Re: [PATCH] powerpc/legacy_serial: Use early_ioremap()
Hi Chris, Le 10/08/2020 à 04:01, Chris Packham a écrit : On 24/03/20 10:54 am, Chris Packham wrote: Hi Christophe, On Wed, 2020-02-05 at 12:03 +, Christophe Leroy wrote: [0.00] ioremap() called early from find_legacy_serial_ports+0x3cc/0x474. Use early_ioremap() instead I was just about to dig into this error message and found you patch. I applied it to a v5.5 base. find_legacy_serial_ports() is called early from setup_arch(), before paging_init(). vmalloc is not available yet, ioremap shouldn't be used that early. Use early_ioremap() and switch to a regular ioremap() later. Signed-off-by: Christophe Leroy On my system (Freescale T2080 SOC) this seems to cause a crash/hang in early boot. Unfortunately because this is affecting the boot console I don't get any earlyprintk output. I've been doing a bit more digging into why Christophe's patch didn't work for me. I noticed the powerpc specific early_ioremap_range() returns addresses around ioremap_bot. Yet the generic early_ioremap() uses addresses around FIXADDR_TOP. If I try the following hack I can make Christophe's patch work diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h index 2ef155a3c821..7bc2f3f73c8b 100644 --- a/arch/powerpc/include/asm/fixmap.h +++ b/arch/powerpc/include/asm/fixmap.h @@ -27,7 +27,7 @@ #include #define FIXADDR_TOP (KASAN_SHADOW_START - PAGE_SIZE) #else -#define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE)) +#define FIXADDR_TOP (IOREMAP_END - PAGE_SIZE) #endif /* I'll admit to being out of my depth. It seems that the generic early_ioremap() is not quite correctly plumbed in for powerpc. Yes that's probably true for PPC64. I see that on PPC32 I had to implement the following changes in order to enable earlier use of early_ioremap() https://github.com/torvalds/linux/commit/925ac141d106b55acbe112a9272f970631a3c082 I have the problem with QEMU with the ppce500 machine. It will allow me to investigate it a bit further.
Re: [PATCH] powerpc/legacy_serial: Use early_ioremap()
On 24/03/20 10:54 am, Chris Packham wrote:
> Hi Christophe,
>
> On Wed, 2020-02-05 at 12:03 +, Christophe Leroy wrote:
>> [0.00] ioremap() called early from
>> find_legacy_serial_ports+0x3cc/0x474. Use early_ioremap() instead
>>
> I was just about to dig into this error message and found you patch. I
> applied it to a v5.5 base.
>
>> find_legacy_serial_ports() is called early from setup_arch(), before
>> paging_init(). vmalloc is not available yet, ioremap shouldn't be
>> used that early.
>>
>> Use early_ioremap() and switch to a regular ioremap() later.
>>
>> Signed-off-by: Christophe Leroy
> On my system (Freescale T2080 SOC) this seems to cause a crash/hang in
> early boot. Unfortunately because this is affecting the boot console I
> don't get any earlyprintk output.
I've been doing a bit more digging into why Christophe's patch didn't
work for me. I noticed the powerpc specific early_ioremap_range()
returns addresses around ioremap_bot. Yet the generic early_ioremap()
uses addresses around FIXADDR_TOP. If I try the following hack I can
make Christophe's patch work
diff --git a/arch/powerpc/include/asm/fixmap.h
b/arch/powerpc/include/asm/fixmap.h
index 2ef155a3c821..7bc2f3f73c8b 100644
--- a/arch/powerpc/include/asm/fixmap.h
+++ b/arch/powerpc/include/asm/fixmap.h
@@ -27,7 +27,7 @@
#include
#define FIXADDR_TOP (KASAN_SHADOW_START - PAGE_SIZE)
#else
-#define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE))
+#define FIXADDR_TOP (IOREMAP_END - PAGE_SIZE)
#endif
/*
I'll admit to being out of my depth. It seems that the generic
early_ioremap() is not quite correctly plumbed in for powerpc.
