(no subject)

[Robert Elliott]

Date: Thu, 17 Dec 2015 17:40:55 -0600
Subject: [PATCH 0/4] x86/efi: support persistent memory in efi_print_memmap

This series adds support for persistent memory type and NV attribute 
in the efi_print_memmap function, which is only used if EFI_DEBUG is true
(which is the case for x86).

Robert Elliott (4):
  x86/efi: show actual ending addresses in efi_print_memmap
  efi: add NV memory attribute
  efi: add Persistent Memory type name
  x86/efi: print size and base in binary units in efi_print_memmap

 arch/x86/platform/efi/efi.c | 29 +++++++++++++++++++++++++----
 drivers/firmware/efi/efi.c  |  8 ++++++--
 include/linux/efi.h         |  1 +
 3 files changed, 32 insertions(+), 6 deletions(-)

-- 
2.4.3

[PATCH 1/4] x86/efi: show actual ending addresses in efi_print_memmap

[Robert Elliott]

Adjust efi_print_memmap to print the real end address of each
range, not 1 byte beyond. This matches other prints like those for
SRAT and nosave memory.

Change the closing ) to ] to match the opening [.

old:
    efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c80000000) (16384MB)

new:
    efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff] (16384MB)

Example other address range prints:
    SRAT: Node 1 PXM 1 [mem 0x480000000-0x87fffffff]
    PM: Registered nosave memory: [mem 0x880000000-0xc7fffffff]

Signed-off-by: Robert Elliott <elliott@hpe.com>
---
 arch/x86/platform/efi/efi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index ad28540..635a955 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -235,10 +235,10 @@ void __init efi_print_memmap(void)
 		char buf[64];
 
 		md = p;
-		pr_info("mem%02u: %s range=[0x%016llx-0x%016llx) (%lluMB)\n",
+		pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
 			i, efi_md_typeattr_format(buf, sizeof(buf), md),
 			md->phys_addr,
-			md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
+			md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
 			(md->num_pages >> (20 - EFI_PAGE_SHIFT)));
 	}
 #endif  /*  EFI_DEBUG  */
-- 
2.4.3

[PATCH 2/4] efi: add NV memory attribute

[Robert Elliott]

Add the NV memory attribute introduced in UEFI 2.5 and add a column
for it in the types and attributes string used when printing the UEFI
memory map.

old:
efi: mem61: [type=14            |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)

new:
efi: mem61: [type=14            |   |  |NV|  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)

Signed-off-by: Robert Elliott <elliott@hpe.com>
---
 drivers/firmware/efi/efi.c | 5 ++++-
 include/linux/efi.h        | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 027ca21..4dd5464 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -611,13 +611,16 @@ char * __init efi_md_typeattr_format(char *buf, size_t size,
 	if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
 		     EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
 		     EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
+		     EFI_MEMORY_NV |
 		     EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
 		snprintf(pos, size, "|attr=0x%016llx]",
 			 (unsigned long long)attr);
 	else
-		snprintf(pos, size, "|%3s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
+		snprintf(pos, size,
+			 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
 			 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
 			 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
+			 attr & EFI_MEMORY_NV      ? "NV"  : "",
 			 attr & EFI_MEMORY_XP      ? "XP"  : "",
 			 attr & EFI_MEMORY_RP      ? "RP"  : "",
 			 attr & EFI_MEMORY_WP      ? "WP"  : "",
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 569b5a8..9ce9e9e 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -97,6 +97,7 @@ typedef	struct {
 #define EFI_MEMORY_WP		((u64)0x0000000000001000ULL)	/* write-protect */
 #define EFI_MEMORY_RP		((u64)0x0000000000002000ULL)	/* read-protect */
 #define EFI_MEMORY_XP		((u64)0x0000000000004000ULL)	/* execute-protect */
+#define EFI_MEMORY_NV		((u64)0x0000000000008000ULL)	/* non-volatile */
 #define EFI_MEMORY_MORE_RELIABLE \
 				((u64)0x0000000000010000ULL)	/* higher reliability */
 #define EFI_MEMORY_RO		((u64)0x0000000000020000ULL)	/* read-only */
-- 
2.4.3

[PATCH 3/4] efi: add Persistent Memory type name

[Robert Elliott]

Add the "Persistent Memory" string for type 14 introduced in
UEFI 2.5.  This is used when printing the UEFI memory map.

old:
efi: mem61: [type=14            |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)

new:
efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)

Signed-off-by: Robert Elliott <elliott@hpe.com>
---
 drivers/firmware/efi/efi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 4dd5464..0b16e88 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -584,7 +584,8 @@ static __initdata char memory_type_name[][20] = {
 	"ACPI Memory NVS",
 	"Memory Mapped I/O",
 	"MMIO Port Space",
-	"PAL Code"
+	"PAL Code",
+	"Persistent Memory"
 };
 
 char * __init efi_md_typeattr_format(char *buf, size_t size,
-- 
2.4.3

[PATCH 4/4] x86/efi: print size and base in binary units in efi_print_memmap

[Robert Elliott]

Print the base address for each range in decimal alongside the size.
Use a "(size @ base)" format similar to the fake_memmap kernel parameter.

Print the range and base in the best-fit B, KiB, MiB, etc. units rather
than always MiB.  This avoids rounding, which can be misleading.

Use proper IEC binary units (KiB, MiB, etc.) rather than misuse SI
decimal units (KB, MB, etc.).

old:
    efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)

new:
    efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff] (16 GiB @ 34 GiB)

Signed-off-by: Robert Elliott <elliott@hpe.com>
---
 arch/x86/platform/efi/efi.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 635a955..030ba91 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -222,6 +222,25 @@ int __init efi_memblock_x86_reserve_range(void)
 	return 0;
 }
 
+char * __init efi_size_format(char *buf, size_t size, u64 bytes)
+{
+	if (!bytes || (bytes & 0x3ff))
+		snprintf(buf, size, "%llu B", bytes);
+	else if (bytes & 0xfffff)
+		snprintf(buf, size, "%llu KiB", bytes >> 10);
+	else if (bytes & 0x3fffffff)
+		snprintf(buf, size, "%llu MiB", bytes >> 20);
+	else if (bytes & 0xffffffffff)
+		snprintf(buf, size, "%llu GiB", bytes >> 30);
+	else if (bytes & 0x3ffffffffffff)
+		snprintf(buf, size, "%llu TiB", bytes >> 40);
+	else if (bytes & 0xfffffffffffffff)
+		snprintf(buf, size, "%llu PiB", bytes >> 50);
+	else
+		snprintf(buf, size, "%llu EiB", bytes >> 60);
+	return buf;
+}
+
 void __init efi_print_memmap(void)
 {
 #ifdef EFI_DEBUG
@@ -232,14 +251,16 @@ void __init efi_print_memmap(void)
 	for (p = memmap.map, i = 0;
 	     p < memmap.map_end;
 	     p += memmap.desc_size, i++) {
-		char buf[64];
+		char buf[64], buf2[32], buf3[32];
 
 		md = p;
-		pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
+		pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%s @ %s)\n",
 			i, efi_md_typeattr_format(buf, sizeof(buf), md),
 			md->phys_addr,
 			md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
-			(md->num_pages >> (20 - EFI_PAGE_SHIFT)));
+			efi_size_format(buf3, sizeof(buf3),
+				md->num_pages << EFI_PAGE_SHIFT),
+			efi_size_format(buf2, sizeof(buf2), md->phys_addr));
 	}
 #endif  /*  EFI_DEBUG  */
 }
-- 
2.4.3

