Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 623dffb2 authored by Toshi Kani's avatar Toshi Kani Committed by Ingo Molnar
Browse files

x86/mm/pat: Add set_memory_wt() for Write-Through type 



Now that reserve_ram_pages_type() accepts the WT type, add
set_memory_wt(), set_memory_array_wt() and set_pages_array_wt()
in order to be able to set memory to Write-Through page cache
mode.

Also, extend ioremap_change_attr() to accept the WT type.

Signed-off-by: default avatarToshi Kani <toshi.kani@hp.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: hch@lst.de
Cc: hmh@hmh.eng.br
Cc: jgross@suse.com
Cc: konrad.wilk@oracle.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: linux-nvdimm@lists.01.org
Cc: stefan.bader@canonical.com
Cc: yigal@plexistor.com
Link: http://lkml.kernel.org/r/1433436928-31903-13-git-send-email-bp@alien8.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 35a5a104

Documentation/x86/pat.txt

+6 −3
Original line number Diff line number Diff line
@@ -48,6 +48,9 @@ set_memory_uc | UC- | -- | -- | 
set_memory_wc          |    WC    |    --      |       --         |

 set_memory_wb         |          |            |                  |

                       |          |            |                  |

set_memory_wt          |    WT    |    --      |       --         |

 set_memory_wb         |          |            |                  |

                       |          |            |                  |

pci sysfs resource     |    --    |    --      |       UC-        |

                       |          |            |                  |

pci sysfs resource_wc  |    --    |    --      |       WC         |
@@ -150,8 +153,8 @@ can be more restrictive, in case of any existing aliasing for that address. 
For example: If there is an existing uncached mapping, a new ioremap_wc can

return uncached mapping in place of write-combine requested.



set_memory_[uc|wc] and set_memory_wb should be used in pairs, where driver will

first make a region uc or wc and switch it back to wb after use.

set_memory_[uc|wc|wt] and set_memory_wb should be used in pairs, where driver

will first make a region uc, wc or wt and switch it back to wb after use.



Over time writes to /proc/mtrr will be deprecated in favor of using PAT based

interfaces. Users writing to /proc/mtrr are suggested to use above interfaces.
@@ -159,7 +162,7 @@ interfaces. Users writing to /proc/mtrr are suggested to use above interfaces. 
Drivers should use ioremap_[uc|wc] to access PCI BARs with [uc|wc] access

types.



Drivers should use set_memory_[uc|wc] to set access type for RAM ranges.

Drivers should use set_memory_[uc|wc|wt] to set access type for RAM ranges.





PAT debugging

arch/x86/include/asm/cacheflush.h

+5 −1
Original line number Diff line number Diff line
@@ -8,7 +8,7 @@ 
/*

 * The set_memory_* API can be used to change various attributes of a virtual

 * address range. The attributes include:

 * Cachability   : UnCached, WriteCombining, WriteBack

 * Cachability   : UnCached, WriteCombining, WriteThrough, WriteBack

 * Executability : eXeutable, NoteXecutable

 * Read/Write    : ReadOnly, ReadWrite

 * Presence      : NotPresent
@@ -35,9 +35,11 @@ 


int _set_memory_uc(unsigned long addr, int numpages);

int _set_memory_wc(unsigned long addr, int numpages);

int _set_memory_wt(unsigned long addr, int numpages);

int _set_memory_wb(unsigned long addr, int numpages);

int set_memory_uc(unsigned long addr, int numpages);

int set_memory_wc(unsigned long addr, int numpages);

int set_memory_wt(unsigned long addr, int numpages);

int set_memory_wb(unsigned long addr, int numpages);

int set_memory_x(unsigned long addr, int numpages);

int set_memory_nx(unsigned long addr, int numpages);
@@ -48,10 +50,12 @@ int set_memory_4k(unsigned long addr, int numpages); 


int set_memory_array_uc(unsigned long *addr, int addrinarray);

int set_memory_array_wc(unsigned long *addr, int addrinarray);

int set_memory_array_wt(unsigned long *addr, int addrinarray);

int set_memory_array_wb(unsigned long *addr, int addrinarray);



int set_pages_array_uc(struct page **pages, int addrinarray);

int set_pages_array_wc(struct page **pages, int addrinarray);

int set_pages_array_wt(struct page **pages, int addrinarray);

int set_pages_array_wb(struct page **pages, int addrinarray);



