[PATCH v6 02/11] powerpc/kexec_file: mark PPC64 specific code

From: Hari Bathini <hbathini@linux.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: Pingfan Liu <piliu@redhat.com>,
	Laurent Dufour <ldufour@linux.ibm.com>,
	Thiago Jung Bauermann <bauerman@linux.ibm.com>,
	Mahesh J Salgaonkar <mahesh@linux.ibm.com>,
	Sourabh Jain <sourabhjain@linux.ibm.com>,
	Vivek Goyal <vgoyal@redhat.com>, Dave Young <dyoung@redhat.com>,
	Petr Tesarik <ptesarik@suse.cz>, Pingfan Liu <piliu@redhat.com>,
	linuxppc-dev <linuxppc-dev@ozlabs.org>,
	Kexec-ml <kexec@lists.infradead.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Pingfan Liu <piliu@redhat.com>,
	Eric Biederman <ebiederm@xmission.com>,
	Thiago Jung Bauermann <bauerman@linux.ibm.com>,
	Mimi Zohar <zohar@linux.ibm.com>,
	Nayna Jain <nayna@linux.ibm.com>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH v6 02/11] powerpc/kexec_file: mark PPC64 specific code
Date: Wed, 29 Jul 2020 17:09:41 +0530	[thread overview]
Message-ID: <159602276920.575379.10390965946438306388.stgit@hbathini> (raw)
In-Reply-To: <159602259854.575379.16910915605574571585.stgit@hbathini>

Some of the kexec_file_load code isn't PPC64 specific. Move PPC64
specific code from kexec/file_load.c to kexec/file_load_64.c. Also,
rename purgatory/trampoline.S to purgatory/trampoline_64.S in the
same spirit. No functional changes.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
---

v5 -> v6:
* Dropped email address from copyright header of the new file being
  added: arch/powerpc/kexec/file_load_64.c

v4 -> v5:
* Unchanged.

v3 -> v4:
* Moved common code back to set_new_fdt() from setup_new_fdt_ppc64()
  function. Added Reviewed-by tags from Laurent & Thiago.

v2 -> v3:
* Unchanged. Added Tested-by tag from Pingfan.

v1 -> v2:
* No changes.


 arch/powerpc/include/asm/kexec.h       |    9 ++
 arch/powerpc/kexec/Makefile            |    2 -
 arch/powerpc/kexec/elf_64.c            |    7 +-
 arch/powerpc/kexec/file_load.c         |   19 +----
 arch/powerpc/kexec/file_load_64.c      |   87 ++++++++++++++++++++++++
 arch/powerpc/purgatory/Makefile        |    4 +
 arch/powerpc/purgatory/trampoline.S    |  117 --------------------------------
 arch/powerpc/purgatory/trampoline_64.S |  117 ++++++++++++++++++++++++++++++++
 8 files changed, 222 insertions(+), 140 deletions(-)
 create mode 100644 arch/powerpc/kexec/file_load_64.c
 delete mode 100644 arch/powerpc/purgatory/trampoline.S
 create mode 100644 arch/powerpc/purgatory/trampoline_64.S

diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index c68476818753..ac8fd4839171 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -116,6 +116,15 @@ int setup_new_fdt(const struct kimage *image, void *fdt,
 		  unsigned long initrd_load_addr, unsigned long initrd_len,
 		  const char *cmdline);
 int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size);
+
+#ifdef CONFIG_PPC64
+int setup_purgatory_ppc64(struct kimage *image, const void *slave_code,
+			  const void *fdt, unsigned long kernel_load_addr,
+			  unsigned long fdt_load_addr);
+int setup_new_fdt_ppc64(const struct kimage *image, void *fdt,
+			unsigned long initrd_load_addr,
+			unsigned long initrd_len, const char *cmdline);
+#endif /* CONFIG_PPC64 */
 #endif /* CONFIG_KEXEC_FILE */
 
