From 77b52b4c5c66175553ee59eb43f74366f1e54bde Mon Sep 17 00:00:00 2001 From: Venki Pallipadi Date: Mon, 5 May 2008 19:09:10 -0700 Subject: x86: add "debugpat" boot option enable debug messages by a boot option "debugpat". Signed-off-by: Venkatesh Pallipadi Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/mm/pat.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 60adbe22efa..1a82f4db8a4 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -42,6 +42,19 @@ static int nopat(char *str) early_param("nopat", nopat); #endif + +static int debug_enable; +static int __init pat_debug_setup(char *str) +{ + debug_enable = 1; + return 0; +} +__setup("debugpat", pat_debug_setup); + +#define dprintk(fmt, arg...) \ + do { if (debug_enable) printk(KERN_INFO fmt, ##arg); } while (0) + + static u64 __read_mostly boot_pat_state; enum { @@ -279,7 +292,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, struct memtype *saved_ptr; if (parse->start >= end) { - pr_debug("New Entry\n"); + dprintk("New Entry\n"); list_add(&new_entry->nd, parse->nd.prev); new_entry = NULL; break; @@ -329,7 +342,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, break; } - pr_debug("Overlap at 0x%Lx-0x%Lx\n", + dprintk("Overlap at 0x%Lx-0x%Lx\n", saved_ptr->start, saved_ptr->end); /* No conflict. Go ahead and add this new entry */ list_add(&new_entry->nd, saved_ptr->nd.prev); @@ -381,7 +394,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, break; } - pr_debug(KERN_INFO "Overlap at 0x%Lx-0x%Lx\n", + dprintk("Overlap at 0x%Lx-0x%Lx\n", saved_ptr->start, saved_ptr->end); /* No conflict. Go ahead and add this new entry */ list_add(&new_entry->nd, &saved_ptr->nd); @@ -403,16 +416,16 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, if (new_entry) { /* No conflict. Not yet added to the list. Add to the tail */ list_add_tail(&new_entry->nd, &memtype_list); - pr_debug("New Entry\n"); + dprintk("New Entry\n"); } if (ret_type) { - pr_debug( + dprintk( "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n", start, end, cattr_name(actual_type), cattr_name(req_type), cattr_name(*ret_type)); } else { - pr_debug( + dprintk( "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n", start, end, cattr_name(actual_type), cattr_name(req_type)); @@ -453,7 +466,7 @@ int free_memtype(u64 start, u64 end) current->comm, current->pid, start, end); } - pr_debug("free_memtype request 0x%Lx-0x%Lx\n", start, end); + dprintk("free_memtype request 0x%Lx-0x%Lx\n", start, end); return err; } -- cgit v1.2.3 From 46dd98a5c0b907f94742579ab605be1933a37abd Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Wed, 14 May 2008 16:10:39 -0700 Subject: arch/x86/mm/pat.c: use boot_cpu_has() arch/x86/mm/pat.c: In function 'phys_mem_access_prot_allowed': arch/x86/mm/pat.c:526: warning: passing argument 2 of 'constant_test_bit' from incompatible pointer type arch/x86/mm/pat.c:526: warning: passing argument 2 of 'variable_test_bit' from incompatible pointer type arch/x86/mm/pat.c:527: warning: passing argument 2 of 'constant_test_bit' from incompatible pointer type arch/x86/mm/pat.c:527: warning: passing argument 2 of 'variable_test_bit' from incompatible pointer type arch/x86/mm/pat.c:528: warning: passing argument 2 of 'constant_test_bit' from incompatible pointer type arch/x86/mm/pat.c:528: warning: passing argument 2 of 'variable_test_bit' from incompatible pointer type arch/x86/mm/pat.c:529: warning: passing argument 2 of 'constant_test_bit' from incompatible pointer type arch/x86/mm/pat.c:529: warning: passing argument 2 of 'variable_test_bit' from incompatible pointer type Don't open-code test_bit() on a __u32 Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index a1cbea0b79b..e83b770676d 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -536,10 +536,10 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, * we maintain the tradition of paranoia in this code. */ if (!pat_wc_enabled && - ! ( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) || - test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) || - test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) || - test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability)) && + ! ( boot_cpu_has(X86_FEATURE_MTRR) || + boot_cpu_has(X86_FEATURE_K6_MTRR) || + boot_cpu_has(X86_FEATURE_CYRIX_ARR) || + boot_cpu_has(X86_FEATURE_CENTAUR_MCR)) && (pfn << PAGE_SHIFT) >= __pa(high_memory)) { flags = _PAGE_CACHE_UC; } -- cgit v1.2.3 From c26421d01986e1521043c8feb47256833df3bf31 Mon Sep 17 00:00:00 2001 From: Venki Pallipadi Date: Thu, 29 May 2008 12:01:44 -0700 Subject: x86: fix Xorg crash with xf86MapVidMem error Clarify the usage of mtrr_lookup() in PAT code, and to make PAT code resilient to mtrr lookup problems. Specifically, pat_x_mtrr_type() is restructured to highlight, under what conditions we look for mtrr hint. pat_x_mtrr_type() uses a default type when there are any errors in mtrr lookup (still maintaining the pat consistency). And, reserve_memtype() highlights its usage ot mtrr_lookup for request type of '-1' and also defaults in a sane way on any mtrr lookup failure. pat.c looks at mtrr type of a range to get a hint on what mapping type to request when user/API: (1) hasn't specified any type (/dev/mem mapping) and we do not want to take performance hit by always mapping UC_MINUS. This will be the case for /dev/mem mappings used to map BIOS area or ACPI region which are WB'able. In this case, as long as MTRR is not WB, PAT will request UC_MINUS for such mappings. (2) user/API requests WB mapping while in reality MTRR may have UC or WC. In this case, PAT can map as WB (without checking MTRR) and still effective type will be UC or WC. But, a subsequent request to map same region as UC or WC may fail, as the region will get trackked as WB in PAT list. Looking at MTRR hint helps us to track based on effective type rather than what user requested. Again, here mtrr_lookup is only used as hint and we fallback to WB mapping (as requested by user) as default. In both cases, after using the mtrr hint, we still go through the memtype list to make sure there are no inconsistencies among multiple users. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha Tested-by: Rufus & Azrael Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 49 ++++++++++++++++++++++++------------------------- 1 file changed, 24 insertions(+), 25 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index e83b770676d..320d644a810 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -164,32 +164,33 @@ static int pat_x_mtrr_type(u64 start, u64 end, unsigned long prot, unsigned long pat_type; u8 mtrr_type; - mtrr_type = mtrr_type_lookup(start, end); - if (mtrr_type == 0xFF) { /* MTRR not enabled */ - *ret_prot = prot; - return 0; - } - if (mtrr_type == 0xFE) { /* MTRR match error */ - *ret_prot = _PAGE_CACHE_UC; - return -1; - } - if (mtrr_type != MTRR_TYPE_UNCACHABLE && - mtrr_type != MTRR_TYPE_WRBACK && - mtrr_type != MTRR_TYPE_WRCOMB) { /* MTRR type unhandled */ - *ret_prot = _PAGE_CACHE_UC; - return -1; - } - pat_type = prot & _PAGE_CACHE_MASK; prot &= (~_PAGE_CACHE_MASK); - /* Currently doing intersection by hand. Optimize it later. */ + /* + * We return the PAT request directly for types where PAT takes + * precedence with respect to MTRR and for