[PATCH] RISC-V: Always compile mm/init.c with cmodel=medany

* [PATCH] RISC-V: Always compile mm/init.c with cmodel=medany
@ 2019-03-24 11:08 Anup Patel
  2019-03-24 14:57 ` Christoph Hellwig
  2019-03-24 19:14 ` Gary Guo
  0 siblings, 2 replies; 7+ messages in thread
From: Anup Patel @ 2019-03-24 11:08 UTC (permalink / raw)
  To: Palmer Dabbelt, Albert Ou
  Cc: Atish Patra, Paul Walmsley, Christoph Hellwig, Mike Rapoport,
	linux-riscv, linux-kernel, Anup Patel, Christoph Hellwig

The Linux RISC-V 32bit kernel is broken after we moved setup_vm() from
kernel/setup.c to mm/init.c because Linux RISC-V 32bit kernel by default
uses cmodel=medlow which results in a non-position-independent setup_vm().

This patch fixes Linux RISC-V 32bit kernel booting by:
1. Forcing cmodel=medany for mm/init.c
2. Moving remaing MM-related stuff va_pa_offset, pfn_base and
   empty_zero_page from kernel/setup.c to mm/init.c

Fixes: 6f1e9e946f0b ("RISC-V: Move setup_vm() to mm/init.c")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
 arch/riscv/kernel/setup.c | 8 --------
 arch/riscv/mm/Makefile    | 2 ++
 arch/riscv/mm/init.c      | 9 +++++++++
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index ecb654f6a79e..540a331d1376 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -48,14 +48,6 @@ struct screen_info screen_info = {
 };
 #endif
 
-unsigned long va_pa_offset;
-EXPORT_SYMBOL(va_pa_offset);
-unsigned long pfn_base;
-EXPORT_SYMBOL(pfn_base);
-
-unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
-EXPORT_SYMBOL(empty_zero_page);
-
 /* The lucky hart to first increment this variable will boot the other cores */
 atomic_t hart_lottery;
 unsigned long boot_cpu_hartid;
diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
index eb22ab49b3e0..7307609d405b 100644
--- a/arch/riscv/mm/Makefile
+++ b/arch/riscv/mm/Makefile
@@ -3,3 +3,5 @@ obj-y += fault.o
 obj-y += extable.o
 obj-y += ioremap.o
 obj-y += cacheflush.o
+
+CFLAGS_init.o := -mcmodel=medany
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index b379a75ac6a6..1e7a106fb583 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -25,6 +25,15 @@
 #include <asm/pgtable.h>
 #include <asm/io.h>
 
+unsigned long va_pa_offset;
+EXPORT_SYMBOL(va_pa_offset);
+unsigned long pfn_base;
+EXPORT_SYMBOL(pfn_base);
+
+unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
+							__page_aligned_bss;
+EXPORT_SYMBOL(empty_zero_page);
+
 static void __init zone_sizes_init(void)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
-- 
2.17.1


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