* [PATCH] earlyprintk: Clean up pciserial
@ 2022-08-25 11:36 Peter Zijlstra
2022-08-25 11:48 ` Greg KH
` (2 more replies)
0 siblings, 3 replies; 7+ messages in thread
From: Peter Zijlstra @ 2022-08-25 11:36 UTC (permalink / raw)
To: x86; +Cc: linux-kernel, bhelgaas, gregkh
While working on a GRUB patch to support PCI-serial, a number of
cleanups were suggested that apply to the code I took inspiration from.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/kernel/early_printk.c | 14 +++++++-------
include/linux/pci_ids.h | 3 +++
2 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index 68b38925a74f..44f937015e1e 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -264,11 +264,11 @@ static __init void early_pci_serial_init(char *s)
bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
/*
- * Verify it is a UART type device
+ * Verify it is a 16550-UART type device
*/
if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
(classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
- (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ {
+ (((classcode >> 8) & 0xff) != PCI_SERIAL_16550_COMPATIBLE)) {
if (!force)
return;
}
@@ -276,22 +276,22 @@ static __init void early_pci_serial_init(char *s)
/*
* Determine if it is IO or memory mapped
*/
- if (bar0 & 0x01) {
+ if ((bar0 & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
/* it is IO mapped */
serial_in = io_serial_in;
serial_out = io_serial_out;
- early_serial_base = bar0&0xfffffffc;
+ early_serial_base = bar0 & PCI_BASE_ADDRESS_IO_MASK;
write_pci_config(bus, slot, func, PCI_COMMAND,
- cmdreg|PCI_COMMAND_IO);
+ cmdreg|PCI_COMMAND_IO);
} else {
/* It is memory mapped - assume 32-bit alignment */
serial_in = mem32_serial_in;
serial_out = mem32_serial_out;
/* WARNING! assuming the address is always in the first 4G */
early_serial_base =
- (unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
+ (unsigned long)early_ioremap(bar0 & PCI_BASE_ADDRESS_MEM_MASK, 0x10);
write_pci_config(bus, slot, func, PCI_COMMAND,
- cmdreg|PCI_COMMAND_MEMORY);
+ cmdreg|PCI_COMMAND_MEMORY);
}
/*
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 6feade66efdb..1d2c7df8cd41 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -75,6 +75,9 @@
#define PCI_CLASS_COMMUNICATION_MODEM 0x0703
#define PCI_CLASS_COMMUNICATION_OTHER 0x0780
+/* I/F for SERIAL/MODEM */
+#define PCI_SERIAL_16550_COMPATIBLE 0x02
+
#define PCI_BASE_CLASS_SYSTEM 0x08
#define PCI_CLASS_SYSTEM_PIC 0x0800
#define PCI_CLASS_SYSTEM_PIC_IOAPIC 0x080010
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] earlyprintk: Clean up pciserial
2022-08-25 11:36 [PATCH] earlyprintk: Clean up pciserial Peter Zijlstra
@ 2022-08-25 11:48 ` Greg KH
2022-08-25 17:39 ` Bjorn Helgaas
2022-08-29 10:52 ` [tip: x86/core] x86/earlyprintk: " tip-bot2 for Peter Zijlstra
2 siblings, 0 replies; 7+ messages in thread
From: Greg KH @ 2022-08-25 11:48 UTC (permalink / raw)
To: Peter Zijlstra; +Cc: x86, linux-kernel, bhelgaas
On Thu, Aug 25, 2022 at 01:36:40PM +0200, Peter Zijlstra wrote:
>
> While working on a GRUB patch to support PCI-serial, a number of
> cleanups were suggested that apply to the code I took inspiration from.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> arch/x86/kernel/early_printk.c | 14 +++++++-------
> include/linux/pci_ids.h | 3 +++
> 2 files changed, 10 insertions(+), 7 deletions(-)
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] earlyprintk: Clean up pciserial
2022-08-25 11:36 [PATCH] earlyprintk: Clean up pciserial Peter Zijlstra
2022-08-25 11:48 ` Greg KH
@ 2022-08-25 17:39 ` Bjorn Helgaas
2022-08-25 19:36 ` Peter Zijlstra
2022-08-29 10:52 ` [tip: x86/core] x86/earlyprintk: " tip-bot2 for Peter Zijlstra
