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[v2,0/3] SRAT/CEDT fixes and updates

Message ID 20240319120026.2246389-1-rrichter@amd.com
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Series SRAT/CEDT fixes and updates | expand

Message

Robert Richter March 19, 2024, noon UTC
Some fixes and updates for SRAT/CEDT parsing code. Patches can be
applied individually and are independent.

First patch fixes a page fault during boot. It should be marked stable.

2nd patch adds diagnostic printouts for CEDT.

3rd patch removes architectural code no longer needed.

Robert Richter (3):
  x86/numa: Fix SRAT lookup of CFMWS ranges with numa_fill_memblks()
  ACPI/NUMA: Print CXL Early Discovery Table (CEDT)
  ACPI/NUMA: Remove architecture dependent remainings

 arch/x86/mm/numa.c       |   4 +-
 drivers/acpi/numa/srat.c | 178 +++++++++++++++++++++++++++++----------
 include/linux/acpi.h     |   5 --
 3 files changed, 134 insertions(+), 53 deletions(-)

Comments

Dan Williams March 19, 2024, 8:15 p.m. UTC | #1
Robert Richter wrote:
> For configurations that have the kconfig option NUMA_KEEP_MEMINFO
> disabled, the SRAT lookup done with numa_fill_memblks() fails
> returning NUMA_NO_MEMBLK (-1). An existing SRAT memory range cannot be
> found for a CFMWS address range. This causes the addition of a
> duplicate numa_memblk with a different node id and a subsequent page
> fault and kernel crash during boot.
> 
> numa_fill_memblks() is implemented and used in the init section only.
> The option NUMA_KEEP_MEMINFO is only for the case when NUMA data will
> be used outside of init. So fix the SRAT lookup by moving
> numa_fill_memblks() out of the NUMA_KEEP_MEMINFO block to make it
> always available in the init section.
> 
> Note that the issue was initially introduced with [1]. But since
> phys_to_target_node() was originally used that returned the valid node
> 0, an additional numa_memblk was not added. Though, the node id was
> wrong too.
> 
> [1] fd49f99c1809 ("ACPI: NUMA: Add a node and memblk for each CFMWS not in SRAT")
> 
> Fixes: 8f1004679987 ("ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window")
> Cc: Derick Marks <derick.w.marks@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Alison Schofield <alison.schofield@intel.com>
> Signed-off-by: Robert Richter <rrichter@amd.com>
> ---
>  arch/x86/mm/numa.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index 65e9a6e391c0..ce84ba86e69e 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -929,6 +929,8 @@ int memory_add_physaddr_to_nid(u64 start)
>  }
>  EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
>  
> +#endif
> +
>  static int __init cmp_memblk(const void *a, const void *b)
>  {
>  	const struct numa_memblk *ma = *(const struct numa_memblk **)a;
> @@ -1001,5 +1003,3 @@ int __init numa_fill_memblks(u64 start, u64 end)
>  	}
>  	return 0;
>  }
> -
> -#endif

Does this achieve the goal without an additional hunk like this?

diff --git a/arch/x86/include/asm/sparsemem.h b/arch/x86/include/asm/sparsemem.h
index 1be13b2dfe8b..1aaa447ef24b 100644
--- a/arch/x86/include/asm/sparsemem.h
+++ b/arch/x86/include/asm/sparsemem.h
@@ -37,9 +37,9 @@ extern int phys_to_target_node(phys_addr_t start);
 #define phys_to_target_node phys_to_target_node
 extern int memory_add_physaddr_to_nid(u64 start);
 #define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
+#endif
 extern int numa_fill_memblks(u64 start, u64 end);
 #define numa_fill_memblks numa_fill_memblks
-#endif
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_X86_SPARSEMEM_H */
Dan Williams March 19, 2024, 8:44 p.m. UTC | #2
Robert Richter wrote:
> With the removal of the Itanium architecture [1] the last architecture
> dependent functions:
> 
>  acpi_numa_slit_init(), acpi_numa_memory_affinity_init()
> 
> were removed. Remove its remainings in the header files too an make
> them static.

It would have helped to clarify that this is a refactoring and absorbing
logic into the helpers to validate the correctness of the conversion
approach. I almost asked for it to be split to make that clearer, but
figured it out eventually.

> [1] cf8e8658100d arch: Remove Itanium (IA-64) architecture

Checkpatch does not like this format and has some other things to say
about this legacy code being touched.

