From: Guo Ren <ren_guo@xxxxxxxxx>
Before this patch csky-linux need CONFIG_RAM_BASE to determine start
physical address. Now we use phys_offset variable to replace the macro
of PHYS_OFFSET and we setup phys_offset with real physical address which
is determined during startup in head.S.
With this patch we needn't re-compile kernel for different start
physical address. ie: 0x0 / 0xc0000000 start physical address could use
the same vmlinux, be care different start address must be 512MB aligned.
Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/csky/abiv1/inc/abi/ckmmu.h | 20 +++++++++++++++++++
arch/csky/abiv1/inc/abi/entry.h | 19 ++++++++++++++++--
arch/csky/abiv2/inc/abi/ckmmu.h | 20 +++++++++++++++++++
arch/csky/abiv2/inc/abi/entry.h | 24 +++++++++++++++++++++--
arch/csky/include/asm/mmu_context.h | 4 ++--
arch/csky/include/asm/page.h | 39 +++++++++++++++----------------------
arch/csky/kernel/setup.c | 5 +++++
7 files changed, 102 insertions(+), 29 deletions(-)
diff --git a/arch/csky/abiv1/inc/abi/ckmmu.h b/arch/csky/abiv1/inc/abi/ckmmu.h
index 3a00201..85339bd 100644
--- a/arch/csky/abiv1/inc/abi/ckmmu.h
+++ b/arch/csky/abiv1/inc/abi/ckmmu.h
@@ -40,6 +40,26 @@ static inline void write_mmu_entryhi(int value)
cpwcr("cpcr4", value);
}
+static inline unsigned long read_mmu_msa0(void)
+{
+ return cprcr("cpcr30");
+}
+
+static inline void write_mmu_msa0(unsigned long value)
+{
+ cpwcr("cpcr30", value);
+}
+
+static inline unsigned long read_mmu_msa1(void)
+{
+ return cprcr("cpcr31");
+}
+
+static inline void write_mmu_msa1(unsigned long value)
+{
+ cpwcr("cpcr31", value);
+}
+
/*
* TLB operations.
*/
diff --git a/arch/csky/abiv1/inc/abi/entry.h b/arch/csky/abiv1/inc/abi/entry.h
index fa26461..1d66bcd 100644
--- a/arch/csky/abiv1/inc/abi/entry.h
+++ b/arch/csky/abiv1/inc/abi/entry.h
@@ -128,9 +128,24 @@
.endm
.macro SETUP_MMU rx
- lrw \rx, PHYS_OFFSET | 0xe
+ /* Select MMU as co-processor */
+ cpseti cp15
+
+ /*
+ * cpcr30 format:
+ * 31 - 29 | 28 - 4 | 3 | 2 | 1 | 0
+ * BA Reserved C D V
+ */
+ cprcr \rx, cpcr30
+ lsri \rx, 28
+ lsli \rx, 28
+ addi \rx, 0xe
cpwcr \rx, cpcr30
- lrw \rx, (PHYS_OFFSET + 0x20000000) | 0xe
+
+ lsri \rx, 28
+ addi \rx, 2
+ lsli \rx, 28
+ addi \rx, 0xe
cpwcr \rx, cpcr31
.endm
diff --git a/arch/csky/abiv2/inc/abi/ckmmu.h b/arch/csky/abiv2/inc/abi/ckmmu.h
index 97230ad..31d75e1 100644
--- a/arch/csky/abiv2/inc/abi/ckmmu.h
+++ b/arch/csky/abiv2/inc/abi/ckmmu.h
@@ -42,6 +42,26 @@ static inline void write_mmu_entryhi(int value)
mtcr("cr<4, 15>", value);
}
+static inline unsigned long read_mmu_msa0(void)
+{
+ return mfcr("cr<30, 15>");
+}
+
+static inline void write_mmu_msa0(unsigned long value)
+{
+ mtcr("cr<30, 15>", value);
+}
+
+static inline unsigned long read_mmu_msa1(void)
+{
+ return mfcr("cr<31, 15>");
+}
+
+static inline void write_mmu_msa1(unsigned long value)
+{
+ mtcr("cr<31, 15>", value);
+}
+
/*
* TLB operations.