2 siblings, 1 reply; 7+ messages in thread
From: Bjorn Helgaas @ 2022-08-25 17:39 UTC (permalink / raw)
To: Peter Zijlstra; +Cc: x86, linux-kernel, bhelgaas, gregkh
On Thu, Aug 25, 2022 at 01:36:40PM +0200, Peter Zijlstra wrote:
>
> While working on a GRUB patch to support PCI-serial, a number of
> cleanups were suggested that apply to the code I took inspiration from.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # pci_ids.h
> ---
> arch/x86/kernel/early_printk.c | 14 +++++++-------
> include/linux/pci_ids.h | 3 +++
> 2 files changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
> index 68b38925a74f..44f937015e1e 100644
> --- a/arch/x86/kernel/early_printk.c
> +++ b/arch/x86/kernel/early_printk.c
> @@ -264,11 +264,11 @@ static __init void early_pci_serial_init(char *s)
> bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
>
> /*
> - * Verify it is a UART type device
> + * Verify it is a 16550-UART type device
> */
> if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
> (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
> - (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ {
> + (((classcode >> 8) & 0xff) != PCI_SERIAL_16550_COMPATIBLE)) {
> if (!force)
> return;
> }
> @@ -276,22 +276,22 @@ static __init void early_pci_serial_init(char *s)
> /*
> * Determine if it is IO or memory mapped
> */
> - if (bar0 & 0x01) {
> + if ((bar0 & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
> /* it is IO mapped */
> serial_in = io_serial_in;
> serial_out = io_serial_out;
> - early_serial_base = bar0&0xfffffffc;
> + early_serial_base = bar0 & PCI_BASE_ADDRESS_IO_MASK;
> write_pci_config(bus, slot, func, PCI_COMMAND,
> - cmdreg|PCI_COMMAND_IO);
> + cmdreg|PCI_COMMAND_IO);
> } else {
> /* It is memory mapped - assume 32-bit alignment */
> serial_in = mem32_serial_in;
> serial_out = mem32_serial_out;
> /* WARNING! assuming the address is always in the first 4G */
> early_serial_base =
> - (unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
> + (unsigned long)early_ioremap(bar0 & PCI_BASE_ADDRESS_MEM_MASK, 0x10);
> write_pci_config(bus, slot, func, PCI_COMMAND,
> - cmdreg|PCI_COMMAND_MEMORY);
> + cmdreg|PCI_COMMAND_MEMORY);
> }
>
> /*
> diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
> index 6feade66efdb..1d2c7df8cd41 100644
> --- a/include/linux/pci_ids.h
> +++ b/include/linux/pci_ids.h
> @@ -75,6 +75,9 @@
> #define PCI_CLASS_COMMUNICATION_MODEM 0x0703
> #define PCI_CLASS_COMMUNICATION_OTHER 0x0780
>
> +/* I/F for SERIAL/MODEM */
I/F? Grep says it's fairly common, but doesn't seem completely
obvious. I guess it means "interface"?
> +#define PCI_SERIAL_16550_COMPATIBLE 0x02
> +
> #define PCI_BASE_CLASS_SYSTEM 0x08
> #define PCI_CLASS_SYSTEM_PIC 0x0800
> #define PCI_CLASS_SYSTEM_PIC_IOAPIC 0x080010
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] earlyprintk: Clean up pciserial
2022-08-25 17:39 ` Bjorn Helgaas
@ 2022-08-25 19:36 ` Peter Zijlstra
2022-08-25 19:51 ` Bjorn Helgaas
0 siblings, 1 reply; 7+ messages in thread
From: Peter Zijlstra @ 2022-08-25 19:36 UTC (permalink / raw)
To: Bjorn Helgaas; +Cc: x86, linux-kernel, bhelgaas, gregkh
On Thu, Aug 25, 2022 at 12:39:59PM -0500, Bjorn Helgaas wrote:
> > - (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ {
> > diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
> > index 6feade66efdb..1d2c7df8cd41 100644
> > --- a/include/linux/pci_ids.h
> > +++ b/include/linux/pci_ids.h
> > @@ -75,6 +75,9 @@
> > #define PCI_CLASS_COMMUNICATION_MODEM 0x0703
> > #define PCI_CLASS_COMMUNICATION_OTHER 0x0780
> >
> > +/* I/F for SERIAL/MODEM */
>
> I/F? Grep says it's fairly common, but doesn't seem completely
> obvious. I guess it means "interface"?
It does, I carried the nomenclature from the above line; happy to change
it if you want.
https://wiki.osdev.org/PCI#Class_Codes
Calls it 'Prog IF'.
> > +#define PCI_SERIAL_16550_COMPATIBLE 0x02
> > +
> > #define PCI_BASE_CLASS_SYSTEM 0x08
> > #define PCI_CLASS_SYSTEM_PIC 0x0800
> > #define PCI_CLASS_SYSTEM_PIC_IOAPIC 0x080010
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] earlyprintk: Clean up pciserial
2022-08-25 19:36 ` Peter Zijlstra
@ 2022-08-25 19:51 ` Bjorn Helgaas
2022-08-25 20:08 ` Peter Zijlstra
0 siblings, 1 reply; 7+ messages in thread
From: Bjorn Helgaas @ 2022-08-25 19:51 UTC (permalink / raw)
To: Peter Zijlstra; +Cc: x86, linux-kernel, bhelgaas, gregkh
On Thu, Aug 25, 2022 at 09:36:35PM +0200, Peter Zijlstra wrote:
> On Thu, Aug 25, 2022 at 12:39:59PM -0500, Bjorn Helgaas wrote:
>
> > > - (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ {
>
> > > diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
> > > index 6feade66efdb..1d2c7df8cd41 100644
> > > --- a/include/linux/pci_ids.h
> > > +++ b/include/linux/pci_ids.h
> > > @@ -75,6 +75,9 @@
> > > #define PCI_CLASS_COMMUNICATION_MODEM 0x0703
> > > #define PCI_CLASS_COMMUNICATION_OTHER 0x0780
> > >
> > > +/* I/F for SERIAL/MODEM */
> >
> > I/F? Grep says it's fairly common, but doesn't seem completely
> > obvious. I guess it means "interface"?
>
> It does, I carried the nomenclature from the above line; happy to change
> it if you want.
>
> https://wiki.osdev.org/PCI#Class_Codes
>
> Calls it 'Prog IF'.
Personally, I would spell it out just to make it less arcane. I
wouldn't know where to find the definition, and the PCI specs don't
seem to use the abbreviation. But no big deal either way.
Bjorn
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] earlyprintk: Clean up pciserial
2022-08-25 19:51 ` Bjorn Helgaas
@ 2022-08-25 20:08 ` Peter Zijlstra
0 siblings, 0 replies; 7+ messages in thread
From: Peter Zijlstra @ 2022-08-25 20:08 UTC (permalink / raw)
To: Bjorn Helgaas; +Cc: x86, linux-kernel, bhelgaas, gregkh
On Thu, Aug 25, 2022 at 02:51:43PM -0500, Bjorn Helgaas wrote:
> On Thu, Aug 25, 2022 at 09:36:35PM +0200, Peter Zijlstra wrote:
> > On Thu, Aug 25, 2022 at 12:39:59PM -0500, Bjorn Helgaas wrote:
> >
> > > > - (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ {
> >
> > > > diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
> > > > index 6feade66efdb..1d2c7df8cd41 100644
> > > > --- a/include/linux/pci_ids.h
> > > > +++ b/include/linux/pci_ids.h
> > > > @@ -75,6 +75,9 @@
> > > > #define PCI_CLASS_COMMUNICATION_MODEM 0x0703
> > > > #define PCI_CLASS_COMMUNICATION_OTHER 0x0780
> > > >
> > > > +/* I/F for SERIAL/MODEM */
> > >
> > > I/F? Grep says it's fairly common, but doesn't seem completely
> > > obvious. I guess it means "interface"?
> >
> > It does, I carried the nomenclature from the above line; happy to change
> > it if you want.
> >
> > https://wiki.osdev.org/PCI#Class_Codes
> >
> > Calls it 'Prog IF'.
>
> Personally, I would spell it out just to make it less arcane. I
> wouldn't know where to find the definition, and the PCI specs don't
> seem to use the abbreviation. But no big deal either way.
