| Message ID | 20220822231501.16827-1-pali@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v2] powerpc: Add support for early debugging via Serial 16550 console | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 10 jobs. |
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 10 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 23 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 6 jobs. |
Hello! Is something else needed for this v2 patch? On Tuesday 23 August 2022 01:15:01 Pali Rohár wrote: > Currently powerpc early debugging contains lot of platform specific > options, but does not support standard UART / serial 16550 console. > > Later legacy_serial.c code supports registering UART as early debug console > from device tree but it is not early during booting, but rather later after > machine description code finishes. > > So for real early debugging via UART is current code unsuitable. > > Add support for new early debugging option CONFIG_PPC_EARLY_DEBUG_16550 > which enable Serial 16550 console on address defined by new option > CONFIG_PPC_EARLY_DEBUG_16550_PHYSADDR and by stride by option > CONFIG_PPC_EARLY_DEBUG_16550_STRIDE. > > With this change it is possible to debug powerpc machine descriptor code. > For example this early debugging code can print on serial console also > "No suitable machine description found" error which is done before > legacy_serial.c code. > > Signed-off-by: Pali Rohár <pali@kernel.org> > --- > Changes in v2: > * Move PPC_EARLY_DEBUG_16550 after PPC_EARLY_DEBUG_MEMCONS, so memcons stay default > * Add missing dependency on PPC_UDBG_16550 > --- > Tested on P2020 board. It allowed me do debug and implement this patch series: > https://lore.kernel.org/linuxppc-dev/20220819191557.28116-1-pali@kernel.org/ > --- > arch/powerpc/Kconfig.debug | 15 +++++++++++++++ > arch/powerpc/include/asm/udbg.h | 1 + > arch/powerpc/kernel/udbg.c | 2 ++ > arch/powerpc/kernel/udbg_16550.c | 33 ++++++++++++++++++++++++++++++++ > 4 files changed, 51 insertions(+) > > diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug > index 9f363c143d86..ad7238d28fa9 100644 > --- a/arch/powerpc/Kconfig.debug > +++ b/arch/powerpc/Kconfig.debug > @@ -283,6 +283,12 @@ config PPC_EARLY_DEBUG_MEMCONS > This console provides input and output buffers stored within the > kernel BSS and should be safe to select on any system. A debugger > can then be used to read kernel output or send input to the console. > + > +config PPC_EARLY_DEBUG_16550 > + bool "Serial 16550" > + depends on PPC_UDBG_16550 > + help > + Select this to enable early debugging via Serial 16550 console > endchoice > > config PPC_MEMCONS_OUTPUT_SIZE > @@ -355,6 +361,15 @@ config PPC_EARLY_DEBUG_CPM_ADDR > platform probing is done, all platforms selected must > share the same address. > > +config PPC_EARLY_DEBUG_16550_PHYSADDR > + hex "Early debug Serial 16550 physical address" > + depends on PPC_EARLY_DEBUG_16550 > + > +config PPC_EARLY_DEBUG_16550_STRIDE > + int "Early debug Serial 16550 stride" > + depends on PPC_EARLY_DEBUG_16550 > + default 1 > + > config FAIL_IOMMU > bool "Fault-injection capability for IOMMU" > depends on FAULT_INJECTION > diff --git a/arch/powerpc/include/asm/udbg.h b/arch/powerpc/include/asm/udbg.h > index b4aa0d88ce2c..20b5a37ab772 100644 > --- a/arch/powerpc/include/asm/udbg.h > +++ b/arch/powerpc/include/asm/udbg.h > @@ -53,6 +53,7 @@ extern void __init udbg_init_ehv_bc(void); > extern void __init udbg_init_ps3gelic(void); > extern void __init udbg_init_debug_opal_raw(void); > extern void __init udbg_init_debug_opal_hvsi(void); > +extern void __init udbg_init_debug_16550(void); > > #endif /* __KERNEL__ */ > #endif /* _ASM_POWERPC_UDBG_H */ > diff --git a/arch/powerpc/kernel/udbg.c b/arch/powerpc/kernel/udbg.c > index b1544b2f6321..92b3fc258d11 100644 > --- a/arch/powerpc/kernel/udbg.c > +++ b/arch/powerpc/kernel/udbg.c > @@ -67,6 +67,8 @@ void __init udbg_early_init(void) > udbg_init_debug_opal_raw(); > #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI) > udbg_init_debug_opal_hvsi(); > +#elif defined(CONFIG_PPC_EARLY_DEBUG_16550) > + udbg_init_debug_16550(); > #endif > > #ifdef CONFIG_PPC_EARLY_DEBUG > diff --git a/arch/powerpc/kernel/udbg_16550.c b/arch/powerpc/kernel/udbg_16550.c > index d3942de254c6..46f2d831d7c9 100644 > --- a/arch/powerpc/kernel/udbg_16550.c > +++ b/arch/powerpc/kernel/udbg_16550.c > @@ -8,6 +8,7 @@ > #include <asm/udbg.h> > #include <asm/io.h> > #include <asm/reg_a2.h> > +#include <asm/early_ioremap.h> > > extern u8 real_readb(volatile u8 __iomem *addr); > extern void real_writeb(u8 data, volatile u8 __iomem *addr); > @@ -335,3 +336,35 @@ void __init udbg_init_debug_microwatt(void) > } > > #endif /* CONFIG_PPC_EARLY_DEBUG_MICROWATT */ > + > +#ifdef CONFIG_PPC_EARLY_DEBUG_16550 > + > +static void __iomem *udbg_uart_early_addr; > + > +void __init udbg_init_debug_16550(void) > +{ > + udbg_uart_early_addr = early_ioremap(CONFIG_PPC_EARLY_DEBUG_16550_PHYSADDR, 0x1000); > + udbg_uart_init_mmio(udbg_uart_early_addr, CONFIG_PPC_EARLY_DEBUG_16550_STRIDE); > +} > + > +static int __init udbg_init_debug_16550_ioremap(void) > +{ > + void __iomem *addr; > + > + if (!udbg_uart_early_addr) > + return 0; > + > + addr = ioremap(CONFIG_PPC_EARLY_DEBUG_16550_PHYSADDR, 0x1000); > + if (WARN_ON(!addr)) > + return -ENOMEM; > + > + udbg_uart_init_mmio(addr, CONFIG_PPC_EARLY_DEBUG_16550_STRIDE); > + early_iounmap(udbg_uart_early_addr, 0x1000); > + udbg_uart_early_addr = NULL; > + > + return 0; > +} > + > +early_initcall(udbg_init_debug_16550_ioremap); > + > +#endif /* CONFIG_PPC_EARLY_DEBUG_16550 */ > -- > 2.20.1 >
On Tue, 23 Aug 2022 01:15:01 +0200, Pali Rohár wrote: > Currently powerpc early debugging contains lot of platform specific > options, but does not support standard UART / serial 16550 console. > > Later legacy_serial.c code supports registering UART as early debug console > from device tree but it is not early during booting, but rather later after > machine description code finishes. > > [...] Applied to powerpc/next. [1/1] powerpc: Add support for early debugging via Serial 16550 console https://git.kernel.org/powerpc/c/b19448fe846baad689ff51a991ebfc74b4b5e0a8 cheers
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug index 9f363c143d86..ad7238d28fa9 100644 --- a/arch/powerpc/Kconfig.debug +++ b/arch/powerpc/Kconfig.debug @@ -283,6 +283,12 @@ config PPC_EARLY_DEBUG_MEMCONS This console provides input and output buffers stored within the kernel BSS and should be safe to select on any system. A debugger can then be used to read kernel output or send input to the console. + +config PPC_EARLY_DEBUG_16550 + bool "Serial 16550" + depends on PPC_UDBG_16550 + help + Select this to enable early debugging via Serial 16550 console endchoice config PPC_MEMCONS_OUTPUT_SIZE @@ -355,6 +361,15 @@ config PPC_EARLY_DEBUG_CPM_ADDR platform probing is done, all platforms selected must share the same address. +config PPC_EARLY_DEBUG_16550_PHYSADDR + hex "Early debug Serial 16550 physical address" + depends on PPC_EARLY_DEBUG_16550 + +config PPC_EARLY_DEBUG_16550_STRIDE + int "Early debug Serial 16550 stride" + depends on PPC_EARLY_DEBUG_16550 + default 1 + config FAIL_IOMMU bool "Fault-injection capability for IOMMU" depends on FAULT_INJECTION diff --git a/arch/powerpc/include/asm/udbg.h b/arch/powerpc/include/asm/udbg.h