*/
diff --git a/arch/csky/abiv2/inc/abi/entry.h b/arch/csky/abiv2/inc/abi/entry.h
index 31d0aa9..15ada63 100644
--- a/arch/csky/abiv2/inc/abi/entry.h
+++ b/arch/csky/abiv2/inc/abi/entry.h
@@ -143,9 +143,29 @@
.endm
.macro SETUP_MMU rx
- lrw \rx, PHYS_OFFSET | 0xe
+ /* Check MMU on | off */
+ mfcr \rx, cr18
+ btsti \rx, 0
+ bt 1f
+ grs \rx, 1f
+ br 2f
+1:
+ /*
+ * cr<30, 15> format:
+ * 31 - 29 | 28 - 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
+ * BA Reserved SH WA B SO SEC C D V
+ */
+ mfcr \rx, cr<30, 15>
+2:
+ lsri \rx, 28
+ lsli \rx, 28
+ addi \rx, 0x1ce
mtcr \rx, cr<30, 15>
- lrw \rx, (PHYS_OFFSET + 0x20000000) | 0xe
+
+ lsri \rx, 28
+ addi \rx, 2
+ lsli \rx, 28
+ addi \rx, 0x1ce
mtcr \rx, cr<31, 15>
.endm
diff --git a/arch/csky/include/asm/mmu_context.h b/arch/csky/include/asm/mmu_context.h
index b2905c0..c41f86b 100644
--- a/arch/csky/include/asm/mmu_context.h
+++ b/arch/csky/include/asm/mmu_context.h
@@ -17,7 +17,7 @@
static inline void tlbmiss_handler_setup_pgd(unsigned long pgd, bool kernel)
{
pgd -= PAGE_OFFSET;
- pgd += PHYS_OFFSET;
+ pgd += phys_offset;
pgd |= 1;
setup_pgd(pgd, kernel);
}
@@ -29,7 +29,7 @@ static inline void tlbmiss_handler_setup_pgd(unsigned long pgd, bool kernel)
static inline unsigned long tlb_get_pgd(void)
{
- return ((get_pgd() - PHYS_OFFSET) & ~1) + PAGE_OFFSET;
+ return ((get_pgd() - phys_offset) & ~1) + PAGE_OFFSET;
}
#define cpu_context(cpu, mm) ((mm)->context.asid[cpu])
diff --git a/arch/csky/include/asm/page.h b/arch/csky/include/asm/page.h
index 73cf2bd..4ce3d5c 100644
--- a/arch/csky/include/asm/page.h
+++ b/arch/csky/include/asm/page.h
@@ -8,7 +8,7 @@
#include <linux/const.h>
/*
- * PAGE_SHIFT determines the page size
+ * PAGE_SHIFT determines the page size: 4KB
*/
#define PAGE_SHIFT 12
#define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT)
@@ -17,12 +17,18 @@
#define THREAD_MASK (~(THREAD_SIZE - 1))
#define THREAD_SHIFT (PAGE_SHIFT + 1)
+
/*
- * NOTE: virtual isn't really correct, actually it should be the offset into the
- * memory node, but we have no highmem, so that works for now.
- * TODO: implement (fast) pfn<->pgdat_idx conversion functions, this makes lots
- * of the shifts unnecessary.
+ * For C-SKY "User-space:Kernel-space" is "2GB:2GB" fixed by hardware and there
+ * are two segment registers (MSA0 + MSA1) to mapping 512MB + 512MB physical
+ * address region. We use them mapping kernel 1GB direct-map address area and
+ * for more than 1GB of memory we use highmem.
*/
+#define PAGE_OFFSET 0x80000000
+#define SSEG_SIZE 0x20000000
+#define LOWMEM_LIMIT (SSEG_SIZE * 2)
+
+#define PHYS_OFFSET_OFFSET (CONFIG_RAM_BASE & (SSEG_SIZE - 1))
#ifndef __ASSEMBLY__
@@ -50,9 +56,6 @@ struct page;
struct vm_area_struct;
-/*
- * These are used to make use of C type-checking..
- */
typedef struct { unsigned long pte_low; } pte_t;
#define pte_val(x) ((x).pte_low)
@@ -69,18 +72,13 @@ typedef struct page *pgtable_t;
#define __pgd(x) ((pgd_t) { (x) })
#define __pgprot(x) ((pgprot_t) { (x) })
-#endif /* !__ASSEMBLY__ */
-
-#define PHYS_OFFSET (CONFIG_RAM_BASE & ~(LOWMEM_LIMIT - 1))
-#define PHYS_OFFSET_OFFSET (CONFIG_RAM_BASE & (LOWMEM_LIMIT - 1))
-#define ARCH_PFN_OFFSET PFN_DOWN(CONFIG_RAM_BASE)
+extern unsigned long phys_offset;
-#define PAGE_OFFSET 0x80000000
-#define LOWMEM_LIMIT 0x40000000
+#define ARCH_PFN_OFFSET PFN_DOWN(phys_offset + PHYS_OFFSET_OFFSET)
-#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + PHYS_OFFSET)
+#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + phys_offset)
#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - \
- PHYS_OFFSET))
+ phys_offset))
#define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0))
#define MAP_NR(x) PFN_DOWN((unsigned long)(x) - PAGE_OFFSET - \
@@ -90,15 +88,10 @@ typedef struct page *pgtable_t;
#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-/*
- * main RAM and kernel working space are coincident at 0x80000000, but to make
- * life more interesting, there's also an uncached virtual shadow at 0xb0000000
- * - these mappings are fixed in the MMU
- */
-
#define pfn_to_kaddr(x) __va(PFN_PHYS(x))
#include <asm-generic/memory_model.h>
#include <asm-generic/getorder.h>
+#endif /* !__ASSEMBLY__ */
#endif /* __ASM_CSKY_PAGE_H */
diff --git a/arch/csky/kernel/setup.c b/arch/csky/kernel/setup.c
index dff8b89..c377194 100644
--- a/arch/csky/kernel/setup.c
+++ b/arch/csky/kernel/setup.c
@@ -142,11 +142,16 @@ void __init setup_arch(char **cmdline_p)
#endif
}
+unsigned long phys_offset;
+EXPORT_SYMBOL(phys_offset);
+
asmlinkage __visible void __init csky_start(unsigned int unused, void *param)
{
/* Clean up bss section */
memset(__bss_start, 0, __bss_stop - __bss_start);
+ phys_offset = read_mmu_msa0() & ~(SSEG_SIZE - 1);
+
pre_trap_init();
pre_mmu_init();
--
2.7.4
