From ba50ea7eb9ce663511013b35608cf0753c9ab674 Mon Sep 17 00:00:00 2001 From: Kalle Jokiniemi Date: Thu, 26 Mar 2009 15:59:00 +0200 Subject: [PATCH] OMAP3: PM: Fix secure SRAM context save/restore The secure sram context save uses dma channels 0 and 1. In order to avoid collision between kernel DMA transfers and ROM code dma transfers, we need to reserve DMA channels 0 1 on high security devices. A bug in ROM code leaves dma irq status bits uncleared. Hence those irq status bits need to be cleared when restoring DMA context after off mode. There was also a faulty parameter given to PPA in the secure ram context save assembly code, which caused interrupts to be enabled during secure ram context save. This caused the save to fail sometimes, which resulted the saved context to be corrupted, but also left DMA channels in secure mode. The secure mode DMA channels caused "DMA secure error with device 0" errors to be displayed. Signed-off-by: Kalle Jokiniemi Signed-off-by: Jouni Hogander Signed-off-by: Kevin Hilman --- arch/arm/mach-omap2/pm34xx.c | 3 --- arch/arm/mach-omap2/sleep34xx.S | 2 +- arch/arm/plat-omap/dma.c | 31 ++++++++++++++++--------------- 3 files changed, 17 insertions(+), 19 deletions(-) diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c index 3f1f656..a9f4034 100644 --- a/arch/arm/mach-omap2/pm34xx.c +++ b/arch/arm/mach-omap2/pm34xx.c @@ -130,9 +130,6 @@ static void omap3_save_secure_ram_context(u32 target_mpu_state) u32 ret; if (omap_type() != OMAP2_DEVICE_TYPE_GP) { - /* Disable dma irq before calling secure rom code API */ - omap_dma_disable_irq(0); - omap_dma_disable_irq(1); /* * MPU next state must be set to POWER_ON temporarily, * otherwise the WFI executed inside the ROM code diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S index db75167..b6abadc 100644 --- a/arch/arm/mach-omap2/sleep34xx.S +++ b/arch/arm/mach-omap2/sleep34xx.S @@ -68,7 +68,7 @@ save_secure_ram_debug: mov r0, #25 @ set service ID for PPA mov r12, r0 @ copy secure service ID in r12 mov r1, #0 @ set task id for ROM code in r1 - mov r2, #7 @ set some flags in r2, r6 + mov r2, #4 @ set some flags in r2, r6 mov r6, #0xff mcr p15, 0, r0, c7, c10, 4 @ data write barrier mcr p15, 0, r0, c7, c10, 5 @ data memory barrier diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index 3105aaa..1b5216f 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -2358,26 +2358,20 @@ void omap_dma_global_context_save(void) void omap_dma_global_context_restore(void) { - dma_write(0x2, OCP_SYSCONFIG); - while (!__raw_readl(omap_dma_base + OMAP_DMA4_SYSSTATUS)) - ; dma_write(omap_dma_global_context.dma_gcr, GCR); dma_write(omap_dma_global_context.dma_ocp_sysconfig, OCP_SYSCONFIG); dma_write(omap_dma_global_context.dma_irqenable_l0, IRQENABLE_L0); -} - -void omap_dma_disable_irq(int lch) -{ - u32 val; - if (cpu_class_is_omap2()) { - /* Disable interrupts */ - val = dma_read(IRQENABLE_L0); - val &= ~(1 << lch); - dma_write(val, IRQENABLE_L0); - } + /* + * A bug in ROM code leaves IRQ status for channels 0 and 1 uncleared + * after secure sram context save and restore. Hence we need to + * manually clear those IRQs to avoid spurious interrupts. This + * affects only secure devices. + */ + if (cpu_is_omap34xx() && (omap_type() != OMAP2_DEVICE_TYPE_GP)) + dma_write(0x3 , IRQSTATUS_L0); } /*----------------------------------------------------------------------------*/ @@ -2515,8 +2509,8 @@ static int __init omap_init_dma(void) setup_irq(irq, &omap24xx_dma_irq); } - /* Enable smartidle idlemodes and autoidle */ if (cpu_is_omap34xx()) { + /* Enable smartidle idlemodes and autoidle */ u32 v = dma_read(OCP_SYSCONFIG); v &= ~(DMA_SYSCONFIG_MIDLEMODE_MASK | DMA_SYSCONFIG_SIDLEMODE_MASK | @@ -2525,6 +2519,13 @@ static int __init omap_init_dma(void) DMA_SYSCONFIG_SIDLEMODE(DMA_IDLEMODE_SMARTIDLE) | DMA_SYSCONFIG_AUTOIDLE); dma_write(v , OCP_SYSCONFIG); + /* reserve dma channels 0 and 1 in high security devices */ + if (omap_type() != OMAP2_DEVICE_TYPE_GP) { + printk(KERN_INFO "Reserving DMA channels 0 and 1 for " + "HS ROM code\n"); + dma_chan[0].dev_id = 0; + dma_chan[1].dev_id = 1; + } } -- 2.7.4