Merge tag 'x86-documentation-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 documentation updates from Ingo Molnar:

 - Misc x86 documentation updates (Randy Dunlap, Daniel Gibson)

* tag 'x86-documentation-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation/arch/x86/amd-debugging: Add example for reset register
  x86/intel/quark: Clean up function kernel-doc
  x86/speculation: Drop Excess function parameter descriptions
  x86/lib: checksum_64.h: Eliminate all kernel-doc warnings
  x86/barrier: Use correct parameter names in kernel-doc

Documentation/arch/x86/amd-debugging.rst

@@ -366,3 +366,8 @@ There are 6 classes of reasons for the reboot:
 This information is read by the kernel at bootup and printed into
 the syslog. When a random reboot occurs this message can be helpful
 to determine the next component to debug.
+
+For example, if bit 19 was set, you will get a message like this in the log on
+next bootup::
+
+  x86/amd: Previous system reset reason [0x00080000]: software wrote 0x6 to reset control register 0xCF9

arch/x86/include/asm/barrier.h

@@ -27,11 +27,11 @@
 /**
  * array_index_mask_nospec() - generate a mask that is ~0UL when the
  * 	bounds check succeeds and 0 otherwise
- * @index: array element index
- * @size: number of elements in array
+ * @idx: array element index
+ * @sz: number of elements in array
  *
  * Returns:
- *     0 - (index < size)
+ *     0 - (@idx < @sz)
  */
 #define array_index_mask_nospec(idx,sz) ({	\
 	typeof((idx)+(sz)) __idx = (idx);	\

arch/x86/include/asm/checksum_64.h

@@ -14,11 +14,13 @@
 
 /**
  * csum_fold - Fold and invert a 32bit checksum.
- * sum: 32bit unfolded sum
+ * @sum: 32bit unfolded sum
  *
  * Fold a 32bit running checksum to 16bit and invert it. This is usually
  * the last step before putting a checksum into a packet.
  * Make sure not to mix with 64bit checksums.
+ *
+ * Returns: new checksum value
  */
 static inline __sum16 csum_fold(__wsum sum)
 {
@@ -40,8 +42,10 @@ static inline __sum16 csum_fold(__wsum sum)
 
 /**
  * ip_fast_csum - Compute the IPv4 header checksum efficiently.
- * iph: ipv4 header
- * ihl: length of header / 4
+ * @iph: ipv4 header
+ * @ihl: length of header / 4
+ *
+ * Returns: header checksum
  */
 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
 {
@@ -74,14 +78,14 @@ static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
 }
 
 /**
- * csum_tcpup_nofold - Compute an IPv4 pseudo header checksum.
+ * csum_tcpudp_nofold - Compute an IPv4 pseudo header checksum.
  * @saddr: source address
  * @daddr: destination address
  * @len: length of packet
  * @proto: ip protocol of packet
  * @sum: initial sum to be added in (32bit unfolded)
  *
- * Returns the pseudo header checksum the input data. Result is
+ * Returns: the pseudo header checksum the input data. Result is
  * 32bit unfolded.
  */
 static inline __wsum
@@ -100,14 +104,14 @@ csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
 
 
 /**
- * csum_tcpup_magic - Compute an IPv4 pseudo header checksum.
+ * csum_tcpudp_magic - Compute an IPv4 pseudo header checksum.
  * @saddr: source address
  * @daddr: destination address
  * @len: length of packet
  * @proto: ip protocol of packet
  * @sum: initial sum to be added in (32bit unfolded)
  *
- * Returns the 16bit pseudo header checksum the input data already
+ * Returns: the 16bit pseudo header checksum the input data already
  * complemented and ready to be filled in.
  */
 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
@@ -123,7 +127,7 @@ static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
  * @len: length of buffer.
  * @sum: initial sum to be added in (32bit unfolded)
  *
- * Returns the 32bit unfolded internet checksum of the buffer.
+ * Returns: the 32bit unfolded internet checksum of the buffer.
  * Before filling it in it needs to be csum_fold()'ed.
  * buff should be aligned to a 64bit boundary if possible.
  */
@@ -141,7 +145,7 @@ extern __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);
  * @buff: buffer address.
  * @len: length of buffer.
  *
- * Returns the 16bit folded/inverted checksum of the passed buffer.
+ * Returns: the 16bit folded/inverted checksum of the passed buffer.
  * Ready to fill in.
  */
 extern __sum16 ip_compute_csum(const void *buff, int len);
@@ -159,15 +163,16 @@ static inline unsigned add32_with_carry(unsigned a, unsigned b)
 
 /**
  * csum_ipv6_magic - Compute checksum of an IPv6 pseudo header.
- * @saddr: source address
- * @daddr: destination address
+ * @_saddr: source address
+ * @_daddr: destination address
  * @len: length of packet
  * @proto: protocol of packet
  * @sum: initial sum (32bit unfolded) to be added in
  *
  * Computes an IPv6 pseudo header checksum. This sum is added the checksum
  * into UDP/TCP packets and contains some link layer information.
- * Returns the unfolded 32bit checksum.
+ *
+ * Returns: the unfolded 32bit checksum.
  */
 
 static inline __sum16 csum_ipv6_magic(

arch/x86/include/asm/spec-ctrl.h

@@ -18,7 +18,6 @@ extern void x86_virt_spec_ctrl(u64 guest_virt_spec_ctrl, bool guest);
 
 /**
  * x86_spec_ctrl_set_guest - Set speculation control registers for the guest
- * @guest_spec_ctrl:		The guest content of MSR_SPEC_CTRL
  * @guest_virt_spec_ctrl:	The guest controlled bits of MSR_VIRT_SPEC_CTRL
  *				(may get translated to MSR_AMD64_LS_CFG bits)
  *
@@ -32,7 +31,6 @@ void x86_spec_ctrl_set_guest(u64 guest_virt_spec_ctrl)
 
 /**
  * x86_spec_ctrl_restore_host - Restore host speculation control registers
- * @guest_spec_ctrl:		The guest content of MSR_SPEC_CTRL
  * @guest_virt_spec_ctrl:	The guest controlled bits of MSR_VIRT_SPEC_CTRL
  *				(may get translated to MSR_AMD64_LS_CFG bits)
  *

arch/x86/platform/intel-quark/imr_selftest.c

@@ -50,7 +50,7 @@ void __init imr_self_test_result(int res, const char *fmt, ...)
 #undef SELFTEST
 
 /**
- * imr_self_test
+ * imr_self_test - perform the IMR self-test
  *
  * Verify IMR self_test with some simple tests to verify overlap,
  * zero sized allocations and 1 KiB sized areas.
@@ -121,9 +121,4 @@ static int __init imr_self_test_init(void)
 	return 0;
 }
 
-/**
- * imr_self_test_exit - exit point for IMR code.
- *
- * return:
- */
 device_initcall(imr_self_test_init);