Hello Adriana,

On Fri, 31 Oct 2025 at 09:41, adriana adriana@arista.com wrote:

From: Adriana Nicolae adriana@arista.com

Signed-off-by: Adriana Nicolae adriana@arista.com

drivers/firmware/dmi_scan.c | 58 +++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+)

diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 70d39adf50dc..acc0e18b8d0f 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -10,6 +10,9 @@ #include <linux/random.h> #include <asm/dmi.h> #include <linux/unaligned.h> +#if IS_ENABLED(CONFIG_OF) +#include <linux/of.h> +#endif

#ifndef SMBIOS_ENTRY_POINT_SCAN_START #define SMBIOS_ENTRY_POINT_SCAN_START 0xF0000 @@ -670,6 +673,54 @@ static int __init dmi_smbios3_present(const u8 *buf) return 1; }

+#if IS_ENABLED(CONFIG_OF) +/**

• • dmi_scan_from_dt - Find and parse DMI/SMBIOS tables from the Device Tree
• • Checks if the bootloader has passed SMBIOS table addresses via the /chosen
• • node in the Device Tree. This follows the standard kernel DT bindings and
• • assumes a fixed 32-byte mapping for the entry point.

Not sure what 'the standard kernel DT bindings' are, or what you mean by 'a fixed 32-byte mapping. You could just drop this sentence, I think, or otherwise, describe that the DT property gives us the physical address of the SMBIOS3 entrypoint structure.

• • Returns true if a valid table is found and successfully parsed.

if a valid entry point is found

• */

+static bool __init dmi_scan_from_dt(void) +{

•   struct device_node *chosen;
  

•   const __be64 *prop;
  

•   char buf[32];
  

•   void __iomem *p;
  

•   bool dmi_available = false;
  

•   u64 addr;
  

•   int len;
  

•   chosen = of_find_node_by_path("/chosen");
  

•   if (!chosen)
  

•           return false;
  

•   prop = of_get_property(chosen, "linux,smbios3-table", &len);
  

•   if (prop && len >= sizeof(u64)) {
  

•           addr = be64_to_cpup(prop);
  

•           p = dmi_early_remap(addr, 32);
  

•           if (p == NULL)
  

•                   goto out;
  

•           memcpy_fromio(buf, p, sizeof(buf));
  

•           dmi_early_unmap(p, 32);
  

•           if (!dmi_smbios3_present(buf)) {
  

•                   dmi_available = true;
  

•                   goto out;
  

•           }
  

•   }
  

+out:

•   of_node_put(chosen);
  

•   return dmi_available;
  

+} +#else +static bool __init dmi_scan_from_dt(void) { return false; } +#endif /* IS_ENABLED(CONFIG_OF) */

static void __init dmi_scan_machine(void) { char __iomem *p, *q; @@ -718,6 +769,13 @@ static void __init dmi_scan_machine(void) dmi_available = 1; return; }

•   } else if (IS_ENABLED(CONFIG_OF) && dmi_scan_from_dt()) {
  

Please drop the IS_ENABLED() here, and fold it into dmi_scan_from_dt(), by doing

if (!IS_ENABLED(CONFIG_OF)) return false;

at the beginning. This removes the need to provide two different versions of dmi_scan_from_dt().

•           /*
  

•            * If EFI is not present or failed, try getting SMBIOS
  

•            * tables from the Device Tree.
  

•            */
  

•           dmi_available = 1;
  

•           return;
    } else if (IS_ENABLED(CONFIG_DMI_SCAN_MACHINE_NON_EFI_FALLBACK)) {
            p = dmi_early_remap(SMBIOS_ENTRY_POINT_SCAN_START, 0x10000);
            if (p == NULL)
  

-- 2.51.0