[PATCH/RFC] FDPIC: add hook for arches to customize program header parsing

[Mike Frysinger <vapier@gentoo.org>]

From: Jie Zhang <jie.zhang@analog.com>

The Blackfin port has custom program header flags/addresses for
automatically loading regions into the dedicated on-chip SRAM.  So add a
hook for ports to leverage.

Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
CC: Bernd Schmidt <bernds_cb1@t-online.de>
---
 arch/blackfin/include/asm/elf.h         |    8 +++
 arch/blackfin/kernel/Makefile           |    1 +
 arch/blackfin/kernel/binfmt_elf_fdpic.c |   80 +++++++++++++++++++++++++++++++
 fs/binfmt_elf_fdpic.c                   |    7 +++
 4 files changed, 96 insertions(+), 0 deletions(-)
 create mode 100644 arch/blackfin/kernel/binfmt_elf_fdpic.c

diff --git a/arch/blackfin/include/asm/elf.h b/arch/blackfin/include/asm/elf.h
index 230e160..aba2506 100644
--- a/arch/blackfin/include/asm/elf.h
+++ b/arch/blackfin/include/asm/elf.h
@@ -124,4 +124,12 @@ do {											\
 
 #define SET_PERSONALITY(ex) set_personality(PER_LINUX)
 
+struct mm_struct;
+struct elf_fdpic_params;
+struct elf32_phdr;
+extern int elf_fdpic_plat_process_phdr(struct mm_struct *, struct elf_fdpic_params *,
+                                       struct elf32_phdr *, unsigned long *, unsigned long *);
+#define ELF_FDPIC_PLAT_PROCESS_PHDR(mm, params, phdr, maddr, disp) \
+	elf_fdpic_plat_process_phdr(mm, params, phdr, maddr, disp)
+
 #endif
diff --git a/arch/blackfin/kernel/Makefile b/arch/blackfin/kernel/Makefile
index fd4d432..71c2291 100644
--- a/arch/blackfin/kernel/Makefile
+++ b/arch/blackfin/kernel/Makefile
@@ -15,6 +15,7 @@ else
     obj-y += time.o
 endif
 
+obj-$(CONFIG_BINFMT_ELF_FDPIC)       += binfmt_elf_fdpic.o
 obj-$(CONFIG_IPIPE)                  += ipipe.o
 obj-$(CONFIG_IPIPE_TRACE_MCOUNT)     += mcount.o
 obj-$(CONFIG_BFIN_GPTIMERS)          += gptimers.o
diff --git a/arch/blackfin/kernel/binfmt_elf_fdpic.c b/arch/blackfin/kernel/binfmt_elf_fdpic.c
new file mode 100644
index 0000000..d8192cf
--- /dev/null
+++ b/arch/blackfin/kernel/binfmt_elf_fdpic.c
@@ -0,0 +1,80 @@
+/*
+ * FDPIC ELF hooks
+ *
+ * Copyright (c) 2006-2009 Analog Devices Inc.
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/mm.h>
+#include <linux/elf.h>
+#include <linux/elf-fdpic.h>
+#include <linux/kernel.h>
+
+#include <asm/cacheflush.h>
+#include <asm/dma.h>
+
+int elf_fdpic_plat_process_phdr(struct mm_struct *mm,
+                                struct elf_fdpic_params *params,
+                                struct elf32_phdr *phdr,
+                                unsigned long *maddr, unsigned long *disp)
+{
+	/* 0xfeb00000, 0xfec00000, 0xff700000, 0xff800000, 0xff900000
+	 * and 0xffa00000 are also used in Dynamic linker and GNU ld.
+	 * They need to be kept synchronized.
+	 */
+	unsigned long flag = 0;
+	const char *type = NULL;
+
+	unsigned int e_flags = params->hdr.e_flags;
+	unsigned long p_vaddr = phdr->p_vaddr;
+	unsigned long p_flags = phdr->p_flags;
+
+	if (((e_flags & EF_BFIN_CODE_IN_L1) || p_vaddr == 0xffa00000) &&
+	    (p_flags & (PF_W | PF_X)) == PF_X)
+	{
+		flag = L1_INST_SRAM;
+		type = "L1 instruction";
+
+	} else if (((e_flags & EF_BFIN_DATA_IN_L1) ||
+	            p_vaddr == 0xff700000 ||
+	            p_vaddr == 0xff800000 ||
+	            p_vaddr == 0xff900000) &&
+	           (p_flags & (PF_X | PF_W)) == PF_W)
+	{
+		if (p_vaddr == 0xff800000) {
+			flag = L1_DATA_A_SRAM;
+			type = "L1 Data A";
+		} else if (p_vaddr == 0xff900000) {
+			flag = L1_DATA_B_SRAM;
+			type = "L1 Data B";
+		} else {
+			flag = L1_DATA_SRAM;
+			type = "L1 Data";
+		}
+
+	} else if (p_vaddr == 0xfeb00000 || p_vaddr == 0xfec00000) {
+		flag = L2_SRAM;
+		type = "L2";
+	}
+
+	if (flag) {
+		void *sram_addr = sram_alloc_with_lsl(phdr->p_memsz, flag);
+		if (sram_addr == NULL) {
+			printk(KERN_ERR "elf_fdpic: not enough %s sram\n", type);
+			return -ENOMEM;
+		}
+
+		if (flag & L1_INST_SRAM)
+			safe_dma_memcpy(sram_addr, (const void *)(*maddr + *disp), phdr->p_memsz);
+		else
+			memcpy(sram_addr, (const void *)(*maddr + *disp), phdr->p_memsz);
+
+		down_write(&mm->mmap_sem);
+		do_munmap(mm, *maddr, phdr->p_memsz + *disp);
+		up_write(&mm->mmap_sem);
+		*maddr = (unsigned long)sram_addr;
+		*disp = 0;
+	}
+
+	return 0;
+}
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index fdb66fa..1bad16c 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1105,6 +1105,13 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
 		    ELF_FDPIC_FLAG_CONTIGUOUS)
 			load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
 
+#ifndef ELF_FDPIC_PLAT_PROCESS_PHDR
+# define ELF_FDPIC_PLAT_PROCESS_PHDR(mm, params, phdr, maddr, disp) 0
+#endif
+		ret = ELF_FDPIC_PLAT_PROCESS_PHDR(mm, params, phdr, &maddr, &disp);
+		if (ret)
+			return ret;
+
 		seg->addr = maddr + disp;
 		seg->p_vaddr = phdr->p_vaddr;
 		seg->p_memsz = phdr->p_memsz;
-- 
1.6.3.1