[PATCH] Documentation and source code comments updates (v1)

[PATCH] Documentation and source code comments updates (v1)

[Konrad Rzeszutek Wilk]

Hey,

Three little patches to update the Documentation/kernel-parameters and
also some of the complex x86 trampoline code.

Nothing serious, just a little cleanup.

[PATCH 1/3] xen/documentation: Mention 'earlyprintk=xen' in the documentation.

[Konrad Rzeszutek Wilk]

The earlyprintk for Xen PV guests utilizes a simple hypercall
(console_io) to provide output to Xen emergency console.

Note that the Xen hypervisor should be booted with 'loglevel=all'
to output said information.

Reported-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 Documentation/kernel-parameters.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 7660877..73d51ed 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -757,6 +757,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 	earlyprintk=	[X86,SH,BLACKFIN]
 			earlyprintk=vga
+			earlyprintk=xen
 			earlyprintk=serial[,ttySn[,baudrate]]
 			earlyprintk=ttySn[,baudrate]
 			earlyprintk=dbgp[debugController#]
@@ -774,6 +775,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			The VGA output is eventually overwritten by the real
 			console.
 
+			The xen output can only be used by Xen PV guests.
+
 	ekgdboc=	[X86,KGDB] Allow early kernel console debugging
 			ekgdboc=kbd
 
-- 
1.8.0.2

[PATCH 2/3] kernel-parameters: Document 'console=hvc<n>'

[Konrad Rzeszutek Wilk]

Both the PowerPC hypervisor and Xen hypervisor can utilize the
hvc driver.

CC: gregkh@linuxfoundation.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 Documentation/kernel-parameters.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 73d51ed..7b41fba 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -564,6 +564,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			UART at the specified I/O port or MMIO address,
 			switching to the matching ttyS device later.  The
 			options are the same as for ttyS, above.
+		hvc<n>	Use the hypervisor console device <n>. This is for
+			both Xen and PowerPC hypervisors.
 
                 If the device connected to the port is not a TTY but a braille
                 device, prepend "brl," before the device type, for instance
-- 
1.8.0.2

[PATCH 3/3] docs: Fix incorrect comment about 64-bit code segment descriptors.

[Konrad Rzeszutek Wilk]

The AMD64 Architecture Programmer's Manual Volume 2, on page
89 mentions: "If the processor is running in 64-bit mode (L=1),
the only valid setting of the D bit is 0." This matches
with what the code does.

CC: hpa@zytor.com
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 arch/x86/kernel/head_64.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index b7de3b2..6859e96 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -48,7 +48,7 @@ L3_START_KERNEL = pud_index(__START_KERNEL_map)
 	.globl startup_64
 startup_64:
 	/*
-	 * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 1,
+	 * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,
 	 * and someone has loaded an identity mapped page table
 	 * for us.  These identity mapped page tables map all of the
 	 * kernel pages and possibly all of memory.
@@ -159,7 +159,7 @@ startup_64:
 	jmp 1f
 ENTRY(secondary_startup_64)
 	/*
-	 * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 1,
+	 * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,
 	 * and someone has loaded a mapped page table.
 	 *
 	 * %rsi holds a physical pointer to real_mode_data.
-- 
1.8.0.2

[tip:x86/urgent] doc, xen: Mention 'earlyprintk=xen' in the documentation.

[tip-bot for Konrad Rzeszutek Wilk]

Commit-ID:  2482a92e7d17187301d7313cfe5021b13393a0b4
Gitweb:     http://git.kernel.org/tip/2482a92e7d17187301d7313cfe5021b13393a0b4
Author:     Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
AuthorDate: Mon, 25 Feb 2013 15:54:08 -0500
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 25 Feb 2013 13:41:18 -0800

doc, xen: Mention 'earlyprintk=xen' in the documentation.

The earlyprintk for Xen PV guests utilizes a simple hypercall
(console_io) to provide output to Xen emergency console.

Note that the Xen hypervisor should be booted with 'loglevel=all'
to output said information.

