RISCV_EFI_BOOT_PROTOCOL support in linux

RFC PATCH Superseded Sunil V L 2 participants 6 messages Mar 3, 2022 – Mar 24, 2022

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RISC-V EFI

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Sunil V L

author

2022-03-03 15:00 UTC #0 lore raw

v2 cover RISCV_EFI_BOOT_PROTOCOL support in linux

This patch adds support for getting the boot hart ID using new RISCV_EFI_BOOT_PROTOCOL in linux efi stub. While there is an existing solution of passing the boot hart ID through Device Tree, it doesn't work for ACPI. Hence an EFI protocol protocol is recommended which works for both DT and ACPI based platforms.

The latest draft spec of this new protocol is available at
https://github.com/riscv-non-isa/riscv-uefi/releases/download/1.0-rc2/RISCV_UEFI_PROTOCOL-spec.pdf

This linux ptach can be found in:
riscv_boot_protocol_rfc_v2 branch at
https://github.com/vlsunil/linux.git

This is tested in qemu with u-boot 2022.04.rc3.

Changes since V1:
- Rebased to get the "Fix get_boot_hartid_from_fdt() return value" patch
- Removed mixed_mode member
- Separated return value and status.

Sunil V L (1):
riscv/efi_stub: Add support for RISCV_EFI_BOOT_PROTOCOL

 drivers/firmware/efi/libstub/efistub.h    |  7 ++++++
 drivers/firmware/efi/libstub/riscv-stub.c | 29 +++++++++++++++++++----
 include/linux/efi.h                       |  1 +
 3 files changed, 32 insertions(+), 5 deletions(-)

Signature · 1 line

2.25.1

Sunil V L

author

2022-03-03 15:00 UTC #1 lore raw

RFC PATCH v2 1/1 riscv/efi_stub: Add support for RISCV_EFI_BOOT_PROTOCOL

This patch adds the support for getting the boot hart ID in Linux EFI stub using RISCV_EFI_BOOT_PROTOCOL. This protocol is preferred method over existing DT based solution since it works irrespective of DT or ACPI.

The specification of the protocol is hosted at:
https://github.com/riscv-non-isa/riscv-uefi

Signed-off-by Sunil V L <[email protected]>

---
 drivers/firmware/efi/libstub/efistub.h    |  7 ++++++
 drivers/firmware/efi/libstub/riscv-stub.c | 29 +++++++++++++++++++----
 include/linux/efi.h                       |  1 +
 3 files changed, 32 insertions(+), 5 deletions(-)

drivers/firmware/efi/libstub/efistub.h +7 -0

index edb77b0621ea..aced62a0907e 100644
@@ -720,6 +720,13 @@ union efi_tcg2_protocol {
 	} mixed_mode;
 };
 
+struct riscv_efi_boot_protocol {
+	u64 revision;
+
+	efi_status_t (__efiapi * get_boot_hartid)(struct riscv_efi_boot_protocol *this,
+						  size_t *boot_hartid);
+};
+
 typedef union efi_load_file_protocol efi_load_file_protocol_t;
 typedef union efi_load_file_protocol efi_load_file2_protocol_t;

drivers/firmware/efi/libstub/riscv-stub.c +24 -5

index 9c460843442f..915ad209d004 100644
@@ -23,7 +23,7 @@
 
 typedef void __noreturn (*jump_kernel_func)(unsigned int, unsigned long);
 
-static u32 hartid;
+static size_t hartid;
 
 static int get_boot_hartid_from_fdt(void)
 {

@@ -47,14 +47,33 @@ static int get_boot_hartid_from_fdt(void)
 	return 0;
 }
 
+static efi_status_t get_boot_hartid_from_efi(void)
+{
+	efi_guid_t boot_protocol_guid = RISCV_EFI_BOOT_PROTOCOL_GUID;
+	efi_status_t status;
+	struct riscv_efi_boot_protocol *boot_protocol;
+
+	status = efi_bs_call(locate_protocol, &boot_protocol_guid, NULL,
+			     (void **)&boot_protocol);
+	if (status == EFI_SUCCESS) {
+		status = efi_call_proto(boot_protocol,
+					get_boot_hartid, &hartid);
+	}
+	return status;
+}
+
 efi_status_t check_platform_features(void)
 {
 	int ret;
+	efi_status_t status;
 
