mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: "tip-bot2 for Borislav Petkov (AMD)" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>,
	Ingo Molnar <mingo@kernel.org>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: x86/urgent] Documentation/x86: Zap the subsection letters
Date: Wed, 09 Apr 2025 12:04:56 -0000	[thread overview]
Message-ID: <174420029649.31282.6766699753807343972.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20250409111435.GEZ_ZWmz3_lkP8S9Lb@fat_crate.local>

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     254a6d14c9c952e8eae0fafd4fed3778721b948e
Gitweb:        https://git.kernel.org/tip/254a6d14c9c952e8eae0fafd4fed3778721b948e
Author:        Borislav Petkov (AMD) <bp@alien8.de>
AuthorDate:    Wed, 09 Apr 2025 13:14:35 +02:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Wed, 09 Apr 2025 13:56:52 +02:00

Documentation/x86: Zap the subsection letters

The subsections already have numbering - no need for the letters too.

Zap the latter.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250409111435.GEZ_ZWmz3_lkP8S9Lb@fat_crate.local
---
 Documentation/arch/x86/cpuinfo.rst | 51 ++++++++++++++++-------------
 1 file changed, 29 insertions(+), 22 deletions(-)

diff --git a/Documentation/arch/x86/cpuinfo.rst b/Documentation/arch/x86/cpuinfo.rst
index 7114f34..f80e2a5 100644
--- a/Documentation/arch/x86/cpuinfo.rst
+++ b/Documentation/arch/x86/cpuinfo.rst
@@ -79,8 +79,9 @@ feature flags.
 How are feature flags created?
 ==============================
 
-a: Feature flags can be derived from the contents of CPUID leaves.
-------------------------------------------------------------------
+Feature flags can be derived from the contents of CPUID leaves
+--------------------------------------------------------------
+
 These feature definitions are organized mirroring the layout of CPUID
 leaves and grouped in words with offsets as mapped in enum cpuid_leafs
 in cpufeatures.h (see arch/x86/include/asm/cpufeatures.h for details).
@@ -89,8 +90,9 @@ cpufeatures.h, and if it is detected at run time, the flags will be
 displayed accordingly in /proc/cpuinfo. For example, the flag "avx2"
 comes from X86_FEATURE_AVX2 in cpufeatures.h.
 
-b: Flags can be from scattered CPUID-based features.
-----------------------------------------------------
+Flags can be from scattered CPUID-based features
+------------------------------------------------
+
 Hardware features enumerated in sparsely populated CPUID leaves get
 software-defined values. Still, CPUID needs to be queried to determine
 if a given feature is present. This is done in init_scattered_cpuid_features().
@@ -104,8 +106,9 @@ has only one feature and would waste 31 bits of space in the x86_capability[]
 array. Since there is a struct cpuinfo_x86 for each possible CPU, the wasted
 memory is not trivial.
 
-c: Flags can be created synthetically under certain conditions for hardware features.
--------------------------------------------------------------------------------------
+Flags can be created synthetically under certain conditions for hardware features
+---------------------------------------------------------------------------------
+
 Examples of conditions include whether certain features are present in
 MSR_IA32_CORE_CAPS or specific CPU models are identified. If the needed
 conditions are met, the features are enabled by the set_cpu_cap or
@@ -114,8 +117,8 @@ the feature X86_FEATURE_SPLIT_LOCK_DETECT will be enabled and
 "split_lock_detect" will be displayed. The flag "ring3mwait" will be
 displayed only when running on INTEL_XEON_PHI_[KNL|KNM] processors.
 
