[PATCH] riscv: Introduce structure that group all variables regarding kernel mapping

From: Alexandre Ghiti
Date: Thu Jun 17 2021 - 09:53:13 EST

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We have a lot of variables that are used to hold kernel mapping addresses,
offsets between physical and virtual mappings and some others used for XIP
kernels: they are all defined at different places in mm/init.c, so group
them into a single structure with, for some of them, more explicit and concise
names.

Signed-off-by: Alexandre Ghiti <alex@xxxxxxxx>
---
arch/riscv/include/asm/page.h | 60 ++++++++++--------
arch/riscv/kernel/asm-offsets.c | 2 +
arch/riscv/kernel/head.S | 4 +-
arch/riscv/kernel/kexec_relocate.S | 4 +-
arch/riscv/kernel/machine_kexec.c | 2 +-
arch/riscv/mm/init.c | 98 +++++++++++-------------------
arch/riscv/mm/physaddr.c | 2 +-
arch/riscv/mm/ptdump.c | 2 +-
8 files changed, 78 insertions(+), 96 deletions(-)

diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index 1c2010c292b3..d093154ac72a 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -79,55 +79,61 @@ typedef struct page *pgtable_t;
#endif

#ifdef CONFIG_MMU
-extern unsigned long va_pa_offset;
-#ifdef CONFIG_64BIT
-extern unsigned long va_kernel_pa_offset;
-#endif
-#ifdef CONFIG_XIP_KERNEL
-extern unsigned long va_kernel_xip_pa_offset;
-#endif
extern unsigned long pfn_base;
-extern uintptr_t load_sz;
#define ARCH_PFN_OFFSET (pfn_base)
#else
-#define va_pa_offset 0
-#ifdef CONFIG_64BIT
-#define va_kernel_pa_offset 0
-#endif
#define ARCH_PFN_OFFSET (PAGE_OFFSET >> PAGE_SHIFT)
#endif /* CONFIG_MMU */

-extern unsigned long kernel_virt_addr;
+struct kernel_mapping {
+ unsigned long virt_addr;
+ uintptr_t phys_addr;
+ uintptr_t size;
+ /* Offset between linear mapping virtual address and kernel load address */
+ unsigned long va_pa_offset;
+#ifdef CONFIG_64BIT
+ /* Offset between kernel mapping virtual address and kernel load address */
+ unsigned long va_kernel_pa_offset;
+#endif
+#ifdef CONFIG_XIP_KERNEL
+ unsigned long va_kernel_xip_pa_offset;
+ uintptr_t xiprom;
+ uintptr_t xiprom_sz;
+#endif
+};
+
+extern struct kernel_mapping kernel_map;

#ifdef CONFIG_64BIT
#define is_kernel_mapping(x) \
- ((x) >= kernel_virt_addr && (x) < (kernel_virt_addr + load_sz))
+ ((x) >= kernel_map.virt_addr && (x) < (kernel_map.virt_addr + kernel_map.size))
#define is_linear_mapping(x) \
- ((x) >= PAGE_OFFSET && (x) < kernel_virt_addr)
+ ((x) >= PAGE_OFFSET && (x) < kernel_map.virt_addr)

-#define linear_mapping_pa_to_va(x) ((void *)((unsigned long)(x) + va_pa_offset))
+#define linear_mapping_pa_to_va(x) ((void *)((unsigned long)(x) + kernel_map.va_pa_offset))
#ifdef CONFIG_XIP_KERNEL
#define kernel_mapping_pa_to_va(y) ({ \
unsigned long _y = y; \
(_y >= CONFIG_PHYS_RAM_BASE) ? \
- (void *)((unsigned long)(_y) + va_kernel_pa_offset + XIP_OFFSET) : \
- (void *)((unsigned long)(_y) + va_kernel_xip_pa_offset); \
+ (void *)((unsigned long)(_y) + kernel_map.va_kernel_pa_offset + XIP_OFFSET) : \
+ (void *)((unsigned long)(_y) + kernel_map.va_kernel_xip_pa_offset); \
})
#else
-#define kernel_mapping_pa_to_va(x) ((void *)((unsigned long)(x) + va_kernel_pa_offset))
+#define kernel_mapping_pa_to_va(x) \
+ ((void *)((unsigned long)(x) + kernel_map.va_kernel_pa_offset))
#endif
#define __pa_to_va_nodebug(x) linear_mapping_pa_to_va(x)