UC_MINUS. + * Consistency checks with other PAT requests is done later + * while going through memtype list. + */ if (pat_type == _PAGE_CACHE_WC) { *ret_prot = prot | _PAGE_CACHE_WC; + return 0; } else if (pat_type == _PAGE_CACHE_UC_MINUS) { *ret_prot = prot | _PAGE_CACHE_UC_MINUS; - } else if (pat_type == _PAGE_CACHE_UC || - mtrr_type == MTRR_TYPE_UNCACHABLE) { + return 0; + } else if (pat_type == _PAGE_CACHE_UC) { + *ret_prot = prot | _PAGE_CACHE_UC; + return 0; + } + + /* + * Look for MTRR hint to get the effective type in case where PAT + * request is for WB. + */ + mtrr_type = mtrr_type_lookup(start, end); + + if (mtrr_type == MTRR_TYPE_UNCACHABLE) { *ret_prot = prot | _PAGE_CACHE_UC; } else if (mtrr_type == MTRR_TYPE_WRCOMB) { *ret_prot = prot | _PAGE_CACHE_WC; @@ -246,14 +247,12 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, if (req_type == -1) { /* - * Special case where caller wants to inherit from mtrr or - * existing pat mapping, defaulting to UC_MINUS in case of - * no match. + * Call mtrr_lookup to get the type hint. This is an + * optimization for /dev/mem mmap'ers into WB memory (BIOS + * tools and ACPI tools). Use WB request for WB memory and use + * UC_MINUS otherwise. */ u8 mtrr_type = mtrr_type_lookup(start, end); - if (mtrr_type == 0xFE) { /* MTRR match error */ - err = -1; - } if (mtrr_type == MTRR_TYPE_WRBACK) { req_type = _PAGE_CACHE_WB; -- cgit v1.2.3 From 97cfab6ac4ddfda0d722393bbf46cc40bc332107 Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Tue, 10 Jun 2008 16:05:18 +0200 Subject: x86: PAT: fix ambiguous paranoia check in pat_init() Starting with commit 8d4a4300854f3971502e81dacd930704cb88f606 (x86: cleanup PAT cpu validation) the PAT CPU feature flag is not cleared anymore. Now the error message "PAT enabled, but CPU feature cleared" in pat_init() is misleading. Furthermore the current code does not check for existence of the PAT CPU feature flag if a CPU is whitelisted in validate_pat_support. This patch clears pat_wc_enabled if boot CPU has no PAT feature flag and adapts the paranoia check. Signed-off-by: Andreas Herrmann Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 320d644a810..65105b1195a 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -76,14 +76,15 @@ void pat_init(void) return; /* Paranoia check. */ - if (!cpu_has_pat) { - printk(KERN_ERR "PAT enabled, but CPU feature cleared\n"); + if (!cpu_has_pat && boot_pat_state) { /* - * Panic if this happens on the secondary CPU, and we + * If this happens we are on a secondary CPU, but * switched to PAT on the boot CPU. We have no way to * undo PAT. - */ - BUG_ON(boot_pat_state); + */ + printk(KERN_ERR "PAT enabled, " + "but not supported by secondary CPU\n"); + BUG(); } /* Set PWT to Write-Combining. All other bits stay the same */ -- cgit v1.2.3 From cd7a4e936d345ab4cb49d68192d90bd4e4c58458 Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Tue, 10 Jun 2008 16:05:39 +0200 Subject: x86: PAT: fixed checkpatch errors (and whitespaces) x86: PAT: fixed checkpatch errors (and whitespaces) Signed-off-by: Andreas Herrmann Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 65105b1195a..a8b69bb2697 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -66,7 +66,7 @@ enum { PAT_UC_MINUS = 7, /* UC, but can be overriden by MTRR */ }; -#define PAT(x,y) ((u64)PAT_ ## y << ((x)*8)) +#define PAT(x, y) ((u64)PAT_ ## y << ((x)*8)) void pat_init(void) { @@ -100,8 +100,8 @@ void pat_init(void) * 011 UC _PAGE_CACHE_UC * PAT bit unused */ - pat = PAT(0,WB) | PAT(1,WC) | PAT(2,UC_MINUS) | PAT(3,UC) | - PAT(4,WB) | PAT(5,WC) | PAT(6,UC_MINUS) | PAT(7,UC); + pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) | + PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC); /* Boot