-d: Flags can represent purely software features.
-------------------------------------------------
+Flags can represent purely software features
+--------------------------------------------
 These flags do not represent hardware features. Instead, they represent a
 software feature implemented in the kernel. For example, Kernel Page Table
 Isolation is purely software feature and its feature flag X86_FEATURE_PTI is
@@ -130,8 +133,8 @@ x86_cap/bug_flags[] arrays in kernel/cpu/capflags.c. The names in the
 resulting x86_cap/bug_flags[] are used to populate /proc/cpuinfo. The naming
 of flags in the x86_cap/bug_flags[] are as follows:
 
-a: Flags do not appear by default in /proc/cpuinfo
---------------------------------------------------
+Flags do not appear by default in /proc/cpuinfo
+-----------------------------------------------
 
 Feature flags are omitted by default from /proc/cpuinfo as it does not make
 sense for the feature to be exposed to userspace in most cases. For example,
@@ -139,8 +142,8 @@ X86_FEATURE_ALWAYS is defined in cpufeatures.h but that flag is an internal
 kernel feature used in the alternative runtime patching functionality. So the
 flag does not appear in /proc/cpuinfo.
 
-b: Specify a flag name if absolutely needed
--------------------------------------------
+Specify a flag name if absolutely needed
+----------------------------------------
 
 If the comment on the line for the #define X86_FEATURE_* starts with a
 double-quote character (""), the string inside the double-quote characters
@@ -155,25 +158,28 @@ shall override the new naming with the name already used in /proc/cpuinfo.
 Flags are missing when one or more of these happen
 ==================================================
 
-a: The hardware does not enumerate support for it.
---------------------------------------------------
+The hardware does not enumerate support for it
+----------------------------------------------
+
 For example, when a new kernel is running on old hardware or the feature is
 not enabled by boot firmware. Even if the hardware is new, there might be a
 problem enabling the feature at run time, the flag will not be displayed.
 
-b: The kernel does not know about the flag.
--------------------------------------------
+The kernel does not know about the flag
+---------------------------------------
+
 For example, when an old kernel is running on new hardware.
 
-c: The kernel disabled support for it at compile-time.
-------------------------------------------------------
+The kernel disabled support for it at compile-time
+--------------------------------------------------
+
 For example, if 5-level-paging is not enabled when building (i.e.,
 CONFIG_X86_5LEVEL is not selected) the flag "la57" will not show up [#f1]_.
 Even though the feature will still be detected via CPUID, the kernel disables
 it by clearing via setup_clear_cpu_cap(X86_FEATURE_LA57).
 
-d: The feature is disabled at boot-time.
-----------------------------------------
+The feature is disabled at boot-time
+------------------------------------
 A feature can be disabled either using a command-line parameter or because
 it failed to be enabled. The command-line parameter clearcpuid= can be used
 to disable features using the feature number as defined in
@@ -186,8 +192,9 @@ disable specific features. The list of parameters includes, but is not limited
 to, nofsgsbase, nosgx, noxsave, etc. 5-level paging can also be disabled using
 "no5lvl".
 
-e: The feature was known to be non-functional.
-----------------------------------------------
+The feature was known to be non-functional
+------------------------------------------
+
 The feature was known to be non-functional because a dependency was
 missing at runtime. For example, AVX flags will not show up if XSAVE feature
 is disabled since they depend on XSAVE feature. Another example would be broken

      reply	other threads:[~2025-04-09 12:04 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-03  9:43 [PATCH] Documentation/x86: Clarify naming of CPU features for /proc/cpuinfo Naveen N Rao (AMD)
2025-04-03 10:55 ` Bagas Sanjaya
2025-04-03 12:17 ` Borislav Petkov
2025-04-03 13:10   ` Naveen N Rao
2025-04-03 13:21     ` Borislav Petkov
2025-04-03 15:02       ` Naveen N Rao
2025-04-09 11:13         ` [PATCH 1/2] Documentation/x86: Update the " Borislav Petkov
2025-04-09 12:04           ` [tip: x86/urgent] " tip-bot2 for Naveen N Rao (AMD)
2025-04-09 11:14         ` [PATCH 2/2] Documentation/x86: Zap the subsection letters Borislav Petkov
2025-04-09 12:04           ` tip-bot2 for Borislav Petkov (AMD) [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=174420029649.31282.6766699753807343972.tip-bot2@tip-bot2 \
    --to=tip-bot2@linutronix.de \
    --cc=bp@alien8.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-tip-commits@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®