index b4aa0d88ce2c..20b5a37ab772 100644 --- a/arch/powerpc/include/asm/udbg.h +++ b/arch/powerpc/include/asm/udbg.h @@ -53,6 +53,7 @@ extern void __init udbg_init_ehv_bc(void); extern void __init udbg_init_ps3gelic(void); extern void __init udbg_init_debug_opal_raw(void); extern void __init udbg_init_debug_opal_hvsi(void); +extern void __init udbg_init_debug_16550(void); #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_UDBG_H */ diff --git a/arch/powerpc/kernel/udbg.c b/arch/powerpc/kernel/udbg.c index b1544b2f6321..92b3fc258d11 100644 --- a/arch/powerpc/kernel/udbg.c +++ b/arch/powerpc/kernel/udbg.c @@ -67,6 +67,8 @@ void __init udbg_early_init(void) udbg_init_debug_opal_raw(); #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI) udbg_init_debug_opal_hvsi(); +#elif defined(CONFIG_PPC_EARLY_DEBUG_16550) + udbg_init_debug_16550(); #endif #ifdef CONFIG_PPC_EARLY_DEBUG diff --git a/arch/powerpc/kernel/udbg_16550.c b/arch/powerpc/kernel/udbg_16550.c index d3942de254c6..46f2d831d7c9 100644 --- a/arch/powerpc/kernel/udbg_16550.c +++ b/arch/powerpc/kernel/udbg_16550.c @@ -8,6 +8,7 @@ #include <asm/udbg.h> #include <asm/io.h> #include <asm/reg_a2.h> +#include <asm/early_ioremap.h> extern u8 real_readb(volatile u8 __iomem *addr); extern void real_writeb(u8 data, volatile u8 __iomem *addr); @@ -335,3 +336,35 @@ void __init udbg_init_debug_microwatt(void) } #endif /* CONFIG_PPC_EARLY_DEBUG_MICROWATT */ + +#ifdef CONFIG_PPC_EARLY_DEBUG_16550 + +static void __iomem *udbg_uart_early_addr; + +void __init udbg_init_debug_16550(void) +{ + udbg_uart_early_addr = early_ioremap(CONFIG_PPC_EARLY_DEBUG_16550_PHYSADDR, 0x1000); + udbg_uart_init_mmio(udbg_uart_early_addr, CONFIG_PPC_EARLY_DEBUG_16550_STRIDE); +} + +static int __init udbg_init_debug_16550_ioremap(void) +{ + void __iomem *addr; + + if (!udbg_uart_early_addr) + return 0; + + addr = ioremap(CONFIG_PPC_EARLY_DEBUG_16550_PHYSADDR, 0x1000); + if (WARN_ON(!addr)) + return -ENOMEM; + + udbg_uart_init_mmio(addr, CONFIG_PPC_EARLY_DEBUG_16550_STRIDE); + early_iounmap(udbg_uart_early_addr, 0x1000); + udbg_uart_early_addr = NULL; + + return 0; +} + +early_initcall(udbg_init_debug_16550_ioremap); + +#endif /* CONFIG_PPC_EARLY_DEBUG_16550 */
Currently powerpc early debugging contains lot of platform specific options, but does not support standard UART / serial 16550 console. Later legacy_serial.c code supports registering UART as early debug console from device tree but it is not early during booting, but rather later after machine description code finishes. So for real early debugging via UART is current code unsuitable. Add support for new early debugging option CONFIG_PPC_EARLY_DEBUG_16550 which enable Serial 16550 console on address defined by new option CONFIG_PPC_EARLY_DEBUG_16550_PHYSADDR and by stride by option CONFIG_PPC_EARLY_DEBUG_16550_STRIDE. With this change it is possible to debug powerpc machine descriptor code. For example this early debugging code can print on serial console also "No suitable machine description found" error which is done before legacy_serial.c code. Signed-off-by: Pali Rohár <pali@kernel.org> --- Changes in v2: * Move PPC_EARLY_DEBUG_16550 after PPC_EARLY_DEBUG_MEMCONS, so memcons stay default * Add missing dependency on PPC_UDBG_16550 --- Tested on P2020 board. It allowed me do debug and implement this patch series: https://lore.kernel.org/linuxppc-dev/20220819191557.28116-1-pali@kernel.org/ --- arch/powerpc/Kconfig.debug | 15 +++++++++++++++ arch/powerpc/include/asm/udbg.h | 1 + arch/powerpc/kernel/udbg.c | 2 ++ arch/powerpc/kernel/udbg_16550.c | 33 ++++++++++++++++++++++++++++++++ 4 files changed, 51 insertions(+)