CPU check */ if (!boot_pat_state) @@ -117,11 +117,11 @@ void pat_init(void) static char *cattr_name(unsigned long flags) { switch (flags & _PAGE_CACHE_MASK) { - case _PAGE_CACHE_UC: return "uncached"; - case _PAGE_CACHE_UC_MINUS: return "uncached-minus"; - case _PAGE_CACHE_WB: return "write-back"; - case _PAGE_CACHE_WC: return "write-combining"; - default: return "broken"; + case _PAGE_CACHE_UC: return "uncached"; + case _PAGE_CACHE_UC_MINUS: return "uncached-minus"; + case _PAGE_CACHE_WB: return "write-back"; + case _PAGE_CACHE_WC: return "write-combining"; + default: return "broken"; } } @@ -536,11 +536,11 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, * we maintain the tradition of paranoia in this code. */ if (!pat_wc_enabled && - ! ( boot_cpu_has(X86_FEATURE_MTRR) || - boot_cpu_has(X86_FEATURE_K6_MTRR) || - boot_cpu_has(X86_FEATURE_CYRIX_ARR) || - boot_cpu_has(X86_FEATURE_CENTAUR_MCR)) && - (pfn << PAGE_SHIFT) >= __pa(high_memory)) { + !(boot_cpu_has(X86_FEATURE_MTRR) || + boot_cpu_has(X86_FEATURE_K6_MTRR) || + boot_cpu_has(X86_FEATURE_CYRIX_ARR) || + boot_cpu_has(X86_FEATURE_CENTAUR_MCR)) && + (pfn << PAGE_SHIFT) >= __pa(high_memory)) { flags = _PAGE_CACHE_UC; } #endif @@ -562,7 +562,7 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, return 0; if (pfn <= max_pfn_mapped && - ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) { + ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) { free_memtype(offset, offset + size); printk(KERN_INFO "%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n", @@ -600,4 +600,3 @@ void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot) free_memtype(addr, addr + size); } - -- cgit v1.2.3 From 499f8f84b8324ba27d756e03f373fa16eeed9ccc Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Tue, 10 Jun 2008 16:06:21 +0200 Subject: x86: rename pat_wc_enabled to pat_enabled BTW, what does pat_wc_enabled stand for? Does it mean "write-combining"? Currently it is used to globally switch on or off PAT support. Thus I renamed it to pat_enabled. I think this increases readability (and hope that I didn't miss something). Signed-off-by: Andreas Herrmann Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index a8b69bb2697..4beccea0897 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -26,11 +26,11 @@ #include #ifdef CONFIG_X86_PAT -int __read_mostly pat_wc_enabled = 1; +int __read_mostly pat_enabled = 1; void __cpuinit pat_disable(char *reason) { - pat_wc_enabled = 0; + pat_enabled = 0; printk(KERN_INFO "%s\n", reason); } @@ -72,7 +72,7 @@ void pat_init(void) { u64 pat; - if (!pat_wc_enabled) + if (!pat_enabled) return; /* Paranoia check. */ @@ -225,8 +225,8 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, unsigned long actual_type; int err = 0; - /* Only track when pat_wc_enabled */ - if (!pat_wc_enabled) { + /* Only track when pat_enabled */ + if (!pat_enabled) { /* This is identical to page table setting without PAT */ if (ret_type) { if (req_type == -1) { @@ -440,8 +440,8 @@ int free_memtype(u64 start, u64 end) struct memtype *ml; int err = -EINVAL; - /* Only track when pat_wc_enabled */ - if (!pat_wc_enabled) { + /* Only track when pat_enabled */ + if (!pat_enabled) { return 0; } @@ -535,7 +535,7 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, * caching for the high addresses through the KEN pin, but * we maintain the tradition of paranoia in this code. */ - if (!pat_wc_enabled && + if (!pat_enabled && !