MIPS: BCM47XX: Detect more then 128 MiB of RAM (HIGHMEM)

So far BCM47XX can only detect amount of HIGHMEM. It still requires
adding (registering) and well-testing before enabling by default.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7396/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Rafał Miłecki 2014-07-17 23:26:33 +02:00 committed by Ralf Baechle
parent d377732c8c
commit 6ee1d93455
5 changed files with 76 additions and 2 deletions

View file

@ -3,6 +3,9 @@
#include <linux/kernel.h>
/* prom.c */
void __init bcm47xx_prom_highmem_init(void);
/* buttons.c */
int __init bcm47xx_buttons_register(void);

View file

@ -51,6 +51,8 @@ __init void bcm47xx_set_system_type(u16 chip_id)
chip_id);
}
static unsigned long lowmem __initdata;
static __init void prom_init_mem(void)
{
unsigned long mem;
@ -87,6 +89,7 @@ static __init void prom_init_mem(void)
if (!memcmp(prom_init, prom_init + mem, 32))
break;
}
lowmem = mem;
/* Ignoring the last page when ddr size is 128M. Cached
* accesses to last page is causing the processor to prefetch
@ -95,7 +98,6 @@ static __init void prom_init_mem(void)
*/
if (c->cputype == CPU_74K && (mem == (128 << 20)))
mem -= 0x1000;
add_memory_region(0, mem, BOOT_MEM_RAM);
}
@ -114,3 +116,67 @@ void __init prom_init(void)
void __init prom_free_prom_memory(void)
{
}
#if defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM)
#define EXTVBASE 0xc0000000
#define ENTRYLO(x) ((pte_val(pfn_pte((x) >> _PFN_SHIFT, PAGE_KERNEL_UNCACHED)) >> 6) | 1)
#include <asm/tlbflush.h>
/* Stripped version of tlb_init, with the call to build_tlb_refill_handler
* dropped. Calling it at this stage causes a hang.
*/
void __cpuinit early_tlb_init(void)
{
write_c0_pagemask(PM_DEFAULT_MASK);
write_c0_wired(0);
temp_tlb_entry = current_cpu_data.tlbsize - 1;
local_flush_tlb_all();
}
void __init bcm47xx_prom_highmem_init(void)
{
unsigned long off = (unsigned long)prom_init;
unsigned long extmem = 0;
bool highmem_region = false;
if (WARN_ON(bcm47xx_bus_type != BCM47XX_BUS_TYPE_BCMA))
return;
if (bcm47xx_bus.bcma.bus.chipinfo.id == BCMA_CHIP_ID_BCM4706)
highmem_region = true;
if (lowmem != 128 << 20 || !highmem_region)
return;
early_tlb_init();
/* Add one temporary TLB entry to map SDRAM Region 2.
* Physical Virtual
* 0x80000000 0xc0000000 (1st: 256MB)
* 0x90000000 0xd0000000 (2nd: 256MB)
*/
add_temporary_entry(ENTRYLO(0x80000000),
ENTRYLO(0x80000000 + (256 << 20)),
EXTVBASE, PM_256M);
off = EXTVBASE + __pa(off);
for (extmem = 128 << 20; extmem < 512 << 20; extmem <<= 1) {
if (!memcmp(prom_init, (void *)(off + extmem), 16))
break;
}
extmem -= lowmem;
early_tlb_init();
if (!extmem)
return;
pr_warn("Found %lu MiB of extra memory, but highmem is unsupported yet!\n",
extmem >> 20);
/* TODO: Register extra memory */
}
#endif /* defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM) */

View file

@ -218,6 +218,9 @@ void __init plat_mem_setup(void)
bcm47xx_bus_type = BCM47XX_BUS_TYPE_BCMA;
bcm47xx_register_bcma();
bcm47xx_set_system_type(bcm47xx_bus.bcma.bus.chipinfo.id);
#ifdef CONFIG_HIGHMEM
bcm47xx_prom_highmem_init();
#endif
#endif
} else {
printk(KERN_INFO "bcm47xx: using ssb bus\n");

View file

@ -18,6 +18,8 @@
#include <asm-generic/pgtable-nopmd.h>
extern int temp_tlb_entry __cpuinitdata;
/*
* - add_temporary_entry() add a temporary TLB entry. We use TLB entries
* starting at the top and working down. This is for populating the

View file

@ -397,7 +397,7 @@ int __init has_transparent_hugepage(void)
* lifetime of the system
*/
static int temp_tlb_entry __cpuinitdata;
int temp_tlb_entry __cpuinitdata;
__init int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
unsigned long entryhi, unsigned long pagemask)