>> ---
>> arch/powerpc/kernel/legacy_serial.c | 33 +
>>
>> 1 file changed, 29 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/legacy_serial.c
>> b/arch/powerpc/kernel/legacy_serial.c
>> index f061e06e9f51..8b2c1a8553a0 100644
>> --- a/arch/powerpc/kernel/legacy_serial.c
>> +++ b/arch/powerpc/kernel/legacy_serial.c
>> @@ -15,6 +15,7 @@
>> #include
>> #include
>> #include
>> +#include
>>
>> #undef DEBUG
>>
>> @@ -34,6 +35,7 @@ static struct legacy_serial_info {
>> unsigned intclock;
>> int irq_check_parent;
>> phys_addr_t taddr;
>> +void __iomem*early_addr;
>> } legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
>>
>> static const struct of_device_id legacy_serial_parents[] __initconst
>> = {
>> @@ -325,17 +327,16 @@ static void __init
>> setup_legacy_serial_console(int console)
>> {
>> struct legacy_serial_info *info =
>> _serial_infos[console];
>> struct plat_serial8250_port *port =
>> _serial_ports[console];
>> -void __iomem *addr;
>> unsigned int stride;
>>
>> stride = 1 << port->regshift;
>>
>> /* Check if a translated MMIO address has been found */
>> if (info->taddr) {
>> -addr = ioremap(info->taddr, 0x1000);
>> -if (addr == NULL)
>> +info->early_addr = early_ioremap(info->taddr, 0x1000);
>> +if (info->early_addr == NULL)
>> return;
>> -udbg_uart_init_mmio(addr, stride);
>> +udbg_uart_init_mmio(info->early_addr, stride);
>> } else {
>> /* Check if it's PIO and we support untranslated PIO */
>> if (port->iotype == UPIO_PORT && isa_io_special)
>> @@ -353,6 +354,30 @@ static void __init
>> setup_legacy_serial_console(int console)
>> udbg_uart_setup(info->speed, info->clock);
>> }
>>
>> +static int __init ioremap_legacy_serial_console(void)
>> +{
>> +struct legacy_serial_info *info =
>> _serial_infos[legacy_serial_console];
>> +struct plat_serial8250_port *port =
>> _serial_ports[legacy_serial_console];
>> +void __iomem *vaddr;
>> +
>> +if (legacy_serial_console < 0)
>> +return 0;
>> +
>> +if (!info->early_addr)
>> +return 0;
>> +
>> +vaddr = ioremap(info->taddr, 0x1000);
>> +if (WARN_ON(!vaddr))
>> +return -ENOMEM;
>> +
>> +udbg_uart_init_mmio(vaddr, 1 << port->regshift);
>> +early_iounmap(info->early_addr, 0x1000);
>> +info->early_addr = NULL;
>> +
>> +return 0;
>> +}
>> +early_initcall(ioremap_legacy_serial_console);
>> +
>> /*
>>* This is called very early, as part of setup_system() or
>> eventually
>>* setup_arch(), basically before anything else in this file. This
>> function
Re: [PATCH] powerpc/legacy_serial: Use early_ioremap()
Hi Christophe,
On Wed, 2020-02-05 at 12:03 +, Christophe Leroy wrote:
> [0.00] ioremap() called early from
> find_legacy_serial_ports+0x3cc/0x474. Use early_ioremap() instead
>
I was just about to dig into this error message and found you patch. I
applied it to a v5.5 base.
> find_legacy_serial_ports() is called early from setup_arch(), before
> paging_init(). vmalloc is not available yet, ioremap shouldn't be
> used that early.
>
> Use early_ioremap() and switch to a regular ioremap() later.
>
> Signed-off-by: Christophe Leroy
On my system (Freescale T2080 SOC) this seems to cause a crash/hang in
early boot. Unfortunately because this is affecting the boot console I
don't get any earlyprintk output.