-#define linear_mapping_va_to_pa(x) ((unsigned long)(x) - va_pa_offset)
+#define linear_mapping_va_to_pa(x) ((unsigned long)(x) - kernel_map.va_pa_offset)
#ifdef CONFIG_XIP_KERNEL
#define kernel_mapping_va_to_pa(y) ({ \
unsigned long _y = y; \
- (_y < kernel_virt_addr + XIP_OFFSET) ? \
- ((unsigned long)(_y) - va_kernel_xip_pa_offset) : \
- ((unsigned long)(_y) - va_kernel_pa_offset - XIP_OFFSET); \
+ (_y < kernel_map.virt_addr + XIP_OFFSET) ? \
+ ((unsigned long)(_y) - kernel_map.va_kernel_xip_pa_offset) : \
+ ((unsigned long)(_y) - kernel_map.va_kernel_pa_offset - XIP_OFFSET); \
})
#else
-#define kernel_mapping_va_to_pa(x) ((unsigned long)(x) - va_kernel_pa_offset)
+#define kernel_mapping_va_to_pa(x) ((unsigned long)(x) - kernel_map.va_kernel_pa_offset)
#endif
#define __va_to_pa_nodebug(x) ({ \
unsigned long _x = x; \
@@ -136,12 +142,12 @@ extern unsigned long kernel_virt_addr;
})
#else
#define is_kernel_mapping(x) \
- ((x) >= kernel_virt_addr && (x) < (kernel_virt_addr + load_sz))
+ ((x) >= kernel_map.virt_addr && (x) < (kernel_map.virt_addr + kernel_map.size))
#define is_linear_mapping(x) \
((x) >= PAGE_OFFSET)

-#define __pa_to_va_nodebug(x) ((void *)((unsigned long) (x) + va_pa_offset))
-#define __va_to_pa_nodebug(x) ((unsigned long)(x) - va_pa_offset)
+#define __pa_to_va_nodebug(x) ((void *)((unsigned long)(x) + kernel_map.va_pa_offset))
+#define __va_to_pa_nodebug(x) ((unsigned long)(x) - kernel_map.va_pa_offset)
#endif

#ifdef CONFIG_DEBUG_VIRTUAL
diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c
index 9ef33346853c..90f8ce64fa6f 100644
--- a/arch/riscv/kernel/asm-offsets.c
+++ b/arch/riscv/kernel/asm-offsets.c
@@ -311,4 +311,6 @@ void asm_offsets(void)
* ensures the alignment is sane.
*/
DEFINE(PT_SIZE_ON_STACK, ALIGN(sizeof(struct pt_regs), STACK_ALIGN));
+
+ OFFSET(KERNEL_MAP_VIRT_ADDR, kernel_mapping, virt_addr);
}
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index 89cc58ab52b4..fce5184b22c3 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -81,9 +81,9 @@ pe_head_start:
#ifdef CONFIG_MMU
relocate:
/* Relocate return address */
- la a1, kernel_virt_addr
+ la a1, kernel_map
XIP_FIXUP_OFFSET a1
- REG_L a1, 0(a1)
+ REG_L a1, KERNEL_MAP_VIRT_ADDR(a1)
la a2, _start
sub a1, a1, a2
add ra, ra, a1
diff --git a/arch/riscv/kernel/kexec_relocate.S b/arch/riscv/kernel/kexec_relocate.S
index 88c3beabe9b4..a80b52a74f58 100644
--- a/arch/riscv/kernel/kexec_relocate.S
+++ b/arch/riscv/kernel/kexec_relocate.S
@@ -20,7 +20,7 @@ SYM_CODE_START(riscv_kexec_relocate)
* s4: Pointer to the destination address for the relocation
* s5: (const) Number of words per page
* s6: (const) 1, used for subtraction
- * s7: (const) va_pa_offset, used when switching MMU off
+ * s7: (const) kernel_map.va_pa_offset, used when switching MMU off
* s8: (const) Physical address of the main loop
* s9: (debug) indirection page counter
* s10: (debug) entry counter
@@ -159,7 +159,7 @@ SYM_CODE_START(riscv_kexec_norelocate)
* s0: (const) Phys address to jump to
* s1: (const) Phys address of the FDT image
* s2: (const) The hartid of the current hart
- * s3: (const) va_pa_offset, used when switching MMU off
+ * s3: (const) kernel_map.va_pa_offset, used when switching MMU off
*/
mv s0, a1
mv s1, a2
diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_kexec.c
index cc048143fba5..3e39fd95e02b 100644
--- a/arch/riscv/kernel/machine_kexec.c
+++ b/arch/riscv/kernel/machine_kexec.c
@@ -188,6 +188,6 @@ machine_kexec(struct kimage *image)
/* Jump to the relocation code */
pr_notice("Bye...\n");
kexec_method(first_ind_entry, jump_addr, fdt_addr,
- this_hart_id, va_pa_offset);
+ this_hart_id, kernel_map.va_pa_offset);
unreachable();
}
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 3d77b04bec54..ed817016df2c 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -30,10 +30,13 @@

