From 85c323c3e89d6e1b624b839c3325ae072952e545 Mon Sep 17 00:00:00 2001 From: Debarshi Dutta Date: Wed, 8 Aug 2018 17:36:01 +0530 Subject: gpu: nvgpu: restrict devfreq during active clk_arb set requests Restrict access to devfreq when there are active set requests in the clk_arbiter. We make the following changes in the patch. 1) Add a global counter in the struct gk20a named clk_arb_global_nr which is used to track the number of active set requests in the system. 2) Anytime a set request is successfully made by the userspace, clk_arb_global_nr is incremented by 1 and during the completion of request(releasing the corresponding file handle), clk_arb_global_nr is decremented by 1. 3) gk20a_scale_target(invoked by devfreq to set the new frequency based on load) atomically checks clk_arb_global_nr. If the value = 0, the code simply continue or else if its > 0, it quits thus making devfreq requests mutually exclusive with the clk_arbiter. Bug 2061372 Change-Id: I5d19de03e45520f4ff8fccb97b1f1589d04c8ab8 Signed-off-by: Debarshi Dutta Reviewed-on: https://git-master.nvidia.com/r/1790002 Reviewed-by: mobile promotions Tested-by: mobile promotions --- drivers/gpu/nvgpu/os/linux/debug_clk_gm20b.c | 3 +++ drivers/gpu/nvgpu/os/linux/driver_common.c | 3 +++ drivers/gpu/nvgpu/os/linux/ioctl_clk_arb.c | 1 + drivers/gpu/nvgpu/os/linux/scale.c | 3 +++ drivers/gpu/nvgpu/os/posix/clk_arb.c | 5 +++++ 5 files changed, 15 insertions(+) (limited to 'drivers/gpu/nvgpu/os') diff --git a/drivers/gpu/nvgpu/os/linux/debug_clk_gm20b.c b/drivers/gpu/nvgpu/os/linux/debug_clk_gm20b.c index 52eea83f..b8b95fd7 100644 --- a/drivers/gpu/nvgpu/os/linux/debug_clk_gm20b.c +++ b/drivers/gpu/nvgpu/os/linux/debug_clk_gm20b.c @@ -17,6 +17,7 @@ #include #include +#include #include "gm20b/clk_gm20b.h" #include "os_linux.h" @@ -33,6 +34,8 @@ static int rate_get(void *data, u64 *val) static int rate_set(void *data, u64 val) { struct gk20a *g = (struct gk20a *)data; + if (nvgpu_clk_arb_has_active_req(g)) + return 0; return g->ops.clk.set_rate(g, CTRL_CLK_DOMAIN_GPCCLK, (u32)val); } DEFINE_SIMPLE_ATTRIBUTE(rate_fops, rate_get, rate_set, "%llu\n"); diff --git a/drivers/gpu/nvgpu/os/linux/driver_common.c b/drivers/gpu/nvgpu/os/linux/driver_common.c index ebd0b40b..0a25cd3f 100644 --- a/drivers/gpu/nvgpu/os/linux/driver_common.c +++ b/drivers/gpu/nvgpu/os/linux/driver_common.c @@ -66,6 +66,9 @@ static void nvgpu_init_vars(struct gk20a *g) nvgpu_mutex_init(&g->tpc_pg_lock); nvgpu_mutex_init(&g->clk_arb_enable_lock); + /* Init the clock req count to 0 */ + nvgpu_atomic_set(&g->clk_arb_global_nr, 0); + l->regs_saved = l->regs; l->bar1_saved = l->bar1; diff --git a/drivers/gpu/nvgpu/os/linux/ioctl_clk_arb.c b/drivers/gpu/nvgpu/os/linux/ioctl_clk_arb.c index 2d9946b1..ff1cc00a 100644 --- a/drivers/gpu/nvgpu/os/linux/ioctl_clk_arb.c +++ b/drivers/gpu/nvgpu/os/linux/ioctl_clk_arb.c @@ -436,6 +436,7 @@ int nvgpu_clk_arb_commit_request_fd(struct gk20a *g, clk_arb_dbg(g, "requested target = %u\n", (u32)dev->gpc2clk_target_mhz); + nvgpu_atomic_inc(&g->clk_arb_global_nr); nvgpu_ref_get(&dev->refcount); nvgpu_spinlock_acquire(&session->session_lock); nvgpu_list_add(&dev->node, &session->targets); diff --git a/drivers/gpu/nvgpu/os/linux/scale.c b/drivers/gpu/nvgpu/os/linux/scale.c index ecc8207a..cbb9fdc5 100644 --- a/drivers/gpu/nvgpu/os/linux/scale.c +++ b/drivers/gpu/nvgpu/os/linux/scale.c @@ -25,6 +25,7 @@ #include #include +#include #include "gk20a/gk20a.h" #include "platform_gk20a.h" @@ -154,6 +155,8 @@ static int gk20a_scale_target(struct device *dev, unsigned long *freq, unsigned long rounded_rate; unsigned long min_freq = 0, max_freq = 0; + if (nvgpu_clk_arb_has_active_req(g)) + return 0; /* * Calculate floor and cap frequency values * diff --git a/drivers/gpu/nvgpu/os/posix/clk_arb.c b/drivers/gpu/nvgpu/os/posix/clk_arb.c index 63ab0f13..fcba0a26 100644 --- a/drivers/gpu/nvgpu/os/posix/clk_arb.c +++ b/drivers/gpu/nvgpu/os/posix/clk_arb.c @@ -52,6 +52,11 @@ int nvgpu_clk_arb_worker_init(struct gk20a *g) return -ENOSYS; } +bool nvgpu_clk_arb_has_active_req(struct gk20a *g) +{ + return false; +} + int nvgpu_clk_arb_get_arbiter_actual_mhz(struct gk20a *g, u32 api_domain, u16 *actual_mhz) { -- cgit v1.2.2