From: Andreas Herrmann <andreas.herrm...@calxeda.com>

In such a case we have to use secure aliases of some non-secure
registers.

This handling is switched on by DT property
"calxeda,smmu-secure-config-access" for an SMMU node.

Signed-off-by: Andreas Herrmann <andreas.herrm...@calxeda.com>
[will: merged with driver option handling patch]
Signed-off-by: Will Deacon <will.dea...@arm.com>
---
 drivers/iommu/arm-smmu.c | 58 +++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 48 insertions(+), 10 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index a3ce60887efa..e04fdcb4b9ba 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -60,6 +60,16 @@
 #define ARM_SMMU_GR0(smmu)             ((smmu)->base)
 #define ARM_SMMU_GR1(smmu)             ((smmu)->base + (smmu)->pagesize)
 
+/*
+ * SMMU global address space with conditional offset to access secure
+ * aliases of non-secure registers (e.g. nsCR0: 0x400, nsGFSR: 0x448,
+ * nsGFSYNR0: 0x450)
+ */
+#define ARM_SMMU_GR0_NS(smmu)                                          \
+       ((smmu)->base +                                                 \
+               ((smmu->options & ARM_SMMU_OPT_SECURE_CFG_ACCESS)       \
+                       ? 0x400 : 0))
+
 /* Page table bits */
 #define ARM_SMMU_PTE_XN                        (((pteval_t)3) << 53)
 #define ARM_SMMU_PTE_CONT              (((pteval_t)1) << 52)
@@ -351,6 +361,9 @@ struct arm_smmu_device {
 #define ARM_SMMU_FEAT_TRANS_S2         (1 << 3)
 #define ARM_SMMU_FEAT_TRANS_NESTED     (1 << 4)
        u32                             features;
+
+#define ARM_SMMU_OPT_SECURE_CFG_ACCESS (1 << 0)
+       u32                             options;
        int                             version;
 
        u32                             num_context_banks;
@@ -401,6 +414,29 @@ struct arm_smmu_domain {
 static DEFINE_SPINLOCK(arm_smmu_devices_lock);
 static LIST_HEAD(arm_smmu_devices);
 
+struct arm_smmu_option_prop {
+       u32 opt;
+       const char *prop;
+};
+
+static struct arm_smmu_option_prop arm_smmu_options [] = {
+       { ARM_SMMU_OPT_SECURE_CFG_ACCESS, "calxeda,smmu-secure-config-access" },
+       { 0, NULL},
+};
+
+static void parse_driver_options(struct arm_smmu_device *smmu)
+{
+       int i = 0;
+       do {
+               if (of_property_read_bool(smmu->dev->of_node,
+                                               arm_smmu_options[i].prop)) {
+                       smmu->options |= arm_smmu_options[i].opt;
+                       dev_notice(smmu->dev, "option %s\n",
+                               arm_smmu_options[i].prop);
+               }
+       } while (arm_smmu_options[++i].opt);
+}
+
 static struct arm_smmu_master *find_smmu_master(struct arm_smmu_device *smmu,
                                                struct device_node *dev_node)
 {
@@ -614,16 +650,16 @@ static irqreturn_t arm_smmu_global_fault(int irq, void 
*dev)
 {
        u32 gfsr, gfsynr0, gfsynr1, gfsynr2;
        struct arm_smmu_device *smmu = dev;
-       void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
+       void __iomem *gr0_base = ARM_SMMU_GR0_NS(smmu);
 
        gfsr = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSR);
-       if (!gfsr)
-               return IRQ_NONE;
-
        gfsynr0 = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSYNR0);
        gfsynr1 = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSYNR1);
        gfsynr2 = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSYNR2);
 
+       if (!gfsr)
+               return IRQ_NONE;
+
        dev_err_ratelimited(smmu->dev,
                "Unexpected global fault, this could be serious\n");
        dev_err_ratelimited(smmu->dev,
@@ -1597,9 +1633,9 @@ static void arm_smmu_device_reset(struct arm_smmu_device 
*smmu)
        int i = 0;
        u32 reg;
 
-       /* Clear Global FSR */
-       reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSR);
-       writel(reg, gr0_base + ARM_SMMU_GR0_sGFSR);
+       /* clear global FSR */
+       reg = readl_relaxed(ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sGFSR);
+       writel(reg, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sGFSR);
 
        /* Mark all SMRn as invalid and all S2CRn as bypass */
        for (i = 0; i < smmu->num_mapping_groups; ++i) {
@@ -1619,7 +1655,7 @@ static void arm_smmu_device_reset(struct arm_smmu_device 
*smmu)
        writel_relaxed(0, gr0_base + ARM_SMMU_GR0_TLBIALLH);
        writel_relaxed(0, gr0_base + ARM_SMMU_GR0_TLBIALLNSNH);
 
-       reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_sCR0);
+       reg = readl_relaxed(ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);
 
        /* Enable fault reporting */
        reg |= (sCR0_GFRE | sCR0_GFIE | sCR0_GCFGFRE | sCR0_GCFGFIE);
@@ -1638,7 +1674,7 @@ static void arm_smmu_device_reset(struct arm_smmu_device 
*smmu)
 
        /* Push the button */
        arm_smmu_tlb_sync(smmu);
-       writel_relaxed(reg, gr0_base + ARM_SMMU_GR0_sCR0);
+       writel(reg, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);
 }
 
 static int arm_smmu_id_size_to_bits(int size)
@@ -1885,6 +1921,8 @@ static int arm_smmu_device_dt_probe(struct 
platform_device *pdev)
        if (err)
                goto out_put_parent;
 
+       parse_driver_options(smmu);
+
        if (smmu->version > 1 &&
            smmu->num_context_banks != smmu->num_context_irqs) {
                dev_err(dev,
@@ -1969,7 +2007,7 @@ static int arm_smmu_device_remove(struct platform_device 
*pdev)
                free_irq(smmu->irqs[i], smmu);
 
        /* Turn the thing off */
-       writel_relaxed(sCR0_CLIENTPD, ARM_SMMU_GR0(smmu) + ARM_SMMU_GR0_sCR0);
+       writel(sCR0_CLIENTPD,ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);
        return 0;
 }
 
-- 
1.8.2.2

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