-	ret = get_boot_hartid_from_fdt();
-	if (ret) {
-		efi_err("/chosen/boot-hartid missing or invalid!\n");
-		return EFI_UNSUPPORTED;
+	status = get_boot_hartid_from_efi();
+	if (status != EFI_SUCCESS) {
+		ret = get_boot_hartid_from_fdt();
+		if (ret) {
+			efi_err("/chosen/boot-hartid missing or invalid!\n");
+			return EFI_UNSUPPORTED;
+		}
 	}
 	return EFI_SUCCESS;
 }

include/linux/efi.h +1 -0

index ccd4d3f91c98..9822c730207c 100644
@@ -380,6 +380,7 @@ void efi_native_runtime_setup(void);
 #define EFI_CONSOLE_OUT_DEVICE_GUID		EFI_GUID(0xd3b36f2c, 0xd551, 0x11d4,  0x9a, 0x46, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d)
 #define APPLE_PROPERTIES_PROTOCOL_GUID		EFI_GUID(0x91bd12fe, 0xf6c3, 0x44fb,  0xa5, 0xb7, 0x51, 0x22, 0xab, 0x30, 0x3a, 0xe0)
 #define EFI_TCG2_PROTOCOL_GUID			EFI_GUID(0x607f766c, 0x7455, 0x42be,  0x93, 0x0b, 0xe4, 0xd7, 0x6d, 0xb2, 0x72, 0x0f)
+#define RISCV_EFI_BOOT_PROTOCOL_GUID		EFI_GUID(0xccd15fec, 0x6f73, 0x4eec,  0x83, 0x95, 0x3e, 0x69, 0xe4, 0xb9, 0x40, 0xbf)
 #define EFI_LOAD_FILE_PROTOCOL_GUID		EFI_GUID(0x56ec3091, 0x954c, 0x11d2,  0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b)
 #define EFI_LOAD_FILE2_PROTOCOL_GUID		EFI_GUID(0x4006c0c1, 0xfcb3, 0x403e,  0x99, 0x6d, 0x4a, 0x6c, 0x87, 0x24, 0xe0, 0x6d)
 #define EFI_RT_PROPERTIES_TABLE_GUID		EFI_GUID(0xeb66918a, 0x7eef, 0x402a,  0x84, 0x2e, 0x93, 0x1d, 0x21, 0xc3, 0x8a, 0xe9)

Signature · 1 line

2.25.1

Palmer Dabbelt

maintainer

2022-03-23 01:32 UTC #2 lore raw

Re: [RFC PATCH V2 1/1] riscv/efi_stub: Add support for RISCV_EFI_BOOT_PROTOCOL

Quoted 69 lines · On Thu, 03 Mar 2022 06:59:44 PST (-0800), [email protected] wrote:

The specification of the protocol is hosted at:
https://github.com/riscv-non-isa/riscv-uefi

Signed-off-by Sunil V L <[email protected]>

---
 drivers/firmware/efi/libstub/efistub.h    |  7 ++++++
 drivers/firmware/efi/libstub/riscv-stub.c | 29 +++++++++++++++++++----
 include/linux/efi.h                       |  1 +
 3 files changed, 32 insertions(+), 5 deletions(-)

drivers/firmware/efi/libstub/efistub.h +7 -0

index edb77b0621ea..aced62a0907e 100644
@@ -720,6 +720,13 @@ union efi_tcg2_protocol {
 	} mixed_mode;
 };
 
+struct riscv_efi_boot_protocol {
+	u64 revision;
+
+	efi_status_t (__efiapi * get_boot_hartid)(struct riscv_efi_boot_protocol *this,
+						  size_t *boot_hartid);
+};
+
 typedef union efi_load_file_protocol efi_load_file_protocol_t;
 typedef union efi_load_file_protocol efi_load_file2_protocol_t;

drivers/firmware/efi/libstub/riscv-stub.c +17 -1

index 9c460843442f..915ad209d004 100644
@@ -23,7 +23,7 @@
 
 typedef void __noreturn (*jump_kernel_func)(unsigned int, unsigned long);
 
