From 24d4e7f642882a8a13da170b4ba86eec8fa91bf2 Mon Sep 17 00:00:00 2001 From: David Daney Date: Thu, 5 Mar 2015 17:31:29 +0300 Subject: [PATCH] MIPS: OCTEON: Add semaphore to serialize bootbus accesses. Some hardware blocks attached to the OCTEON bootbus run asynchronously to accesses from the CPUs. These include MMC/SD host, CF(when using DMA), and NAND controller. A bus error, or corrupt data may occur if a CPU is trying to access a bootbus connected device at the same time the bus is running asynchronous operations. To work around these problems we add this semaphore that must be acquired before initiating bootbus activity. Subsequent patches will add users for this. Signed-off-by: David Daney [aleksey.makarov@auriga.com: combine the patches] Signed-off-by: Aleksey Makarov Signed-off-by: Chandrakala Chavva Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9459/ Signed-off-by: Ralf Baechle --- arch/mips/cavium-octeon/setup.c | 3 +++ arch/mips/include/asm/octeon/octeon.h | 2 ++ 2 files changed, 5 insertions(+) diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c index a42110e7edbc..01130e93126d 100644 --- a/arch/mips/cavium-octeon/setup.c +++ b/arch/mips/cavium-octeon/setup.c @@ -51,6 +51,9 @@ extern void pci_console_init(const char *arg); static unsigned long long MAX_MEMORY = 512ull << 20; +DEFINE_SEMAPHORE(octeon_bootbus_sem); +EXPORT_SYMBOL(octeon_bootbus_sem); + struct octeon_boot_descriptor *octeon_boot_desc_ptr; struct cvmx_bootinfo *octeon_bootinfo; diff --git a/arch/mips/include/asm/octeon/octeon.h b/arch/mips/include/asm/octeon/octeon.h index 041596570856..de9f74ee5dd0 100644 --- a/arch/mips/include/asm/octeon/octeon.h +++ b/arch/mips/include/asm/octeon/octeon.h @@ -335,4 +335,6 @@ void octeon_irq_set_ip4_handler(octeon_irq_ip4_handler_t); extern void octeon_fixup_irqs(void); +extern struct semaphore octeon_bootbus_sem; + #endif /* __ASM_OCTEON_OCTEON_H */ -- GitLab