Messages in this thread | | | From | Richard Hughes <> | Date | Thu, 14 May 2020 13:53:23 +0100 | Subject | Re: [PATCH] mfd: Export LPC attributes for the system SPI chip |
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On Thu, 14 May 2020 at 13:15, Mika Westerberg <mika.westerberg@linux.intel.com> wrote: > > +What: /sys/kernel/security/firmware/bioswe > Should this still be "firmware_protections" or similar. Plain "firmware" > sounds again too generic. Maybe its just me..
It's not always going to be protections provided by the firmware; it might also be restrictions put on the firmware. My first choice was /sys/kernel/security/firmware_security/ but having the double 'security' just looked redundant.
> > + LPC_SPT, /* Sunrise Point */ > > + LPC_KBL, /* Kaby Lake */ > > + LPC_TGL, /* Tiger Lake */ > > These all have the SPI-NOR controller as separate PCI device (as ICL and > others).
For Sunrise Point I see:
00:1f.0 ISA bridge [0601]: Intel Corporation CM236 Chipset LPC/eSPI Controller [8086:a150] (rev 31) 00:1f.0 ISA bridge [0601]: Intel Corporation Sunrise Point LPC Controller/eSPI Controller [8086:9d4e] (rev 21)
For Kaby Lake I see:
00:1f.0 ISA bridge [0601]: Intel Corporation HM175 Chipset LPC/eSPI Controller [8086:a152] (rev 31)",
You're indeed correct about Tiger Lake, my apologies.
> > + [LPC_SPT] = { > > + .name = "Sunrise Point", > > + .spi_type = INTEL_SPI_LPC, > > + }, > > So all of these have LCP/eSPI controller but the SPI-NOR controller is > not accessible through it - it is a separate PCI device.
I have a Sunrise Point system here -- the lspci is here: https://people.freedesktop.org/~hughsient/temp/lspci.txt
Is the SPI-NOR controller perhaps hidden? If I read the BCR @ 0xdc from the 00:1f.0 ISB bridge I get the expected BIOS_WE, BLE and SMM_BWP results.
> Like you said, Evolution seems to mangle these.
I'll use git for future patches, thanks.
> > + pci_read_config_dword(dev, BCR, &bcr); > > + info->writeable = !!(bcr & BCR_WPD); > > + break; > > + > > + case INTEL_SPI_LPC: > > So instead of this, you can add the security attributes to the existing > entries where we are sure there is SPI-NOR controller behind LPC. Here > it is not the case and further..
Sooo I'd use INTEL_SPI_LPT? On my system RCBA isn't set, and so "if (!res->start)" bails out with return -ENODEV;"
> Otherwise this looks good, nice work :)
I thank you for your patience so far, what I've got the hang of this I promise to start being more useful.
Richard.
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