> ---
> arch/powerpc/kernel/legacy_serial.c | 33 +
>
> 1 file changed, 29 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/kernel/legacy_serial.c
> b/arch/powerpc/kernel/legacy_serial.c
> index f061e06e9f51..8b2c1a8553a0 100644
> --- a/arch/powerpc/kernel/legacy_serial.c
> +++ b/arch/powerpc/kernel/legacy_serial.c
> @@ -15,6 +15,7 @@
> #include
> #include
> #include
> +#include
>
> #undef DEBUG
>
> @@ -34,6 +35,7 @@ static struct legacy_serial_info {
> unsigned intclock;
> int irq_check_parent;
> phys_addr_t taddr;
> + void __iomem*early_addr;
> } legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
>
> static const struct of_device_id legacy_serial_parents[] __initconst
> = {
> @@ -325,17 +327,16 @@ static void __init
> setup_legacy_serial_console(int console)
> {
> struct legacy_serial_info *info =
> _serial_infos[console];
> struct plat_serial8250_port *port =
> _serial_ports[console];
> - void __iomem *addr;
> unsigned int stride;
>
> stride = 1 << port->regshift;
>
> /* Check if a translated MMIO address has been found */
> if (info->taddr) {
> - addr = ioremap(info->taddr, 0x1000);
> - if (addr == NULL)
> + info->early_addr = early_ioremap(info->taddr, 0x1000);
> + if (info->early_addr == NULL)
> return;
> - udbg_uart_init_mmio(addr, stride);
> + udbg_uart_init_mmio(info->early_addr, stride);
> } else {
> /* Check if it's PIO and we support untranslated PIO */
> if (port->iotype == UPIO_PORT && isa_io_special)
> @@ -353,6 +354,30 @@ static void __init
> setup_legacy_serial_console(int console)
> udbg_uart_setup(info->speed, info->clock);
> }
>
> +static int __init ioremap_legacy_serial_console(void)
> +{
> + struct legacy_serial_info *info =
> _serial_infos[legacy_serial_console];
> + struct plat_serial8250_port *port =
> _serial_ports[legacy_serial_console];
> + void __iomem *vaddr;
> +
> + if (legacy_serial_console < 0)
> + return 0;
> +
> + if (!info->early_addr)
> + return 0;
> +
> + vaddr = ioremap(info->taddr, 0x1000);
> + if (WARN_ON(!vaddr))
> + return -ENOMEM;
> +
> + udbg_uart_init_mmio(vaddr, 1 << port->regshift);
> + early_iounmap(info->early_addr, 0x1000);
> + info->early_addr = NULL;
> +
> + return 0;
> +}
> +early_initcall(ioremap_legacy_serial_console);
> +
> /*
> * This is called very early, as part of setup_system() or
> eventually
> * setup_arch(), basically before anything else in this file. This
> function
[PATCH] powerpc/legacy_serial: Use early_ioremap()
[0.00] ioremap() called early from
find_legacy_serial_ports+0x3cc/0x474. Use early_ioremap() instead
find_legacy_serial_ports() is called early from setup_arch(), before
paging_init(). vmalloc is not available yet, ioremap shouldn't be
used that early.
Use early_ioremap() and switch to a regular ioremap() later.
Signed-off-by: Christophe Leroy
---
arch/powerpc/kernel/legacy_serial.c | 33 +
1 file changed, 29 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/legacy_serial.c
b/arch/powerpc/kernel/legacy_serial.c
index f061e06e9f51..8b2c1a8553a0 100644
--- a/arch/powerpc/kernel/legacy_serial.c
+++ b/arch/powerpc/kernel/legacy_serial.c
@@ -15,6 +15,7 @@
#include
#include
#include
+#include
#undef DEBUG
@@ -34,6 +35,7 @@ static struct legacy_serial_info {
unsigned intclock;
int irq_check_parent;
phys_addr_t taddr;
+ void __iomem*early_addr;
} legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
static const struct of_device_id legacy_serial_parents[] __initconst = {
@@ -325,17 +327,16 @@ static void __init setup_legacy_serial_console(int
console)
{
struct legacy_serial_info *info = _serial_infos[console];
struct plat_serial8250_port *port = _serial_ports[console];
- void __iomem *addr;
unsigned int stride;
stride = 1 << port->regshift;
/* Check if a translated MMIO address has been found */
if (info->taddr) {
- addr = ioremap(info->taddr, 0x1000);
- if (addr == NULL)
+ info->early_addr = early_ioremap(info->taddr, 0x1000);
+ if (info->early_addr == NULL)
return;
- udbg_uart_init_mmio(addr, stride);
+ udbg_uart_init_mmio(info->early_addr, stride);
} else {
/* Check if it's PIO and we support untranslated PIO */
if (port->iotype == UPIO_PORT && isa_io_special)
@@ -353,6 +354,30 @@ static void __init setup_legacy_serial_console(int console)
udbg_uart_setup(info->speed, info->clock);
}
+static int __init ioremap_legacy_serial_console(void)
+{
+ struct legacy_serial_info *info =
_serial_infos[legacy_serial_console];
+ struct plat_serial8250_port *port =
_serial_ports[legacy_serial_console];
+ void __iomem *vaddr;
+
+ if (legacy_serial_console < 0)
+ return 0;
+
+ if (!info->early_addr)
+ return 0;
+
+ vaddr = ioremap(info->taddr, 0x1000);
+ if (WARN_ON(!vaddr))
+ return -ENOMEM;
+
+ udbg_uart_init_mmio(vaddr, 1 << port->regshift);
+ early_iounmap(info->early_addr, 0x1000);
+ info->early_addr = NULL;
+
+ return 0;
+}
+early_initcall(ioremap_legacy_serial_console);
+
/*
* This is called very early, as part of setup_system() or eventually
* setup_arch(), basically before anything else in this file. This function
--
2.25.0