Re: [PATCH 1/4] x86/efi: show actual ending addresses in efi_print_memmap

[Matt Fleming]

On Thu, 17 Dec, at 07:28:31PM, Robert Elliott wrote:
> Adjust efi_print_memmap to print the real end address of each
> range, not 1 byte beyond. This matches other prints like those for
> SRAT and nosave memory.
> 
> Change the closing ) to ] to match the opening [.
> 
> old:
>     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c80000000) (16384MB)
> 
> new:
>     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff] (16384MB)
> 
> Example other address range prints:
>     SRAT: Node 1 PXM 1 [mem 0x480000000-0x87fffffff]
>     PM: Registered nosave memory: [mem 0x880000000-0xc7fffffff]
> 
> Signed-off-by: Robert Elliott <elliott@hpe.com>
> ---
>  arch/x86/platform/efi/efi.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Is this change purely for aesthetic reasons? We're usually not in the
habit of changing the output of print messages without a good reason
because people downstream do rely on them being consistent.

Re: [PATCH 2/4] efi: add NV memory attribute

[Matt Fleming]

(Cc'ing people that have worked in this area recently)

On Thu, 17 Dec, at 07:28:32PM, Robert Elliott wrote:
> Add the NV memory attribute introduced in UEFI 2.5 and add a column
> for it in the types and attributes string used when printing the UEFI
> memory map.
> 
> old:
> efi: mem61: [type=14            |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)
> 
> new:
> efi: mem61: [type=14            |   |  |NV|  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)
> 
> Signed-off-by: Robert Elliott <elliott@hpe.com>
> ---
>  drivers/firmware/efi/efi.c | 5 ++++-
>  include/linux/efi.h        | 1 +
>  2 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 027ca21..4dd5464 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -611,13 +611,16 @@ char * __init efi_md_typeattr_format(char *buf, size_t size,
>  	if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
>  		     EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
>  		     EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
> +		     EFI_MEMORY_NV |
>  		     EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
>  		snprintf(pos, size, "|attr=0x%016llx]",
>  			 (unsigned long long)attr);
>  	else
> -		snprintf(pos, size, "|%3s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
> +		snprintf(pos, size,
> +			 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
>  			 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
>  			 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
> +			 attr & EFI_MEMORY_NV      ? "NV"  : "",
>  			 attr & EFI_MEMORY_XP      ? "XP"  : "",
>  			 attr & EFI_MEMORY_RP      ? "RP"  : "",
>  			 attr & EFI_MEMORY_WP      ? "WP"  : "",
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index 569b5a8..9ce9e9e 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -97,6 +97,7 @@ typedef	struct {
>  #define EFI_MEMORY_WP		((u64)0x0000000000001000ULL)	/* write-protect */
>  #define EFI_MEMORY_RP		((u64)0x0000000000002000ULL)	/* read-protect */
>  #define EFI_MEMORY_XP		((u64)0x0000000000004000ULL)	/* execute-protect */
> +#define EFI_MEMORY_NV		((u64)0x0000000000008000ULL)	/* non-volatile */
>  #define EFI_MEMORY_MORE_RELIABLE \
>  				((u64)0x0000000000010000ULL)	/* higher reliability */
>  #define EFI_MEMORY_RO		((u64)0x0000000000020000ULL)	/* read-only */

Seems straight forward to me.

Applied, thanks.

Re: [PATCH 1/4] x86/efi: show actual ending addresses in efi_print_memmap

[Matt Fleming]

On Mon, 21 Dec, at 03:50:38PM, Matt Fleming wrote:
> On Thu, 17 Dec, at 07:28:31PM, Robert Elliott wrote:
> > Adjust efi_print_memmap to print the real end address of each
> > range, not 1 byte beyond. This matches other prints like those for
> > SRAT and nosave memory.
> > 
> > Change the closing ) to ] to match the opening [.
> > 
> > old:
> >     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c80000000) (16384MB)
> > 
> > new:
> >     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff] (16384MB)
> > 
> > Example other address range prints:
> >     SRAT: Node 1 PXM 1 [mem 0x480000000-0x87fffffff]
> >     PM: Registered nosave memory: [mem 0x880000000-0xc7fffffff]
> > 
> > Signed-off-by: Robert Elliott <elliott@hpe.com>
> > ---
> >  arch/x86/platform/efi/efi.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> Is this change purely for aesthetic reasons? We're usually not in the
> habit of changing the output of print messages without a good reason
> because people downstream do rely on them being consistent.

I just noticed the bracket change.

My comment above only refers to printing the range addresses. Swapping
')' for ']' is a perfectly valid change.

Re: [PATCH 4/4] x86/efi: print size and base in binary units in efi_print_memmap

[Matt Fleming]

On Thu, 17 Dec, at 07:28:34PM, Robert Elliott wrote:
> Print the base address for each range in decimal alongside the size.
> Use a "(size @ base)" format similar to the fake_memmap kernel parameter.
> 
> Print the range and base in the best-fit B, KiB, MiB, etc. units rather
> than always MiB.  This avoids rounding, which can be misleading.
> 
> Use proper IEC binary units (KiB, MiB, etc.) rather than misuse SI
> decimal units (KB, MB, etc.).
> 
> old:
>     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)
> 
> new:
>     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff] (16 GiB @ 34 GiB)
> 
> Signed-off-by: Robert Elliott <elliott@hpe.com>
> ---
>  arch/x86/platform/efi/efi.c | 27 ++++++++++++++++++++++++---
>  1 file changed, 24 insertions(+), 3 deletions(-)
 
I'm not at all sure of the value of printing the physical address as a
size. I would have thought that you'd have to convert it back to an
address whenever you wanted to use it anyway.

> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> index 635a955..030ba91 100644
> --- a/arch/x86/platform/efi/efi.c
> +++ b/arch/x86/platform/efi/efi.c
> @@ -222,6 +222,25 @@ int __init efi_memblock_x86_reserve_range(void)
>  	return 0;
>  }
>  
> +char * __init efi_size_format(char *buf, size_t size, u64 bytes)
> +{
> +	if (!bytes || (bytes & 0x3ff))
> +		snprintf(buf, size, "%llu B", bytes);
> +	else if (bytes & 0xfffff)
> +		snprintf(buf, size, "%llu KiB", bytes >> 10);
> +	else if (bytes & 0x3fffffff)
> +		snprintf(buf, size, "%llu MiB", bytes >> 20);
> +	else if (bytes & 0xffffffffff)
> +		snprintf(buf, size, "%llu GiB", bytes >> 30);
> +	else if (bytes & 0x3ffffffffffff)
> +		snprintf(buf, size, "%llu TiB", bytes >> 40);
> +	else if (bytes & 0xfffffffffffffff)
> +		snprintf(buf, size, "%llu PiB", bytes >> 50);
> +	else
> +		snprintf(buf, size, "%llu EiB", bytes >> 60);
> +	return buf;
> +}
> +

Can we use string_get_size() instead of rolling our own function?

