iommu/io-pgtable: Add MTK 4GB mode in Short-descriptor

In MT8173, Normally the first 1GB PA is for the HW SRAM and Regs,
so the PA will be 33bits if the dram size is 4GB. We have a
"DRAM 4GB mode" toggle bit for this. If it's enabled, from CPU's
point of view, the dram PA will be from 0x1_00000000~0x1_ffffffff.

In short descriptor, the pagetable descriptor is always 32bit.
Mediatek extend bit9 in the lvl1 and lvl2 pgtable descriptor
as the 4GB mode.

In the 4GB mode, the bit9 must be set, then M4U help add 0x1_00000000
based on the PA in pagetable. Thus the M4U output address to EMI is
always 33bits(the input address is still 32bits).

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.wu@mediatek.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index 9488e3c97bcb76db4342a3c6294b6273a398329e..0f93dc2f98a3bcde76f7b1ab5f735abb3dde0c02 100644 (file)
--- 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_ARM_MTK_4GB)
+               pte |= ARM_V7S_ATTR_MTK_4GB;
+
        if (num_entries > 1)
                pte = arm_v7s_pte_to_cont(pte, lvl);
 
@@ -625,9 +630,15 @@ 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_ARM_MTK_4GB))
                return NULL;
 
+       /* If ARM_MTK_4GB is enabled, the NO_PERMS is also expected. */
+       if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_4GB &&
+           !(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 d4f502742e3b4af6948a7256de5f338a9a2a1547..969d82cc92ca62b71bf564fb251a20d6f1cf5eeb 100644 (file)
--- 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_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all
+        *      PTEs, for Mediatek IOMMUs which treat it as a 33rd address bit
+        *      when the SoC is in "4GB mode" and they can only access the high
+        *      remap of DRAM (0x1_00000000 to 0x1_ffffffff).
         */
        #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_ARM_MTK_4GB    BIT(3)
        unsigned long                   quirks;
        unsigned long                   pgsize_bitmap;
        unsigned int                    ias;