| Message ID | 20220202153525.1693378-4-terry.bowman@amd.com |
|---|---|
| State | New |
| Headers | show |
| Series | Watchdog: sp5100_tco: Replace cd6h/cd7h port I/O accesses with MMIO accesses | expand |
On Wed, Feb 02, 2022 at 09:35:24AM -0600, Terry Bowman wrote: > cd6h/cd7h port I/O can be disabled on recent AMD hardware. Read > accesses to disabled cd6h/cd7h port I/O will return F's and written > data is dropped. It is recommended to replace the cd6h/cd7h > port I/O with MMIO. > > Co-developed-by: Robert Richter <rrichter@amd.com> > Signed-off-by: Robert Richter <rrichter@amd.com> > Signed-off-by: Terry Bowman <terry.bowman@amd.com> > Tested-by: Jean Delvare <jdelvare@suse.de> > Reviewed-by: Jean Delvare <jdelvare@suse.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > drivers/watchdog/sp5100_tco.c | 100 +++++++++++++++++++++++++++++++++- > drivers/watchdog/sp5100_tco.h | 5 ++ > 2 files changed, 104 insertions(+), 1 deletion(-) > > diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c > index 8db7504f0aa4..e02399ea8730 100644 > --- a/drivers/watchdog/sp5100_tco.c > +++ b/drivers/watchdog/sp5100_tco.c > @@ -49,7 +49,7 @@ > /* internal variables */ > > enum tco_reg_layout { > - sp5100, sb800, efch > + sp5100, sb800, efch, efch_mmio > }; > > struct sp5100_tco { > @@ -209,6 +209,8 @@ static void tco_timer_enable(struct sp5100_tco *tco) > ~EFCH_PM_WATCHDOG_DISABLE, > EFCH_PM_DECODEEN_SECOND_RES); > break; > + default: > + break; > } > } > > @@ -307,6 +309,99 @@ static int sp5100_tco_timer_init(struct sp5100_tco *tco) > return 0; > } > > +static u8 efch_read_pm_reg8(void __iomem *addr, u8 index) > +{ > + return readb(addr + index); > +} > + > +static void efch_update_pm_reg8(void __iomem *addr, u8 index, u8 reset, u8 set) > +{ > + u8 val; > + > + val = readb(addr + index); > + val &= reset; > + val |= set; > + writeb(val, addr + index); > +} > + > +static void tco_timer_enable_mmio(void __iomem *addr) > +{ > + efch_update_pm_reg8(addr, EFCH_PM_DECODEEN3, > + ~EFCH_PM_WATCHDOG_DISABLE, > + EFCH_PM_DECODEEN_SECOND_RES); > +} > + > +static int sp5100_tco_setupdevice_mmio(struct device *dev, > + struct watchdog_device *wdd) > +{ > + struct sp5100_tco *tco = watchdog_get_drvdata(wdd); > + const char *dev_name = SB800_DEVNAME; > + u32 mmio_addr = 0, alt_mmio_addr = 0; > + struct resource *res; > + void __iomem *addr; > + int ret; > + u32 val; > + > + res = request_mem_region_muxed(EFCH_PM_ACPI_MMIO_PM_ADDR, > + EFCH_PM_ACPI_MMIO_PM_SIZE, > + "sp5100_tco"); > + > + if (!res) { > + dev_err(dev, > + "Memory region 0x%08x already in use\n", > + EFCH_PM_ACPI_MMIO_PM_ADDR); > + return -EBUSY; > + } > + > + addr = ioremap(EFCH_PM_ACPI_MMIO_PM_ADDR, EFCH_PM_ACPI_MMIO_PM_SIZE); > + if (!addr) { > + dev_err(dev, "Address mapping failed\n"); > + ret = -ENOMEM; > + goto out; > + } > + > + /* > + * EFCH_PM_DECODEEN_WDT_TMREN is dual purpose. This bitfield > + * enables sp5100_tco register MMIO space decoding. The bitfield > + * also starts the timer operation. Enable if not already enabled. > + */ > + val = efch_read_pm_reg8(addr, EFCH_PM_DECODEEN); > + if (!