RE: [PATCH 1/4] x86/efi: show actual ending addresses in efi_print_memmap

[Elliott, Robert (Persistent Memory)]

> -----Original Message-----
> From: Matt Fleming [mailto:matt@codeblueprint.co.uk]
> Sent: Monday, December 21, 2015 9:51 AM
> To: Elliott, Robert (Persistent Memory) <elliott@hpe.com>
> Cc: tglx@linutronix.de; mingo@redhat.com; hpa@zytor.com; x86@kernel.org;
> linux-efi@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH 1/4] x86/efi: show actual ending addresses in
> efi_print_memmap
> 
> On Thu, 17 Dec, at 07:28:31PM, Robert Elliott wrote:
> > Adjust efi_print_memmap to print the real end address of each
> > range, not 1 byte beyond. This matches other prints like those for
> > SRAT and nosave memory.
> >
> > Change the closing ) to ] to match the opening [.
> >
> > old:
> >     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC]
> range=[0x0000000880000000-0x0000000c80000000) (16384MB)
> >
> > new:
> >     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC]
> range=[0x0000000880000000-0x0000000c7fffffff] (16384MB)
> >
> > Example other address range prints:
> >     SRAT: Node 1 PXM 1 [mem 0x480000000-0x87fffffff]
> >     PM: Registered nosave memory: [mem 0x880000000-0xc7fffffff]
> >
> > Signed-off-by: Robert Elliott <elliott@hpe.com>
> > ---
> >  arch/x86/platform/efi/efi.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> Is this change purely for aesthetic reasons? We're usually not in the
> habit of changing the output of print messages without a good reason
> because people downstream do rely on them being consistent.

The format of that line is architecture-specific and only appears
under the efi=debug kernel parameter, so I don't know how much
anyone relies on the specific format.  Good question for the lists.

arch/ia64/kernel/efi.c shares the range=[...) format, but prints
the range after the bitmask rather than before:
	printk("mem%02d: %s "
		"range=[0x%016lx-0x%016lx) (%4lu%s)\n",
		i, efi_md_typeattr_format(buf, sizeof(buf), md),
		md->phys_addr,
		md->phys_addr + efi_md_size(md), size, unit);

arch/arm64/kernel/efi.c has no mem prefix, or range=[...) text
surrounding the range:
	pr_info("  0x%012llx-0x%012llx %s",
		paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
		efi_md_typeattr_format(buf, sizeof(buf), md));
	pr_cont("*");
	pr_cont("\n");

The x86 code is inside ifdef EFI_DEBUG, which is always
defined in that file.  I wonder if it was supposed to change
to efi_enabled(EFI_DBG) to be based off the efi=debug kernel
parameter?  efi_init() qualified the call to this function
based on that:
        if (efi_enabled(EFI_DBG))
                efi_print_memmap();

In arch/ia64/kernel/efi.c efi_init(), EFI_DEBUG is set to 0
so the print doesn't happen at all without editing the
source code.  It doesn't use efi_enabled(EFI_DBG).

arch/arm64/kernel/efi.c uses efi_enabled(EFI_DBG) exclusively.

---
Robert Elliott, HPE Persistent Memory

RE: [PATCH 1/4] x86/efi: show actual ending addresses in efi_print_memmap

[Elliott, Robert (Persistent Memory)]

---
Robert Elliott, HPE Persistent Memory


> -----Original Message-----
> From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel-
> owner@vger.kernel.org] On Behalf Of Matt Fleming
> Sent: Monday, December 21, 2015 10:06 AM
> To: Elliott, Robert (Persistent Memory) <elliott@hpe.com>
> Cc: tglx@linutronix.de; mingo@redhat.com; hpa@zytor.com; x86@kernel.org;
> linux-efi@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH 1/4] x86/efi: show actual ending addresses in
> efi_print_memmap
> 
> On Mon, 21 Dec, at 03:50:38PM, Matt Fleming wrote:
> > On Thu, 17 Dec, at 07:28:31PM, Robert Elliott wrote:
> > > Adjust efi_print_memmap to print the real end address of each
> > > range, not 1 byte beyond. This matches other prints like those for
> > > SRAT and nosave memory.
> > >
> > > Change the closing ) to ] to match the opening [.
> > >
> > > old:
> > >     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |
> |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c80000000) (16384MB)
> > >
> > > new:
> > >     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |
> |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff] (16384MB)
> > >
> > > Example other address range prints:
> > >     SRAT: Node 1 PXM 1 [mem 0x480000000-0x87fffffff]
> > >     PM: Registered nosave memory: [mem 0x880000000-0xc7fffffff]
> > >
> > > Signed-off-by: Robert Elliott <elliott@hpe.com>
> > > ---
> > >  arch/x86/platform/efi/efi.c | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > Is this change purely for aesthetic reasons? We're usually not in the
> > habit of changing the output of print messages without a good reason
> > because people downstream do rely on them being consistent.
> 
> I just noticed the bracket change.
> 
> My comment above only refers to printing the range addresses. Swapping
> ')' for ']' is a perfectly valid change.

While investigating the grub persistent memory corruption
issues, it was helpful to make this table match the ending
address convention used by:
* the kernel's e820 table prints
* the kernel's nosave memory prints
* grub's lsmmap and lsefimmap commands
* the UEFI shell's memmap command

Using the excerpts from the patch, if you grep all the various
logs for c7fffffff, you won't find the line with c80000000.

RE: [PATCH 4/4] x86/efi: print size and base in binary units in efi_print_memmap

[Elliott, Robert (Persistent Memory)]

> -----Original Message-----
> From: Matt Fleming [mailto:matt@codeblueprint.co.uk]
> Sent: Monday, December 21, 2015 10:16 AM
> To: Elliott, Robert (Persistent Memory) <elliott@hpe.com>
> Cc: tglx@linutronix.de; mingo@redhat.com; hpa@zytor.com; x86@kernel.org;
> linux-efi@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH 4/4] x86/efi: print size and base in binary units in
> efi_print_memmap
> 
> On Thu, 17 Dec, at 07:28:34PM, Robert Elliott wrote:
> > Print the base address for each range in decimal alongside the size.
> > Use a "(size @ base)" format similar to the fake_memmap kernel
> parameter.
> >
> > Print the range and base in the best-fit B, KiB, MiB, etc. units rather
> > than always MiB.  This avoids rounding, which can be misleading.
> >
> > Use proper IEC binary units (KiB, MiB, etc.) rather than misuse SI
> > decimal units (KB, MB, etc.).
> >
> > old:
> >     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC]
> range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)
> >
> > new:
> >     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC]
> range=[0x0000000880000000-0x0000000c7fffffff] (16 GiB @ 34 GiB)
> >
> > Signed-off-by: Robert Elliott <elliott@hpe.com>
> > ---
> >  arch/x86/platform/efi/efi.c | 27 ++++++++++++++++++++++++---
> >  1 file changed, 24 insertions(+), 3 deletions(-)
> 
> I'm not at all sure of the value of printing the physical address as a
> size. I would have thought that you'd have to convert it back to an
> address whenever you wanted to use it anyway.