(boot_cpu_has(X86_FEATURE_MTRR) || boot_cpu_has(X86_FEATURE_K6_MTRR) || boot_cpu_has(X86_FEATURE_CYRIX_ARR) || -- cgit v1.2.3 From 6cf514fce18589ea1e0521c5f2d7c2bb280fefc7 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Mon, 16 Jun 2008 18:42:43 +0100 Subject: x86: PAT: make pat_x_mtrr_type() more readable Clean up over-complications in pat_x_mtrr_type(). And if reserve_memtype() ignores stray req_type bits when pat_enabled, it's better to mask them off when not also. Signed-off-by: Hugh Dickins Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 47 ++++++++++++----------------------------------- 1 file changed, 12 insertions(+), 35 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 7c21572bbdd..ac3a2b11eb3 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -159,47 +159,31 @@ static DEFINE_SPINLOCK(memtype_lock); /* protects memtype list */ * The intersection is based on "Effective Memory Type" tables in IA-32 * SDM vol 3a */ -static int pat_x_mtrr_type(u64 start, u64 end, unsigned long prot, - unsigned long *ret_prot) +static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type) { - unsigned long pat_type; u8 mtrr_type; - pat_type = prot & _PAGE_CACHE_MASK; - prot &= (~_PAGE_CACHE_MASK); - /* * We return the PAT request directly for types where PAT takes * precedence with respect to MTRR and for UC_MINUS. * Consistency checks with other PAT requests is done later * while going through memtype list. */ - if (pat_type == _PAGE_CACHE_WC) { - *ret_prot = prot | _PAGE_CACHE_WC; - return 0; - } else if (pat_type == _PAGE_CACHE_UC_MINUS) { - *ret_prot = prot | _PAGE_CACHE_UC_MINUS; - return 0; - } else if (pat_type == _PAGE_CACHE_UC) { - *ret_prot = prot | _PAGE_CACHE_UC; - return 0; - } + if (req_type == _PAGE_CACHE_WC || + req_type == _PAGE_CACHE_UC_MINUS || + req_type == _PAGE_CACHE_UC) + return req_type; /* * Look for MTRR hint to get the effective type in case where PAT * request is for WB. */ mtrr_type = mtrr_type_lookup(start, end); - - if (mtrr_type == MTRR_TYPE_UNCACHABLE) { - *ret_prot = prot | _PAGE_CACHE_UC; - } else if (mtrr_type == MTRR_TYPE_WRCOMB) { - *ret_prot = prot | _PAGE_CACHE_WC; - } else { - *ret_prot = prot | _PAGE_CACHE_WB; - } - - return 0; + if (mtrr_type == MTRR_TYPE_UNCACHABLE) + return _PAGE_CACHE_UC; + if (mtrr_type == MTRR_TYPE_WRCOMB) + return _PAGE_CACHE_WC; + return _PAGE_CACHE_WB; } /* @@ -232,7 +216,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, if (req_type == -1) { *ret_type = _PAGE_CACHE_WB; } else { - *ret_type = req_type; + *ret_type = req_type & _PAGE_CACHE_MASK; } } return 0; @@ -264,14 +248,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, } } else { req_type &= _PAGE_CACHE_MASK; - err = pat_x_mtrr_type(start, end, req_type, &actual_type); - } - - if (err) { - if (ret_type) - *ret_type = actual_type; - - return -EINVAL; + actual_type = pat_x_mtrr_type(start, end, req_type); } new_entry = kmalloc(sizeof(struct memtype), GFP_KERNEL); -- cgit v1.2.3 From dd0c7c4903c29da9aa3bf33deecf064d190a0d81 Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Wed, 18 Jun 2008 15:38:57 +0200 Subject: x86: shrink pat_x_mtrr_type to its essentials Signed-off-by: Andreas Herrmann Cc: Venkatesh Pallipadi Cc: Suresh B Siddha Cc: Hugh Dickins Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 30 +++++++++++------------------- 1 file changed, 11 insertions(+), 19 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index ac3a2b11eb3..227df3ca9bf 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -161,29 +161,21 @@ static DEFINE_SPINLOCK(memtype_lock); /* protects memtype list */ */ static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type) { - u8 mtrr_type; - - /* - * We return the PAT request directly for types where PAT takes - * precedence