 #else /* !CONFIG_KEXEC_CORE */
diff --git a/arch/powerpc/kexec/Makefile b/arch/powerpc/kexec/Makefile
index 86380c69f5ce..67c355329457 100644
--- a/arch/powerpc/kexec/Makefile
+++ b/arch/powerpc/kexec/Makefile
@@ -7,7 +7,7 @@ obj-y				+= core.o crash.o core_$(BITS).o
 
 obj-$(CONFIG_PPC32)		+= relocate_32.o
 
-obj-$(CONFIG_KEXEC_FILE)	+= file_load.o elf_$(BITS).o
+obj-$(CONFIG_KEXEC_FILE)	+= file_load.o file_load_$(BITS).o elf_$(BITS).o
 
 ifdef CONFIG_HAVE_IMA_KEXEC
 ifdef CONFIG_IMA
diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
index 3072fd6dbe94..23ad04ccaf8e 100644
--- a/arch/powerpc/kexec/elf_64.c
+++ b/arch/powerpc/kexec/elf_64.c
@@ -88,7 +88,8 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
 		goto out;
 	}
 
-	ret = setup_new_fdt(image, fdt, initrd_load_addr, initrd_len, cmdline);
+	ret = setup_new_fdt_ppc64(image, fdt, initrd_load_addr,
+				  initrd_len, cmdline);
 	if (ret)
 		goto out;
 
@@ -107,8 +108,8 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
 	pr_debug("Loaded device tree at 0x%lx\n", fdt_load_addr);
 
 	slave_code = elf_info.buffer + elf_info.proghdrs[0].p_offset;
-	ret = setup_purgatory(image, slave_code, fdt, kernel_load_addr,
-			      fdt_load_addr);
+	ret = setup_purgatory_ppc64(image, slave_code, fdt, kernel_load_addr,
+				    fdt_load_addr);
 	if (ret)
 		pr_err("Error setting up the purgatory.\n");
 
diff --git a/arch/powerpc/kexec/file_load.c b/arch/powerpc/kexec/file_load.c
index 143c91724617..38439aba27d7 100644
--- a/arch/powerpc/kexec/file_load.c
+++ b/arch/powerpc/kexec/file_load.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * ppc64 code to implement the kexec_file_load syscall
+ * powerpc code to implement the kexec_file_load syscall
  *
  * Copyright (C) 2004  Adam Litke (agl@us.ibm.com)
  * Copyright (C) 2004  IBM Corp.
@@ -20,22 +20,7 @@
 #include <linux/libfdt.h>
 #include <asm/ima.h>
 
-#define SLAVE_CODE_SIZE		256
-
-const struct kexec_file_ops * const kexec_file_loaders[] = {
-	&kexec_elf64_ops,
-	NULL
-};
-
-int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
-				  unsigned long buf_len)
-{
-	/* We don't support crash kernels yet. */
-	if (image->type == KEXEC_TYPE_CRASH)
-		return -EOPNOTSUPP;
-
-	return kexec_image_probe_default(image, buf, buf_len);
-}
+#define SLAVE_CODE_SIZE		256	/* First 0x100 bytes */
 
