From linux-ia64 Wed Jan 19 22:53:00 2005 From: Jesse Barnes Date: Wed, 19 Jan 2005 22:53:00 +0000 To: linux-ia64 Subject: Re: pgprot_writecombine & shub 1.x Message-Id: <200501191453.00489.jbarnes () sgi ! com> X-MARC-Message: https://marc.info/?l=linux-ia64&m=110617521605244 MIME-Version: 1 Content-Type: multipart/mixed; boundary="--Boundary-00=_MTu7BiNe8RrJW+X" --Boundary-00=_MTu7BiNe8RrJW+X Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline On Wednesday, January 19, 2005 2:39 pm, David Mosberger wrote: > Jesse> Sounds good, though that could be a long wait. Should we add > Jesse> this new EFI call anyway? Seems like it'll be useful > Jesse> regardless... > > I agree. Ok, here you go Tony. This one fixes the loop and also fixes drm_vm.c. All of the bits aside from the efi.h bit are ia64 specific (either under arch/ia64 or __ia64__), so your tree is probably the right place for all of it. This patch adds efi_range_is_wc() to efi.h. It's used to determine whether an address range can be mapped with the write coalescing attribute. It also fixes up some ia64 specific callers to use the new routine instead of unconditionally calling pgprot_writecombined, which can be dangerous if used on ranges that don't support it. Signed-off-by: Jesse Barnes Thanks, Jesse --Boundary-00=_MTu7BiNe8RrJW+X Content-Type: text/plain; charset="iso-8859-1"; name="efi-check-wc-range-6.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="efi-check-wc-range-6.patch" ===== arch/ia64/pci/pci.c 1.65 vs edited ===== --- 1.65/arch/ia64/pci/pci.c 2005-01-12 10:08:48 -08:00 +++ edited/arch/ia64/pci/pci.c 2005-01-19 11:09:32 -08:00 @@ -539,7 +539,8 @@ */ vma->vm_flags |= (VM_SHM | VM_RESERVED | VM_IO); - if (write_combine) + if (write_combine && efi_range_is_wc(vma->vm_start, + vma->vm_end - vma->vm_start)) vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); else vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); ===== drivers/char/drm/drm_vm.c 1.36 vs edited ===== --- 1.36/drivers/char/drm/drm_vm.c 2004-11-04 02:35:43 -08:00 +++ edited/drivers/char/drm/drm_vm.c 2005-01-19 14:31:47 -08:00 @@ -612,8 +612,13 @@ vma->vm_flags |= VM_IO; /* not in core dump */ } #if defined(__ia64__) - if (map->type != _DRM_AGP) - vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); + if (efi_range_is_wc(vma->vm_start, vma->vm_end - + vma->vm_start)) + vma->vm_page_prot = + pgprot_writecombine(vma->vm_page_prot); + else + vma->vm_page_prot = + pgprot_noncached(vma->vm_page_prot); #endif offset = dev->driver->get_reg_ofs(dev); #ifdef __sparc__ ===== drivers/video/fbmem.c 1.148 vs edited ===== --- 1.148/drivers/video/fbmem.c 2005-01-05 15:46:41 -08:00 +++ edited/drivers/video/fbmem.c 2005-01-19 14:52:06 -08:00 @@ -35,6 +35,7 @@ #include #include #include +#include #if defined(__mc68000__) || defined(CONFIG_APUS) #include @@ -950,9 +951,13 @@ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); #elif defined(__hppa__) pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE; -#elif defined(__ia64__) || defined(__arm__) || defined(__sh__) || \ - defined(__m32r__) +#elif defined(__arm__) || defined(__sh__) || defined(__m32r__) vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); +#elif defined(__ia64__) + if (efi_range_is_wc(vma->vm_start, vma->vm_end - vma->vm_start)) + vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); + else + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); #else #warning What do we have to do here?? #endif ===== include/linux/efi.h 1.12 vs edited ===== --- 1.12/include/linux/efi.h 2004-11-18 23:03:10 -08:00 +++ edited/include/linux/efi.h 2005-01-19 14:04:14 -08:00 @@ -305,6 +305,27 @@ extern int __init efi_set_rtc_mmss(unsigned long nowtime); extern struct efi_memory_map memmap; +/** + * efi_range_is_wc - check the WC bit on an address range + * @start: starting kvirt address + * @len: length of range + * + * Consult the EFI memory map and make sure it's ok to set this range WC. + * Returns true or false. + */ +static inline int efi_range_is_wc(unsigned long start, unsigned long len) +{ + int i; + + for (i = 0; i < len; i += (1UL << EFI_PAGE_SHIFT)) { + unsigned long paddr = __pa(start + i); + if (!(efi_mem_attributes(paddr) & EFI_MEMORY_WC)) + return 0; + } + /* The range checked out */ + return 1; +} + #ifdef CONFIG_EFI_PCDP extern int __init efi_setup_pcdp_console(char *); #endif --Boundary-00=_MTu7BiNe8RrJW+X-- - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html