| Message ID | 1448294264-17388-5-git-send-email-somlo@cmu.edu |
|---|---|
| State | New |
| Headers | show |
On 11/23/15 16:57, Gabriel L. Somlo wrote: > From: Gabriel Somlo <somlo@cmu.edu> > > Remove fw_cfg hardware interface details from > Documentation/devicetree/bindings/arm/fw-cfg.txt, > and replace them with a pointer to the authoritative > documentation in the QEMU source tree. > > Signed-off-by: Gabriel Somlo <somlo@cmu.edu> > Cc: Laszlo Ersek <lersek@redhat.com> > --- > Documentation/devicetree/bindings/arm/fw-cfg.txt | 38 ++---------------------- > 1 file changed, 2 insertions(+), 36 deletions(-) > > diff --git a/Documentation/devicetree/bindings/arm/fw-cfg.txt b/Documentation/devicetree/bindings/arm/fw-cfg.txt > index 953fb64..ce27386 100644 > --- a/Documentation/devicetree/bindings/arm/fw-cfg.txt > +++ b/Documentation/devicetree/bindings/arm/fw-cfg.txt > @@ -11,43 +11,9 @@ QEMU exposes the control and data register to ARM guests as memory mapped > registers; their location is communicated to the guest's UEFI firmware in the > DTB that QEMU places at the bottom of the guest's DRAM. > > -The guest writes a selector value (a key) to the selector register, and then > -can read the corresponding data (produced by QEMU) via the data register. If > -the selected entry is writable, the guest can rewrite it through the data > -register. > +The authoritative guest-side hardware interface documentation to the fw_cfg > +device ca be found in "docs/specs/fw_cfg.txt" in the QEMU source tree. ca[n] be found > > -The selector register takes keys in big endian byte order. > - > -The data register allows accesses with 8, 16, 32 and 64-bit width (only at > -offset 0 of the register). Accesses larger than a byte are interpreted as > -arrays, bundled together only for better performance. The bytes constituting > -such a word, in increasing address order, correspond to the bytes that would > -have been transferred by byte-wide accesses in chronological order. > - > -The interface allows guest firmware to download various parameters and blobs > -that affect how the firmware works and what tables it installs for the guest > -OS. For example, boot order of devices, ACPI tables, SMBIOS tables, kernel and > -initrd images for direct kernel booting, virtual machine UUID, SMP information, > -virtual NUMA topology, and so on. > - > -The authoritative registry of the valid selector values and their meanings is > -the QEMU source code; the structure of the data blobs corresponding to the > -individual key values is also defined in the QEMU source code. > - > -The presence of the registers can be verified by selecting the "signature" blob > -with key 0x0000, and reading four bytes from the data register. The returned > -signature is "QEMU". > - > -The outermost protocol (involving the write / read sequences of the control and > -data registers) is expected to be versioned, and/or described by feature bits. > -The interface revision / feature bitmap can be retrieved with key 0x0001. The > -blob to be read from the data register has size 4, and it is to be interpreted > -as a uint32_t value in little endian byte order. The current value > -(corresponding to the above outer protocol) is zero. > - > -The guest kernel is not expected to use these registers (although it is > -certainly allowed to); the device tree bindings are documented here because > -this is where device tree bindings reside in general. > > Required properties: > > As long as Peter is fine with this, I don't object. With the typo fixed: Reviewed-by: Laszlo Ersek <lersek@redhat.com>
On Mon, Nov 23, 2015 at 05:35:51PM +0100, Laszlo Ersek wrote: > On 11/23/15 16:57, Gabriel L. Somlo wrote: > > From: Gabriel Somlo <somlo@cmu.edu> > > > > Remove fw_cfg hardware interface details from > > Documentation/devicetree/bindings/arm/fw-cfg.txt, > > and replace them with a pointer to the authoritative > > documentation in the QEMU source tree. > > > > Signed-off-by: Gabriel Somlo <somlo@cmu.edu> > > Cc: Laszlo Ersek <lersek@redhat.com> > > --- > > Documentation/devicetree/bindings/arm/fw-cfg.txt | 38 ++---------------------- > > 1 file changed, 2 insertions(+), 36 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/arm/fw-cfg.txt b/Documentation/devicetree/bindings/arm/fw-cfg.txt > > index 953fb64..ce27386 100644 > > --- a/Documentation/devicetree/bindings/arm/fw-cfg.txt > > +++ b/Documentation/devicetree/bindings/arm/fw-cfg.txt > > @@ -11,43 +11,9 @@ QEMU exposes the control and data register to ARM guests as memory mapped > > registers; their