 /**
  * setup_purgatory - initialize the purgatory's global variables
diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
new file mode 100644
index 000000000000..3e9ac5f216b0
--- /dev/null
+++ b/arch/powerpc/kexec/file_load_64.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ppc64 code to implement the kexec_file_load syscall
+ *
+ * Copyright (C) 2004  Adam Litke (agl@us.ibm.com)
+ * Copyright (C) 2004  IBM Corp.
+ * Copyright (C) 2004,2005  Milton D Miller II, IBM Corporation
+ * Copyright (C) 2005  R Sharada (sharada@in.ibm.com)
+ * Copyright (C) 2006  Mohan Kumar M (mohan@in.ibm.com)
+ * Copyright (C) 2020  IBM Corporation
+ *
+ * Based on kexec-tools' kexec-ppc64.c, kexec-elf-rel-ppc64.c, fs2dt.c.
+ * Heavily modified for the kernel by
+ * Hari Bathini, IBM Corporation.
+ */
+
+#include <linux/kexec.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
+
+const struct kexec_file_ops * const kexec_file_loaders[] = {
+	&kexec_elf64_ops,
+	NULL
+};
+
+/**
+ * setup_purgatory_ppc64 - initialize PPC64 specific purgatory's global
+ *                         variables and call setup_purgatory() to initialize
+ *                         common global variable.
+ * @image:                 kexec image.
+ * @slave_code:            Slave code for the purgatory.
+ * @fdt:                   Flattened device tree for the next kernel.
+ * @kernel_load_addr:      Address where the kernel is loaded.
+ * @fdt_load_addr:         Address where the flattened device tree is loaded.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int setup_purgatory_ppc64(struct kimage *image, const void *slave_code,
+			  const void *fdt, unsigned long kernel_load_addr,
+			  unsigned long fdt_load_addr)
+{
+	int ret;
+
+	ret = setup_purgatory(image, slave_code, fdt, kernel_load_addr,
+			      fdt_load_addr);
+	if (ret)
+		pr_err("Failed to setup purgatory symbols");
+	return ret;
+}
+
+/**
+ * setup_new_fdt_ppc64 - Update the flattend device-tree of the kernel
+ *                       being loaded.
+ * @image:               kexec image being loaded.
+ * @fdt:                 Flattened device tree for the next kernel.
+ * @initrd_load_addr:    Address where the next initrd will be loaded.
+ * @initrd_len:          Size of the next initrd, or 0 if there will be none.
+ * @cmdline:             Command line for the next kernel, or NULL if there will
+ *                       be none.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int setup_new_fdt_ppc64(const struct kimage *image, void *fdt,
+			unsigned long initrd_load_addr,
+			unsigned long initrd_len, const char *cmdline)
+{
+	return setup_new_fdt(image, fdt, initrd_load_addr, initrd_len, cmdline);
+}
+
+/**
+ * arch_kexec_kernel_image_probe - Does additional handling needed to setup
+ *                                 kexec segments.
+ * @image:                         kexec image being loaded.
+ * @buf:                           Buffer pointing to elf data.
+ * @buf_len:                       Length of the buffer.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
+				  unsigned long buf_len)
+{
+	/* We don't support crash kernels yet. */
+	if (image->type == KEXEC_TYPE_CRASH)
+		return -EOPNOTSUPP;
+
+	return kexec_image_probe_default(image, buf, buf_len);
+}
diff --git a/arch/powerpc/purgatory/Makefile b/arch/powerpc/purgatory/Makefile
index 7c6d8b14f440..348f59581052 100644
--- a/arch/powerpc/purgatory/Makefile
+++ b/arch/powerpc/purgatory/Makefile
@@ -2,11 +2,11 @@
 
 KASAN_SANITIZE := n
 
-targets += trampoline.o purgatory.ro kexec-purgatory.c
+targets += trampoline_$(BITS).o purgatory.ro kexec-purgatory.c
 
 LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined
 
-$(obj)/purgatory.ro: $(obj)/trampoline.o FORCE
+$(obj)/purgatory.ro: $(obj)/trampoline_$(BITS).o FORCE
 		$(call if_changed,ld)
 