Ok,
/* Interface for SERIAL/MODEM */
it is.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [tip: x86/core] x86/earlyprintk: Clean up pciserial
2022-08-25 11:36 [PATCH] earlyprintk: Clean up pciserial Peter Zijlstra
2022-08-25 11:48 ` Greg KH
2022-08-25 17:39 ` Bjorn Helgaas
@ 2022-08-29 10:52 ` tip-bot2 for Peter Zijlstra
2 siblings, 0 replies; 7+ messages in thread
From: tip-bot2 for Peter Zijlstra @ 2022-08-29 10:52 UTC (permalink / raw)
To: linux-tip-commits
Cc: Peter Zijlstra (Intel),
Bjorn Helgaas, Greg Kroah-Hartman, x86, linux-kernel
The following commit has been merged into the x86/core branch of tip:
Commit-ID: bc12b70f7d216b36bd87701349374a13e486f8eb
Gitweb: https://git.kernel.org/tip/bc12b70f7d216b36bd87701349374a13e486f8eb
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Thu, 25 Aug 2022 13:36:40 +02:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 29 Aug 2022 12:19:25 +02:00
x86/earlyprintk: Clean up pciserial
While working on a GRUB patch to support PCI-serial, a number of
cleanups were suggested that apply to the code I took inspiration from.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # pci_ids.h
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lkml.kernel.org/r/YwdeyCEtW+wa+QhH@worktop.programming.kicks-ass.net
---
arch/x86/kernel/early_printk.c | 14 +++++++-------
include/linux/pci_ids.h | 3 +++
2 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index 68b3892..44f9370 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -264,11 +264,11 @@ static __init void early_pci_serial_init(char *s)
bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
/*
- * Verify it is a UART type device
+ * Verify it is a 16550-UART type device
*/
if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
(classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
- (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ {
+ (((classcode >> 8) & 0xff) != PCI_SERIAL_16550_COMPATIBLE)) {
if (!force)
return;
}
@@ -276,22 +276,22 @@ static __init void early_pci_serial_init(char *s)
/*
* Determine if it is IO or memory mapped
*/
- if (bar0 & 0x01) {
+ if ((bar0 & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
/* it is IO mapped */
serial_in = io_serial_in;
serial_out = io_serial_out;
- early_serial_base = bar0&0xfffffffc;
+ early_serial_base = bar0 & PCI_BASE_ADDRESS_IO_MASK;
write_pci_config(bus, slot, func, PCI_COMMAND,
- cmdreg|PCI_COMMAND_IO);
+ cmdreg|PCI_COMMAND_IO);
} else {
/* It is memory mapped - assume 32-bit alignment */
serial_in = mem32_serial_in;
serial_out = mem32_serial_out;
/* WARNING! assuming the address is always in the first 4G */
early_serial_base =
- (unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
+ (unsigned long)early_ioremap(bar0 & PCI_BASE_ADDRESS_MEM_MASK, 0x10);
write_pci_config(bus, slot, func, PCI_COMMAND,
- cmdreg|PCI_COMMAND_MEMORY);
+ cmdreg|PCI_COMMAND_MEMORY);
}
/*
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 6feade6..41b3fff 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -75,6 +75,9 @@
#define PCI_CLASS_COMMUNICATION_MODEM 0x0703
#define PCI_CLASS_COMMUNICATION_OTHER 0x0780
+/* Interface for SERIAL/MODEM */
+#define PCI_SERIAL_16550_COMPATIBLE 0x02
+
#define PCI_BASE_CLASS_SYSTEM 0x08
#define PCI_CLASS_SYSTEM_PIC 0x0800
#define PCI_CLASS_SYSTEM_PIC_IOAPIC 0x080010
^ permalink raw reply related [flat|nested] 7+ messages in thread
end of thread, other threads:[~2022-08-29 10:52 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2022-08-25 11:36 [PATCH] earlyprintk: Clean up pciserial Peter Zijlstra
2022-08-25 11:48 ` Greg KH
2022-08-25 17:39 ` Bjorn Helgaas
2022-08-25 19:36 ` Peter Zijlstra
2022-08-25 19:51 ` Bjorn Helgaas
2022-08-25 20:08 ` Peter Zijlstra
2022-08-29 10:52 ` [tip: x86/core] x86/earlyprintk: " tip-bot2 for Peter Zijlstra
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