I was trying to make it resemble the memmap=size@address 
kernel parameter format for creating e820 entries, which
does accept abbreviations in addition to hex values:
	memmap=nn[KMG]@ss[KMG] for usable DRAM
	memmap=nn[KMG]#ss[KMG] for ACPI data
	memmap=nn[KMG]$ss[KMG] for reserved
	memmap=nn[KMG]!ss[KMG] for persistent memory

Mapping the UEFI type to the corresponding @, #, $, or ! was
more than I wanted to tackle, so it's not a drop-in
replacement string.

memparse() also accepts T, P, and E units; I guess those
need to be added to Documentation/kernel-parameters.txt.

> > diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> > index 635a955..030ba91 100644
> > --- a/arch/x86/platform/efi/efi.c
> > +++ b/arch/x86/platform/efi/efi.c
> > @@ -222,6 +222,25 @@ int __init efi_memblock_x86_reserve_range(void)
> >  	return 0;
> >  }
> >
> > +char * __init efi_size_format(char *buf, size_t size, u64 bytes)
> > +{
> > +	if (!bytes || (bytes & 0x3ff))
> > +		snprintf(buf, size, "%llu B", bytes);
> > +	else if (bytes & 0xfffff)
> > +		snprintf(buf, size, "%llu KiB", bytes >> 10);
> > +	else if (bytes & 0x3fffffff)
> > +		snprintf(buf, size, "%llu MiB", bytes >> 20);
> > +	else if (bytes & 0xffffffffff)
> > +		snprintf(buf, size, "%llu GiB", bytes >> 30);
> > +	else if (bytes & 0x3ffffffffffff)
> > +		snprintf(buf, size, "%llu TiB", bytes >> 40);
> > +	else if (bytes & 0xfffffffffffffff)
> > +		snprintf(buf, size, "%llu PiB", bytes >> 50);
> > +	else
> > +		snprintf(buf, size, "%llu EiB", bytes >> 60);
> > +	return buf;
> > +}
> > +
> 
> Can we use string_get_size() instead of rolling our own function?

Thanks for the pointer; I wondered if there was a similar
function somewhere.  However, that function throws away
precision in favor of printing just 3 significant digits;
I think that's dangerous.  Its non-integer output is not
supported by memmap=, and the function appears to use
assembly code to get CPU divide instructions, losing the
ability to use shifts for these power of two divisions.

Example results...

efi: mem01:... range=[0x0000000000093000-0x0000000000093fff] (4 KiB @ 588 KiB)
efi: mem01:... range=[0x0000000000093000-0x0000000000093fff] (4.00 KiB @ 588 KiB) SGS

efi: mem03:... range=[0x0000000000100000-0x00000000013e8fff] (19364 KiB @ 1 MiB)
efi: mem03:... range=[0x0000000000100000-0x00000000013e8fff] (18.9 MiB @ 1.00 MiB) SGS
(example of lost precision: 19364 KiB is really 18.91015625 MiB)

efi: mem04:... range=[0x00000000013e9000-0x0000000001ffffff] (12380 KiB @ 20388 KiB)
efi: mem04:... range=[0x00000000013e9000-0x0000000001ffffff] (12.0 MiB @ 19.9 MiB) SGS

efi: mem28:... range=[0x00000000717c2000-0x0000000072acafff] (19492 KiB @ 1859336 KiB)
efi: mem28:... range=[0x00000000717c2000-0x0000000072acafff] (19.0 MiB @ 1.77 GiB) SGS

efi: mem57:... range=[0x0000000880000000-0x0000000e7fffffff] (24 GiB @ 34 GiB)
efi: mem57:... range=[0x0000000880000000-0x0000000e7fffffff] (24.0 GiB @ 34.0 GiB) SGS

---
Robert Elliott, HPE Persistent Memory

Re: [PATCH 1/4] x86/efi: show actual ending addresses in efi_print_memmap

[Matt Fleming]

On Tue, 22 Dec, at 08:08:19PM, Elliott, Robert (Persistent Memory) wrote:
> 
> While investigating the grub persistent memory corruption
> issues, it was helpful to make this table match the ending
> address convention used by:
> * the kernel's e820 table prints
> * the kernel's nosave memory prints
> * grub's lsmmap and lsefimmap commands
> * the UEFI shell's memmap command
> 
> Using the excerpts from the patch, if you grep all the various
> logs for c7fffffff, you won't find the line with c80000000.

I like this. This is reasonable justification. Please inclue it in the
commit log.

Re: [PATCH 1/4] x86/efi: show actual ending addresses in efi_print_memmap

[Matt Fleming]

On Mon, 21 Dec, at 04:44:19PM, Elliott, Robert (Persistent Memory) wrote:
> 
> The format of that line is architecture-specific and only appears
> under the efi=debug kernel parameter, so I don't know how much
> anyone relies on the specific format.  Good question for the lists.
 
Both kernel and non-kernel developers are consumers of these debug
statements, and people do come to rely on the format of the text.

I have certainly become acustomed to the current format we have,
particularly when debugging issues via other users, i.e. when I'm not
the person running the kernel being debugged.

Just because it's a debug option doesn't mean it's completely open to
modification. Reasonable Justification must be provided. Having said
that, I think you provide a good argument in your other email,

  https://lkml.kernel.org/r/94D0CD8314A33A4D9D801C0FE68B40295BEC74CF@G9W0745.americas.hpqcorp.net

> arch/ia64/kernel/efi.c shares the range=[...) format, but prints
> the range after the bitmask rather than before:
> 	printk("mem%02d: %s "
> 		"range=[0x%016lx-0x%016lx) (%4lu%s)\n",
> 		i, efi_md_typeattr_format(buf, sizeof(buf), md),
> 		md->phys_addr,
> 		md->phys_addr + efi_md_size(md), size, unit);
> 
> arch/arm64/kernel/efi.c has no mem prefix, or range=[...) text
> surrounding the range:
> 	pr_info("  0x%012llx-0x%012llx %s",
> 		paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
> 		efi_md_typeattr_format(buf, sizeof(buf), md));
> 	pr_cont("*");
> 	pr_cont("\n");
> 
> The x86 code is inside ifdef EFI_DEBUG, which is always
> defined in that file.  I wonder if it was supposed to change
> to efi_enabled(EFI_DBG) to be based off the efi=debug kernel
> parameter?  efi_init() qualified the call to this function
> based on that:
>         if (efi_enabled(EFI_DBG))
>                 efi_print_memmap();
 
The EFI_DEBUG symbol should just be deleted. It's been enabled since
forever and really provides no value, because as you point out,
printing of the memory map is guarded by EFI_DBG anyway.

