From de32400dd26e743c5d500aa42d8d6818b79edb73 Mon Sep 17 00:00:00 2001 From: Albert Herranz Date: Sat, 12 Dec 2009 06:31:53 +0000 Subject: wii: use both mem1 and mem2 as ram The Nintendo Wii video game console has two discontiguous RAM regions: - MEM1: 24MB @ 0x00000000 - MEM2: 64MB @ 0x10000000 Unfortunately, the kernel currently does not support discontiguous RAM memory regions on 32-bit PowerPC platforms. This patch adds a series of workarounds to allow the use of the second memory region (MEM2) as RAM by the kernel. Basically, a single range of memory from the beginning of MEM1 to the end of MEM2 is reported to the kernel, and a memory reservation is created for the hole between MEM1 and MEM2. With this patch the system is able to use all the available RAM and not just ~27% of it. This will no longer be needed when proper discontig memory support for 32-bit PowerPC is added to the kernel. Signed-off-by: Albert Herranz Acked-by: Benjamin Herrenschmidt Signed-off-by: Grant Likely --- arch/powerpc/mm/init_32.c | 4 ++++ arch/powerpc/mm/mmu_decl.h | 10 +++++++++- arch/powerpc/mm/pgtable_32.c | 32 ++++++++++++++++++++++++++++---- arch/powerpc/mm/ppc_mmu_32.c | 4 ++-- 4 files changed, 43 insertions(+), 7 deletions(-) (limited to 'arch/powerpc/mm') diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c index 9ddcfb4dc13..703c7c2e0d9 100644 --- a/arch/powerpc/mm/init_32.c +++ b/arch/powerpc/mm/init_32.c @@ -131,9 +131,13 @@ void __init MMU_init(void) MMU_setup(); if (lmb.memory.cnt > 1) { +#ifndef CONFIG_WII lmb.memory.cnt = 1; lmb_analyze(); printk(KERN_WARNING "Only using first contiguous memory region"); +#else + wii_memory_fixups(); +#endif } total_lowmem = total_memory = lmb_end_of_DRAM() - memstart_addr; diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index d2e5321d5ea..9aa39fe74f8 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -136,6 +136,14 @@ extern phys_addr_t total_lowmem; extern phys_addr_t memstart_addr; extern phys_addr_t lowmem_end_addr; +#ifdef CONFIG_WII +extern unsigned long wii_hole_start; +extern unsigned long wii_hole_size; + +extern unsigned long wii_mmu_mapin_mem2(unsigned long top); +extern void wii_memory_fixups(void); +#endif + /* ...and now those things that may be slightly different between processor * architectures. -- Dan */ @@ -155,5 +163,5 @@ extern void adjust_total_lowmem(void); #elif defined(CONFIG_PPC32) /* anything 32-bit except 4xx or 8xx */ extern void MMU_init_hw(void); -extern unsigned long mmu_mapin_ram(void); +extern unsigned long mmu_mapin_ram(unsigned long top); #endif diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c index cb96cb2e17c..b55bbe87acb 100644 --- a/arch/powerpc/mm/pgtable_32.c +++ b/arch/powerpc/mm/pgtable_32.c @@ -283,18 +283,18 @@ int map_page(unsigned long va, phys_addr_t pa, int flags) } /* - * Map in a big chunk of physical memory starting at PAGE_OFFSET. + * Map in a chunk of physical memory starting at start. */ -void __init mapin_ram(void) +void __init __mapin_ram_chunk(unsigned long offset, unsigned long top) { unsigned long v, s, f; phys_addr_t p; int ktext; - s = mmu_mapin_ram(); + s = offset; v = PAGE_OFFSET + s; p = memstart_addr + s; - for (; s < total_lowmem; s += PAGE_SIZE) { + for (; s < top; s += PAGE_SIZE) { ktext = ((char *) v >= _stext && (char *) v < etext); f = ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL; map_page(v, p, f); @@ -307,6 +307,30 @@ void __init mapin_ram(void) } } +void __init mapin_ram(void) +{ + unsigned long s, top; + +#ifndef CONFIG_WII + top = total_lowmem; + s = mmu_mapin_ram(top); + __mapin_ram_chunk(s, top); +#else + if (!wii_hole_size) { + s = mmu_mapin_ram(total_lowmem); + __mapin_ram_chunk(s, total_lowmem); + } else { + top = wii_hole_start; + s = mmu_mapin_ram(top); + __mapin_ram_chunk(s, top); + + top = lmb_end_of_DRAM(); + s = wii_mmu_mapin_mem2(top); + __mapin_ram_chunk(s, top); + } +#endif +} + /* Scan the real Linux page tables and return a PTE pointer for * a virtual address in a context. * Returns true (1) if PTE was found, zero otherwise. The pointer to diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c index 2d2a87e1015..f11c2cdcb0f 100644 --- a/arch/powerpc/mm/ppc_mmu_32.c +++ b/arch/powerpc/mm/ppc_mmu_32.c @@ -72,7 +72,7 @@ unsigned long p_mapped_by_bats(phys_addr_t pa) return 0; } -unsigned long __init mmu_mapin_ram(void) +unsigned long __init mmu_mapin_ram(unsigned long top) { unsigned long tot, bl, done; unsigned long max_size = (256<<20); @@ -86,7 +86,7 @@ unsigned long __init mmu_mapin_ram(void) /* Make sure we don't map a block larger than the smallest alignment of the physical address. */ - tot = total_lowmem; + tot = top; for (bl = 128<<10; bl < max_size; bl <<= 1) { if (bl * 2 > tot) break; -- cgit v1.2.3