Reported-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1361825650-14031-2-git-send-email-konrad.wilk@oracle.com
Cc: <stable@vger.kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
 Documentation/kernel-parameters.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 6c72381..c4cc199 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -754,6 +754,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 	earlyprintk=	[X86,SH,BLACKFIN]
 			earlyprintk=vga
+			earlyprintk=xen
 			earlyprintk=serial[,ttySn[,baudrate]]
 			earlyprintk=ttySn[,baudrate]
 			earlyprintk=dbgp[debugController#]
@@ -771,6 +772,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			The VGA output is eventually overwritten by the real
 			console.
 
+			The xen output can only be used by Xen PV guests.
+
 	ekgdboc=	[X86,KGDB] Allow early kernel console debugging
 			ekgdboc=kbd
 

[tip:x86/urgent] doc, kernel-parameters: Document 'console=hvc<n> '

[tip-bot for Konrad Rzeszutek Wilk]

Commit-ID:  a2fd6419174470f5ae6383f5037d0ee21ed9833f
Gitweb:     http://git.kernel.org/tip/a2fd6419174470f5ae6383f5037d0ee21ed9833f
Author:     Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
AuthorDate: Mon, 25 Feb 2013 15:54:09 -0500
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 25 Feb 2013 13:42:15 -0800

doc, kernel-parameters: Document 'console=hvc<n>'

Both the PowerPC hypervisor and Xen hypervisor can utilize the
hvc driver.

Cc: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1361825650-14031-3-git-send-email-konrad.wilk@oracle.com
Cc: <stable@vger.kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
 Documentation/kernel-parameters.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index c4cc199..986614d 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -564,6 +564,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			UART at the specified I/O port or MMIO address,
 			switching to the matching ttyS device later.  The
 			options are the same as for ttyS, above.
+		hvc<n>	Use the hypervisor console device <n>. This is for
+			both Xen and PowerPC hypervisors.
 
                 If the device connected to the port is not a TTY but a braille
                 device, prepend "brl," before the device type, for instance

[tip:x86/urgent] x86, doc: Fix incorrect comment about 64-bit code segment descriptors

[tip-bot for Konrad Rzeszutek Wilk]

Commit-ID:  1256276c98dbcfb009ac8e0687df9a1e291fd149
Gitweb:     http://git.kernel.org/tip/1256276c98dbcfb009ac8e0687df9a1e291fd149
Author:     Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
AuthorDate: Mon, 25 Feb 2013 15:54:10 -0500
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 25 Feb 2013 13:42:37 -0800

x86, doc: Fix incorrect comment about 64-bit code segment descriptors

The AMD64 Architecture Programmer's Manual Volume 2, on page
89 mentions: "If the processor is running in 64-bit mode (L=1),
the only valid setting of the D bit is 0." This matches
with what the code does.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1361825650-14031-4-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
 arch/x86/kernel/head_64.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 980053c..37f5304 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -49,7 +49,7 @@ L3_START_KERNEL = pud_index(__START_KERNEL_map)
 startup_64:
 
 	/*
-	 * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 1,
+	 * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,
 	 * and someone has loaded an identity mapped page table
 	 * for us.  These identity mapped page tables map all of the
 	 * kernel pages and possibly all of memory.
@@ -146,7 +146,7 @@ ident_complete:
 	jmp secondary_startup_64
 ENTRY(secondary_startup_64)
 	/*
-	 * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 1,
+	 * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,
 	 * and someone has loaded a mapped page table.
 	 *
 	 * %esi holds a physical pointer to real_mode_data.

Re: [PATCH] Documentation and source code comments updates (v1)

[Rob Landley]

On 02/25/2013 02:54:07 PM, Konrad Rzeszutek Wilk wrote:
> Hey,
> 
> Three little patches to update the Documentation/kernel-parameters and
> also some of the complex x86 trampoline code.
> 
> Nothing serious, just a little cleanup.

Did I miss an attachment?

Rob

Re: [PATCH] Documentation and source code comments updates (v1)

[Konrad Rzeszutek Wilk]

On Mon, Feb 25, 2013 at 11:08:16PM -0600, Rob Landley wrote:
> On 02/25/2013 02:54:07 PM, Konrad Rzeszutek Wilk wrote:
> >Hey,
> >
> >Three little patches to update the Documentation/kernel-parameters and
> >also some of the complex x86 trampoline code.
> >
> >Nothing serious, just a little cleanup.
> 
> Did I miss an attachment?

No? They were part of the email thread.
> 
> Rob