Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-14 16:12:02 +00:00
Code Issues Packages Projects Releases Wiki Activity

ARM: mm: Recreate kernel mappings in early_paging_init()

Browse Source 
This patch adds a step in the init sequence, in order to recreate
the kernel code/data page table mappings prior to full paging
initialization.  This is necessary on LPAE systems that run out of
a physical address space outside the 4G limit.  On these systems,
this implementation provides a machine descriptor hook that allows
the PHYS_OFFSET to be overridden in a machine specific fashion.

Cc: Russell King <linux@arm.linux.org.uk>

Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: R Sricharan <r.sricharan@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
This commit is contained in:
Santosh Shilimkar 2013-07-31 12:44:46 -04:00
parent f52bb72254
commit a77e0c7b27
3 changed files with 87 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/arm/include/asm/mach/arch.h
View File

@ -49,6 +49,7 @@ struct machine_desc {
bool (*smp_init)(void);
void (*fixup)(struct tag *, char **,
struct meminfo *);
void (*init_meminfo)(void);
void (*reserve)(void);/* reserve mem blocks */
void (*map_io)(void);/* IO mapping function */
void (*init_early)(void);

4
arch/arm/kernel/setup.c
View File

@ -73,6 +73,8 @@ __setup("fpe=", fpe_setup);
#endif
extern void paging_init(const struct machine_desc *desc);
extern void early_paging_init(const struct machine_desc *,
struct proc_info_list *);
extern void sanity_check_meminfo(void);
extern enum reboot_mode reboot_mode;
extern void setup_dma_zone(const struct machine_desc *desc);
@ -878,6 +880,8 @@ void __init setup_arch(char **cmdline_p)
parse_early_param();
sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL);
early_paging_init(mdesc, lookup_processor_type(read_cpuid_id()));
sanity_check_meminfo();
arm_memblock_init(&meminfo, mdesc);

82
arch/arm/mm/mmu.c
View File

@ -28,6 +28,8 @@
#include <asm/highmem.h>
#include <asm/system_info.h>
#include <asm/traps.h>
#include <asm/procinfo.h>
#include <asm/memory.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
@ -1315,6 +1317,86 @@ static void __init map_lowmem(void)
}
}
#ifdef CONFIG_ARM_LPAE
/*
* early_paging_init() recreates boot time page table setup, allowing machines
* to switch over to a high (>4G) address space on LPAE systems
*/
void __init early_paging_init(const struct machine_desc *mdesc,
struct proc_info_list *procinfo)
{
pmdval_t pmdprot = procinfo->__cpu_mm_mmu_flags;
unsigned long map_start, map_end;
pgd_t *pgd0, *pgdk;
pud_t *pud0, *pudk, *pud_start;
pmd_t *pmd0, *pmdk;
phys_addr_t phys;
int i;
if (!(mdesc->init_meminfo))
return;
/* remap kernel code and data */
map_start = init_mm.start_code;
map_end = init_mm.brk;
/* get a handle on things... */
pgd0 = pgd_offset_k(0);
pud_start = pud0 = pud_offset(pgd0, 0);
pmd0 = pmd_offset(pud0, 0);
pgdk = pgd_offset_k(map_start);
pudk = pud_offset(pgdk, map_start);
pmdk = pmd_offset(pudk, map_start);
mdesc->init_meminfo();
/* Run the patch stub to update the constants */
fixup_pv_table(&__pv_table_begin,
(&__pv_table_end - &__pv_table_begin) << 2);
/*
* Cache cleaning operations for self-modifying code
* We should clean the entries by MVA but running a
* for loop over every pv_table entry pointer would
* just complicate the code.
*/
flush_cache_louis();
dsb();
isb();
/* remap level 1 table */
for (i = 0; i < PTRS_PER_PGD; pud0++, i++) {
set_pud(pud0,
__pud(__pa(pmd0) | PMD_TYPE_TABLE | L_PGD_SWAPPER));
pmd0 += PTRS_PER_PMD;
}
/* remap pmds for kernel mapping */
phys = __pa(map_start) & PMD_MASK;
do {
*pmdk++ = __pmd(phys | pmdprot);
phys += PMD_SIZE;
} while (phys < map_end);
flush_cache_all();
cpu_switch_mm(pgd0, &init_mm);
cpu_set_ttbr(1, __pa(pgd0) + TTBR1_OFFSET);
local_flush_bp_all();
local_flush_tlb_all();
}
#else
void __init early_paging_init(const struct machine_desc *mdesc,
struct proc_info_list *procinfo)
{
if (mdesc->init_meminfo)
mdesc->init_meminfo();
}
#endif
/*
* paging_init() sets up the page tables, initialises the zone memory
* maps, and sets up the zero page, bad page and bad page tables.