-static u32 hartid;
+static size_t hartid;
 
 static int get_boot_hartid_from_fdt(void)
 {

@@ -47,14 +47,33 @@ static int get_boot_hartid_from_fdt(void)
 	return 0;
 }
 
+static efi_status_t get_boot_hartid_from_efi(void)
+{
+	efi_guid_t boot_protocol_guid = RISCV_EFI_BOOT_PROTOCOL_GUID;
+	efi_status_t status;
+	struct riscv_efi_boot_protocol *boot_protocol;
+
+	status = efi_bs_call(locate_protocol, &boot_protocol_guid, NULL,
+			     (void **)&boot_protocol);
+	if (status == EFI_SUCCESS) {
+		status = efi_call_proto(boot_protocol,
+					get_boot_hartid, &hartid);
+	}
+	return status;
+}
+
 efi_status_t check_platform_features(void)
 {
 	int ret;
+	efi_status_t status;

drivers/firmware/efi/libstub/riscv-stub.c static int get_boot_hartid_from_fdt(void) · line 74

Quoted 10 lines

drivers/firmware/efi/libstub/riscv-stub.c +5 -4

 
-	ret = get_boot_hartid_from_fdt();
-	if (ret) {
-		efi_err("/chosen/boot-hartid missing or invalid!\n");
-		return EFI_UNSUPPORTED;
+	status = get_boot_hartid_from_efi();
+	if (status != EFI_SUCCESS) {
+		ret = get_boot_hartid_from_fdt();
+		if (ret) {
+			efi_err("/chosen/boot-hartid missing or invalid!\n");

Is that the right error message? IIUC it doesn't really make sense in an ACPI context, that's a DT-ism.

Quoted 17 lines

drivers/firmware/efi/libstub/riscv-stub.c +2 -0

+			return EFI_UNSUPPORTED;
+		}
 	}
 	return EFI_SUCCESS;
 }

include/linux/efi.h +1 -0

index ccd4d3f91c98..9822c730207c 100644
@@ -380,6 +380,7 @@ void efi_native_runtime_setup(void);
 #define EFI_CONSOLE_OUT_DEVICE_GUID		EFI_GUID(0xd3b36f2c, 0xd551, 0x11d4,  0x9a, 0x46, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d)
 #define APPLE_PROPERTIES_PROTOCOL_GUID		EFI_GUID(0x91bd12fe, 0xf6c3, 0x44fb,  0xa5, 0xb7, 0x51, 0x22, 0xab, 0x30, 0x3a, 0xe0)
 #define EFI_TCG2_PROTOCOL_GUID			EFI_GUID(0x607f766c, 0x7455, 0x42be,  0x93, 0x0b, 0xe4, 0xd7, 0x6d, 0xb2, 0x72, 0x0f)
+#define RISCV_EFI_BOOT_PROTOCOL_GUID		EFI_GUID(0xccd15fec, 0x6f73, 0x4eec,  0x83, 0x95, 0x3e, 0x69, 0xe4, 0xb9, 0x40, 0xbf)
 #define EFI_LOAD_FILE_PROTOCOL_GUID		EFI_GUID(0x56ec3091, 0x954c, 0x11d2,  0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b)
 #define EFI_LOAD_FILE2_PROTOCOL_GUID		EFI_GUID(0x4006c0c1, 0xfcb3, 0x403e,  0x99, 0x6d, 0x4a, 0x6c, 0x87, 0x24, 0xe0, 0x6d)
 #define EFI_RT_PROPERTIES_TABLE_GUID		EFI_GUID(0xeb66918a, 0x7eef, 0x402a,  0x84, 0x2e, 0x93, 0x1d, 0x21, 0xc3, 0x8a, 0xe9)

Sunil V L

author

2022-03-24 11:01 UTC #3 lore raw

Re: [RFC PATCH V2 1/1] riscv/efi_stub: Add support for RISCV_EFI_BOOT_PROTOCOL

Quoted 71 lines · Palmer Dabbelt

Quoted 70 lines · On Thu, 03 Mar 2022 06:59:44 PST (-0800), [email protected] wrote:

The specification of the protocol is hosted at:
https://github.com/riscv-non-isa/riscv-uefi

Signed-off-by Sunil V L <[email protected]>

---
 drivers/firmware/efi/libstub/efistub.h    |  7 ++++++
 drivers/firmware/efi/libstub/riscv-stub.c | 29 +++++++++++++++++++----
 include/linux/efi.h                       |  1 +
 3 files changed, 32 insertions(+), 5 deletions(-)

drivers/firmware/efi/libstub/efistub.h +7 -0

index edb77b0621ea..aced62a0907e 100644
@@ -720,6 +720,13 @@ union efi_tcg2_protocol {
 	} mixed_mode;
 };
 