I'll send out a patch for ripping that out.

> In arch/ia64/kernel/efi.c efi_init(), EFI_DEBUG is set to 0
> so the print doesn't happen at all without editing the
> source code.  It doesn't use efi_enabled(EFI_DBG).
> 
> arch/arm64/kernel/efi.c uses efi_enabled(EFI_DBG) exclusively.

Re: [PATCH 4/4] x86/efi: print size and base in binary units in efi_print_memmap

[Matt Fleming]

On Wed, 23 Dec, at 12:11:56AM, Elliott, Robert (Persistent Memory) wrote:
> 
> I was trying to make it resemble the memmap=size@address 
> kernel parameter format for creating e820 entries, which
> does accept abbreviations in addition to hex values:
> 	memmap=nn[KMG]@ss[KMG] for usable DRAM
> 	memmap=nn[KMG]#ss[KMG] for ACPI data
> 	memmap=nn[KMG]$ss[KMG] for reserved
> 	memmap=nn[KMG]!ss[KMG] for persistent memory
> 
> Mapping the UEFI type to the corresponding @, #, $, or ! was
> more than I wanted to tackle, so it's not a drop-in
> replacement string.
> 
> memparse() also accepts T, P, and E units; I guess those
> need to be added to Documentation/kernel-parameters.txt.
 
I think the value of the "@ address" portion of the string is
questionable.

> Thanks for the pointer; I wondered if there was a similar
> function somewhere.  However, that function throws away
> precision in favor of printing just 3 significant digits;
> I think that's dangerous.  Its non-integer output is not
> supported by memmap=, and the function appears to use
> assembly code to get CPU divide instructions, losing the
> ability to use shifts for these power of two divisions.
> 
> Example results...
> 
> efi: mem01:... range=[0x0000000000093000-0x0000000000093fff] (4 KiB @ 588 KiB)
> efi: mem01:... range=[0x0000000000093000-0x0000000000093fff] (4.00 KiB @ 588 KiB) SGS
> 
> efi: mem03:... range=[0x0000000000100000-0x00000000013e8fff] (19364 KiB @ 1 MiB)
> efi: mem03:... range=[0x0000000000100000-0x00000000013e8fff] (18.9 MiB @ 1.00 MiB) SGS
> (example of lost precision: 19364 KiB is really 18.91015625 MiB)
> 
> efi: mem04:... range=[0x00000000013e9000-0x0000000001ffffff] (12380 KiB @ 20388 KiB)
> efi: mem04:... range=[0x00000000013e9000-0x0000000001ffffff] (12.0 MiB @ 19.9 MiB) SGS
> 
> efi: mem28:... range=[0x00000000717c2000-0x0000000072acafff] (19492 KiB @ 1859336 KiB)
> efi: mem28:... range=[0x00000000717c2000-0x0000000072acafff] (19.0 MiB @ 1.77 GiB) SGS
> 
> efi: mem57:... range=[0x0000000880000000-0x0000000e7fffffff] (24 GiB @ 34 GiB)
> efi: mem57:... range=[0x0000000880000000-0x0000000e7fffffff] (24.0 GiB @ 34.0 GiB) SGS

Good points! I agree that string_get_size() (unfortunately) doesn't
look useful in this scenario. The code in efi_size_format() looks
fine.

[PATCH v2 1/4] x86/efi: show actual ending addresses in efi_print_memmap

[Robert Elliott]

Adjust efi_print_memmap to print the real end address of each
range, not 1 byte beyond. This matches other prints like those for
SRAT and nosave memory.

While investigating grub persistent memory corruption issues, it
was helpful to make this table match the ending address convention
used by:
* the kernel's e820 table prints
	BIOS-e820: [mem 0x0000001680000000-0x0000001c7fffffff] reserved
* the kernel's nosave memory prints
	PM: Registered nosave memory: [mem 0x880000000-0xc7fffffff]
* the kernel's ACPI System Resource Affinity Table prints
	SRAT: Node 1 PXM 1 [mem 0x480000000-0x87fffffff]
* grub's lsmmap and lsefimmap commands
	reserved  0000001680000000-0000001c7fffffff 00600000     24GiB UC WC WT WB NV
* the UEFI shell's memmap command
	Reserved   000000007FC00000-000000007FFFFFFF 0000000000000400 0000000000000001

For example, if you grep all the various logs for c7fffffff, you
won't find the kernel's line if it uses c80000000.

Also, change the closing ) to ] to match the opening [.

old:
    efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c80000000) (16384MB)

new:
    efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff] (16384MB)

Signed-off-by: Robert Elliott <elliott@hpe.com>
---
Changes in v2:
 - Expanded rationale in the commit message
---
 arch/x86/platform/efi/efi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index ad28540..635a955 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -235,10 +235,10 @@ void __init efi_print_memmap(void)
 		char buf[64];
 
 		md = p;
-		pr_info("mem%02u: %s range=[0x%016llx-0x%016llx) (%lluMB)\n",
+		pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
 			i, efi_md_typeattr_format(buf, sizeof(buf), md),
 			md->phys_addr,
-			md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
+			md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
 			(md->num_pages >> (20 - EFI_PAGE_SHIFT)));
 	}
 #endif  /*  EFI_DEBUG  */
-- 
2.4.3

Re: [PATCH 4/4] x86/efi: print size and base in binary units in efi_print_memmap

[Andy Shevchenko]

On Mon, Dec 21, 2015 at 6:16 PM, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> On Thu, 17 Dec, at 07:28:34PM, Robert Elliott wrote:
>> Print the base address for each range in decimal alongside the size.
>> Use a "(size @ base)" format similar to the fake_memmap kernel parameter.
>>
>> Print the range and base in the best-fit B, KiB, MiB, etc. units rather
>> than always MiB.  This avoids rounding, which can be misleading.
>>
>> Use proper IEC binary units (KiB, MiB, etc.) rather than misuse SI
>> decimal units (KB, MB, etc.).
>>
>> old:
>>     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)
>>
>> new:
>>     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff] (16 GiB @ 34 GiB)
>>
>> Signed-off-by: Robert Elliott <elliott@hpe.com>
>> ---
>>  arch/x86/platform/efi/efi.c | 27 ++++++++++++++++++++++++---
>>  1 file changed, 24 insertions(+), 3 deletions(-)
>
> I'm not at all sure of the value of printing the physical address as a
> size. I would have thought that you'd have to convert it back to an
> address whenever you wanted to use it anyway.
>
>> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
>> index 635a955..030ba91 100644
>> --- a/arch/x86/platform/efi/efi.c
>> +++ b/arch/x86/platform/efi/efi.c
>> @@ -222,6 +222,25 @@ int __init efi_memblock_x86_reserve_range(void)
>>       return 0;
>>  }
>>
>> +char * __init efi_size_format(char *buf, size_t size, u64 bytes)
>> +{
>> +     if (!bytes || (bytes & 0x3ff))
>> +             snprintf(buf, size, "%llu B", bytes);
>> +     else if (bytes & 0xfffff)
>> +             snprintf(buf, size, "%llu KiB", bytes >> 10);
>> +     else if (bytes & 0x3fffffff)
>> +             snprintf(buf, size, "%llu MiB", bytes >> 20);
>> +     else if (bytes & 0xffffffffff)
>> +             snprintf(buf, size, "%llu GiB", bytes >> 30);
>> +     else if (bytes & 0x3ffffffffffff)
>> +             snprintf(buf, size, "%llu TiB", bytes >> 40);
>> +     else if (bytes & 0xfffffffffffffff)
>> +             snprintf(buf, size, "%llu PiB", bytes >> 50);
>> +     else
>> +             snprintf(buf, size, "%llu EiB", bytes >> 60);
>> +     return buf;

For me it looks like ffs with name in the table can be used.