 quiet_cmd_bin2c = BIN2C   $@
diff --git a/arch/powerpc/purgatory/trampoline.S b/arch/powerpc/purgatory/trampoline.S
deleted file mode 100644
index a5a83c3f53e6..000000000000
--- a/arch/powerpc/purgatory/trampoline.S
+++ /dev/null
@@ -1,117 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * kexec trampoline
- *
- * Based on code taken from kexec-tools and kexec-lite.
- *
- * Copyright (C) 2004 - 2005, Milton D Miller II, IBM Corporation
- * Copyright (C) 2006, Mohan Kumar M, IBM Corporation
- * Copyright (C) 2013, Anton Blanchard, IBM Corporation
- */
-
-#include <asm/asm-compat.h>
-
-	.machine ppc64
-	.balign 256
-	.globl purgatory_start
-purgatory_start:
-	b	master
-
-	/* ABI: possible run_at_load flag at 0x5c */
-	.org purgatory_start + 0x5c
-	.globl run_at_load
-run_at_load:
-	.long 0
-	.size run_at_load, . - run_at_load
-
-	/* ABI: slaves start at 60 with r3=phys */
-	.org purgatory_start + 0x60
-slave:
-	b .
-	/* ABI: end of copied region */
-	.org purgatory_start + 0x100
-	.size purgatory_start, . - purgatory_start
-
-/*
- * The above 0x100 bytes at purgatory_start are replaced with the
- * code from the kernel (or next stage) by setup_purgatory().
- */
-
-master:
-	or	%r1,%r1,%r1	/* low priority to let other threads catchup */
-	isync
-	mr	%r17,%r3	/* save cpu id to r17 */
-	mr	%r15,%r4	/* save physical address in reg15 */
-
-	or	%r3,%r3,%r3	/* ok now to high priority, lets boot */
-	lis	%r6,0x1
-	mtctr	%r6		/* delay a bit for slaves to catch up */
-	bdnz	.		/* before we overwrite 0-100 again */
-
-	bl	0f		/* Work out where we're running */
-0:	mflr	%r18
-
-	/* load device-tree address */
-	ld	%r3, (dt_offset - 0b)(%r18)
-	mr	%r16,%r3	/* save dt address in reg16 */
-	li	%r4,20
-	LWZX_BE	%r6,%r3,%r4	/* fetch __be32 version number at byte 20 */
-	cmpwi	%cr0,%r6,2	/* v2 or later? */
-	blt	1f
-	li	%r4,28
-	STWX_BE	%r17,%r3,%r4	/* Store my cpu as __be32 at byte 28 */
-1:
-	/* load the kernel address */
-	ld	%r4,(kernel - 0b)(%r18)
-
-	/* load the run_at_load flag */
-	/* possibly patched by kexec */
-	ld	%r6,(run_at_load - 0b)(%r18)
-	/* and patch it into the kernel */
-	stw	%r6,(0x5c)(%r4)
-
-	mr	%r3,%r16	/* restore dt address */
-
-	li	%r5,0		/* r5 will be 0 for kernel */
-
-	mfmsr	%r11
-	andi.	%r10,%r11,1	/* test MSR_LE */
-	bne	.Little_endian
-
-	mtctr	%r4		/* prepare branch to */
-	bctr			/* start kernel */
-
-.Little_endian:
-	mtsrr0	%r4		/* prepare branch to */
-
-	clrrdi	%r11,%r11,1	/* clear MSR_LE */
-	mtsrr1	%r11
-
-	rfid			/* update MSR and start kernel */
-
-
-	.balign 8
-	.globl kernel
-kernel:
-	.8byte  0x0
-	.size kernel, . - kernel
-
-	.balign 8
-	.globl dt_offset
-dt_offset:
-	.8byte  0x0
-	.size dt_offset, . - dt_offset
-
-
-	.data
-	.balign 8
-.globl purgatory_sha256_digest
-purgatory_sha256_digest:
-	.skip	32
-	.size purgatory_sha256_digest, . - purgatory_sha256_digest
-
-	.balign 8
-.globl purgatory_sha_regions
-purgatory_sha_regions:
-	.skip	8 * 2 * 16
-	.size purgatory_sha_regions, . - purgatory_sha_regions
