ARM: tegra: Add firmware calls required for suspend-resume on Tegra30

In order to suspend-resume CPU with Trusted Foundations firmware being
present on Tegra30, the LP1/LP2 boot vectors and CPU caches need to be
set up using the firmware calls and then suspend code shall avoid
re-disabling parts that were disabled by the firmware.

Tested-by: Robert Yang <decatf@gmail.com>
Tested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/arch/arm/mach-tegra/pm.c b/arch/arm/mach-tegra/pm.c
index 1ad5719..abf5f88 100644 (file)
--- a/arch/arm/mach-tegra/pm.c
+++ b/arch/arm/mach-tegra/pm.c
@@ -33,11 +33,13 @@
 #include <soc/tegra/pmc.h>
 
 #include <asm/cacheflush.h>
+#include <asm/firmware.h>
 #include <asm/idmap.h>
 #include <asm/proc-fns.h>
 #include <asm/smp_plat.h>
 #include <asm/suspend.h>
 #include <asm/tlbflush.h>
+#include <asm/trusted_foundations.h>
 
 #include "iomap.h"
 #include "pm.h"
@@ -159,6 +161,28 @@ int tegra_cpu_do_idle(void)
 
 static int tegra_sleep_cpu(unsigned long v2p)
 {
+       /*
+        * L2 cache disabling using kernel API only allowed when all
+        * secondary CPU's are offline. Cache have to be disabled with
+        * MMU-on if cache maintenance is done via Trusted Foundations
+        * firmware. Note that CPUIDLE won't ever enter powergate on Tegra30
+        * if any of secondary CPU's is online and this is the LP2-idle
+        * code-path only for Tegra20/30.
+        */
+       if (trusted_foundations_registered())
+               outer_disable();
+
+       /*
+        * Note that besides of setting up CPU reset vector this firmware
+        * call may also do the following, depending on the FW version:
+        *  1) Disable L2. But this doesn't matter since we already
+        *     disabled the L2.
+        *  2) Disable D-cache. This need to be taken into account in
+        *     particular by the tegra_disable_clean_inv_dcache() which
+        *     shall avoid the re-disable.
+        */
+       call_firmware_op(prepare_idle, TF_PM_MODE_LP2);
+
        setup_mm_for_reboot();
        tegra_sleep_cpu_finish(v2p);
 
@@ -197,6 +221,14 @@ void tegra_idle_lp2_last(void)
 
        cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
 
+       /*
+        * Resume L2 cache if it wasn't re-enabled early during resume,
+        * which is the case for Tegra30 that has to re-enable the cache
+        * via firmware call. In other cases cache is already enabled and
+        * hence re-enabling is a no-op. This is always a no-op on Tegra114+.
+        */
+       outer_resume();
+
        restore_cpu_complex();
        cpu_cluster_pm_exit();
 }
@@ -215,6 +247,15 @@ enum tegra_suspend_mode tegra_pm_validate_suspend_mode(
 
 static int tegra_sleep_core(unsigned long v2p)
 {
+       /*
+        * Cache have to be disabled with MMU-on if cache maintenance is done
+        * via Trusted Foundations firmware. This is a no-op on Tegra114+.
+        */
+       if (trusted_foundations_registered())
+               outer_disable();
+
+       call_firmware_op(prepare_idle, TF_PM_MODE_LP1);
+
        setup_mm_for_reboot();
        tegra_sleep_core_finish(v2p);
 
@@ -342,6 +383,14 @@ static int tegra_suspend_enter(suspend_state_t state)
 
        cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, tegra_sleep_func);
 
+       /*
+        * Resume L2 cache if it wasn't re-enabled early during resume,
+        * which is the case for Tegra30 that has to re-enable the cache
+        * via firmware call. In other cases cache is already enabled and
+        * hence re-enabling is a no-op.
+        */
+       outer_resume();
+
        switch (mode) {
        case TEGRA_SUSPEND_LP1:
                tegra_suspend_exit_lp1();

diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
index 31fb53f..cd94d7c 100644 (file)
--- a/arch/arm/mach-tegra/reset-handler.S
+++ b/arch/arm/mach-tegra/reset-handler.S
@@ -20,6 +20,7 @@
 #include <soc/tegra/flowctrl.h>
 #include <soc/tegra/fuse.h>
 
+#include <asm/assembler.h>
 #include <asm/asm-offsets.h>
 #include <asm/cache.h>
 
@@ -76,6 +77,7 @@ ENTRY(tegra_resume)
        orr     r1, r1, #1
        str     r1, [r0]
 #endif
+       bl      tegra_resume_trusted_foundations
 
 #ifdef CONFIG_CACHE_L2X0
        /* L2 cache resume & re-enable */
@@ -88,6 +90,30 @@ end_ca9_scu_l2_resume:
 
        b       cpu_resume
 ENDPROC(tegra_resume)
+
+/*
+ *     tegra_resume_trusted_foundations
+ *
+ *       Trusted Foundations firmware initialization.
+ *
+ *     Doesn't return if firmware presents.
+ *     Corrupted registers: r1, r2
+ */
+ENTRY(tegra_resume_trusted_foundations)
+       /* Check whether Trusted Foundations firmware presents. */
+       mov32   r2, TEGRA_IRAM_BASE + TEGRA_IRAM_RESET_HANDLER_OFFSET
+       ldr     r1, =__tegra_cpu_reset_handler_data_offset + \
+                                                       RESET_DATA(TF_PRESENT)
+       ldr     r1, [r2, r1]
+       cmp     r1, #0
+       reteq   lr
+
+ .arch_extension sec
+       /* First call after suspend wakes firmware. No arguments required. */
+       smc     #0
+
+       b       cpu_resume
+ENDPROC(tegra_resume_trusted_foundations)
 #endif
 
        .align L1_CACHE_SHIFT

diff --git a/arch/arm/mach-tegra/sleep.S b/arch/arm/mach-tegra/sleep.S
index 5e34967..1735ded 100644 (file)
--- a/arch/arm/mach-tegra/sleep.S
+++ b/arch/arm/mach-tegra/sleep.S
@@ -49,8 +49,9 @@ ENTRY(tegra_disable_clean_inv_dcache)
 
        /* Disable the D-cache */
        mrc     p15, 0, r2, c1, c0, 0
+       tst     r2, #CR_C                       @ see tegra_sleep_cpu()
        bic     r2, r2, #CR_C
-       mcr     p15, 0, r2, c1, c0, 0
+       mcrne   p15, 0, r2, c1, c0, 0
        isb
 
        /* Flush the D-cache */
@@ -132,10 +133,13 @@ ENTRY(tegra_shut_off_mmu)
 #ifdef CONFIG_CACHE_L2X0
        /* Disable L2 cache */
        check_cpu_part_num 0xc09, r9, r10
-       movweq  r2, #:lower16:(TEGRA_ARM_PERIF_BASE + 0x3000)
-       movteq  r2, #:upper16:(TEGRA_ARM_PERIF_BASE + 0x3000)
-       moveq   r3, #0
-       streq   r3, [r2, #L2X0_CTRL]
+       retne   r0
+
+       mov32   r2, TEGRA_ARM_PERIF_BASE + 0x3000
+       ldr     r3, [r2, #L2X0_CTRL]
+       tst     r3, #L2X0_CTRL_EN               @ see tegra_sleep_cpu()
+       mov     r3, #0
+       strne   r3, [r2, #L2X0_CTRL]
 #endif
        ret     r0
 ENDPROC(tegra_shut_off_mmu)