AArch32: Add support to PSCI lib
authorSoby Mathew <[email protected]>
Thu, 5 May 2016 13:11:23 +0000 (14:11 +0100)
committerSoby Mathew <[email protected]>
Wed, 10 Aug 2016 13:43:48 +0000 (14:43 +0100)
This patch adds AArch32 support to PSCI library, as follows :

* The `psci_helpers.S` is implemented for AArch32.

* AArch32 version of internal helper function `psci_get_ns_ep_info()` is
  defined.

* The PSCI Library is responsible for the Non Secure context initialization.
  Hence a library interface `psci_prepare_next_non_secure_ctx()` is introduced
  to enable EL3 runtime firmware to initialize the non secure context without
  invoking context management library APIs.

Change-Id: I25595b0cc2dbfdf39dbf7c589b875cba33317b9d

include/lib/psci/psci.h
lib/psci/aarch32/psci_helpers.S [new file with mode: 0644]
lib/psci/psci_common.c
lib/psci/psci_lib.mk
lib/psci/psci_setup.c

index c3e9ef7ed3d2a9608a091aa7707a97c116cb4bab..a583fef7e680bc5869017a854950071d77a778c4 100644 (file)
@@ -359,6 +359,8 @@ u_register_t psci_smc_handler(uint32_t smc_fid,
 int psci_setup(uintptr_t mailbox_ep);
 void psci_warmboot_entrypoint(void);
 void psci_register_spd_pm_hook(const spd_pm_ops_t *pm);
+void psci_prepare_next_non_secure_ctx(
+                         struct entry_point_info *next_image_info);
 