> 
> Signed-off-by: Robert Richter <rrichter@amd.com>
> ---
>  drivers/acpi/numa/srat.c | 68 +++++++++++++---------------------------
>  include/linux/acpi.h     |  5 ---
>  2 files changed, 21 insertions(+), 52 deletions(-)
> 
> diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
> index 50ae8557e8d1..910609a9754b 100644
> --- a/drivers/acpi/numa/srat.c
> +++ b/drivers/acpi/numa/srat.c
> @@ -208,16 +208,21 @@ int __init srat_disabled(void)
>  	return acpi_numa < 0;
>  }
>  
> -#if defined(CONFIG_X86) || defined(CONFIG_ARM64) || defined(CONFIG_LOONGARCH)
>  /*
>   * Callback for SLIT parsing.  pxm_to_node() returns NUMA_NO_NODE for
>   * I/O localities since SRAT does not list them.  I/O localities are
>   * not supported at this point.
>   */
> -void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
> +static int __init acpi_parse_slit(struct acpi_table_header *table)
>  {
> +	struct acpi_table_slit *slit = (struct acpi_table_slit *)table;
>  	int i, j;
>  
> +	if (!slit_valid(slit)) {
> +		pr_info("SLIT table looks invalid. Not used.\n");
> +		return -EINVAL;
> +	}
> +
>  	for (i = 0; i < slit->locality_count; i++) {
>  		const int from_node = pxm_to_node(i);
>  
> @@ -234,19 +239,25 @@ void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
>  				slit->entry[slit->locality_count * i + j]);
>  		}
>  	}
> +
> +	return 0;
>  }
>  
> -/*
> - * Default callback for parsing of the Proximity Domain <-> Memory
> - * Area mappings
> - */
> -int __init
> -acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
> +static int __initdata parsed_numa_memblks;

Checkpatch wants __initdata moved after the symbol name.

Otherwise this conversion looks correct.

> +static int __init
> +acpi_parse_memory_affinity(union acpi_subtable_headers * header,
> +			   const unsigned long table_end)
>  {
> +	struct acpi_srat_mem_affinity *ma;
>  	u64 start, end;
>  	u32 hotpluggable;
>  	int node, pxm;
>  
> +	ma = (struct acpi_srat_mem_affinity *)header;
> +
> +	acpi_table_print_srat_entry(&header->common);
> +
>  	if (srat_disabled())
>  		goto out_err;
>  	if (ma->header.length < sizeof(struct acpi_srat_mem_affinity)) {
> @@ -293,6 +304,8 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
>  
>  	max_possible_pfn = max(max_possible_pfn, PFN_UP(end - 1));
>  
> +	parsed_numa_memblks++;
> +
>  	return 0;
>  out_err_bad_srat:
>  	bad_srat();
> @@ -448,27 +461,6 @@ static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
>  	(*fake_pxm)++;
>  	return 0;
>  }
> -#else
> -static inline void acpi_table_print_cedt(void) {}

Would be nice to move this patch before the printing patch otherwise
feels icky to add a line in patch2 that gets deleted in patch3.
Robert Richter March 21, 2024, 8:09 a.m. UTC | #3
Dan,

On 19.03.24 13:15:48, Dan Williams wrote:
> Does this achieve the goal without an additional hunk like this?
> 
> diff --git a/arch/x86/include/asm/sparsemem.h b/arch/x86/include/asm/sparsemem.h
> index 1be13b2dfe8b..1aaa447ef24b 100644
> --- a/arch/x86/include/asm/sparsemem.h
> +++ b/arch/x86/include/asm/sparsemem.h
> @@ -37,9 +37,9 @@ extern int phys_to_target_node(phys_addr_t start);
>  #define phys_to_target_node phys_to_target_node
>  extern int memory_add_physaddr_to_nid(u64 start);
>  #define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
> +#endif
>  extern int numa_fill_memblks(u64 start, u64 end);
>  #define numa_fill_memblks numa_fill_memblks
> -#endif
>  #endif /* __ASSEMBLY__ */
>  
>  #endif /* _ASM_X86_SPARSEMEM_H */

right, there are some build issues that need to be fixed in this
patch. Sorry for that.

