The following commit has been merged into the timers/core branch of tip: Commit-ID: 4775bc63f880001ee4fbd6456b12ab04674149e3 Gitweb: https://git.kernel.org/tip/4775bc63f880001ee4fbd6456b12ab04674149e3 Author: Marc Zyngier <maz@xxxxxxxxxx> AuthorDate: Sun, 17 Oct 2021 13:42:09 +01:00 Committer: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> CommitterDate: Sun, 17 Oct 2021 21:45:48 +02:00 clocksource/arm_arch_timer: Add build-time guards for unhandled register accesses As we are about to change the registers that are used by the driver, start by adding build-time checks to ensure that we always handle all registers and access modes. Suggested-by: Mark Rutland <mark.rutland@xxxxxxx> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> Link: https://lore.kernel.org/r/20211017124225.3018098-2-maz@xxxxxxxxxx Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> --- arch/arm/include/asm/arch_timer.h | 12 ++++++++++++ arch/arm64/include/asm/arch_timer.h | 13 ++++++++++++- drivers/clocksource/arm_arch_timer.c | 8 ++++++++ 3 files changed, 32 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h index 9917581..a5d27cf 100644 --- a/arch/arm/include/asm/arch_timer.h +++ b/arch/arm/include/asm/arch_timer.h @@ -34,6 +34,8 @@ void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u32 val) case ARCH_TIMER_REG_TVAL: asm volatile("mcr p15, 0, %0, c14, c2, 0" : : "r" (val)); break; + default: + BUILD_BUG(); } } else if (access == ARCH_TIMER_VIRT_ACCESS) { switch (reg) { @@ -43,7 +45,11 @@ void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u32 val) case ARCH_TIMER_REG_TVAL: asm volatile("mcr p15, 0, %0, c14, c3, 0" : : "r" (val)); break; + default: + BUILD_BUG(); } + } else { + BUILD_BUG(); } isb(); @@ -62,6 +68,8 @@ u32 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg) case ARCH_TIMER_REG_TVAL: asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val)); break; + default: + BUILD_BUG(); } } else if (access == ARCH_TIMER_VIRT_ACCESS) { switch (reg) { @@ -71,7 +79,11 @@ u32 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg) case ARCH_TIMER_REG_TVAL: asm volatile("mrc p15, 0, %0, c14, c3, 0" : "=r" (val)); break; + default: + BUILD_BUG(); } + } else { + BUILD_BUG(); } return val; diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h index 88d20f0..fa12ea4 100644 --- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -112,6 +112,8 @@ void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u32 val) case ARCH_TIMER_REG_TVAL: write_sysreg(val, cntp_tval_el0); break; + default: + BUILD_BUG(); } } else if (access == ARCH_TIMER_VIRT_ACCESS) { switch (reg) { @@ -121,7 +123,11 @@ void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u32 val) case ARCH_TIMER_REG_TVAL: write_sysreg(val, cntv_tval_el0); break; + default: + BUILD_BUG(); } + } else { + BUILD_BUG(); } isb(); @@ -136,6 +142,8 @@ u32 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg) return read_sysreg(cntp_ctl_el0); case ARCH_TIMER_REG_TVAL: return arch_timer_reg_read_stable(cntp_tval_el0); + default: + BUILD_BUG(); } } else if (access == ARCH_TIMER_VIRT_ACCESS) { switch (reg) { @@ -143,10 +151,13 @@ u32 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg) return read_sysreg(cntv_ctl_el0); case ARCH_TIMER_REG_TVAL: return arch_timer_reg_read_stable(cntv_tval_el0); + default: + BUILD_BUG(); } } - BUG(); + BUILD_BUG(); + unreachable(); } static inline u32 arch_timer_get_cntfrq(void) diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index be6d741..3b7d46d 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -112,6 +112,8 @@ void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 val, case ARCH_TIMER_REG_TVAL: writel_relaxed(val, timer->base + CNTP_TVAL); break; + default: + BUILD_BUG(); } } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) { struct arch_timer *timer = to_arch_timer(clk); @@ -122,6 +124,8 @@ void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 val, case ARCH_TIMER_REG_TVAL: writel_relaxed(val, timer->base + CNTV_TVAL); break; + default: + BUILD_BUG(); } } else { arch_timer_reg_write_cp15(access, reg, val); @@ -143,6 +147,8 @@ u32 arch_timer_reg_read(int access, enum arch_timer_reg reg, case ARCH_TIMER_REG_TVAL: val = readl_relaxed(timer->base + CNTP_TVAL); break; + default: + BUILD_BUG(); } } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) { struct arch_timer *timer = to_arch_timer(clk); @@ -153,6 +159,8 @@ u32 arch_timer_reg_read(int access, enum arch_timer_reg reg, case ARCH_TIMER_REG_TVAL: val = readl_relaxed(timer->base + CNTV_TVAL); break; + default: + BUILD_BUG(); } } else { val = arch_timer_reg_read_cp15(access, reg);