with respect to MTRR and for UC_MINUS. - * Consistency checks with other PAT requests is done later - * while going through memtype list. - */ - if (req_type == _PAGE_CACHE_WC || - req_type == _PAGE_CACHE_UC_MINUS || - req_type == _PAGE_CACHE_UC) - return req_type; - /* * Look for MTRR hint to get the effective type in case where PAT * request is for WB. */ - mtrr_type = mtrr_type_lookup(start, end); - if (mtrr_type == MTRR_TYPE_UNCACHABLE) - return _PAGE_CACHE_UC; - if (mtrr_type == MTRR_TYPE_WRCOMB) - return _PAGE_CACHE_WC; - return _PAGE_CACHE_WB; + if (req_type == _PAGE_CACHE_WB) { + u8 mtrr_type; + + mtrr_type = mtrr_type_lookup(start, end); + if (mtrr_type == MTRR_TYPE_UNCACHABLE) + return _PAGE_CACHE_UC; + if (mtrr_type == MTRR_TYPE_WRCOMB) + return _PAGE_CACHE_WC; + } + + return req_type; } /* -- cgit v1.2.3 From bcc643dc287cb732e96a1685ac130c3ae8b1c960 Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Fri, 20 Jun 2008 21:58:46 +0200 Subject: x86: introduce macro to check whether an address range is in the ISA range Signed-off-by: Andreas Herrmann Cc: Venkatesh Pallipadi Cc: Suresh B Siddha Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 227df3ca9bf..5bbc22efe4e 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -215,7 +215,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, } /* Low ISA region is always mapped WB in page table. No need to track */ - if (start >= ISA_START_ADDRESS && (end - 1) <= ISA_END_ADDRESS) { + if (is_ISA_range(start, end - 1)) { if (ret_type) *ret_type = _PAGE_CACHE_WB; @@ -415,9 +415,8 @@ int free_memtype(u64 start, u64 end) } /* Low ISA region is always mapped WB. No need to track */ - if (start >= ISA_START_ADDRESS && end <= ISA_END_ADDRESS) { + if (is_ISA_range(start, end - 1)) return 0; - } spin_lock(&memtype_lock); list_for_each_entry(ml, &memtype_list, nd) { -- cgit v1.2.3 From ac97991ec9e0a05c8860f4a04f8477227b1c03f2 Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Fri, 20 Jun 2008 22:01:49 +0200 Subject: x86: pat.c choose more crisp variable names - parse/ml => entry (within list_for_each and friends) - new_entry => new - ret_type => new_type (to avoid confusion with req_type) (... to make it more readable...) Signed-off-by: Andreas Herrmann Cc: Venkatesh Pallipadi Cc: Suresh B Siddha Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 127 ++++++++++++++++++++++++++---------------------------- 1 file changed, 62 insertions(+), 65 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 5bbc22efe4e..a6507bfb12a 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -188,37 +188,34 @@ static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type) * req_type will have a special case value '-1', when requester want to inherit * the memory type from mtrr (if WB), existing PAT, defaulting to UC_MINUS. * - * If ret_type is NULL, function will return an error if it cannot reserve the - * region with req_type. If ret_type is non-null, function will return - * available type in ret_type in case of no error. In case of any error + * If new_type is NULL, function will return an error if it cannot reserve the + * region with req_type. If new_type is non-NULL, function will return + * available type in new_type in case of no error. In case of any error * it will return a negative return value. */ int reserve_memtype(u64 start, u64 end, unsigned long req_type, - unsigned long *ret_type) + unsigned long *new_type) { - struct memtype *new_entry = NULL; - struct memtype *parse; + struct memtype *new, *entry; unsigned long actual_type; int err = 0; /* Only track when pat_enabled */ if (!pat_enabled) { /* This is identical to page