>> +}
>> +
>
> Can we use string_get_size() instead of rolling our own function?
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/



-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2 1/4] x86/efi: show actual ending addresses in efi_print_memmap

[Matt Fleming]

On Wed, 23 Dec, at 07:07:23PM, Robert Elliott wrote:
> Adjust efi_print_memmap to print the real end address of each
> range, not 1 byte beyond. This matches other prints like those for
> SRAT and nosave memory.
> 
> While investigating grub persistent memory corruption issues, it
> was helpful to make this table match the ending address convention
> used by:
> * the kernel's e820 table prints
> 	BIOS-e820: [mem 0x0000001680000000-0x0000001c7fffffff] reserved
> * the kernel's nosave memory prints
> 	PM: Registered nosave memory: [mem 0x880000000-0xc7fffffff]
> * the kernel's ACPI System Resource Affinity Table prints
> 	SRAT: Node 1 PXM 1 [mem 0x480000000-0x87fffffff]
> * grub's lsmmap and lsefimmap commands
> 	reserved  0000001680000000-0000001c7fffffff 00600000     24GiB UC WC WT WB NV
> * the UEFI shell's memmap command
> 	Reserved   000000007FC00000-000000007FFFFFFF 0000000000000400 0000000000000001
> 
> For example, if you grep all the various logs for c7fffffff, you
> won't find the kernel's line if it uses c80000000.
> 
> Also, change the closing ) to ] to match the opening [.
> 
> old:
>     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c80000000) (16384MB)
> 
> new:
>     efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff] (16384MB)
> 
> Signed-off-by: Robert Elliott <elliott@hpe.com>
> ---
> Changes in v2:
>  - Expanded rationale in the commit message
> ---
>  arch/x86/platform/efi/efi.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Thanks Robert, I've queued this up for v4.6.

Re: [PATCH 4/4] x86/efi: print size and base in binary units in efi_print_memmap

[Matt Fleming]

On Sun, 27 Dec, at 04:35:12PM, Andy Shevchenko wrote:
> On Mon, Dec 21, 2015 at 6:16 PM, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> >> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> >> index 635a955..030ba91 100644
> >> --- a/arch/x86/platform/efi/efi.c
> >> +++ b/arch/x86/platform/efi/efi.c
> >> @@ -222,6 +222,25 @@ int __init efi_memblock_x86_reserve_range(void)
> >>       return 0;
> >>  }
> >>
> >> +char * __init efi_size_format(char *buf, size_t size, u64 bytes)
> >> +{
> >> +     if (!bytes || (bytes & 0x3ff))
> >> +             snprintf(buf, size, "%llu B", bytes);
> >> +     else if (bytes & 0xfffff)
> >> +             snprintf(buf, size, "%llu KiB", bytes >> 10);
> >> +     else if (bytes & 0x3fffffff)
> >> +             snprintf(buf, size, "%llu MiB", bytes >> 20);
> >> +     else if (bytes & 0xffffffffff)
> >> +             snprintf(buf, size, "%llu GiB", bytes >> 30);
> >> +     else if (bytes & 0x3ffffffffffff)
> >> +             snprintf(buf, size, "%llu TiB", bytes >> 40);
> >> +     else if (bytes & 0xfffffffffffffff)
> >> +             snprintf(buf, size, "%llu PiB", bytes >> 50);
> >> +     else
> >> +             snprintf(buf, size, "%llu EiB", bytes >> 60);
> >> +     return buf;
> 
> For me it looks like ffs with name in the table can be used.

Could you provide a patch?

Re: [PATCH 3/4] efi: add Persistent Memory type name

[Matt Fleming]

On Thu, 17 Dec, at 07:28:33PM, Robert Elliott wrote:
> Add the "Persistent Memory" string for type 14 introduced in
> UEFI 2.5.  This is used when printing the UEFI memory map.
> 
> old:
> efi: mem61: [type=14            |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)
> 
> new:
> efi: mem61: [Persistent Memory  |   |  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000880000000-0x0000000c7fffffff) (16384MB)
> 
> Signed-off-by: Robert Elliott <elliott@hpe.com>
> ---
>  drivers/firmware/efi/efi.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Thanks, applied.

RE: [PATCH 4/4] x86/efi: print size and base in binary units in efi_print_memmap

[Elliott, Robert (Persistent Memory)]

> -----Original Message-----
> From: Matt Fleming [mailto:matt@codeblueprint.co.uk]
> Sent: Friday, January 8, 2016 6:19 AM
> To: Andy Shevchenko <andy.shevchenko@gmail.com>
> Cc: Elliott, Robert (Persistent Memory) <elliott@hpe.com>; Thomas Gleixner
> <tglx@linutronix.de>; Ingo Molnar <mingo@redhat.com>; H. Peter Anvin
> <hpa@zytor.com>; x86@kernel.org; linux-efi@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Subject: Re: [PATCH 4/4] x86/efi: print size and base in binary units in
> efi_print_memmap
> 
> On Sun, 27 Dec, at 04:35:12PM, Andy Shevchenko wrote:
> > On Mon, Dec 21, 2015 at 6:16 PM, Matt Fleming <matt@codeblueprint.co.uk>
> wrote:
> > >> diff --git a/arch/x86/platform/efi/efi.c
> b/arch/x86/platform/efi/efi.c
> > >> index 635a955..030ba91 100644
> > >> --- a/arch/x86/platform/efi/efi.c
> > >> +++ b/arch/x86/platform/efi/efi.c
> > >> @@ -222,6 +222,25 @@ int __init efi_memblock_x86_reserve_range(void)
> > >>       return 0;
> > >>  }
> > >>
> > >> +char * __init efi_size_format(char *buf, size_t size, u64 bytes)
> > >> +{
> > >> +     if (!bytes || (bytes & 0x3ff))
> > >> +             snprintf(buf, size, "%llu B", bytes);
> > >> +     else if (bytes & 0xfffff)
> > >> +             snprintf(buf, size, "%llu KiB", bytes >> 10);
> > >> +     else if (bytes & 0x3fffffff)
> > >> +             snprintf(buf, size, "%llu MiB", bytes >> 20);
> > >> +     else if (bytes & 0xffffffffff)
> > >> +             snprintf(buf, size, "%llu GiB", bytes >> 30);
> > >> +     else if (bytes & 0x3ffffffffffff)
> > >> +             snprintf(buf, size, "%llu TiB", bytes >> 40);
> > >> +     else if (bytes & 0xfffffffffffffff)
> > >> +             snprintf(buf, size, "%llu PiB", bytes >> 50);
> > >> +     else
> > >> +             snprintf(buf, size, "%llu EiB", bytes >> 60);
> > >> +     return buf;
> >
> > For me it looks like ffs with name in the table can be used.
> 
> Could you provide a patch?