#include "../kernel/head.h"

-unsigned long kernel_virt_addr = KERNEL_LINK_ADDR;
-EXPORT_SYMBOL(kernel_virt_addr);
+struct kernel_mapping kernel_map __ro_after_init;
+EXPORT_SYMBOL(kernel_map);
+#ifdef CONFIG_XIP_KERNEL
+#define kernel_map (*(struct kernel_mapping *)XIP_FIXUP(&kernel_map))
+#endif
+
#ifdef CONFIG_XIP_KERNEL
-#define kernel_virt_addr (*((unsigned long *)XIP_FIXUP(&kernel_virt_addr)))
extern char _xiprom[], _exiprom[];
#endif

@@ -211,25 +214,6 @@ static struct pt_alloc_ops _pt_ops __initdata;
#define pt_ops _pt_ops
#endif

-/* Offset between linear mapping virtual address and kernel load address */
-unsigned long va_pa_offset __ro_after_init;
-EXPORT_SYMBOL(va_pa_offset);
-#ifdef CONFIG_XIP_KERNEL
-#define va_pa_offset (*((unsigned long *)XIP_FIXUP(&va_pa_offset)))
-#endif
-/* Offset between kernel mapping virtual address and kernel load address */
-#ifdef CONFIG_64BIT
-unsigned long va_kernel_pa_offset __ro_after_init;
-EXPORT_SYMBOL(va_kernel_pa_offset);
-#endif
-#ifdef CONFIG_XIP_KERNEL
-#define va_kernel_pa_offset (*((unsigned long *)XIP_FIXUP(&va_kernel_pa_offset)))
-#endif
-unsigned long va_kernel_xip_pa_offset __ro_after_init;
-EXPORT_SYMBOL(va_kernel_xip_pa_offset);
-#ifdef CONFIG_XIP_KERNEL
-#define va_kernel_xip_pa_offset (*((unsigned long *)XIP_FIXUP(&va_kernel_xip_pa_offset)))
-#endif
unsigned long pfn_base __ro_after_init;
EXPORT_SYMBOL(pfn_base);

@@ -345,7 +329,7 @@ static pmd_t *__init get_pmd_virt_late(phys_addr_t pa)

static phys_addr_t __init alloc_pmd_early(uintptr_t va)
{
- BUG_ON((va - kernel_virt_addr) >> PGDIR_SHIFT);
+ BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);

return (uintptr_t)early_pmd;
}
@@ -509,36 +493,24 @@ static __init pgprot_t pgprot_from_va(uintptr_t va)
#error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
#endif

-static uintptr_t load_pa __initdata;
-uintptr_t load_sz;
-#ifdef CONFIG_XIP_KERNEL
-#define load_pa (*((uintptr_t *)XIP_FIXUP(&load_pa)))
-#define load_sz (*((uintptr_t *)XIP_FIXUP(&load_sz)))
-#endif
-
#ifdef CONFIG_XIP_KERNEL
-static uintptr_t xiprom __initdata;
-static uintptr_t xiprom_sz __initdata;
-#define xiprom_sz (*((uintptr_t *)XIP_FIXUP(&xiprom_sz)))
-#define xiprom (*((uintptr_t *)XIP_FIXUP(&xiprom)))
-
static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size,
__always_unused bool early)
{
uintptr_t va, end_va;

/* Map the flash resident part */
- end_va = kernel_virt_addr + xiprom_sz;
- for (va = kernel_virt_addr; va < end_va; va += map_size)
+ end_va = kernel_map.virt_addr + kernel_map.xiprom_sz;
+ for (va = kernel_map.virt_addr; va < end_va; va += map_size)
create_pgd_mapping(pgdir, va,
- xiprom + (va - kernel_virt_addr),
+ kernel_map.xiprom + (va - kernel_map.virt_addr),
map_size, PAGE_KERNEL_EXEC);

/* Map the data in RAM */
- end_va = kernel_virt_addr + XIP_OFFSET + load_sz;
- for (va = kernel_virt_addr + XIP_OFFSET; va < end_va; va += map_size)
+ end_va = kernel_map.virt_addr + XIP_OFFSET + kernel_map.size;
+ for (va = kernel_map.virt_addr + XIP_OFFSET; va < end_va; va += map_size)
create_pgd_mapping(pgdir, va,
- load_pa + (va - (kernel_virt_addr + XIP_OFFSET)),
+ kernel_map.phys_addr + (va - (kernel_map.virt_addr + XIP_OFFSET)),
map_size, PAGE_KERNEL);
}
#else
@@ -546,10 +518,10 @@ static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size, bo
{
uintptr_t va, end_va;