Thanks,

-Robert
Alison Schofield March 21, 2024, 6:39 p.m. UTC | #4
On Thu, Mar 21, 2024 at 05:55:57PM +0100, Robert Richter wrote:
> Alison,
> 
> On 20.03.24 10:46:07, Alison Schofield wrote:
> > On Tue, Mar 19, 2024 at 01:00:23PM +0100, Robert Richter wrote:
> > > For configurations that have the kconfig option NUMA_KEEP_MEMINFO
> > > disabled, the SRAT lookup done with numa_fill_memblks() fails
> > > returning NUMA_NO_MEMBLK (-1). An existing SRAT memory range cannot be
> > > found for a CFMWS address range. This causes the addition of a
> > > duplicate numa_memblk with a different node id and a subsequent page
> > > fault and kernel crash during boot.
> > > 
> > > numa_fill_memblks() is implemented and used in the init section only.
> > > The option NUMA_KEEP_MEMINFO is only for the case when NUMA data will
> > > be used outside of init. So fix the SRAT lookup by moving
> > > numa_fill_memblks() out of the NUMA_KEEP_MEMINFO block to make it
> > > always available in the init section.
> > > 
> > > Note that the issue was initially introduced with [1]. But since
> > > phys_to_target_node() was originally used that returned the valid node
> > > 0, an additional numa_memblk was not added. Though, the node id was
> > > wrong too.
> > 
> > Hi Richard,
> > 
> > I recall a bit of wrangling w #defines to make ARM64 and LOONGARCH build.
> > I'm seeing an x86 build error today:
> > 
> > >> arch/x86/mm/numa.c:957:12: error: redefinition of 'numa_fill_memblks'
> >      957 | int __init numa_fill_memblks(u64 start, u64 end)
> > 
> > include/linux/numa.h:40:26: note: previous definition of 'numa_fill_memblks' with type
> > +'int(u64,  u64)' {aka 'int(long long unsigned int,  long long unsigned int)'}
> >       40 | static inline int __init numa_fill_memblks(u64 start, u64 end)
> >          |                          ^~~~~~~~~~~~~~~~~
> > 
> > In addition to what you suggest, would something like this diff below be
> > a useful safety measure to distinguish num_fill_memblks() success (rc:0)
> > and possible non-existence (rc:-1). I don't think it hurts to take a
> > second look using phys_to_target_node() (totall untested)
> > 
> > diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
> > index 070a52e4daa8..0c48fe32ced4 100644
> > --- a/drivers/acpi/numa/srat.c
> > +++ b/drivers/acpi/numa/srat.c
> > @@ -437,9 +437,16 @@ static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
> >          * found for any portion of the window to cover the entire
> >          * window.
> >          */
> > -       if (!numa_fill_memblks(start, end))
> > +       rc = numa_fill_memblks(start, end);
> > +       if (!rc)
> >                 return 0;
> >  
> > +       if (rc == NUMA_NO_MEMBLK) {
> > +               node = phys_to_target_node(start);
> > +               if (node != NUMA_NO_NODE)
> > +                       return 0;
> > +       }
> > +
> 
> for non-x86 the numa_add_memblk() function looks good in a way that it
> is able to handle presumable overlapping regions. numa_fill_memblks()
> would just fail then and numa_add_memblk() being called. For x86 we
> need numa_fill_memblks() since x86 specific numa_add_memblk() cannot
> handle the overlapping case.
> 
> That said, we do not need the 2nd check. It looks to me that it
> actually breaks non-x86 as the whole block may not be registered (if
> it is larger than anything existing).
> 
> For x86 the 2nd check may never happen if numa_fill_memblks() is
> always enabled (which is this patch for).

Hi Robert, (<-- got it right this time ;))

I wasn't thinking of x86, but rather archs that may not support
numa_fill_memblks() and return NUMA_NO_MEMBLK (-1) per the 
#ifndef numa_fill_memblks in include/linux/numa.h

In those cases, take a second look at phys_to_targe_node() before
blindly adding another memblk. Is that the failure signature you
reported here?

I can wait and see your final patch and how the different archs
will handle it. I'm worried that NUMA_NO_MEMBLK is overloaded and
we need to diffentiate between archs that don't even look for a 
node, versus archs that look but don't find a node.

--Alison




> 
> So we should be good without your change.
> 
> Thanks,
> 
> -Robert
> 
> >         /* No SRAT description. Create a new node. */
> > 
> > --Alison
> > 
> > > 
> > > [1] fd49f99c1809 ("ACPI: NUMA: Add a node and memblk for each CFMWS not in SRAT")
> > > 
> > > Fixes: 8f1004679987 ("ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window")
> > > Cc: Derick Marks <derick.w.marks@intel.com>
> > > Cc: Dan Williams <dan.j.williams@intel.com>
> > > Cc: Alison Schofield <alison.schofield@intel.com>
> > > Signed-off-by: Robert Richter <rrichter@amd.com>
> > > ---
> > >  arch/x86/mm/numa.c | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> > > index 65e9a6e391c0..ce84ba86e69e 100644
> > > --- a/arch/x86/mm/numa.c
> > > +++ b/arch/x86/mm/numa.c
> > > @@ -929,6 +929,8 @@ int memory_add_physaddr_to_nid(u64 start)
> > >  }
> > >  EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
> > >  
> > > +#endif
> > > +
> > >  static int __init cmp_memblk(const void *a, const void *b)
> > >  {
> > >  	const struct numa_memblk *ma = *(const struct numa_memblk **)a;
> > > @@ -1001,5 +1003,3 @@ int __init numa_fill_memblks(u64 start, u64 end)
> > >  	}
> > >  	return 0;
> > >  }
> > > -
> > > -#endif
> > > -- 
> > > 2.39.2
> > >