From 63f2be5c3b358db031f86eafa9cd450f6558a55b Mon Sep 17 00:00:00 2001 From: "J. German Rivera" Date: Sat, 17 Oct 2015 15:33:15 -0500 Subject: [PATCH] staging: fsl-mc: Added serialization to mc_send_command() When the same portal is used to call mc_send_command() from two different threads or a thread and an interrupt handler, serialization is required, as the MC only supports one outstanding command per MC portal. Thus, a new command should not be sent to the MC until the last command sent has been responded by the MC. Signed-off-by: J. German Rivera Signed-off-by: Greg Kroah-Hartman --- drivers/staging/fsl-mc/bus/mc-sys.c | 25 ++++++++++++++++++--- drivers/staging/fsl-mc/include/mc-sys.h | 29 +++++++++++++++++++++++++ 2 files changed, 51 insertions(+), 3 deletions(-) diff --git a/drivers/staging/fsl-mc/bus/mc-sys.c b/drivers/staging/fsl-mc/bus/mc-sys.c index 6eeb9fa8ae6a..6e1489246066 100644 --- a/drivers/staging/fsl-mc/bus/mc-sys.c +++ b/drivers/staging/fsl-mc/bus/mc-sys.c @@ -88,6 +88,11 @@ int __must_check fsl_create_mc_io(struct device *dev, mc_io->flags = flags; mc_io->portal_phys_addr = mc_portal_phys_addr; mc_io->portal_size = mc_portal_size; + if (flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL) + spin_lock_init(&mc_io->spinlock); + else + mutex_init(&mc_io->mutex); + res = devm_request_mem_region(dev, mc_portal_phys_addr, mc_portal_size, @@ -391,11 +396,17 @@ int mc_send_command(struct fsl_mc_io *mc_io, struct mc_command *cmd) { int error; enum mc_cmd_status status; + unsigned long irq_flags = 0; if (WARN_ON(in_irq() && !(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))) return -EINVAL; + if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL) + spin_lock_irqsave(&mc_io->spinlock, irq_flags); + else + mutex_lock(&mc_io->mutex); + /* * Send command to the MC hardware: */ @@ -410,7 +421,7 @@ int mc_send_command(struct fsl_mc_io *mc_io, struct mc_command *cmd) error = mc_polling_wait_atomic(mc_io, cmd, &status); if (error < 0) - return error; + goto common_exit; if (status != MC_CMD_STATUS_OK) { pr_debug("MC command failed: portal: %#llx, obj handle: %#x, command: %#x, status: %s (%#x)\n", @@ -420,9 +431,17 @@ int mc_send_command(struct fsl_mc_io *mc_io, struct mc_command *cmd) mc_status_to_string(status), (unsigned int)status); - return mc_status_to_error(status); + error = mc_status_to_error(status); + goto common_exit; } - return 0; + error = 0; +common_exit: + if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL) + spin_unlock_irqrestore(&mc_io->spinlock, irq_flags); + else + mutex_unlock(&mc_io->mutex); + + return error; } EXPORT_SYMBOL(mc_send_command); diff --git a/drivers/staging/fsl-mc/include/mc-sys.h b/drivers/staging/fsl-mc/include/mc-sys.h index 15e19af31115..c5038cc77240 100644 --- a/drivers/staging/fsl-mc/include/mc-sys.h +++ b/drivers/staging/fsl-mc/include/mc-sys.h @@ -39,6 +39,8 @@ #include #include #include +#include +#include /** * Bit masks for a MC I/O object (struct fsl_mc_io) flags @@ -56,6 +58,20 @@ struct mc_command; * @portal_phys_addr: MC command portal physical address * @portal_virt_addr: MC command portal virtual address * @dpmcp_dev: pointer to the DPMCP device associated with the MC portal. + * + * Fields are only meaningful if the FSL_MC_IO_ATOMIC_CONTEXT_PORTAL flag is not + * set: + * @mutex: Mutex to serialize mc_send_command() calls that use the same MC + * portal, if the fsl_mc_io object was created with the + * FSL_MC_IO_ATOMIC_CONTEXT_PORTAL flag off. mc_send_command() calls for this + * fsl_mc_io object must be made only from non-atomic context. + * + * Fields are only meaningful if the FSL_MC_IO_ATOMIC_CONTEXT_PORTAL flag is + * set: + * @spinlock: Spinlock to serialize mc_send_command() calls that use the same MC + * portal, if the fsl_mc_io object was created with the + * FSL_MC_IO_ATOMIC_CONTEXT_PORTAL flag on. mc_send_command() calls for this + * fsl_mc_io object can be made from atomic or non-atomic context. */ struct fsl_mc_io { struct device *dev; @@ -64,6 +80,19 @@ struct fsl_mc_io { phys_addr_t portal_phys_addr; void __iomem *portal_virt_addr; struct fsl_mc_device *dpmcp_dev; + union { + /* + * This field is only meaningful if the + * FSL_MC_IO_ATOMIC_CONTEXT_PORTAL flag is not set + */ + struct mutex mutex; /* serializes mc_send_command() */ + + /* + * This field is only meaningful if the + * FSL_MC_IO_ATOMIC_CONTEXT_PORTAL flag is set + */ + spinlock_t spinlock; /* serializes mc_send_command() */ + }; }; int __must_check fsl_create_mc_io(struct device *dev, -- GitLab