Trusted Foundations firmware require MMU to be enabled for L2 cache
maintenance on Tegra30, hence perform the maintenance early-late on
suspend-resume respectively.

Signed-off-by: Dmitry Osipenko <dig...@gmail.com>
---
 arch/arm/mach-tegra/pm.c            | 36 +++++++++++++++++++++++++++++
 arch/arm/mach-tegra/reset-handler.S |  8 ++-----
 arch/arm/mach-tegra/sleep.S         |  4 ++++
 3 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/arch/arm/mach-tegra/pm.c b/arch/arm/mach-tegra/pm.c
index 1ad5719779b0..66c8cd63dd86 100644
--- a/arch/arm/mach-tegra/pm.c
+++ b/arch/arm/mach-tegra/pm.c
@@ -38,6 +38,7 @@
 #include <asm/smp_plat.h>
 #include <asm/suspend.h>
 #include <asm/tlbflush.h>
+#include <asm/trusted_foundations.h>
 
 #include "iomap.h"
 #include "pm.h"
@@ -195,8 +196,27 @@ void tegra_idle_lp2_last(void)
        cpu_cluster_pm_enter();
        suspend_cpu_complex();
 
+       /*
+        * L2 cache disabling using kernel API only allowed when all
+        * secondary CPU's are offline. Cache have to be disabled early
+        * 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 codepath only
+        * for Tegra20/30.
+        */
+       if (trusted_foundations_registered())
+               outer_disable();
+
        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.
+        */
+       outer_resume();
+
        restore_cpu_complex();
        cpu_cluster_pm_exit();
 }
@@ -340,8 +360,24 @@ static int tegra_suspend_enter(suspend_state_t state)
                break;
        }
 
+       /*
+        * Cache have to be disabled early if cache maintenance is done
+        * via Trusted Foundations firmware. Otherwise this is a no-op,
+        * like on Tegra114+.
+        */
+       if (trusted_foundations_registered())
+               outer_disable();
+
        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 555c652f5a07..4973ea053bd7 100644
--- a/arch/arm/mach-tegra/reset-handler.S
+++ b/arch/arm/mach-tegra/reset-handler.S
@@ -69,7 +69,7 @@ ENTRY(tegra_resume)
 
        mov32   r9, 0xc09
        cmp     r8, r9
-       bne     end_ca9_scu_l2_resume
+       bne     end_ca9_scu_resume
 #ifdef CONFIG_HAVE_ARM_SCU
        /* enable SCU */
        mov32   r0, TEGRA_ARM_PERIF_BASE
@@ -78,11 +78,7 @@ ENTRY(tegra_resume)
        str     r1, [r0]
 #endif
 
-#ifdef CONFIG_CACHE_L2X0
-       /* L2 cache resume & re-enable */
-       bl      l2c310_early_resume
-#endif
-end_ca9_scu_l2_resume:
+end_ca9_scu_resume:
        mov32   r9, 0xc0f
        cmp     r8, r9
        bleq    tegra_init_l2_for_a15
diff --git a/arch/arm/mach-tegra/sleep.S b/arch/arm/mach-tegra/sleep.S
index 5e3496753df1..b96126fe5dc5 100644
--- a/arch/arm/mach-tegra/sleep.S
+++ b/arch/arm/mach-tegra/sleep.S
@@ -132,8 +132,12 @@ ENTRY(tegra_shut_off_mmu)
 #ifdef CONFIG_CACHE_L2X0
        /* Disable L2 cache */
        check_cpu_part_num 0xc09, r9, r10
+       retne   r0
+
        movweq  r2, #:lower16:(TEGRA_ARM_PERIF_BASE + 0x3000)
        movteq  r2, #:upper16:(TEGRA_ARM_PERIF_BASE + 0x3000)
+       ldr     r3, [r2, #L2X0_CTRL]
+       cmp     r3, #1
        moveq   r3, #0
        streq   r3, [r2, #L2X0_CTRL]
 #endif
-- 
2.18.0

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