 #endif /*__ASSEMBLY__*/
 
diff --git a/lib/psci/aarch32/psci_helpers.S b/lib/psci/aarch32/psci_helpers.S
new file mode 100644 (file)
index 0000000..36d5d7d
--- /dev/null
@@ -0,0 +1,180 @@
+/*
+ * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <asm_macros.S>
+#include <platform_def.h>
+#include <psci.h>
+
+       .globl  psci_do_pwrdown_cache_maintenance
+       .globl  psci_do_pwrup_cache_maintenance
+       .globl  psci_power_down_wfi
+
+/* -----------------------------------------------------------------------
+ * void psci_do_pwrdown_cache_maintenance(unsigned int power level);
+ *
+ * This function performs cache maintenance for the specified power
+ * level. The levels of cache affected are determined by the power
+ * level which is passed as the argument i.e. level 0 results
+ * in a flush of the L1 cache. Both the L1 and L2 caches are flushed
+ * for a higher power level.
+ *
+ * Additionally, this function also ensures that stack memory is correctly
+ * flushed out to avoid coherency issues due to a change in its memory
+ * attributes after the data cache is disabled.
+ * -----------------------------------------------------------------------
+ */
+func psci_do_pwrdown_cache_maintenance
+       push    {r4, lr}
+
+       /* ----------------------------------------------
+        * Turn OFF cache and do stack maintenance
+        * prior to cpu operations . This sequence is
+        * different from AArch64 because in AArch32 the
+        * assembler routines for cpu operations utilize
+        * the stack whereas in AArch64 it doesn't.
+        * ----------------------------------------------
+        */
+       mov     r4, r0
+       bl      do_stack_maintenance
+
+       /* ---------------------------------------------
+        * Determine how many levels of cache will be
+        * subject to cache maintenance. Power level
+        * 0 implies that only the cpu is being powered
+        * down. Only the L1 data cache needs to be
+        * flushed to the PoU in this case. For a higher
+        * power level we are assuming that a flush
+        * of L1 data and L2 unified cache is enough.
+        * This information should be provided by the
+        * platform.
+        * ---------------------------------------------
+        */
+       cmp     r4, #PSCI_CPU_PWR_LVL
+       pop     {r4,lr}
+
+       beq     prepare_core_pwr_dwn
+       b       prepare_cluster_pwr_dwn
+endfunc psci_do_pwrdown_cache_maintenance
+
+
+/* -----------------------------------------------------------------------
+ * void psci_do_pwrup_cache_maintenance(void);
+ *
+ * This function performs cache maintenance after this cpu is powered up.
+ * Currently, this involves managing the used stack memory before turning
+ * on the data cache.
+ * -----------------------------------------------------------------------
+ */
+func psci_do_pwrup_cache_maintenance
+       push    {lr}
+
+       /* ---------------------------------------------
+        * Ensure any inflight stack writes have made it
+        * to main memory.
+        * ---------------------------------------------
+        */
+       dmb     st
+
+       /* ---------------------------------------------
+        * Calculate and store the size of the used
+        * stack memory in r1. Calculate and store the
+        * stack base address in r0.
+        * ---------------------------------------------
+        */
+       bl      plat_get_my_stack
+       mov     r1, sp
+       sub     r1, r0, r1
+       mov     r0, sp
+       bl      inv_dcache_range
+
+       /* ---------------------------------------------
+        * Enable the data cache.
+        * ---------------------------------------------
+        */
+       ldcopr  r0, SCTLR
+       orr     r0, r0, #SCTLR_C_BIT
+       stcopr  r0, SCTLR
+       isb
+
+       pop     {pc}
+endfunc psci_do_pwrup_cache_maintenance
+
+       /* ---------------------------------------------
+        * void do_stack_maintenance(void)
+        * Do stack maintenance by flushing the used
+        * stack to the main memory and invalidating the
+        * remainder.
+        * ---------------------------------------------
+        */
+func do_stack_maintenance
+       push    {r4, lr}
+       bl      plat_get_my_stack
+
+       /* Turn off the D-cache */
+       ldcopr  r1, SCTLR
+       bic     r1, #SCTLR_C_BIT
+       stcopr  r1, SCTLR
+       isb
+
+       /* ---------------------------------------------
+        * Calculate and store the size of the used
+        * stack memory in r1.
+        * ---------------------------------------------
+        */
+       mov     r4, r0
+       mov     r1, sp
+       sub     r1, r0, r1
+       mov     r0, sp
+       bl      flush_dcache_range
+
+       /* ---------------------------------------------
+        * Calculate and store the size of the unused
+        * stack memory in r1. Calculate and store the
+        * stack base address in r0.
+        * ---------------------------------------------
+        */
+       sub     r0, r4, #PLATFORM_STACK_SIZE
+       sub     r1, sp, r0
+       bl      inv_dcache_range
+
+       pop     {r4, pc}
+endfunc do_stack_maintenance
+
+/* -----------------------------------------------------------------------
+ * This function is called to indicate to the power controller that it
+ * is safe to power down this cpu. It should not exit the wfi and will
+ * be released from reset upon power up.
+ * -----------------------------------------------------------------------
+ */
+func psci_power_down_wfi
+       dsb     sy              // ensure write buffer empty
+       wfi
+       bl      plat_panic_handler
+endfunc psci_power_down_wfi
index e87e8c054d387b826e7ebf86a96a0210b315c4f3..68cdd6eb12f7cb34c4dcaf92804c66bc5fe17c9b 100644 (file)
@@ -592,6 +592,53 @@ int psci_validate_mpidr(u_register_t mpidr)
  * This function determines the full entrypoint information for the requested
  * PSCI entrypoint on power on/resume and returns it.
  ******************************************************************************/
+#ifdef AARCH32
+static int psci_get_ns_ep_info(entry_point_info_t *ep,
+                              uintptr_t entrypoint,
+                              u_register_t context_id)
+{
+       u_register_t ep_attr;
+       unsigned int aif, ee, mode;
+       u_register_t scr = read_scr();
+       u_register_t ns_sctlr, sctlr;
+
+       /* Switch to non secure state */
+       write_scr(scr | SCR_NS_BIT);
+       isb();
+       ns_sctlr = read_sctlr();
+
+       sctlr = scr & SCR_HCE_BIT ? read_hsctlr() : ns_sctlr;
+
+       /* Return to original state */
+       write_scr(scr);
+       isb();
+       ee = 0;
+
+       ep_attr = NON_SECURE | EP_ST_DISABLE;
+       if (sctlr & SCTLR_EE_BIT) {
+               ep_attr |= EP_EE_BIG;
+               ee = 1;
+       }
+       SET_PARAM_HEAD(ep, PARAM_EP, VERSION_1, ep_attr);
+
+       ep->pc = entrypoint;
+       memset(&ep->args, 0, sizeof(ep->args));
+       ep->args.arg0 = context_id;
+
+       mode = scr & SCR_HCE_BIT ? MODE32_hyp : MODE32_svc;
+
+       /*
+        * TODO: Choose async. exception bits if HYP mode is not
+        * implemented according to the values of SCR.{AW, FW} bits
+        */
+       aif = SPSR_ABT_BIT | SPSR_IRQ_BIT | SPSR_FIQ_BIT;
+
+       ep->spsr = SPSR_MODE32(mode, entrypoint & 0x1, ee, aif);
+
+       return PSCI_E_SUCCESS;
+}
+
+#else
 static int psci_get_ns_ep_info(entry_point_info_t *ep,
                               uintptr_t entrypoint,
                               u_register_t context_id)
@@ -646,6 +693,7 @@ static int psci_get_ns_ep_info(entry_point_info_t *ep,
 