+struct riscv_efi_boot_protocol {
+	u64 revision;
+
+	efi_status_t (__efiapi * get_boot_hartid)(struct riscv_efi_boot_protocol *this,
+						  size_t *boot_hartid);
+};
+
 typedef union efi_load_file_protocol efi_load_file_protocol_t;
 typedef union efi_load_file_protocol efi_load_file2_protocol_t;

drivers/firmware/efi/libstub/riscv-stub.c +17 -1

index 9c460843442f..915ad209d004 100644
@@ -23,7 +23,7 @@
 
 typedef void __noreturn (*jump_kernel_func)(unsigned int, unsigned long);
 
-static u32 hartid;
+static size_t hartid;
 
 static int get_boot_hartid_from_fdt(void)
 {

@@ -47,14 +47,33 @@ static int get_boot_hartid_from_fdt(void)
 	return 0;
 }
 
+static efi_status_t get_boot_hartid_from_efi(void)
+{
+	efi_guid_t boot_protocol_guid = RISCV_EFI_BOOT_PROTOCOL_GUID;
+	efi_status_t status;
+	struct riscv_efi_boot_protocol *boot_protocol;
+
+	status = efi_bs_call(locate_protocol, &boot_protocol_guid, NULL,
+			     (void **)&boot_protocol);
+	if (status == EFI_SUCCESS) {
+		status = efi_call_proto(boot_protocol,
+					get_boot_hartid, &hartid);
+	}
+	return status;
+}
+
 efi_status_t check_platform_features(void)
 {
 	int ret;
+	efi_status_t status;

Quoted 12 lines

drivers/firmware/efi/libstub/riscv-stub.c static int get_boot_hartid_from_fdt(void) · line 74
Quoted 9 lines
drivers/firmware/efi/libstub/riscv-stub.c +5 -4
-	ret = get_boot_hartid_from_fdt();
-	if (ret) {
-		efi_err("/chosen/boot-hartid missing or invalid!\n");
-		return EFI_UNSUPPORTED;
+	status = get_boot_hartid_from_efi();
+	if (status != EFI_SUCCESS) {
+		ret = get_boot_hartid_from_fdt();
+		if (ret) {
+			efi_err("/chosen/boot-hartid missing or invalid!\n");
Is that the right error message? IIUC it doesn't really make sense in an ACPI context, that's a DT-ism.

Sure. Will update this message in next version.

Thanks
Sunil

Quoted 18 lines

drivers/firmware/efi/libstub/riscv-stub.c +2 -0

+			return EFI_UNSUPPORTED;
+		}
 	}
 	return EFI_SUCCESS;
 }

include/linux/efi.h +1 -0

index ccd4d3f91c98..9822c730207c 100644
@@ -380,6 +380,7 @@ void efi_native_runtime_setup(void);
 #define EFI_CONSOLE_OUT_DEVICE_GUID		EFI_GUID(0xd3b36f2c, 0xd551, 0x11d4,  0x9a, 0x46, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d)
 #define APPLE_PROPERTIES_PROTOCOL_GUID		EFI_GUID(0x91bd12fe, 0xf6c3, 0x44fb,  0xa5, 0xb7, 0x51, 0x22, 0xab, 0x30, 0x3a, 0xe0)
 #define EFI_TCG2_PROTOCOL_GUID			EFI_GUID(0x607f766c, 0x7455, 0x42be,  0x93, 0x0b, 0xe4, 0xd7, 0x6d, 0xb2, 0x72, 0x0f)
+#define RISCV_EFI_BOOT_PROTOCOL_GUID		EFI_GUID(0xccd15fec, 0x6f73, 0x4eec,  0x83, 0x95, 0x3e, 0x69, 0xe4, 0xb9, 0x40, 0xbf)
 #define EFI_LOAD_FILE_PROTOCOL_GUID		EFI_GUID(0x56ec3091, 0x954c, 0x11d2,  0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b)
 #define EFI_LOAD_FILE2_PROTOCOL_GUID		EFI_GUID(0x4006c0c1, 0xfcb3, 0x403e,  0x99, 0x6d, 0x4a, 0x6c, 0x87, 0x24, 0xe0, 0x6d)
 #define EFI_RT_PROPERTIES_TABLE_GUID		EFI_GUID(0xeb66918a, 0x7eef, 0x402a,  0x84, 0x2e, 0x93, 0x1d, 0x21, 0xc3, 0x8a, 0xe9)