(val & EFCH_PM_DECODEEN_WDT_TMREN)) { > + efch_update_pm_reg8(addr, EFCH_PM_DECODEEN, 0xff, > + EFCH_PM_DECODEEN_WDT_TMREN); > + } > + > + /* Error if the timer could not be enabled */ > + val = efch_read_pm_reg8(addr, EFCH_PM_DECODEEN); > + if (!(val & EFCH_PM_DECODEEN_WDT_TMREN)) { > + dev_err(dev, "Failed to enable the timer\n"); > + ret = -EFAULT; > + goto out; > + } > + > + mmio_addr = EFCH_PM_WDT_ADDR; > + > + /* Determine alternate MMIO base address */ > + val = efch_read_pm_reg8(addr, EFCH_PM_ISACONTROL); > + if (val & EFCH_PM_ISACONTROL_MMIOEN) > + alt_mmio_addr = EFCH_PM_ACPI_MMIO_ADDR + > + EFCH_PM_ACPI_MMIO_WDT_OFFSET; > + > + ret = sp5100_tco_prepare_base(tco, mmio_addr, alt_mmio_addr, dev_name); > + if (!ret) { > + tco_timer_enable_mmio(addr); > + ret = sp5100_tco_timer_init(tco); > + } > + > +out: > + if (addr) > + iounmap(addr); > + > + release_resource(res); > + > + return ret; > +} > + > static int sp5100_tco_setupdevice(struct device *dev, > struct watchdog_device *wdd) > { > @@ -316,6 +411,9 @@ static int sp5100_tco_setupdevice(struct device *dev, > u32 alt_mmio_addr = 0; > int ret; > > + if (tco->tco_reg_layout == efch_mmio) > + return sp5100_tco_setupdevice_mmio(dev, wdd); > + > /* Request the IO ports used by this driver */ > if (!request_muxed_region(SP5100_IO_PM_INDEX_REG, > SP5100_PM_IOPORTS_SIZE, "sp5100_tco")) { > diff --git a/drivers/watchdog/sp5100_tco.h b/drivers/watchdog/sp5100_tco.h > index daee872f9b71..8ca1b215e3ce 100644 > --- a/drivers/watchdog/sp5100_tco.h > +++ b/drivers/watchdog/sp5100_tco.h > @@ -83,4 +83,9 @@ > #define EFCH_PM_ISACONTROL_MMIOEN BIT(1) > > #define EFCH_PM_ACPI_MMIO_ADDR 0xfed80000 > +#define EFCH_PM_ACPI_MMIO_PM_OFFSET 0x00000300 > #define EFCH_PM_ACPI_MMIO_WDT_OFFSET 0x00000b00 > + > +#define EFCH_PM_ACPI_MMIO_PM_ADDR (EFCH_PM_ACPI_MMIO_ADDR + \ > + EFCH_PM_ACPI_MMIO_PM_OFFSET) > +#define EFCH_PM_ACPI_MMIO_PM_SIZE 8 > -- > 2.30.2 >
diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c index 8db7504f0aa4..e02399ea8730 100644 --- a/drivers/watchdog/sp5100_tco.c +++ b/drivers/watchdog/sp5100_tco.c @@ -49,7 +49,7 @@ /* internal variables */ enum tco_reg_layout { - sp5100, sb800, efch + sp5100, sb800, efch, efch_mmio }; struct sp5100_tco { @@ -209,6 +209,8 @@ static void tco_timer_enable(struct sp5100_tco *tco) ~EFCH_PM_WATCHDOG_DISABLE, EFCH_PM_DECODEEN_SECOND_RES); break; + default: + break; } } @@ -307,6 +309,99 @@ static int sp5100_tco_timer_init(struct sp5100_tco *tco) return 0; } +static u8 efch_read_pm_reg8(void __iomem *addr, u8 index) +{ + return readb(addr + index); +} + +static void efch_update_pm_reg8(void __iomem *addr, u8 index, u8 reset, u8 set) +{ + u8 val; + + val = readb(addr + index); + val &= reset; + val |= set; + writeb(val, addr + index); +} + +static void tco_timer_enable_mmio(void __iomem *addr) +{ + efch_update_pm_reg8(addr, EFCH_PM_DECODEEN3, + ~EFCH_PM_WATCHDOG_DISABLE, + EFCH_PM_DECODEEN_SECOND_RES); +} + +static int sp5100_tco_setupdevice_mmio(struct device *dev, + struct watchdog_device *wdd) +{ + struct sp5100_tco *tco = watchdog_get_drvdata(wdd); + const char *dev_name = SB800_DEVNAME; + u32 mmio_addr = 0, alt_mmio_addr = 0; + struct resource *res; + void __iomem *addr; + int ret; + u32 val; + + res = request_mem_region_muxed(EFCH_PM_ACPI_MMIO_PM_ADDR, + EFCH_PM_ACPI_MMIO_PM_SIZE, + "sp5100_tco"); + + if (!res) { + dev_err(dev, + "Memory region 0x%08x already in use\n", + EFCH_PM_ACPI_MMIO_PM_ADDR); + return -EBUSY; + } + + addr = ioremap(EFCH_PM_ACPI_MMIO_PM_ADDR, EFCH_PM_ACPI_MMIO_PM_SIZE); + if (!addr) { + dev_err(dev, "Address mapping failed\n"); + ret = -ENOMEM; + goto out; + } + + /* + * EFCH_PM_DECODEEN_WDT_TMREN is dual purpose. This bitfield + * enables sp5100_tco register MMIO space decoding. The bitfield + * also starts the timer operation. Enable if not already enabled. + */ + val = efch_read_pm_reg8(addr, EFCH_PM_DECODEEN); + if (!(val & EFCH_PM_DECODEEN_WDT_TMREN)) { + efch_update_pm_reg8(addr, EFCH_PM_DECODEEN, 0xff, + EFCH_PM_DECODEEN_WDT_TMREN); + } + + /* Error if the timer could not be enabled */ + val = efch_read_pm_reg8(addr, EFCH_PM_DECODEEN); + if (!(val & EFCH_PM_DECODEEN_WDT_TMREN)) { + dev_err(dev, "Failed to enable the timer\n"); + ret = -EFAULT; + goto out; + } + + mmio_addr = EFCH_PM_WDT_ADDR; + + /* Determine alternate MMIO base address */ + val = efch_read_pm_reg8(addr, EFCH_PM_ISACONTROL); + if (val & EFCH_PM_ISACONTROL_MMIOEN) + alt_mmio_addr = EFCH_PM_ACPI_MMIO_ADDR + + EFCH_PM_ACPI_MMIO_WDT_OFFSET; + + ret = sp5100_tco_prepare_base(tco, mmio_addr, alt_mmio_addr, dev_name); + if (!ret) { + tco_timer_enable_mmio(addr); + ret = sp5100_tco_timer_init(tco); + } + +out: + if (addr) + iounmap(addr); + + release_resource(res); + + return ret; +} + static int sp5100_tco_setupdevice(struct device *dev, struct watchdog_device *wdd) { @@ -316,6 +411,9 @@ static int sp5100_tco_setupdevice(struct device *dev, u32 alt_mmio_addr = 0; int ret; + if (tco->tco_reg_layout == efch_mmio) + return sp5100_tco_setupdevice_mmio(dev, wdd); + /* Request the IO ports used by this driver */ if (!request_muxed_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE, "sp5100_tco")) { diff --git a/drivers/watchdog/sp5100_tco.h b/drivers/watchdog/sp5100_tco.h index daee872f9b71..8ca1b215e3ce 100644 --- a/drivers/watchdog/sp5100_tco.h +++ b/drivers/watchdog/sp5100_tco.h @@ -83,4 +83,9 @@ #define EFCH_PM_ISACONTROL_MMIOEN BIT(1) #define EFCH_PM_ACPI_MMIO_ADDR 0xfed80000 +#define EFCH_PM_ACPI_MMIO_PM_OFFSET 0x00000300 #define EFCH_PM_ACPI_MMIO_WDT_OFFSET 0x00000b00 + +#define EFCH_PM_ACPI_MMIO_PM_ADDR (EFCH_PM_ACPI_MMIO_ADDR + \ + EFCH_PM_ACPI_MMIO_PM_OFFSET) +#define EFCH_PM_ACPI_MMIO_PM_SIZE 8