        return PSCI_E_SUCCESS;
 }
+#endif
 
 /*******************************************************************************
  * This function validates the entrypoint with the platform layer if the
index 3a5833ba2e96b8cb16d0ae69ac9b248a841e20c5..8daa831826516bbbf346ed8e70f52744c6e137a3 100644 (file)
 #
 
 PSCI_LIB_SOURCES       :=      lib/el3_runtime/cpu_data_array.c        \
-                               lib/el3_runtime/aarch64/context.S       \
-                               lib/el3_runtime/aarch64/cpu_data.S      \
-                               lib/el3_runtime/aarch64/context_mgmt.c  \
-                               lib/cpus/aarch64/cpu_helpers.S          \
-                               lib/locks/exclusive/aarch64/spinlock.S  \
+                               lib/el3_runtime/${ARCH}/cpu_data.S      \
+                               lib/el3_runtime/${ARCH}/context_mgmt.c  \
+                               lib/cpus/${ARCH}/cpu_helpers.S          \
+                               lib/locks/exclusive/${ARCH}/spinlock.S  \
                                lib/psci/psci_off.c                     \
                                lib/psci/psci_on.c                      \
                                lib/psci/psci_suspend.c                 \
@@ -41,7 +40,11 @@ PSCI_LIB_SOURCES     :=      lib/el3_runtime/cpu_data_array.c        \
                                lib/psci/psci_main.c                    \
                                lib/psci/psci_setup.c                   \
                                lib/psci/psci_system_off.c              \
-                               lib/psci/aarch64/psci_helpers.S
+                               lib/psci/${ARCH}/psci_helpers.S
+
+ifeq (${ARCH}, aarch64)
+PSCI_LIB_SOURCES       +=      lib/el3_runtime/aarch64/context.S
+endif
 
 ifeq (${USE_COHERENT_MEM}, 1)
 PSCI_LIB_SOURCES               +=      lib/locks/bakery/bakery_lock_coherent.c
index d35e0001eacbec0d26c73b7a10da526749257040..20d06352c41ba621515ccb6b6723386ddd6162e3 100644 (file)
@@ -278,3 +278,15 @@ void psci_arch_setup(void)
        /* Initialize the cpu_ops pointer. */
        init_cpu_ops();
 }
+
+/******************************************************************************
+ * PSCI Library interface to initialize the cpu context for the next non
+ * secure image during cold boot. The relevant registers in the cpu context
+ * need to be retrieved and programmed on return from this interface.
+ *****************************************************************************/
+void psci_prepare_next_non_secure_ctx(entry_point_info_t *next_image_info)
+{
+       assert(GET_SECURITY_STATE(next_image_info->h.attr) == NON_SECURE);
+       cm_init_my_context(next_image_info);
+       cm_prepare_el3_exit(NON_SECURE);
+}