location is communicated to the guest's UEFI firmware in the > > DTB that QEMU places at the bottom of the guest's DRAM. > > > > -The guest writes a selector value (a key) to the selector register, and then > > -can read the corresponding data (produced by QEMU) via the data register. If > > -the selected entry is writable, the guest can rewrite it through the data > > -register. > > +The authoritative guest-side hardware interface documentation to the fw_cfg > > +device ca be found in "docs/specs/fw_cfg.txt" in the QEMU source tree. > > ca[n] be found Same typo occurred in Patch 1/4 as well (both doc files refer to the QEMU fw_cfg spec), so I pre-emptively fixed it there as well. Thanks! --Gabriel > > > > > -The selector register takes keys in big endian byte order. > > - > > -The data register allows accesses with 8, 16, 32 and 64-bit width (only at > > -offset 0 of the register). Accesses larger than a byte are interpreted as > > -arrays, bundled together only for better performance. The bytes constituting > > -such a word, in increasing address order, correspond to the bytes that would > > -have been transferred by byte-wide accesses in chronological order. > > - > > -The interface allows guest firmware to download various parameters and blobs > > -that affect how the firmware works and what tables it installs for the guest > > -OS. For example, boot order of devices, ACPI tables, SMBIOS tables, kernel and > > -initrd images for direct kernel booting, virtual machine UUID, SMP information, > > -virtual NUMA topology, and so on. > > - > > -The authoritative registry of the valid selector values and their meanings is > > -the QEMU source code; the structure of the data blobs corresponding to the > > -individual key values is also defined in the QEMU source code. > > - > > -The presence of the registers can be verified by selecting the "signature" blob > > -with key 0x0000, and reading four bytes from the data register. The returned > > -signature is "QEMU". > > - > > -The outermost protocol (involving the write / read sequences of the control and > > -data registers) is expected to be versioned, and/or described by feature bits. > > -The interface revision / feature bitmap can be retrieved with key 0x0001. The > > -blob to be read from the data register has size 4, and it is to be interpreted > > -as a uint32_t value in little endian byte order. The current value > > -(corresponding to the above outer protocol) is zero. > > - > > -The guest kernel is not expected to use these registers (although it is > > -certainly allowed to); the device tree bindings are documented here because > > -this is where device tree bindings reside in general. > > > > Required properties: > > > > > > As long as Peter is fine with this, I don't object. > > With the typo fixed: > > Reviewed-by: Laszlo Ersek <lersek@redhat.com>
On Mon, Nov 23, 2015 at 10:57:44AM -0500, Gabriel L. Somlo wrote: > From: Gabriel Somlo <somlo@cmu.edu> > > Remove fw_cfg hardware interface details from > Documentation/devicetree/bindings/arm/fw-cfg.txt, > and replace them with a pointer to the authoritative > documentation in the QEMU source tree. > > Signed-off-by: Gabriel Somlo <somlo@cmu.edu> > Cc: Laszlo Ersek <lersek@redhat.com> Acked-by: Rob Herring <robh@kernel.org> > --- > Documentation/devicetree/bindings/arm/fw-cfg.txt | 38 ++---------------------- > 1 file changed, 2 insertions(+), 36 deletions(-) > > diff --git a/Documentation/devicetree/bindings/arm/fw-cfg.txt b/Documentation/devicetree/bindings/arm/fw-cfg.txt > index 953fb64..ce27386 100644 > --- a/Documentation/devicetree/bindings/arm/fw-cfg.txt > +++ b/Documentation/devicetree/bindings/arm/fw-cfg.txt > @@ -11,43 +11,9 @@ QEMU exposes the control and data register to ARM guests as memory mapped > registers; their location is communicated to the guest's UEFI firmware in the > DTB that QEMU places at the bottom of the guest's DRAM. > > -The guest writes a selector value (a key) to the selector register, and then > -can read the corresponding data (produced by QEMU) via the data register. If > -the selected entry is writable, the guest can rewrite it through the data > -register. > +The authoritative guest-side hardware interface documentation to the fw_cfg > +device ca be found in "docs/specs/fw_cfg.txt" in the QEMU source tree. > > -The selector register takes keys in big endian byte order. > - > -The data register allows accesses with 8, 16, 32 and 64-bit width (only at > -offset 0 of the register). Accesses larger than a byte are interpreted as > -arrays, bundled