在2022年1月15日一月 下午7:32，Laurent Vivier写道： > The goldfish device always uses the same endianness as the architecture > using it: > https://android.googlesource.com/platform/external/qemu/+/refs/heads/emu-master-dev/hw/timer/goldfish_timer.c#177 > > On a big-endian machine, the device is also big-endian, on a > little-endian machine the device is little-endian. > > So we need to use the right accessor to read/write values to the goldfish > registers: ioread32()/iowrite32() on a little-endian machine, > ioread32be()/iowrite32be() on a big-endian machine. > > This patch introduces goldfish_ioread32()/goldfish_iowrite32() that uses > the expected accessor according to the machine endianness. > > Signed-off-by: Laurent Vivier <laurent@xxxxxxxxx> Acked-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> > --- > drivers/rtc/rtc-goldfish.c | 39 +++++++++++++++++++++++--------------- > 1 file changed, 24 insertions(+), 15 deletions(-) > > diff --git a/drivers/rtc/rtc-goldfish.c b/drivers/rtc/rtc-goldfish.c > index 7ab95d052644..b0cae4729b03 100644 > --- a/drivers/rtc/rtc-goldfish.c > +++ b/drivers/rtc/rtc-goldfish.c > @@ -23,6 +23,15 @@ > #define TIMER_ALARM_STATUS 0x18 > #define TIMER_CLEAR_INTERRUPT 0x1c > > +/* goldfish endianness depends on CPU endianness */ > +#ifdef CONFIG_CPU_BIG_ENDIAN > +#define goldfish_ioread32 ioread32be > +#define goldfish_iowrite32 iowrite32be > +#else > +#define goldfish_ioread32 ioread32 > +#define goldfish_iowrite32 iowrite32 > +#endif > + > struct goldfish_rtc { > void __iomem *base; > int irq; > @@ -41,8 +50,8 @@ static int goldfish_rtc_read_alarm(struct device *dev, > rtcdrv = dev_get_drvdata(dev); > base = rtcdrv->base; > > - rtc_alarm_low = readl(base + TIMER_ALARM_LOW); > - rtc_alarm_high = readl(base + TIMER_ALARM_HIGH); > + rtc_alarm_low = goldfish_ioread32(base + TIMER_ALARM_LOW); > + rtc_alarm_high = goldfish_ioread32(base + TIMER_ALARM_HIGH); > rtc_alarm = (rtc_alarm_high << 32) | rtc_alarm_low; > > do_div(rtc_alarm, NSEC_PER_SEC); > @@ -50,7 +59,7 @@ static int goldfish_rtc_read_alarm(struct device *dev, > > rtc_time64_to_tm(rtc_alarm, &alrm->time); > > - if (readl(base + TIMER_ALARM_STATUS)) > + if (goldfish_ioread32(base + TIMER_ALARM_STATUS)) > alrm->enabled = 1; > else > alrm->enabled = 0; > @@ -71,18 +80,18 @@ static int goldfish_rtc_set_alarm(struct device *dev, > > if (alrm->enabled) { > rtc_alarm64 = rtc_tm_to_time64(&alrm->time) * NSEC_PER_SEC; > - writel((rtc_alarm64 >> 32), base + TIMER_ALARM_HIGH); > - writel(rtc_alarm64, base + TIMER_ALARM_LOW); > - writel(1, base + TIMER_IRQ_ENABLED); > + goldfish_iowrite32((rtc_alarm64 >> 32), base + TIMER_ALARM_HIGH); > + goldfish_iowrite32(rtc_alarm64, base + TIMER_ALARM_LOW); > + goldfish_iowrite32(1, base + TIMER_IRQ_ENABLED); > } else { > /* > * if this function was called with enabled=0 > * then it could mean that the application is > * trying to cancel an ongoing alarm > */ > - rtc_status_reg = readl(base + TIMER_ALARM_STATUS); > + rtc_status_reg = goldfish_ioread32(base + TIMER_ALARM_STATUS); > if (rtc_status_reg) > - writel(1, base + TIMER_CLEAR_ALARM); > + goldfish_iowrite32(1, base + TIMER_CLEAR_ALARM); > } > > return 0; > @@ -98,9 +107,9 @@ static int goldfish_rtc_alarm_irq_enable(struct device *dev, > base = rtcdrv->base; > > if (enabled) > - writel(1, base + TIMER_IRQ_ENABLED); > + goldfish_iowrite32(1, base + TIMER_IRQ_ENABLED); > else > - writel(0, base + TIMER_IRQ_ENABLED); > + goldfish_iowrite32(0, base + TIMER_IRQ_ENABLED); > > return 0; > } > @@ -110,7 +119,7 @@ static irqreturn_t goldfish_rtc_interrupt(int irq, > void *dev_id) > struct goldfish_rtc *rtcdrv = dev_id; > void __iomem *base = rtcdrv->base; > > - writel(1, base + TIMER_CLEAR_INTERRUPT); > + goldfish_iowrite32(1, base + TIMER_CLEAR_INTERRUPT); > > rtc_update_irq(rtcdrv->rtc, 1, RTC_IRQF | RTC_AF); > > @@ -128,8 +137,8 @@ static int goldfish_rtc_read_time(struct device > *dev, struct rtc_time *tm) > rtcdrv = dev_get_drvdata(dev); > base = rtcdrv->base; > > - time_low = readl(base + TIMER_TIME_LOW); > - time_high = readl(base + TIMER_TIME_HIGH); > + time_low = goldfish_ioread32(base + TIMER_TIME_LOW); > + time_high = goldfish_ioread32(base + TIMER_TIME_HIGH); > time = (time_high << 32) | time_low; > > do_div(time, NSEC_PER_SEC); > @@ -149,8 +158,8 @@ static int goldfish_rtc_set_time(struct device > *dev, struct rtc_time *tm) > base = rtcdrv->base; > > now64 = rtc_tm_to_time64(tm) * NSEC_PER_SEC; > - writel((now64 >> 32), base + TIMER_TIME_HIGH); > - writel(now64, base + TIMER_TIME_LOW); > + goldfish_iowrite32((now64 >> 32), base + TIMER_TIME_HIGH); > + goldfish_iowrite32(now64, base + TIMER_TIME_LOW); > > return 0; > } > -- > 2.34.1 -- - Jiaxun
