[PATCH 2/2] OMAP: IOMMU: add support to callback during fault handling
David Cohen
dacohen at gmail.com
Tue Feb 15 08:20:33 EST 2011
Add support to register a callback for IOMMU fault situations. Drivers using
IOMMU module might want to be informed when such errors happen in order to
debug it or react.
Signed-off-by: David Cohen <dacohen at gmail.com>
---
arch/arm/mach-omap2/iommu2.c | 21 +++++++++++++--
arch/arm/plat-omap/include/plat/iommu.h | 15 ++++++++++-
arch/arm/plat-omap/iommu.c | 41 ++++++++++++++++++++++++++++---
3 files changed, 69 insertions(+), 8 deletions(-)
diff --git a/arch/arm/mach-omap2/iommu2.c b/arch/arm/mach-omap2/iommu2.c
index 4244a07..559a066 100644
--- a/arch/arm/mach-omap2/iommu2.c
+++ b/arch/arm/mach-omap2/iommu2.c
@@ -143,10 +143,10 @@ static void omap2_iommu_set_twl(struct iommu *obj, bool on)
__iommu_set_twl(obj, false);
}
-static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra)
+static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra, u32 *iommu_errs)
{
int i;
- u32 stat, da;
+ u32 stat, da, errs;
const char *err_msg[] = {
"tlb miss",
"translation fault",
@@ -157,8 +157,10 @@ static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra)
stat = iommu_read_reg(obj, MMU_IRQSTATUS);
stat &= MMU_IRQ_MASK;
- if (!stat)
+ if (!stat) {
+ *iommu_errs = 0;
return 0;
+ }
da = iommu_read_reg(obj, MMU_FAULT_AD);
*ra = da;
@@ -171,6 +173,19 @@ static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra)
}
printk(KERN_DEBUG "\n");
+ errs = 0;
+ if (stat & MMU_IRQ_TLBMISS)
+ errs |= OMAP_IOMMU_ERR_TLB_MISS;
+ if (stat & MMU_IRQ_TRANSLATIONFAULT)
+ errs |= OMAP_IOMMU_ERR_TRANS_FAULT;
+ if (stat & MMU_IRQ_EMUMISS)
+ errs |= OMAP_IOMMU_ERR_EMU_MISS;
+ if (stat & MMU_IRQ_TABLEWALKFAULT)
+ errs |= OMAP_IOMMU_ERR_TBLWALK_FAULT;
+ if (stat & MMU_IRQ_MULTIHITFAULT)
+ errs |= OMAP_IOMMU_ERR_MULTIHIT_FAULT;
+ *iommu_errs = errs;
+
iommu_write_reg(obj, stat, MMU_IRQSTATUS);
return stat;
diff --git a/arch/arm/plat-omap/include/plat/iommu.h b/arch/arm/plat-omap/include/plat/iommu.h
index 19cbb5e..5a2475f 100644
--- a/arch/arm/plat-omap/include/plat/iommu.h
+++ b/arch/arm/plat-omap/include/plat/iommu.h
@@ -31,6 +31,7 @@ struct iommu {
struct clk *clk;
void __iomem *regbase;
struct device *dev;
+ void *fault_cb_priv;
unsigned int refcount;
struct mutex iommu_lock; /* global for this whole object */
@@ -48,6 +49,7 @@ struct iommu {
struct mutex mmap_lock; /* protect mmap */
int (*isr)(struct iommu *obj);
+ void (*fault_cb)(struct iommu *obj, u32 da, u32 iommu_errs, void *priv);
void *ctx; /* iommu context: registres saved area */
u32 da_start;
@@ -83,7 +85,7 @@ struct iommu_functions {
int (*enable)(struct iommu *obj);
void (*disable)(struct iommu *obj);
void (*set_twl)(struct iommu *obj, bool on);
- u32 (*fault_isr)(struct iommu *obj, u32 *ra);
+ u32 (*fault_isr)(struct iommu *obj, u32 *ra, u32 *iommu_errs);
void (*tlb_read_cr)(struct iommu *obj, struct cr_regs *cr);
void (*tlb_load_cr)(struct iommu *obj, struct cr_regs *cr);
@@ -109,6 +111,13 @@ struct iommu_platform_data {
u32 da_end;
};
+/* IOMMU errors */
+#define OMAP_IOMMU_ERR_TLB_MISS (1 << 0)
+#define OMAP_IOMMU_ERR_TRANS_FAULT (1 << 1)
+#define OMAP_IOMMU_ERR_EMU_MISS (1 << 2)
+#define OMAP_IOMMU_ERR_TBLWALK_FAULT (1 << 3)
+#define OMAP_IOMMU_ERR_MULTIHIT_FAULT (1 << 4)
+
#if defined(CONFIG_ARCH_OMAP1)
#error "iommu for this processor not implemented yet"
#else
@@ -161,6 +170,10 @@ extern size_t iopgtable_clear_entry(struct iommu *obj, u32 iova);
extern int iommu_set_da_range(struct iommu *obj, u32 start, u32 end);
extern struct iommu *iommu_get(const char *name);
extern void iommu_put(struct iommu *obj);
+extern int iommu_set_fault_callback(const char *name,
+ void (*fault_cb)(struct iommu *obj, u32 da,
+ u32 errs, void *priv),
+ void *fault_cb_priv);
extern void iommu_save_ctx(struct iommu *obj);
extern void iommu_restore_ctx(struct iommu *obj);
diff --git a/arch/arm/plat-omap/iommu.c b/arch/arm/plat-omap/iommu.c
index b1107c0..7f780ee 100644
--- a/arch/arm/plat-omap/iommu.c
+++ b/arch/arm/plat-omap/iommu.c
@@ -163,9 +163,9 @@ static u32 get_iopte_attr(struct iotlb_entry *e)
return arch_iommu->get_pte_attr(e);
}
-static u32 iommu_report_fault(struct iommu *obj, u32 *da)
+static u32 iommu_report_fault(struct iommu *obj, u32 *da, u32 *iommu_errs)
{
- return arch_iommu->fault_isr(obj, da);
+ return arch_iommu->fault_isr(obj, da, iommu_errs);
}
static void iotlb_lock_get(struct iommu *obj, struct iotlb_lock *l)
@@ -780,7 +780,7 @@ static void iopgtable_clear_entry_all(struct iommu *obj)
*/
static irqreturn_t iommu_fault_handler(int irq, void *data)
{
- u32 stat, da;
+ u32 stat, da, errs;
u32 *iopgd, *iopte;
int err = -EIO;
struct iommu *obj = data;
@@ -796,13 +796,19 @@ static irqreturn_t iommu_fault_handler(int irq, void *data)
return IRQ_HANDLED;
clk_enable(obj->clk);
- stat = iommu_report_fault(obj, &da);
+ stat = iommu_report_fault(obj, &da, &errs);
clk_disable(obj->clk);
if (!stat)
return IRQ_HANDLED;
iommu_disable(obj);
+ if (obj->fault_cb) {
+ obj->fault_cb(obj, da, errs, obj->fault_cb_priv);
+ /* No need to print error message as callback is called */
+ return IRQ_NONE;
+ }
+
iopgd = iopgd_offset(obj, da);
if (!iopgd_is_table(*iopgd)) {
@@ -917,6 +923,33 @@ void iommu_put(struct iommu *obj)
}
EXPORT_SYMBOL_GPL(iommu_put);
+int iommu_set_fault_callback(const char *name,
+ void (*fault_cb)(struct iommu *obj, u32 da,
+ u32 iommu_errs, void *priv),
+ void *fault_cb_priv)
+{
+ struct device *dev;
+ struct iommu *obj;
+
+ dev = driver_find_device(&omap_iommu_driver.driver, NULL, (void *)name,
+ device_match_by_alias);
+ if (!dev)
+ return -ENODEV;
+
+ obj = to_iommu(dev);
+ mutex_lock(&obj->iommu_lock);
+ if (obj->refcount != 0) {
+ mutex_unlock(&obj->iommu_lock);
+ return -EBUSY;
+ }
+ obj->fault_cb = fault_cb;
+ obj->fault_cb_priv = fault_cb_priv;
+ mutex_unlock(&obj->iommu_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(iommu_set_fault_callback);
+
/*
* OMAP Device MMU(IOMMU) detection
*/
--
1.7.2.3
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