Merge pull request #246 from soby-mathew/sm/route_IRQ_EL3
Demonstrate model for routing IRQs to EL3
diff --git a/bl31/interrupt_mgmt.c b/bl31/interrupt_mgmt.c
index e595634..5478902 100644
--- a/bl31/interrupt_mgmt.c
+++ b/bl31/interrupt_mgmt.c
@@ -158,6 +158,45 @@
return 0;
}
+/******************************************************************************
+ * This function disables the routing model of interrupt 'type' from the
+ * specified 'security_state' on the local core. The disable is in effect
+ * till the core powers down or till the next enable for that interrupt
+ * type.
+ *****************************************************************************/
+int disable_intr_rm_local(uint32_t type, uint32_t security_state)
+{
+ uint32_t bit_pos, flag;
+
+ assert(intr_type_descs[type].handler);
+
+ flag = get_interrupt_rm_flag(INTR_DEFAULT_RM, security_state);
+
+ bit_pos = plat_interrupt_type_to_line(type, security_state);
+ cm_write_scr_el3_bit(security_state, bit_pos, flag);
+
+ return 0;
+}
+
+/******************************************************************************
+ * This function enables the routing model of interrupt 'type' from the
+ * specified 'security_state' on the local core.
+ *****************************************************************************/
+int enable_intr_rm_local(uint32_t type, uint32_t security_state)
+{
+ uint32_t bit_pos, flag;
+
+ assert(intr_type_descs[type].handler);
+
+ flag = get_interrupt_rm_flag(intr_type_descs[type].flags,
+ security_state);
+
+ bit_pos = plat_interrupt_type_to_line(type, security_state);
+ cm_write_scr_el3_bit(security_state, bit_pos, flag);
+
+ return 0;
+}
+
/*******************************************************************************
* This function registers a handler for the 'type' of interrupt specified. It
* also validates the routing model specified in the 'flags' for this type of
diff --git a/docs/user-guide.md b/docs/user-guide.md
index 5ad44a8..b07dd5f 100644
--- a/docs/user-guide.md
+++ b/docs/user-guide.md
@@ -251,6 +251,11 @@
(Coherent memory region is included) or 0 (Coherent memory region is
excluded). Default is 1.
+* `TSPD_ROUTE_IRQ_TO_EL3`: A non zero value enables the routing model
+ for non-secure interrupts in which they are routed to EL3 (TSPD). The
+ default model (when the value is 0) is to route non-secure interrupts
+ to S-EL1 (TSP).
+
#### FVP specific build options
* `FVP_TSP_RAM_LOCATION`: location of the TSP binary. Options:
diff --git a/include/bl31/interrupt_mgmt.h b/include/bl31/interrupt_mgmt.h
index 3a2c00c..e07ddf8 100644
--- a/include/bl31/interrupt_mgmt.h
+++ b/include/bl31/interrupt_mgmt.h
@@ -63,7 +63,8 @@
#define INTR_NS_VALID_RM0 0x0
/* Routed to EL1/EL2 from NS and to EL3 from Secure */
#define INTR_NS_VALID_RM1 0x1
-
+/* This is the default routing model */
+#define INTR_DEFAULT_RM 0x0
/*******************************************************************************
* Constants for the _individual_ routing model bits in the 'flags' field for
@@ -123,6 +124,8 @@
interrupt_type_handler_t handler,
uint32_t flags);
interrupt_type_handler_t get_interrupt_type_handler(uint32_t interrupt_type);
+int disable_intr_rm_local(uint32_t type, uint32_t security_state);
+int enable_intr_rm_local(uint32_t type, uint32_t security_state);
#endif /*__ASSEMBLY__*/
#endif /* __INTERRUPT_MGMT_H__ */
diff --git a/services/spd/tspd/tspd.mk b/services/spd/tspd/tspd.mk
index cd4b45a..139c7d7 100644
--- a/services/spd/tspd/tspd.mk
+++ b/services/spd/tspd/tspd.mk
@@ -52,3 +52,10 @@
# Let the top-level Makefile know that we intend to build the SP from source
NEED_BL32 := yes
+
+# Flag used to enable routing of non-secure interrupts to EL3 when they are
+# generated while the code is executing in S-EL1/0.
