The msgbox clock is critical because the hardware it controls is shared between Linux and system firmware. The message box may be used by the EL3 secure monitor's PSCI implementation. On 64-bit sunxi SoCs, this is provided by ARM TF-A; 32-bit SoCs use a different implementation. The secure monitor uses the message box to forward requests to power management firmware running on a separate CPU. It is not enough for the secure monitor to enable the clock each time Linux performs a SMC into EL3, as both the firmware and Linux can run concurrently on separate CPUs. So it is never safe for Linux to turn this clock off, and it should be marked as critical. At this time, such power management firmware only exists for the A64 and H5 SoCs. However, it makes sense to take care of all CCU drivers now for consistency, and to ease the transition in the future once firmware is ported to the other SoCs. Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx> --- drivers/clk/sunxi-ng/ccu-sun50i-a64.c | 3 ++- drivers/clk/sunxi-ng/ccu-sun50i-h6.c | 3 ++- drivers/clk/sunxi-ng/ccu-sun8i-a23.c | 3 ++- drivers/clk/sunxi-ng/ccu-sun8i-a33.c | 3 ++- drivers/clk/sunxi-ng/ccu-sun8i-a83t.c | 3 ++- drivers/clk/sunxi-ng/ccu-sun8i-h3.c | 3 ++- drivers/clk/sunxi-ng/ccu-sun9i-a80.c | 3 ++- 7 files changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c index 932836d26e2b..22c8de3546e6 100644 --- a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c +++ b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c @@ -349,8 +349,9 @@ static SUNXI_CCU_GATE(bus_de_clk, "bus-de", "ahb1", 0x064, BIT(12), 0); static SUNXI_CCU_GATE(bus_gpu_clk, "bus-gpu", "ahb1", 0x064, BIT(20), 0); +/* Used for communication between firmware components at runtime */ static SUNXI_CCU_GATE(bus_msgbox_clk, "bus-msgbox", "ahb1", - 0x064, BIT(21), 0); + 0x064, BIT(21), CLK_IS_CRITICAL); static SUNXI_CCU_GATE(bus_spinlock_clk, "bus-spinlock", "ahb1", 0x064, BIT(22), 0); diff --git a/drivers/clk/sunxi-ng/ccu-sun50i-h6.c b/drivers/clk/sunxi-ng/ccu-sun50i-h6.c index 139e8389615c..02b10ba6f4ce 100644 --- a/drivers/clk/sunxi-ng/ccu-sun50i-h6.c +++ b/drivers/clk/sunxi-ng/ccu-sun50i-h6.c @@ -339,8 +339,9 @@ static SUNXI_CCU_GATE(bus_vp9_clk, "bus-vp9", "psi-ahb1-ahb2", static SUNXI_CCU_GATE(bus_dma_clk, "bus-dma", "psi-ahb1-ahb2", 0x70c, BIT(0), 0); +/* Used for communication between firmware components at runtime */ static SUNXI_CCU_GATE(bus_msgbox_clk, "bus-msgbox", "psi-ahb1-ahb2", - 0x71c, BIT(0), 0); + 0x71c, BIT(0), CLK_IS_CRITICAL); static SUNXI_CCU_GATE(bus_spinlock_clk, "bus-spinlock", "psi-ahb1-ahb2", 0x72c, BIT(0), 0); diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-a23.c b/drivers/clk/sunxi-ng/ccu-sun8i-a23.c index a4fa2945f230..d4eeef69de52 100644 --- a/drivers/clk/sunxi-ng/ccu-sun8i-a23.c +++ b/drivers/clk/sunxi-ng/ccu-sun8i-a23.c @@ -262,8 +262,9 @@ static SUNXI_CCU_GATE(bus_de_fe_clk, "bus-de-fe", "ahb1", 0x064, BIT(14), 0); static SUNXI_CCU_GATE(bus_gpu_clk, "bus-gpu", "ahb1", 0x064, BIT(20), 0); +/* Used for communication between firmware