together only for better performance. The bytes constituting > -such a word, in increasing address order, correspond to the bytes that would > -have been transferred by byte-wide accesses in chronological order. > - > -The interface allows guest firmware to download various parameters and blobs > -that affect how the firmware works and what tables it installs for the guest > -OS. For example, boot order of devices, ACPI tables, SMBIOS tables, kernel and > -initrd images for direct kernel booting, virtual machine UUID, SMP information, > -virtual NUMA topology, and so on. > - > -The authoritative registry of the valid selector values and their meanings is > -the QEMU source code; the structure of the data blobs corresponding to the > -individual key values is also defined in the QEMU source code. > - > -The presence of the registers can be verified by selecting the "signature" blob > -with key 0x0000, and reading four bytes from the data register. The returned > -signature is "QEMU". > - > -The outermost protocol (involving the write / read sequences of the control and > -data registers) is expected to be versioned, and/or described by feature bits. > -The interface revision / feature bitmap can be retrieved with key 0x0001. The > -blob to be read from the data register has size 4, and it is to be interpreted > -as a uint32_t value in little endian byte order. The current value > -(corresponding to the above outer protocol) is zero. > - > -The guest kernel is not expected to use these registers (although it is > -certainly allowed to); the device tree bindings are documented here because > -this is where device tree bindings reside in general. > > Required properties: > > -- > 2.4.3 > > -- > To unsubscribe from this list: send the line "unsubscribe devicetree" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/devicetree/bindings/arm/fw-cfg.txt b/Documentation/devicetree/bindings/arm/fw-cfg.txt index 953fb64..ce27386 100644 --- a/Documentation/devicetree/bindings/arm/fw-cfg.txt +++ b/Documentation/devicetree/bindings/arm/fw-cfg.txt @@ -11,43 +11,9 @@ QEMU exposes the control and data register to ARM guests as memory mapped registers; their location is communicated to the guest's UEFI firmware in the DTB that QEMU places at the bottom of the guest's DRAM. -The guest writes a selector value (a key) to the selector register, and then -can read the corresponding data (produced by QEMU) via the data register. If -the selected entry is writable, the guest can rewrite it through the data -register. +The authoritative guest-side hardware interface documentation to the fw_cfg +device ca be found in "docs/specs/fw_cfg.txt" in the QEMU source tree. -The selector register takes keys in big endian byte order. - -The data register allows accesses with 8, 16, 32 and 64-bit width (only at -offset 0 of the register). Accesses larger than a byte are interpreted as -arrays, bundled together only for better performance. The bytes constituting -such a word, in increasing address order, correspond to the bytes that would -have been transferred by byte-wide accesses in chronological order. - -The interface allows guest firmware to download various parameters and blobs -that affect how the firmware works and what tables it installs for the guest -OS. For example, boot order of devices, ACPI tables, SMBIOS tables, kernel and -initrd images for direct kernel booting, virtual machine UUID, SMP information, -virtual NUMA topology, and so on. - -The authoritative registry of the valid selector values and their meanings is -the QEMU source code; the structure of the data blobs corresponding to the -individual key values is also defined in the QEMU source code. - -The presence of the registers can be verified by selecting the "signature" blob -with key 0x0000, and reading four bytes from the data register. The returned -signature is "QEMU". - -The outermost protocol (involving the write / read sequences of the control and -data registers) is expected to be versioned, and/or described by feature bits. -The interface revision / feature bitmap can be retrieved with key 0x0001. The -blob to be read from the data register has size 4, and it is to be interpreted -as a uint32_t value in little endian byte order. The current value -(corresponding to the above outer protocol) is zero. - -The guest kernel is not expected to use these registers (although it is -certainly allowed to); the device tree bindings are documented here because -this is where device tree bindings reside in general. Required properties: