Commit 21440cf0 authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: Preliminary support for SH-X2 MMU. 



This adds some preliminary support for the SH-X2 MMU, used by
newer SH-4A parts (particularly SH7785).

This MMU implements a 'compat' mode with SH-X MMUs and an
'extended' mode for SH-X2 extended features. Extended features
include additional page sizes (8kB, 4MB, 64MB), as well as the
addition of page execute permissions.

The extended mode attributes are placed in a second data array,
which requires us to switch to 64-bit PTEs when in X2 mode.

With the addition of the exec perms, we also overhaul the mmap
prots somewhat, now that it's possible to handle them more
intelligently.

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent b552c7e8

arch/sh/mm/Kconfig

+47 −2
Original line number Diff line number Diff line
@@ -235,13 +235,22 @@ config MEMORY_SIZE 


config 32BIT

	bool "Support 32-bit physical addressing through PMB"

	depends on CPU_SH4A && MMU

	depends on CPU_SH4A && MMU && (!X2TLB || BROKEN)

	default y

	help

	  If you say Y here, physical addressing will be extended to

	  32-bits through the SH-4A PMB. If this is not set, legacy

	  29-bit physical addressing will be used.



config X2TLB

	bool "Enable extended TLB mode"

	depends on CPU_SUBTYPE_SH7785 && MMU && EXPERIMENTAL

	help

	  Selecting this option will enable the extended mode of the SH-X2

	  TLB. For legacy SH-X behaviour and interoperability, say N. For

	  all of the fun new features and a willingless to submit bug reports,

	  say Y.



config VSYSCALL

	bool "Support vsyscall page"

	depends on MMU
@@ -255,17 +264,53 @@ config VSYSCALL 
	  For systems with an MMU that can afford to give up a page,

	  (the default value) say Y.



choice

	prompt "Kernel page size"

	default PAGE_SIZE_4KB



config PAGE_SIZE_4KB

	bool "4kB"

	help

	  This is the default page size used by all SuperH CPUs.



config PAGE_SIZE_8KB

	bool "8kB"

	depends on EXPERIMENTAL && X2TLB

	help

	  This enables 8kB pages as supported by SH-X2 and later MMUs.



config PAGE_SIZE_64KB

	bool "64kB"

	depends on EXPERIMENTAL && CPU_SH4

	help

	  This enables support for 64kB pages, possible on all SH-4

	  CPUs and later. Highly experimental, not recommended.



endchoice



choice

	prompt "HugeTLB page size"

	depends on HUGETLB_PAGE && CPU_SH4 && MMU

	default HUGETLB_PAGE_SIZE_64K



config HUGETLB_PAGE_SIZE_64K

	bool "64K"

	bool "64kB"



config HUGETLB_PAGE_SIZE_256K

	bool "256kB"

	depends on X2TLB



config HUGETLB_PAGE_SIZE_1MB

	bool "1MB"



config HUGETLB_PAGE_SIZE_4MB

	bool "4MB"

	depends on X2TLB



config HUGETLB_PAGE_SIZE_64MB

	bool "64MB"

	depends on X2TLB



endchoice



source "mm/Kconfig"

arch/sh/mm/init.c

+2 −2
Original line number Diff line number Diff line
@@ -93,7 +93,7 @@ static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot) 
	pud = pud_offset(pgd, addr);

	if (pud_none(*pud)) {

		pmd = (pmd_t *)get_zeroed_page(GFP_ATOMIC);

		set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));

		set_pud(pud, __pud(__pa(pmd) | _PAGE_TABLE));

		if (pmd != pmd_offset(pud, 0)) {

			pud_ERROR(*pud);

			return;
@@ -103,7 +103,7 @@ static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot) 
	pmd = pmd_offset(pud, addr);

	if (pmd_none(*pmd)) {

		pte = (pte_t *)get_zeroed_page(GFP_ATOMIC);

		set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));

		set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));

		if (pte != pte_offset_kernel(pmd, 0)) {

			pmd_ERROR(*pmd);

			return;

arch/sh/mm/ioremap.c

+1 −3
Original line number Diff line number Diff line
@@ -28,9 +28,7 @@ static inline void remap_area_pte(pte_t * pte, unsigned long address, 
{

	unsigned long end;

	unsigned long pfn;

	pgprot_t pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW |

				   _PAGE_DIRTY | _PAGE_ACCESSED |

				   _PAGE_HW_SHARED | _PAGE_FLAGS_HARD | flags);

	pgprot_t pgprot = __pgprot(pgprot_val(PAGE_KERNEL_NOCACHE) | flags);



	address &= ~PMD_MASK;

	end = address + size;

arch/sh/mm/pg-sh4.c

+2 −10
Original line number Diff line number Diff line
@@ -37,10 +37,6 @@ void clear_user_page(void *to, unsigned long address, struct page *page) 
	if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)

		clear_page(to);

	else {

		pgprot_t pgprot = __pgprot(_PAGE_PRESENT |

					   _PAGE_RW | _PAGE_CACHABLE |

					   _PAGE_DIRTY | _PAGE_ACCESSED |

					   _PAGE_HW_SHARED | _PAGE_FLAGS_HARD);

		unsigned long phys_addr = PHYSADDR(to);

		unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);

		pgd_t *pgd = pgd_offset_k(p3_addr);
@@ -50,7 +46,7 @@ void clear_user_page(void *to, unsigned long address, struct page *page) 
		pte_t entry;

		unsigned long flags;



		entry = pfn_pte(phys_addr >> PAGE_SHIFT, pgprot);

		entry = pfn_pte(phys_addr >> PAGE_SHIFT, PAGE_KERNEL);

		down(&p3map_sem[(address & CACHE_ALIAS)>>12]);

		set_pte(pte, entry);

		local_irq_save(flags);
@@ -77,10 +73,6 @@ void copy_user_page(void *to, void *from, unsigned long address, 
	if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)

		copy_page(to, from);

	else {

		pgprot_t pgprot = __pgprot(_PAGE_PRESENT |

					   _PAGE_RW | _PAGE_CACHABLE |

					   _PAGE_DIRTY | _PAGE_ACCESSED |

					   _PAGE_HW_SHARED | _PAGE_FLAGS_HARD);

		unsigned long phys_addr = PHYSADDR(to);

		unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);

		pgd_t *pgd = pgd_offset_k(p3_addr);
@@ -90,7 +82,7 @@ void copy_user_page(void *to, void *from, unsigned long address, 
		pte_t entry;

		unsigned long flags;



		entry = pfn_pte(phys_addr >> PAGE_SHIFT, pgprot);

		entry = pfn_pte(phys_addr >> PAGE_SHIFT, PAGE_KERNEL);

		down(&p3map_sem[(address & CACHE_ALIAS)>>12]);

		set_pte(pte, entry);

		local_irq_save(flags);

include/asm-sh/elf.h

+1 −1
Original line number Diff line number Diff line
@@ -74,7 +74,7 @@ typedef struct user_fpu_struct elf_fpregset_t; 
#define ELF_ARCH	EM_SH



#define USE_ELF_CORE_DUMP

#define ELF_EXEC_PAGESIZE	4096

#define ELF_EXEC_PAGESIZE	PAGE_SIZE



/* This is the location that an ET_DYN program is loaded if exec'ed.  Typical

   use of this is to invoke "./ld.so someprog" to test out a new version of