components at runtime */ static SUNXI_CCU_GATE(bus_msgbox_clk, "bus-msgbox", "ahb1", - 0x064, BIT(21), 0); + 0x064, BIT(21), CLK_IS_CRITICAL); static SUNXI_CCU_GATE(bus_spinlock_clk, "bus-spinlock", "ahb1", 0x064, BIT(22), 0); static SUNXI_CCU_GATE(bus_drc_clk, "bus-drc", "ahb1", diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-a33.c b/drivers/clk/sunxi-ng/ccu-sun8i-a33.c index c7bf814dfd2b..66d958ba86cc 100644 --- a/drivers/clk/sunxi-ng/ccu-sun8i-a33.c +++ b/drivers/clk/sunxi-ng/ccu-sun8i-a33.c @@ -274,8 +274,9 @@ static SUNXI_CCU_GATE(bus_de_fe_clk, "bus-de-fe", "ahb1", 0x064, BIT(14), 0); static SUNXI_CCU_GATE(bus_gpu_clk, "bus-gpu", "ahb1", 0x064, BIT(20), 0); +/* Used for communication between firmware components at runtime */ static SUNXI_CCU_GATE(bus_msgbox_clk, "bus-msgbox", "ahb1", - 0x064, BIT(21), 0); + 0x064, BIT(21), CLK_IS_CRITICAL); static SUNXI_CCU_GATE(bus_spinlock_clk, "bus-spinlock", "ahb1", 0x064, BIT(22), 0); static SUNXI_CCU_GATE(bus_drc_clk, "bus-drc", "ahb1", diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-a83t.c b/drivers/clk/sunxi-ng/ccu-sun8i-a83t.c index 2d6555d73170..24166609fd03 100644 --- a/drivers/clk/sunxi-ng/ccu-sun8i-a83t.c +++ b/drivers/clk/sunxi-ng/ccu-sun8i-a83t.c @@ -346,8 +346,9 @@ static SUNXI_CCU_GATE(bus_de_clk, "bus-de", "ahb1", 0x064, BIT(12), 0); static SUNXI_CCU_GATE(bus_gpu_clk, "bus-gpu", "ahb1", 0x064, BIT(20), 0); +/* Used for communication between firmware components at runtime */ static SUNXI_CCU_GATE(bus_msgbox_clk, "bus-msgbox", "ahb1", - 0x064, BIT(21), 0); + 0x064, BIT(21), CLK_IS_CRITICAL); static SUNXI_CCU_GATE(bus_spinlock_clk, "bus-spinlock", "ahb1", 0x064, BIT(22), 0); diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-h3.c b/drivers/clk/sunxi-ng/ccu-sun8i-h3.c index e71e2451c2e3..66777bff86e0 100644 --- a/drivers/clk/sunxi-ng/ccu-sun8i-h3.c +++ b/drivers/clk/sunxi-ng/ccu-sun8i-h3.c @@ -280,8 +280,9 @@ static SUNXI_CCU_GATE(bus_de_clk, "bus-de", "ahb1", 0x064, BIT(12), 0); static SUNXI_CCU_GATE(bus_gpu_clk, "bus-gpu", "ahb1", 0x064, BIT(20), 0); +/* Used for communication between firmware components at runtime */ static SUNXI_CCU_GATE(bus_msgbox_clk, "bus-msgbox", "ahb1", - 0x064, BIT(21), 0); + 0x064, BIT(21), CLK_IS_CRITICAL); static SUNXI_CCU_GATE(bus_spinlock_clk, "bus-spinlock", "ahb1", 0x064, BIT(22), 0); diff --git a/drivers/clk/sunxi-ng/ccu-sun9i-a80.c b/drivers/clk/sunxi-ng/ccu-sun9i-a80.c index 8936ef87652c..40b16cdcc98b 100644 --- a/drivers/clk/sunxi-ng/ccu-sun9i-a80.c +++ b/drivers/clk/sunxi-ng/ccu-sun9i-a80.c @@ -755,8 +755,9 @@ static SUNXI_CCU_GATE(bus_usb_clk, "bus-usb", "ahb1", 0x584, BIT(1), 0); static SUNXI_CCU_GATE(bus_gmac_clk, "bus-gmac", "ahb1", 0x584, BIT(17), 0); +/* Used for communication between firmware components at runtime */ static SUNXI_CCU_GATE(bus_msgbox_clk, "bus-msgbox", "ahb1", - 0x584, BIT(21), 0); + 0x584, BIT(21), CLK_IS_CRITICAL); static SUNXI_CCU_GATE(bus_spinlock_clk, "bus-spinlock", "ahb1", 0x584, BIT(22), 0); static SUNXI_CCU_GATE(bus_hstimer_clk, "bus-hstimer", "ahb1", -- 2.19.2
