NULL;
diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h
index d4f5027..a84a60a 100644
--- a/drivers/iommu/io-pgtable.h
+++ b/drivers/iommu/io-pgtable.h
@@ -60,10 +60,16 @@ struct io_pgtable_cfg {
         * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid
         *      (unmapped) entries but the hardware might do so anyway, perform
         *      TLB maintenance when mapping as well as when unmapping.
+        *
+        * IO_PGTABLE_QUIRK_MTK_4GB_EXT: Mediatek extend bit9 in the lvl1 and
+        *      lvl2 descriptor of the Short-descriptor as the 4GB mode.
+        *      Note that: Bit9 in the lvl1 is "IMPLEMENTATION DEFINED", while
+        *      it is AP[2] in the lvl2.
         */
        #define IO_PGTABLE_QUIRK_ARM_NS         BIT(0)
        #define IO_PGTABLE_QUIRK_NO_PERMS       BIT(1)
        #define IO_PGTABLE_QUIRK_TLBI_ON_MAP    BIT(2)
+       #define IO_PGTABLE_QUIRK_MTK_4GB_EXT    BIT(3)
        unsigned long                   quirks;
        unsigned long                   pgsize_bitmap;
        unsigned int                    ias;
-- 
1.8.1.1.dirty

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