+TSPD_ROUTE_IRQ_TO_EL3 := 0
+
+$(eval $(call assert_boolean,TSPD_ROUTE_IRQ_TO_EL3))
+$(eval $(call add_define,TSPD_ROUTE_IRQ_TO_EL3))
diff --git a/services/spd/tspd/tspd_main.c b/services/spd/tspd/tspd_main.c
index b8d4569..ee17483 100644
--- a/services/spd/tspd/tspd_main.c
+++ b/services/spd/tspd/tspd_main.c
@@ -48,6 +48,7 @@
#include <platform.h>
#include <runtime_svc.h>
#include <stddef.h>
+#include <string.h>
#include <tsp.h>
#include <uuid.h>
#include "tspd_private.h"
@@ -71,6 +72,24 @@
int32_t tspd_init(void);
+uint64_t tspd_handle_sp_preemption(void *handle)
+{
+ cpu_context_t *ns_cpu_context;
+ assert(handle == cm_get_context(SECURE));
+ cm_el1_sysregs_context_save(SECURE);
+ /* Get a reference to the non-secure context */
+ ns_cpu_context = cm_get_context(NON_SECURE);
+ assert(ns_cpu_context);
+
+ /*
+ * Restore non-secure state. The secure system
+ * register context will be saved when required.
+ */
+ cm_el1_sysregs_context_restore(NON_SECURE);
+ cm_set_next_eret_context(NON_SECURE);
+
+ SMC_RET1(ns_cpu_context, SMC_PREEMPTED);
+}
/*******************************************************************************
* This function is the handler registered for S-EL1 interrupts by the TSPD. It
* validates the interrupt and upon success arranges entry into the TSP at
@@ -120,11 +139,16 @@
CTX_SPSR_EL3);
tsp_ctx->saved_elr_el3 = SMC_GET_EL3(&tsp_ctx->cpu_ctx,
CTX_ELR_EL3);
+#if TSPD_ROUTE_IRQ_TO_EL3
+ /*Need to save the previously interrupted secure context */
+ memcpy(&tsp_ctx->sp_ctx, &tsp_ctx->cpu_ctx, TSPD_SP_CTX_SIZE);
+#endif
}
cm_el1_sysregs_context_restore(SECURE);
cm_set_elr_spsr_el3(SECURE, (uint64_t) &tsp_vectors->fiq_entry,
SPSR_64(MODE_EL1, MODE_SP_ELX, DISABLE_ALL_EXCEPTIONS));
+
cm_set_next_eret_context(SECURE);
/*
@@ -136,6 +160,34 @@
*/
SMC_RET2(&tsp_ctx->cpu_ctx, TSP_HANDLE_FIQ_AND_RETURN, read_elr_el3());
}
+
+#if TSPD_ROUTE_IRQ_TO_EL3
+/*******************************************************************************
+ * This function is the handler registered for S-EL1 interrupts by the TSPD. It
+ * validates the interrupt and upon success arranges entry into the TSP at
+ * 'tsp_fiq_entry()' for handling the interrupt.
+ ******************************************************************************/
+static uint64_t tspd_ns_interrupt_handler(uint32_t id,
+ uint32_t flags,
+ void *handle,
+ void *cookie)
+{
+ /* Check the security state when the exception was generated */
+ assert(get_interrupt_src_ss(flags) == SECURE);
+
+#if IMF_READ_INTERRUPT_ID
+ /* Check the security status of the interrupt */
+ assert(plat_ic_get_interrupt_type(id) == INTR_TYPE_NS);
+#endif
+ /*
+ * Disable the routing of NS interrupts from secure world to EL3 while
+ * interrupted on this core.
+ */
+ disable_intr_rm_local(INTR_TYPE_NS, SECURE);
+
+ return tspd_handle_sp_preemption(handle);
+}
+#endif
/*******************************************************************************
* Secure Payload Dispatcher setup. The SPD finds out the SP entrypoint and type
@@ -270,21 +322,7 @@
if (ns)
SMC_RET1(handle, SMC_UNK);
- assert(handle == cm_get_context(SECURE));
- cm_el1_sysregs_context_save(SECURE);
- /* Get a reference to the non-secure context */
- ns_cpu_context = cm_get_context(NON_SECURE);
- assert(ns_cpu_context);
-
- /*
- * Restore non-secure state. There is no need to save the
- * secure system register context since the TSP was supposed
- * to preserve it during S-EL1 interrupt handling.
