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.chen@xxxxxxxxxxxx/ [2] https://lore.kernel.org/lkml/20200604080120.2628-1-miles.chen@xxxxxxxxxxxx/ [3] https://lore.kernel.org/lkml/20200715205120.GA778876@bogus/ Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Yong Wu <yong.wu@xxxxxxxxxxxx> Cc: Yingjoe Chen <yingjoe.chen@xxxxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Rob Herring <robh@xxxxxxxxxx> Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx> Cc: Joerg Roedel <joro@xxxxxxxxxx> Reviewed-by: Matthias Brugger <matthias.bgg@xxxxxxxxx> Signed-off-by: Miles Chen <miles.chen@xxxxxxxxxxxx> --- 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 <yong.wu@xxxxxxxxxxxx> */ -#include <linux/memblock.h> #include <linux/bug.h> #include <linux/clk.h> #include <linux/component.h> @@ -15,13 +14,16 @@ #include <linux/iommu.h> #include <linux/iopoll.h> #include <linux/list.h> +#include <linux/mfd/syscon.h> #include <linux/of_address.h> #include <linux/of_iommu.h> #include <linux/of_irq.h> #include <linux/of_platform.h> #include <linux/platform_device.h> +#include <linux/regmap.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/soc/mediatek/infracfg.h> #include <asm/barrier.h> #include <soc/mediatek/smi.h> @@ -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, &val); + 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