Palmer Dabbelt

maintainer Acked-by on the v2 series

2022-03-23 01:32 UTC #4 lore raw

In reply to Sunil V L

Quoted 8 lines · On Thu, 03 Mar 2022 06:59:43 PST (-0800), [email protected] wrote:

This patch adds support for getting the boot hart ID using new RISCV_EFI_BOOT_PROTOCOL in linux efi stub. While there is an existing solution of passing the boot hart ID through Device Tree, it doesn't work for ACPI. Hence an EFI protocol protocol is recommended which works for both DT and ACPI based platforms.
The latest draft spec of this new protocol is available at
https://github.com/riscv-non-isa/riscv-uefi/releases/download/1.0-rc2/RISCV_UEFI_PROTOCOL-spec.pdf

This looks fine to me, but we need the spec folk to commit to this being a stable interface before we can start using it. Historically that's been "frozen" for RISC-V specs, but I'm not sure how that all fits together in EFI land as IIUC we also have to follow the UEFI forum's process. Last I checked you guys understood that better than I did, so

Acked-by Palmer Dabbelt <[email protected]> # pending spec freeze

I had a minor comment about the error message, as well.

Thanks!

Quoted 19 lines

This linux ptach can be found in:
riscv_boot_protocol_rfc_v2 branch at
https://github.com/vlsunil/linux.git
This is tested in qemu with u-boot 2022.04.rc3.
Changes since V1:
- Rebased to get the "Fix get_boot_hartid_from_fdt() return value" patch
- Removed mixed_mode member
- Separated return value and status.
Sunil V L (1):
riscv/efi_stub: Add support for RISCV_EFI_BOOT_PROTOCOL
 drivers/firmware/efi/libstub/efistub.h    |  7 ++++++
 drivers/firmware/efi/libstub/riscv-stub.c | 29 +++++++++++++++++++----
 include/linux/efi.h                       |  1 +
 3 files changed, 32 insertions(+), 5 deletions(-)

Sunil V L

author

2022-03-23 16:28 UTC #5 lore raw

Quoted 7 lines · Palmer Dabbelt

Quoted 6 lines · On Thu, 03 Mar 2022 06:59:43 PST (-0800), [email protected] wrote:
This patch adds support for getting the boot hart ID using new RISCV_EFI_BOOT_PROTOCOL in linux efi stub. While there is an existing solution of passing the boot hart ID through Device Tree, it doesn't work for ACPI. Hence an EFI protocol protocol is recommended which works for both DT and ACPI based platforms.

Quoted 8 lines

Quoted 2 lines
The latest draft spec of this new protocol is available at
https://github.com/riscv-non-isa/riscv-uefi/releases/download/1.0-rc2/RISCV_UEFI_PROTOCOL-spec.pdf
This looks fine to me, but we need the spec folk to commit to this being a stable interface before we can start using it. Historically that's been "frozen" for RISC-V specs, but I'm not sure how that all fits together in EFI land as IIUC we also have to follow the UEFI forum's process. Last I checked you guys understood that better than I did, so

Thank you Palmer. The specification is in frozen state now.
http://lists.infradead.org/pipermail/linux-riscv/2022-March/013431.html.

Thanks
Sunil

Quoted 26 lines

Acked-by Palmer Dabbelt <[email protected]> # pending spec freeze
I had a minor comment about the error message, as well.
Thanks!
Quoted 19 lines
This linux ptach can be found in:
riscv_boot_protocol_rfc_v2 branch at
https://github.com/vlsunil/linux.git
This is tested in qemu with u-boot 2022.04.rc3.
Changes since V1:
- Rebased to get the "Fix get_boot_hartid_from_fdt() return value" patch
- Removed mixed_mode member
- Separated return value and status.
Sunil V L (1):
riscv/efi_stub: Add support for RISCV_EFI_BOOT_PROTOCOL
 drivers/firmware/efi/libstub/efistub.h    |  7 ++++++
 drivers/firmware/efi/libstub/riscv-stub.c | 29 +++++++++++++++++++----
 include/linux/efi.h                       |  1 +
 3 files changed, 32 insertions(+), 5 deletions(-)