- end_va = kernel_virt_addr + load_sz;
- for (va = kernel_virt_addr; va < end_va; va += map_size)
+ end_va = kernel_map.virt_addr + kernel_map.size;
+ for (va = kernel_map.virt_addr; va < end_va; va += map_size)
create_pgd_mapping(pgdir, va,
- load_pa + (va - kernel_virt_addr),
+ kernel_map.phys_addr + (va - kernel_map.virt_addr),
map_size, early ? PAGE_KERNEL_EXEC : pgprot_from_va(va));
}
#endif
@@ -562,25 +534,27 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
pmd_t fix_bmap_spmd, fix_bmap_epmd;
#endif

+ kernel_map.virt_addr = KERNEL_LINK_ADDR;
+
#ifdef CONFIG_XIP_KERNEL
- xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
- xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);
+ kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
+ kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);

- load_pa = (uintptr_t)CONFIG_PHYS_RAM_BASE;
- load_sz = (uintptr_t)(&_end) - (uintptr_t)(&_sdata);
+ kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE;
+ kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_sdata);

- va_kernel_xip_pa_offset = kernel_virt_addr - xiprom;
+ kernel_map.va_kernel_xip_pa_offset = kernel_map.virt_addr - kernel_map.xiprom;
#else
- load_pa = (uintptr_t)(&_start);
- load_sz = (uintptr_t)(&_end) - load_pa;
+ kernel_map.phys_addr = (uintptr_t)(&_start);
+ kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr;
#endif

- va_pa_offset = PAGE_OFFSET - load_pa;
+ kernel_map.va_pa_offset = PAGE_OFFSET - kernel_map.phys_addr;
#ifdef CONFIG_64BIT
- va_kernel_pa_offset = kernel_virt_addr - load_pa;
+ kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr;
#endif

- pfn_base = PFN_DOWN(load_pa);
+ pfn_base = PFN_DOWN(kernel_map.phys_addr);

/*
* Enforce boot alignment requirements of RV32 and
@@ -590,7 +564,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)

/* Sanity check alignment and size */
BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
- BUG_ON((load_pa % map_size) != 0);
+ BUG_ON((kernel_map.phys_addr % map_size) != 0);

pt_ops.alloc_pte = alloc_pte_early;
pt_ops.get_pte_virt = get_pte_virt_early;
@@ -607,19 +581,19 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
create_pmd_mapping(fixmap_pmd, FIXADDR_START,
(uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
/* Setup trampoline PGD and PMD */
- create_pgd_mapping(trampoline_pg_dir, kernel_virt_addr,
+ create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
(uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
#ifdef CONFIG_XIP_KERNEL
- create_pmd_mapping(trampoline_pmd, kernel_virt_addr,
- xiprom, PMD_SIZE, PAGE_KERNEL_EXEC);
+ create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
+ kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC);
#else
- create_pmd_mapping(trampoline_pmd, kernel_virt_addr,
- load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
+ create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
+ kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC);
#endif
#else
/* Setup trampoline PGD */
- create_pgd_mapping(trampoline_pg_dir, kernel_virt_addr,
- load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
+ create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
+ kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC);
#endif

/*
diff --git a/arch/riscv/mm/physaddr.c b/arch/riscv/mm/physaddr.c
index 35703d5ef5fd..e7fd0c253c7b 100644
--- a/arch/riscv/mm/physaddr.c
+++ b/arch/riscv/mm/physaddr.c
@@ -23,7 +23,7 @@ EXPORT_SYMBOL(__virt_to_phys);

phys_addr_t __phys_addr_symbol(unsigned long x)
{
- unsigned long kernel_start = (unsigned long)kernel_virt_addr;
+ unsigned long kernel_start = kernel_map.virt_addr;
unsigned long kernel_end = (unsigned long)_end;

/*
diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c
index 0536ac84b730..ee4e5c1c39c5 100644
--- a/arch/riscv/mm/ptdump.c
+++ b/arch/riscv/mm/ptdump.c
@@ -379,7 +379,7 @@ static int __init ptdump_init(void)
address_markers[PAGE_OFFSET_NR].start_address = PAGE_OFFSET;
#ifdef CONFIG_64BIT
address_markers[MODULES_MAPPING_NR].start_address = MODULES_VADDR;
- address_markers[KERNEL_MAPPING_NR].start_address = kernel_virt_addr;
+ address_markers[KERNEL_MAPPING_NR].start_address = kernel_map.virt_addr;
#endif

kernel_ptd_info.base_addr = KERN_VIRT_START;
--
2.30.2

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