Il 27/07/22 12:45, Chengci.Xu ha scritto:
For concerns about security, the register to enable/disable IOMMU of
SMI LARB should only be configured in secure world. Thus, we add some
SMC command for multimedia master to enable/disable MM IOMMU in ATF by
setting the register of SMI LARB. This function is prepared for MT8188.
Signed-off-by: Chengci.Xu <chengci.xu@xxxxxxxxxxxx>
---
drivers/memory/mtk-smi.c | 11 +++++++++++
include/linux/soc/mediatek/mtk_sip_svc.h | 3 +++
include/soc/mediatek/smi.h | 7 +++++++
3 files changed, 21 insertions(+)
diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c
index d7cb7ead2ac7..41ce66c39123 100644
--- a/drivers/memory/mtk-smi.c
+++ b/drivers/memory/mtk-smi.c
@@ -3,6 +3,7 @@
* Copyright (c) 2015-2016 MediaTek Inc.
* Author: Yong Wu <yong.wu@xxxxxxxxxxxx>
*/
+#include <linux/arm-smccc.h>
#include <linux/clk.h>
#include <linux/component.h>
#include <linux/device.h>
@@ -14,6 +15,7 @@
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/soc/mediatek/mtk_sip_svc.h>
#include <soc/mediatek/smi.h>
#include <dt-bindings/memory/mt2701-larb-port.h>
#include <dt-bindings/memory/mtk-memory-port.h>
@@ -89,6 +91,7 @@
#define MTK_SMI_FLAG_THRT_UPDATE BIT(0)
#define MTK_SMI_FLAG_SW_FLAG BIT(1)
#define MTK_SMI_FLAG_SLEEP_CTL BIT(2)
+#define MTK_SMI_FLAG_SEC_REG BIT(3)
#define MTK_SMI_CAPS(flags, _x) (!!((flags) & (_x)))
struct mtk_smi_reg_pair {
@@ -235,6 +238,7 @@ static void mtk_smi_larb_config_port_gen2_general(struct device *dev)
struct mtk_smi_larb *larb = dev_get_drvdata(dev);
u32 reg, flags_general = larb->larb_gen->flags_general;
const u8 *larbostd = larb->larb_gen->ostd ? larb->larb_gen->ostd[larb->larbid] : NULL;
+ struct arm_smccc_res res;
int i;
if (BIT(larb->larbid) & larb->larb_gen->larb_direct_to_common_mask)
@@ -259,6 +263,13 @@ static void mtk_smi_larb_config_port_gen2_general(struct device *dev)
reg |= BANK_SEL(larb->bank[i]);
writel(reg, larb->base + SMI_LARB_NONSEC_CON(i));
}
+
+ if (MTK_SMI_CAPS(flags_general, MTK_SMI_FLAG_SEC_REG)) {
+ arm_smccc_smc(MTK_SIP_KERNEL_IOMMU_CONTROL, IOMMU_ATF_CMD_CONFIG_SMI_LARB,
+ larb->larbid, (u32)(*larb->mmu), 0, 0, 0, 0, &res);
+ if (res.a0 != 0)
+ dev_err(dev, "Enable iommu fail, ret %ld\n", res.a0);
This means that the system will eventually crash or anyway be unstable: in this
case, we should not allow further interaction with the IOMMUs and/or SMI.
So, if you place this here, you will have to change this function to return
something for the caller to take action.
+ }
}
static const u8 mtk_smi_larb_mt8195_ostd[][SMI_LARB_PORT_NR_MAX] = {
diff --git a/include/linux/soc/mediatek/mtk_sip_svc.h b/include/linux/soc/mediatek/mtk_sip_svc.h
index 082398e0cfb1..0761128b4354 100644
--- a/include/linux/soc/mediatek/mtk_sip_svc.h
+++ b/include/linux/soc/mediatek/mtk_sip_svc.h
@@ -22,4 +22,7 @@
ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, MTK_SIP_SMC_CONVENTION, \
ARM_SMCCC_OWNER_SIP, fn_id)
+/* IOMMU related SMC call */
+#define MTK_SIP_KERNEL_IOMMU_CONTROL MTK_SIP_SMC_CMD(0x514)
+
#endif
diff --git a/include/soc/mediatek/smi.h b/include/soc/mediatek/smi.h
index 11f7d6b59642..8c781b7bd88d 100644
--- a/include/soc/mediatek/smi.h
+++ b/include/soc/mediatek/smi.h
@@ -9,6 +9,13 @@
#include <linux/bitops.h>
#include <linux/device.h>
+/* IOMMU & SMI ATF CMD */
+
+enum IOMMU_ATF_CMD {
Why do you have an enumeration when you're defining just one command?
Is it expected to have more?
Besides, the enum name should be lower case, and...
+ IOMMU_ATF_CMD_CONFIG_SMI_LARB, /* For mm master to en/disable iommu */
+ IOMMU_ATF_CMD_COUNT,
if IOMMU_ATF_CMD_COUNT means "end of this enumeration", please call it
IOMMU_ATF_CMD_MAX instead.
+};
+
#if IS_ENABLED(CONFIG_MTK_SMI)
#define MTK_SMI_MMU_EN(port) BIT(port)
