From: Colin Cross ccr...@android.com
'Workaround for ROM bug because of CA9 r2pX gic control'
register change disables the gic distributor while the secondary
cpu is being booted. If a localtimer interrupt on the primary cpu
occurs when the distributor is turned off, the interrupt is lost,
and the localtimer never fires again.
Make the primary cpu wait for the secondary cpu to reenable the
gic distributor (with interrupts off for safety), and then
check if the pending bit is set in the localtimer but not the
gic. If so, ack it in the localtimer, and reset the timer with
the minimum timeout to trigger a new timer interrupt.
Signed-off-by: Colin Cross ccr...@android.com
[s-...@ti.com: adapted to k3.4 + validated functionality]
Signed-off-by: Sebastien Jan s-...@ti.com
[t-kri...@ti.com: dropped generic ARM kernel exports from the code, rebased
to mainline]
Signed-off-by: Tero Kristo t-kri...@ti.com
---
arch/arm/mach-omap2/common.h |2 ++
arch/arm/mach-omap2/omap-smp.c | 13 -
arch/arm/mach-omap2/omap4-common.c | 34 ++
3 files changed, 48 insertions(+), 1 deletions(-)
diff --git a/arch/arm/mach-omap2/common.h b/arch/arm/mach-omap2/common.h
index 70993a9..d29dbaa 100644
--- a/arch/arm/mach-omap2/common.h
+++ b/arch/arm/mach-omap2/common.h
@@ -276,6 +276,8 @@ static inline void __iomem *omap4_get_scu_base(void)
extern void __init gic_init_irq(void);
extern void gic_dist_disable(void);
+extern bool gic_dist_disabled(void);
+extern void gic_timer_retrigger(void);
extern void omap_smc1(u32 fn, u32 arg);
extern void __iomem *omap4_get_sar_ram_base(void);
extern void omap_do_wfi(void);
diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
index 7d9c0e3..49a08df 100644
--- a/arch/arm/mach-omap2/omap-smp.c
+++ b/arch/arm/mach-omap2/omap-smp.c
@@ -134,11 +134,22 @@ static int __cpuinit omap4_boot_secondary(unsigned int
cpu, struct task_struct *
* 2) CPU1 must re-enable the GIC distributor on
* it's wakeup path.
*/
- if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD))
+ if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
+ local_irq_disable();
gic_dist_disable();
+ }
clkdm_wakeup(cpu1_clkdm);
clkdm_allow_idle(cpu1_clkdm);
+
+ if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
+ while (gic_dist_disabled()) {
+ udelay(1);
+ cpu_relax();
+ }
+ gic_timer_retrigger();
+ local_irq_enable();
+ }
} else {
dsb_sev();
booted = true;
diff --git a/arch/arm/mach-omap2/omap4-common.c
b/arch/arm/mach-omap2/omap4-common.c
index 72cf396..6f94b4e 100644
--- a/arch/arm/mach-omap2/omap4-common.c
+++ b/arch/arm/mach-omap2/omap4-common.c
@@ -14,6 +14,7 @@
#include linux/kernel.h
#include linux/init.h
#include linux/io.h
+#include linux/irq.h
#include linux/platform_device.h
#include linux/memblock.h
#include linux/of_irq.h
@@ -24,6 +25,7 @@
#include asm/hardware/cache-l2x0.h
#include asm/mach/map.h
#include asm/memblock.h
+#include asm/smp_twd.h
#include plat/sram.h
#include plat/omap-secure.h
@@ -42,6 +44,9 @@ static void __iomem *l2cache_base;
static void __iomem *sar_ram_base;
static void __iomem *gic_dist_base_addr;
+static void __iomem *twd_base;
+
+#define IRQ_LOCALTIMER 29
#ifdef CONFIG_OMAP4_ERRATA_I688
/* Used to implement memory barrier on DRAM path */
@@ -101,6 +106,9 @@ void __init gic_init_irq(void)
gic_dist_base_addr = ioremap(OMAP44XX_GIC_DIST_BASE, SZ_4K);
BUG_ON(!gic_dist_base_addr);
+ twd_base = ioremap(OMAP44XX_LOCAL_TWD_BASE, SZ_4K);
+ BUG_ON(!twd_base);
+
/* Static mapping, never released */
omap_irq_base = ioremap(OMAP44XX_GIC_CPU_BASE, SZ_512);
BUG_ON(!omap_irq_base);
@@ -116,6 +124,32 @@ void gic_dist_disable(void)
__raw_writel(0x0, gic_dist_base_addr + GIC_DIST_CTRL);
}
+bool gic_dist_disabled(void)
+{
+ return !(__raw_readl(gic_dist_base_addr + GIC_DIST_CTRL) 0x1);
+}
+
+void gic_timer_retrigger(void)
+{
+ u32 twd_int = __raw_readl(twd_base + TWD_TIMER_INTSTAT);
+ u32 gic_int = __raw_readl(gic_dist_base_addr + GIC_DIST_PENDING_SET);
+ u32 twd_ctrl = __raw_readl(twd_base + TWD_TIMER_CONTROL);
+
+ if (twd_int !(gic_int BIT(IRQ_LOCALTIMER))) {
+ /*
+* The local timer interrupt got lost while the distributor was
+* disabled. Ack the pending interrupt, and retrigger it.
+*/
+ pr_warn(%s: lost localtimer interrupt\n, __func__);
+ __raw_writel(1, twd_base + TWD_TIMER_INTSTAT);
+