/*

arch/x86/mm/ioremap.c

+3 −0
Original line number Diff line number Diff line
@@ -42,6 +42,9 @@ int ioremap_change_attr(unsigned long vaddr, unsigned long size, 
	case _PAGE_CACHE_MODE_WC:

		err = _set_memory_wc(vaddr, nrpages);

		break;

	case _PAGE_CACHE_MODE_WT:

		err = _set_memory_wt(vaddr, nrpages);

		break;

	case _PAGE_CACHE_MODE_WB:

		err = _set_memory_wb(vaddr, nrpages);

		break;

arch/x86/mm/pageattr.c

+49 −13
Original line number Diff line number Diff line
@@ -1503,12 +1503,10 @@ EXPORT_SYMBOL(set_memory_uc); 
static int _set_memory_array(unsigned long *addr, int addrinarray,

		enum page_cache_mode new_type)

{

	enum page_cache_mode set_type;

	int i, j;

	int ret;



	/*

	 * for now UC MINUS. see comments in ioremap_nocache()

	 */

	for (i = 0; i < addrinarray; i++) {

		ret = reserve_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE,

					new_type, NULL);
@@ -1516,9 +1514,12 @@ static int _set_memory_array(unsigned long *addr, int addrinarray, 
			goto out_free;

	}



	/* If WC, set to UC- first and then WC */

	set_type = (new_type == _PAGE_CACHE_MODE_WC) ?

				_PAGE_CACHE_MODE_UC_MINUS : new_type;



	ret = change_page_attr_set(addr, addrinarray,

				   cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS),

				   1);

				   cachemode2pgprot(set_type), 1);



	if (!ret && new_type == _PAGE_CACHE_MODE_WC)

		ret = change_page_attr_set_clr(addr, addrinarray,
@@ -1550,6 +1551,12 @@ int set_memory_array_wc(unsigned long *addr, int addrinarray) 
}

EXPORT_SYMBOL(set_memory_array_wc);



int set_memory_array_wt(unsigned long *addr, int addrinarray)

{

	return _set_memory_array(addr, addrinarray, _PAGE_CACHE_MODE_WT);

}

EXPORT_SYMBOL_GPL(set_memory_array_wt);



int _set_memory_wc(unsigned long addr, int numpages)

{

	int ret;
@@ -1575,20 +1582,38 @@ int set_memory_wc(unsigned long addr, int numpages) 
	ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,

		_PAGE_CACHE_MODE_WC, NULL);

	if (ret)

		goto out_err;

		return ret;



	ret = _set_memory_wc(addr, numpages);

	if (ret)

		goto out_free;

		free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);



	return 0;

	return ret;

}

EXPORT_SYMBOL(set_memory_wc);



out_free:

int _set_memory_wt(unsigned long addr, int numpages)

{

	return change_page_attr_set(&addr, numpages,

				    cachemode2pgprot(_PAGE_CACHE_MODE_WT), 0);

}



int set_memory_wt(unsigned long addr, int numpages)

{

	int ret;



	ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,

			      _PAGE_CACHE_MODE_WT, NULL);

	if (ret)

		return ret;



	ret = _set_memory_wt(addr, numpages);

	if (ret)

		free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);

out_err:



	return ret;

}

EXPORT_SYMBOL(set_memory_wc);

EXPORT_SYMBOL_GPL(set_memory_wt);



int _set_memory_wb(unsigned long addr, int numpages)

{
@@ -1680,6 +1705,7 @@ static int _set_pages_array(struct page **pages, int addrinarray, 
{

	unsigned long start;

	unsigned long end;

	enum page_cache_mode set_type;

	int i;

	int free_idx;

	int ret;
@@ -1693,8 +1719,12 @@ static int _set_pages_array(struct page **pages, int addrinarray, 
			goto err_out;

	}



	/* If WC, set to UC- first and then WC */

	set_type = (new_type == _PAGE_CACHE_MODE_WC) ?

				_PAGE_CACHE_MODE_UC_MINUS : new_type;



	ret = cpa_set_pages_array(pages, addrinarray,

			cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS));

				  cachemode2pgprot(set_type));

	if (!ret && new_type == _PAGE_CACHE_MODE_WC)

		ret = change_page_attr_set_clr(NULL, addrinarray,

					       cachemode2pgprot(
@@ -1728,6 +1758,12 @@ int set_pages_array_wc(struct page **pages, int addrinarray) 
}

EXPORT_SYMBOL(set_pages_array_wc);



int set_pages_array_wt(struct page **pages, int addrinarray)

{

	return _set_pages_array(pages, addrinarray, _PAGE_CACHE_MODE_WT);

}

EXPORT_SYMBOL_GPL(set_pages_array_wt);



int set_pages_wb(struct page *page, int numpages)

{

	unsigned long addr = (unsigned long)page_address(page);