I think this is functionally equivalent:
#include <string.h>

char * efi_size_format_ffsl(char *buf, size_t size, u64 bytes)
{
	if (!bytes || ffsl(bytes) < 10)
		snprintf(buf, size, "%llu B", bytes);
	else if (ffsl(bytes) < 20)
		snprintf(buf, size, "%llu KiB", bytes >> 10);
	else if (ffsl(bytes) < 30)
		snprintf(buf, size, "%llu MiB", bytes >> 20);
	else if (ffsl(bytes) < 40)
		snprintf(buf, size, "%llu GiB", bytes >> 30);
	else if (ffsl(bytes) < 50)
		snprintf(buf, size, "%llu TiB", bytes >> 40);
	else if (ffsl(bytes) < 60)
		snprintf(buf, size, "%llu PiB", bytes >> 50);
	else
		snprintf(buf, size, "%llu EiB", bytes >> 60);
	return buf;
}

Compiled as a user program with gcc -O2, the original results
in mov and testq instructions:
        movq    %rdi, %rbx
        je      .L2
        testl   $1023, %edx
        jne     .L2
        testl   $1048575, %edx
        jne     .L15
        testl   $1073741823, %edx
        jne     .L16
        movabsq $1099511627775, %rax
        testq   %rax, %rdx
        jne     .L17
        movabsq $1125899906842623, %rax
        testq   %rax, %rdx
        jne     .L18
        movabsq $1152921504606846975, %rax
        movq    %rdx, %rcx
        testq   %rax, %rdx
        jne     .L19

while the ffs version uses bit scan forward (bsfq)
and only needs cmpl instructions since the values 
are smaller:
        movq    %rdi, %rbx
        je      .L21
        bsfq    %rdx, %rcx
        addq    $1, %rcx
        cmpl    $9, %ecx
        jle     .L21
        cmpl    $19, %ecx
        jle     .L33
        cmpl    $29, %ecx
        jle     .L34
        cmpl    $39, %ecx
        .p2align 4,,2
        jle     .L35
        cmpl    $49, %ecx
        .p2align 4,,2
        jle     .L36
        cmpl    $59, %ecx
        .p2align 4,,2
        jle     .L37

The kernel offers ffs(int x) but not ffsl(), and it 
uses inline assembly for one of these:
	bsfl 
	bsfl, cmovzl
	bsfl, jnz, movl

I don't know which code is the most efficient.
---
Robert Elliott, HPE Persistent Memory

Re: [PATCH 4/4] x86/efi: print size and base in binary units in efi_print_memmap

[Andy Shevchenko]

On Fri, Jan 8, 2016 at 2:19 PM, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> On Sun, 27 Dec, at 04:35:12PM, Andy Shevchenko wrote:
>> On Mon, Dec 21, 2015 at 6:16 PM, Matt Fleming <matt@codeblueprint.co.uk> wrote:
>> >> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
>> >> index 635a955..030ba91 100644
>> >> --- a/arch/x86/platform/efi/efi.c
>> >> +++ b/arch/x86/platform/efi/efi.c
>> >> @@ -222,6 +222,25 @@ int __init efi_memblock_x86_reserve_range(void)
>> >>       return 0;
>> >>  }
>> >>
>> >> +char * __init efi_size_format(char *buf, size_t size, u64 bytes)
>> >> +{
>> >> +     if (!bytes || (bytes & 0x3ff))
>> >> +             snprintf(buf, size, "%llu B", bytes);
>> >> +     else if (bytes & 0xfffff)
>> >> +             snprintf(buf, size, "%llu KiB", bytes >> 10);
>> >> +     else if (bytes & 0x3fffffff)
>> >> +             snprintf(buf, size, "%llu MiB", bytes >> 20);
>> >> +     else if (bytes & 0xffffffffff)
>> >> +             snprintf(buf, size, "%llu GiB", bytes >> 30);
>> >> +     else if (bytes & 0x3ffffffffffff)
>> >> +             snprintf(buf, size, "%llu TiB", bytes >> 40);
>> >> +     else if (bytes & 0xfffffffffffffff)
>> >> +             snprintf(buf, size, "%llu PiB", bytes >> 50);
>> >> +     else
>> >> +             snprintf(buf, size, "%llu EiB", bytes >> 60);
>> >> +     return buf;
>>
>> For me it looks like ffs with name in the table can be used.
>
> Could you provide a patch?

I will prepare something this weekend, or latest next week.

I suppose I can apply Robert's one on top of your efi/next and update it, right?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH 4/4] x86/efi: print size and base in binary units in efi_print_memmap

[Andy Shevchenko]