- */
- cm_el1_sysregs_context_restore(NON_SECURE);
- cm_set_next_eret_context(NON_SECURE);
-
- SMC_RET1(ns_cpu_context, SMC_PREEMPTED);
+ return tspd_handle_sp_preemption(handle);
/*
* This function ID is used only by the TSP to indicate that it has
@@ -308,6 +346,14 @@
SMC_SET_EL3(&tsp_ctx->cpu_ctx,
CTX_ELR_EL3,
tsp_ctx->saved_elr_el3);
+#if TSPD_ROUTE_IRQ_TO_EL3
+ /*
+ * Need to restore the previously interrupted
+ * secure context.
+ */
+ memcpy(&tsp_ctx->cpu_ctx, &tsp_ctx->sp_ctx,
+ TSPD_SP_CTX_SIZE);
+#endif
}
/* Get a reference to the non-secure context */
@@ -389,6 +435,28 @@
flags);
if (rc)
panic();
+
+#if TSPD_ROUTE_IRQ_TO_EL3
+ /*
+ * Register an interrupt handler for NS interrupts when
+ * generated during code executing in secure state are
+ * routed to EL3.
+ */
+ flags = 0;
+ set_interrupt_rm_flag(flags, SECURE);
+
+ rc = register_interrupt_type_handler(INTR_TYPE_NS,
+ tspd_ns_interrupt_handler,
+ flags);
+ if (rc)
+ panic();
+
+ /*
+ * Disable the interrupt NS locally since it will be enabled globally
+ * within cm_init_context.
+ */
+ disable_intr_rm_local(INTR_TYPE_NS, SECURE);
+#endif
}
@@ -507,6 +575,13 @@
set_std_smc_active_flag(tsp_ctx->state);
cm_set_elr_el3(SECURE, (uint64_t)
&tsp_vectors->std_smc_entry);
+#if TSPD_ROUTE_IRQ_TO_EL3
+ /*
+ * Enable the routing of NS interrupts to EL3
+ * during STD SMC processing on this core.
+ */
+ enable_intr_rm_local(INTR_TYPE_NS, SECURE);
+#endif
}
cm_el1_sysregs_context_restore(SECURE);
@@ -529,8 +604,18 @@
/* Restore non-secure state */
cm_el1_sysregs_context_restore(NON_SECURE);
cm_set_next_eret_context(NON_SECURE);
- if (GET_SMC_TYPE(smc_fid) == SMC_TYPE_STD)
+ if (GET_SMC_TYPE(smc_fid) == SMC_TYPE_STD) {
clr_std_smc_active_flag(tsp_ctx->state);
+#if TSPD_ROUTE_IRQ_TO_EL3
+ /*
+ * Disable the routing of NS interrupts to EL3
+ * after STD SMC processing is finished on this
+ * core.
+ */
+ disable_intr_rm_local(INTR_TYPE_NS, SECURE);
+#endif
+ }
+
SMC_RET3(ns_cpu_context, x1, x2, x3);
}
@@ -564,6 +649,15 @@
* We are done stashing the non-secure context. Ask the
* secure payload to do the work now.
*/
+#if TSPD_ROUTE_IRQ_TO_EL3
+ /*
+ * Enable the routing of NS interrupts to EL3 during resumption
+ * of STD SMC call on this core.
+ */
+ enable_intr_rm_local(INTR_TYPE_NS, SECURE);
+#endif
+
+
/* We just need to return to the preempted point in
* TSP and the execution will resume as normal.
diff --git a/services/spd/tspd/tspd_pm.c b/services/spd/tspd/tspd_pm.c
index 17abaea..009ff5f 100644
--- a/services/spd/tspd/tspd_pm.c
+++ b/services/spd/tspd/tspd_pm.c
@@ -133,6 +133,14 @@
/* Initialise this cpu's secure context */
cm_init_context(mpidr, &tsp_on_entrypoint);
+#if TSPD_ROUTE_IRQ_TO_EL3
+ /*
+ * Disable the NS interrupt locally since it will be enabled globally
+ * within cm_init_context.