diff --git a/arch/powerpc/purgatory/trampoline_64.S b/arch/powerpc/purgatory/trampoline_64.S
new file mode 100644
index 000000000000..a5a83c3f53e6
--- /dev/null
+++ b/arch/powerpc/purgatory/trampoline_64.S
@@ -0,0 +1,117 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * kexec trampoline
+ *
+ * Based on code taken from kexec-tools and kexec-lite.
+ *
+ * Copyright (C) 2004 - 2005, Milton D Miller II, IBM Corporation
+ * Copyright (C) 2006, Mohan Kumar M, IBM Corporation
+ * Copyright (C) 2013, Anton Blanchard, IBM Corporation
+ */
+
+#include <asm/asm-compat.h>
+
+	.machine ppc64
+	.balign 256
+	.globl purgatory_start
+purgatory_start:
+	b	master
+
+	/* ABI: possible run_at_load flag at 0x5c */
+	.org purgatory_start + 0x5c
+	.globl run_at_load
+run_at_load:
+	.long 0
+	.size run_at_load, . - run_at_load
+
+	/* ABI: slaves start at 60 with r3=phys */
+	.org purgatory_start + 0x60
+slave:
+	b .
+	/* ABI: end of copied region */
+	.org purgatory_start + 0x100
+	.size purgatory_start, . - purgatory_start
+
+/*
+ * The above 0x100 bytes at purgatory_start are replaced with the
+ * code from the kernel (or next stage) by setup_purgatory().
+ */
+
+master:
+	or	%r1,%r1,%r1	/* low priority to let other threads catchup */
+	isync
+	mr	%r17,%r3	/* save cpu id to r17 */
+	mr	%r15,%r4	/* save physical address in reg15 */
+
+	or	%r3,%r3,%r3	/* ok now to high priority, lets boot */
+	lis	%r6,0x1
+	mtctr	%r6		/* delay a bit for slaves to catch up */
+	bdnz	.		/* before we overwrite 0-100 again */
+
+	bl	0f		/* Work out where we're running */
+0:	mflr	%r18
+
+	/* load device-tree address */
+	ld	%r3, (dt_offset - 0b)(%r18)
+	mr	%r16,%r3	/* save dt address in reg16 */
+	li	%r4,20
+	LWZX_BE	%r6,%r3,%r4	/* fetch __be32 version number at byte 20 */
+	cmpwi	%cr0,%r6,2	/* v2 or later? */
+	blt	1f
+	li	%r4,28
+	STWX_BE	%r17,%r3,%r4	/* Store my cpu as __be32 at byte 28 */
+1:
+	/* load the kernel address */
+	ld	%r4,(kernel - 0b)(%r18)
+
+	/* load the run_at_load flag */
+	/* possibly patched by kexec */
+	ld	%r6,(run_at_load - 0b)(%r18)
+	/* and patch it into the kernel */
+	stw	%r6,(0x5c)(%r4)
+
+	mr	%r3,%r16	/* restore dt address */
+
+	li	%r5,0		/* r5 will be 0 for kernel */
+
+	mfmsr	%r11
+	andi.	%r10,%r11,1	/* test MSR_LE */
+	bne	.Little_endian
+
+	mtctr	%r4		/* prepare branch to */
+	bctr			/* start kernel */
+
+.Little_endian:
+	mtsrr0	%r4		/* prepare branch to */
+
+	clrrdi	%r11,%r11,1	/* clear MSR_LE */
+	mtsrr1	%r11
+
+	rfid			/* update MSR and start kernel */
+
+
+	.balign 8
+	.globl kernel
+kernel:
+	.8byte  0x0
+	.size kernel, . - kernel
+
+	.balign 8
+	.globl dt_offset
+dt_offset:
+	.8byte  0x0
+	.size dt_offset, . - dt_offset
+
+
+	.data
+	.balign 8
+.globl purgatory_sha256_digest
+purgatory_sha256_digest:
+	.skip	32
+	.size purgatory_sha256_digest, . - purgatory_sha256_digest
+
+	.balign 8
+.globl purgatory_sha_regions
+purgatory_sha_regions:
+	.skip	8 * 2 * 16
+	.size purgatory_sha_regions, . - purgatory_sha_regions