On Fri, Jan 8, 2016 at 6:38 PM, Elliott, Robert (Persistent Memory)
<elliott@hpe.com> wrote:
>> -----Original Message-----
>> From: Matt Fleming [mailto:matt@codeblueprint.co.uk]
>> Sent: Friday, January 8, 2016 6:19 AM
>> To: Andy Shevchenko <andy.shevchenko@gmail.com>
>> Cc: Elliott, Robert (Persistent Memory) <elliott@hpe.com>; Thomas Gleixner
>> <tglx@linutronix.de>; Ingo Molnar <mingo@redhat.com>; H. Peter Anvin
>> <hpa@zytor.com>; x86@kernel.org; linux-efi@vger.kernel.org; linux-
>> kernel@vger.kernel.org
>> Subject: Re: [PATCH 4/4] x86/efi: print size and base in binary units in
>> efi_print_memmap
>>
>> On Sun, 27 Dec, at 04:35:12PM, Andy Shevchenko wrote:
>> > On Mon, Dec 21, 2015 at 6:16 PM, Matt Fleming <matt@codeblueprint.co.uk>
>> wrote:
>> > >> diff --git a/arch/x86/platform/efi/efi.c
>> b/arch/x86/platform/efi/efi.c
>> > >> index 635a955..030ba91 100644
>> > >> --- a/arch/x86/platform/efi/efi.c
>> > >> +++ b/arch/x86/platform/efi/efi.c
>> > >> @@ -222,6 +222,25 @@ int __init efi_memblock_x86_reserve_range(void)
>> > >>       return 0;
>> > >>  }
>> > >>
>> > >> +char * __init efi_size_format(char *buf, size_t size, u64 bytes)
>> > >> +{
>> > >> +     if (!bytes || (bytes & 0x3ff))
>> > >> +             snprintf(buf, size, "%llu B", bytes);
>> > >> +     else if (bytes & 0xfffff)
>> > >> +             snprintf(buf, size, "%llu KiB", bytes >> 10);
>> > >> +     else if (bytes & 0x3fffffff)
>> > >> +             snprintf(buf, size, "%llu MiB", bytes >> 20);
>> > >> +     else if (bytes & 0xffffffffff)
>> > >> +             snprintf(buf, size, "%llu GiB", bytes >> 30);
>> > >> +     else if (bytes & 0x3ffffffffffff)
>> > >> +             snprintf(buf, size, "%llu TiB", bytes >> 40);
>> > >> +     else if (bytes & 0xfffffffffffffff)
>> > >> +             snprintf(buf, size, "%llu PiB", bytes >> 50);
>> > >> +     else
>> > >> +             snprintf(buf, size, "%llu EiB", bytes >> 60);
>> > >> +     return buf;
>> >
>> > For me it looks like ffs with name in the table can be used.
>>
>> Could you provide a patch?
>
> I think this is functionally equivalent:
> #include <string.h>
>
> char * efi_size_format_ffsl(char *buf, size_t size, u64 bytes)
> {
>         if (!bytes || ffsl(bytes) < 10)
>                 snprintf(buf, size, "%llu B", bytes);
>         else if (ffsl(bytes) < 20)
>                 snprintf(buf, size, "%llu KiB", bytes >> 10);
>         else if (ffsl(bytes) < 30)
>                 snprintf(buf, size, "%llu MiB", bytes >> 20);
>         else if (ffsl(bytes) < 40)
>                 snprintf(buf, size, "%llu GiB", bytes >> 30);
>         else if (ffsl(bytes) < 50)
>                 snprintf(buf, size, "%llu TiB", bytes >> 40);
>         else if (ffsl(bytes) < 60)
>                 snprintf(buf, size, "%llu PiB", bytes >> 50);
>         else
>                 snprintf(buf, size, "%llu EiB", bytes >> 60);
>         return buf;
> }

No, no, I meant something slightly different.

We already have a table of units. Needs to be shared (patch already
cooked), second stage is to provide proper number and units.

Something like

units = string_units_2;
units_index = __ffs64(value) / 10;
value >>= units_index * 10;

snprintf("%llu%s", value, units[units_index]);


>
> Compiled as a user program with gcc -O2, the original results
> in mov and testq instructions:
>         movq    %rdi, %rbx
>         je      .L2
>         testl   $1023, %edx
>         jne     .L2
>         testl   $1048575, %edx
>         jne     .L15
>         testl   $1073741823, %edx
>         jne     .L16
>         movabsq $1099511627775, %rax
>         testq   %rax, %rdx
>         jne     .L17
>         movabsq $1125899906842623, %rax
>         testq   %rax, %rdx
>         jne     .L18
>         movabsq $1152921504606846975, %rax
>         movq    %rdx, %rcx
>         testq   %rax, %rdx
>         jne     .L19
>
> while the ffs version uses bit scan forward (bsfq)
> and only needs cmpl instructions since the values
> are smaller:
>         movq    %rdi, %rbx
>         je      .L21
>         bsfq    %rdx, %rcx
>         addq    $1, %rcx
>         cmpl    $9, %ecx
>         jle     .L21
>         cmpl    $19, %ecx
>         jle     .L33
>         cmpl    $29, %ecx
>         jle     .L34
>         cmpl    $39, %ecx
>         .p2align 4,,2
>         jle     .L35
>         cmpl    $49, %ecx
>         .p2align 4,,2
>         jle     .L36
>         cmpl    $59, %ecx
>         .p2align 4,,2
>         jle     .L37
>
> The kernel offers ffs(int x) but not ffsl(),

See above.

> and it
> uses inline assembly for one of these:
>         bsfl
>         bsfl, cmovzl
>         bsfl, jnz, movl
>
> I don't know which code is the most efficient.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH 4/4] x86/efi: print size and base in binary units in efi_print_memmap

[Matt Fleming]

On Fri, 08 Jan, at 06:39:28PM, Andy Shevchenko wrote:
> On Fri, Jan 8, 2016 at 2:19 PM, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> > On Sun, 27 Dec, at 04:35:12PM, Andy Shevchenko wrote:
> >> On Mon, Dec 21, 2015 at 6:16 PM, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> >> >> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> >> >> index 635a955..030ba91 100644
> >> >> --- a/arch/x86/platform/efi/efi.c
> >> >> +++ b/arch/x86/platform/efi/efi.c
> >> >> @@ -222,6 +222,25 @@ int __init efi_memblock_x86_reserve_range(void)
> >> >>       return 0;
> >> >>  }
> >> >>
> >> >> +char * __init efi_size_format(char *buf, size_t size, u64 bytes)
> >> >> +{
> >> >> +     if (!bytes || (bytes & 0x3ff))
> >> >> +             snprintf(buf, size, "%llu B", bytes);
> >> >> +     else if (bytes & 0xfffff)
> >> >> +             snprintf(buf, size, "%llu KiB", bytes >> 10);
> >> >> +     else if (bytes & 0x3fffffff)
> >> >> +             snprintf(buf, size, "%llu MiB", bytes >> 20);
> >> >> +     else if (bytes & 0xffffffffff)
> >> >> +             snprintf(buf, size, "%llu GiB", bytes >> 30);
> >> >> +     else if (bytes & 0x3ffffffffffff)
> >> >> +             snprintf(buf, size, "%llu TiB", bytes >> 40);
> >> >> +     else if (bytes & 0xfffffffffffffff)
> >> >> +             snprintf(buf, size, "%llu PiB", bytes >> 50);
> >> >> +     else
> >> >> +             snprintf(buf, size, "%llu EiB", bytes >> 60);
> >> >> +     return buf;
> >>
> >> For me it looks like ffs with name in the table can be used.
> >
> > Could you provide a patch?
> 
> I will prepare something this weekend, or latest next week.
> 
> I suppose I can apply Robert's one on top of your efi/next and update it, right?

Yeah, that should work. Thanks.

Re: [PATCH 4/4] x86/efi: print size and base in binary units in efi_print_memmap

[Andy Shevchenko]

On Mon, Jan 11, 2016 at 4:09 PM, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> On Fri, 08 Jan, at 06:39:28PM, Andy Shevchenko wrote:
>> On Fri, Jan 8, 2016 at 2:19 PM, Matt Fleming <matt@codeblueprint.co.uk> wrote:
>> > On Sun, 27 Dec, at 04:35:12PM, Andy Shevchenko wrote:
>> >> On Mon, Dec 21, 2015 at 6:16 PM, Matt Fleming <matt@codeblueprint.co.uk> wrote:

>> I will prepare something this weekend, or latest next week.
>>
>> I suppose I can apply Robert's one on top of your efi/next and update it, right?
>
> Yeah, that should work. Thanks.

Just sent as promised.

-- 
With Best Regards,
Andy Shevchenko