+ */
+ disable_intr_rm_local(INTR_TYPE_NS, SECURE);
+#endif
+
/* Enter the TSP */
rc = tspd_synchronous_sp_entry(tsp_ctx);
diff --git a/services/spd/tspd/tspd_private.h b/services/spd/tspd/tspd_private.h
index 4d48dbd..5f6fb2b 100644
--- a/services/spd/tspd/tspd_private.h
+++ b/services/spd/tspd/tspd_private.h
@@ -120,6 +120,34 @@
#define TSPD_C_RT_CTX_SIZE 0x60
#define TSPD_C_RT_CTX_ENTRIES (TSPD_C_RT_CTX_SIZE >> DWORD_SHIFT)
+/*******************************************************************************
+ * Constants that allow assembler code to preserve caller-saved registers of the
+ * SP context while performing a TSP preemption.
+ * Note: These offsets have to match with the offsets for the corresponding
+ * registers in cpu_context as we are using memcpy to copy the values from
+ * cpu_context to sp_ctx.
+ ******************************************************************************/
+#define TSPD_SP_CTX_X0 0x0
+#define TSPD_SP_CTX_X1 0x8
+#define TSPD_SP_CTX_X2 0x10
+#define TSPD_SP_CTX_X3 0x18
+#define TSPD_SP_CTX_X4 0x20
+#define TSPD_SP_CTX_X5 0x28
+#define TSPD_SP_CTX_X6 0x30
+#define TSPD_SP_CTX_X7 0x38
+#define TSPD_SP_CTX_X8 0x40
+#define TSPD_SP_CTX_X9 0x48
+#define TSPD_SP_CTX_X10 0x50
+#define TSPD_SP_CTX_X11 0x58
+#define TSPD_SP_CTX_X12 0x60
+#define TSPD_SP_CTX_X13 0x68
+#define TSPD_SP_CTX_X14 0x70
+#define TSPD_SP_CTX_X15 0x78
+#define TSPD_SP_CTX_X16 0x80
+#define TSPD_SP_CTX_X17 0x88
+#define TSPD_SP_CTX_SIZE 0x90
+#define TSPD_SP_CTX_ENTRIES (TSPD_SP_CTX_SIZE >> DWORD_SHIFT)
+
#ifndef __ASSEMBLY__
#include <cassert.h>
@@ -142,6 +170,17 @@
CASSERT(TSPD_C_RT_CTX_SIZE == sizeof(c_rt_regs_t), \
assert_spd_c_rt_regs_size_mismatch);
+/* SEL1 Secure payload (SP) caller saved register context structure. */
+DEFINE_REG_STRUCT(sp_ctx_regs, TSPD_SP_CTX_ENTRIES);
+
+/*
+ * Compile time assertion to ensure that both the compiler and linker
+ * have the same double word aligned view of the size of the C runtime
+ * register context.
+ */
+CASSERT(TSPD_SP_CTX_SIZE == sizeof(sp_ctx_regs_t), \
+ assert_spd_sp_regs_size_mismatch);
+
/*******************************************************************************
* Structure which helps the SPD to maintain the per-cpu state of the SP.
* 'saved_spsr_el3' - temporary copy to allow FIQ handling when the TSP has been
@@ -155,6 +194,10 @@
* 'cpu_ctx' - space to maintain SP architectural state
* 'saved_tsp_args' - space to store arguments for TSP arithmetic operations
* which will queried using the TSP_GET_ARGS SMC by TSP.
+ * 'sp_ctx' - space to save the SEL1 Secure Payload(SP) caller saved
+ * register context after it has been preempted by an EL3
+ * routed NS interrupt and when a Secure Interrupt is taken
+ * to SP.
******************************************************************************/
typedef struct tsp_context {
uint64_t saved_elr_el3;
@@ -164,6 +207,9 @@
uint64_t c_rt_ctx;
cpu_context_t cpu_ctx;
uint64_t saved_tsp_args[TSP_NUM_ARGS];
+#if TSPD_ROUTE_IRQ_TO_EL3
+ sp_ctx_regs_t sp_ctx;
+#endif
} tsp_context_t;
/* Helper macros to store and retrieve tsp args from tsp_context */