In previous discussion [1] and [2], we found that it is risky to
use max_pfn or totalram_pages to tell if 4GB mode is enabled.
Check 4GB mode by reading infracfg register, remove the usage
of the un-exported symbol max_pfn.
This is a step towards building mtk_iommu as a kernel module.
[1] https://lore.kernel.org/lkml/20200603161132.2441-1-miles.c...@mediatek.com/
[2] https://lore.kernel.org/lkml/20200604080120.2628-1-miles.c...@mediatek.com/
[3] https://lore.kernel.org/lkml/20200715205120.GA778876@bogus/
Cc: Mike Rapoport
Cc: David Hildenbrand
Cc: Yong Wu
Cc: Yingjoe Chen
Cc: Christoph Hellwig
Cc: Rob Herring
Cc: Matthias Brugger
Signed-off-by: Miles Chen
---
Change since v4
- remove unnecessary data->enable_4GB = false, since it is kzalloc()ed.
Change since v3
- use lore.kernel.org links
- move "change since..." after "---"
Change since v2:
- determine compatible string by m4u_plat
- rebase to next-20200720
- add "---"
Change since v1:
- remove the phandle usage, search for infracfg instead [3]
- use infracfg instead of infracfg_regmap
- move infracfg definitaions to linux/soc/mediatek/infracfg.h
- update enable_4GB only when has_4gb_mode
---
drivers/iommu/mtk_iommu.c | 33 +++
include/linux/soc/mediatek/infracfg.h | 3 +++
2 files changed, 31 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 785b228d39a6..e7b8b2bb08a9 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -3,7 +3,6 @@
* Copyright (c) 2015-2016 MediaTek Inc.
* Author: Yong Wu
*/
-#include
#include
#include
#include
@@ -15,13 +14,16 @@
#include
#include
#include
+#include
#include
#include
#include
#include
#include
+#include
#include
#include
+#include
#include
#include
@@ -640,8 +642,11 @@ static int mtk_iommu_probe(struct platform_device *pdev)
struct resource *res;
resource_size_t ioaddr;
struct component_match *match = NULL;
+ struct regmap *infracfg;
void*protect;
int i, larb_nr, ret;
+ u32 val;
+ char*p;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
@@ -655,10 +660,28 @@ static int mtk_iommu_probe(struct platform_device *pdev)
return -ENOMEM;
data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
- /* Whether the current dram is over 4GB */
- data->enable_4GB = !!(max_pfn > (BIT_ULL(32) >> PAGE_SHIFT));
- if (!MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE))
- data->enable_4GB = false;
+ if (MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE)) {
+ switch (data->plat_data->m4u_plat) {
+ case M4U_MT2712:
+ p = "mediatek,mt2712-infracfg";
+ break;
+ case M4U_MT8173:
+ p = "mediatek,mt8173-infracfg";
+ break;
+ default:
+ p = NULL;
+ }
+
+ infracfg = syscon_regmap_lookup_by_compatible(p);
+
+ if (IS_ERR(infracfg))
+ return PTR_ERR(infracfg);
+
+ ret = regmap_read(infracfg, REG_INFRA_MISC, );
+ if (ret)
+ return ret;
+ data->enable_4GB = !!(val & F_DDR_4GB_SUPPORT_EN);
+ }
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
data->base = devm_ioremap_resource(dev, res);
diff --git a/include/linux/soc/mediatek/infracfg.h
b/include/linux/soc/mediatek/infracfg.h
index fd25f0148566..233463d789c6 100644
--- a/include/linux/soc/mediatek/infracfg.h
+++ b/include/linux/soc/mediatek/infracfg.h
@@ -32,6 +32,9 @@
#define MT7622_TOP_AXI_PROT_EN_WB (BIT(2) | BIT(6) | \
BIT(7) | BIT(8))
+#define REG_INFRA_MISC 0xf00
+#define F_DDR_4GB_SUPPORT_EN BIT(13)
+
int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
bool reg_update);
int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
--
2.18.0
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