table setting without PAT */ - if (ret_type) { - if (req_type == -1) { - *ret_type = _PAGE_CACHE_WB; - } else { - *ret_type = req_type & _PAGE_CACHE_MASK; - } + if (new_type) { + if (req_type == -1) + *new_type = _PAGE_CACHE_WB; + else + *new_type = req_type & _PAGE_CACHE_MASK; } return 0; } /* Low ISA region is always mapped WB in page table. No need to track */ if (is_ISA_range(start, end - 1)) { - if (ret_type) - *ret_type = _PAGE_CACHE_WB; - + if (new_type) + *new_type = _PAGE_CACHE_WB; return 0; } @@ -243,65 +240,65 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, actual_type = pat_x_mtrr_type(start, end, req_type); } - new_entry = kmalloc(sizeof(struct memtype), GFP_KERNEL); - if (!new_entry) + new = kmalloc(sizeof(struct memtype), GFP_KERNEL); + if (!new) return -ENOMEM; - new_entry->start = start; - new_entry->end = end; - new_entry->type = actual_type; + new->start = start; + new->end = end; + new->type = actual_type; - if (ret_type) - *ret_type = actual_type; + if (new_type) + *new_type = actual_type; spin_lock(&memtype_lock); /* Search for existing mapping that overlaps the current range */ - list_for_each_entry(parse, &memtype_list, nd) { + list_for_each_entry(entry, &memtype_list, nd) { struct memtype *saved_ptr; - if (parse->start >= end) { + if (entry->start >= end) { dprintk("New Entry\n"); - list_add(&new_entry->nd, parse->nd.prev); - new_entry = NULL; + list_add(&new->nd, entry->nd.prev); + new = NULL; break; } - if (start <= parse->start && end >= parse->start) { - if (actual_type != parse->type && ret_type) { - actual_type = parse->type; - *ret_type = actual_type; - new_entry->type = actual_type; + if (start <= entry->start && end >= entry->start) { + if (actual_type != entry->type && new_type) { + actual_type = entry->type; + *new_type = actual_type; + new->type = actual_type; } - if (actual_type != parse->type) { + if (actual_type != entry->type) { printk( KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n", current->comm, current->pid, start, end, cattr_name(actual_type), - cattr_name(parse->type)); + cattr_name(entry->type)); err = -EBUSY; break; } - saved_ptr = parse; + saved_ptr = entry; /* * Check to see whether the request overlaps more * than one entry in the list */ - list_for_each_entry_continue(parse, &memtype_list, nd) { - if (end <= parse->start) { + list_for_each_entry_continue(entry, &memtype_list, nd) { + if (end <= entry->start) { break; } - if (actual_type != parse->type) { + if (actual_type != entry->type) { printk( KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n", current->comm, current->pid, start, end, cattr_name(actual_type), - cattr_name(parse->type)); + cattr_name(entry->type)); err = -EBUSY; break; } @@ -314,46 +311,46 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, dprintk("Overlap at 0x%Lx-0x%Lx\n", saved_ptr->start, saved_ptr->end); /* No conflict. Go ahead and add this new entry */ - list_add(&new_entry->nd, saved_ptr->nd.prev); - new_entry = NULL; + list_add(&new->nd, saved_ptr->nd.prev); + new = NULL; break; } - if (start < parse->end) { - if (actual_type != parse->type && ret_type) { - actual_type = parse->type; - *ret_type = actual_type; - new_entry->type = actual_type; + if (start < entry->end) { + if (actual_type != entry->type && new_type) { + actual_type = entry->type; + *new_type = actual_type; + new->type = actual_type; } - if (actual_type != parse->type) { + if (actual_type != entry->type) { printk( KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n", current->comm, current->pid, start, end, cattr_name(actual_type), - cattr_name(parse->type)); + cattr_name(entry->type)); err = -EBUSY; break; } - saved_ptr = parse; + saved_ptr = entry; /* * Check to see whether the request overlaps more * than one entry in the list */ - list_for_each_entry_continue(parse, &memtype_list, nd) { - if (end <= parse->start) { + list_for_each_entry_continue(entry, &memtype_list, nd) { + if (end <= entry->start) { break; } - if (actual_type != parse->type) { + if (actual_type != entry->type) { printk( KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n", current->comm, current->pid, start, end, cattr_name(actual_type), - cattr_name(parse->type)); + cattr_name(entry->type)); err = -EBUSY; break; } @@ -366,8 +363,8 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, dprintk("Overlap at 0x%Lx-0x%Lx\n", saved_ptr->start, saved_ptr->end); /* No conflict. Go ahead and add this new entry */ - list_add(&new_entry->nd, &saved_ptr->nd); - new_entry = NULL; + list_add(&new->nd, &saved_ptr->nd); + new = NULL; break; } } @@ -375,24 +372,24 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, if (err) { printk(KERN_INFO "reserve_memtype failed 0x%Lx-0x%Lx, track %s, req %s\n", - start, end, cattr_name(new_entry->type), + start, end, cattr_name(new->type), cattr_name(req_type)); - kfree(new_entry); + kfree(new); spin_unlock(&memtype_lock); return err; } - if (new_entry) { + if (new) { /* No conflict. Not yet added to the list. Add to the tail */ - list_add_tail(&new_entry->nd, &memtype_list); + list_add_tail(&new->nd, &memtype_list); dprintk("New Entry\n"); } - if (ret_type) { + if (new_type) { dprintk( "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n", start, end, cattr_name(actual_type), - cattr_name(req_type), cattr_name(*ret_type)); + cattr_name(req_type), cattr_name(*new_type)); } else { dprintk( "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n", @@ -406,7 +403,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, int free_memtype(u64 start, u64 end) { - struct memtype *ml; + struct memtype *entry; int err = -EINVAL; /* Only track when pat_enabled */ @@ -419,10 +416,10 @@ int free_memtype(u64 start, u64 end) return 0; spin_lock(&memtype_lock); - list_for_each_entry(ml, &memtype_list, nd) { - if (ml->start == start && ml->end == end) { - list_del(&ml->nd); - kfree(ml); + list_for_each_entry(entry, &memtype_list, nd) { + if (entry->start == start && entry->end == end) { + list_del(&entry->nd); + kfree(entry); err = 0; break; } -- cgit v1.2.3 From 69e26be9b1d0c83d3581475095ce2a1ccc578215 Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Fri, 20 Jun 2008 22:03:06 +0200 Subject: x86: pat.c more trivial changes - add BUG statement to catch invalid start and end parameters - No need to track the actual type in both req_type and actual_type -- keep req_type unchanged. - removed (IMHO) superfluous comments Signed-off-by: Andreas Herrmann Cc: Venkatesh Pallipadi Cc: Suresh B Siddha Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index a6507bfb12a..c996a364120 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -200,7 +200,8 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, unsigned long actual_type; int err = 0; - /* Only track when pat_enabled */ + BUG_ON(start >= end); /* end is exclusive */ + if (!pat_enabled) { /* This is identical to page table setting without PAT */ if (new_type) { @@ -228,17 +229,13 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, */ u8 mtrr_type = mtrr_type_lookup(start, end); - if (mtrr_type == MTRR_TYPE_WRBACK) { - req_type = _PAGE_CACHE_WB; + if (mtrr_type == MTRR_TYPE_WRBACK) actual_type = _PAGE_CACHE_WB; - } else { - req_type = _PAGE_CACHE_UC_MINUS; + else actual_type = _PAGE_CACHE_UC_MINUS; - } - } else { - req_type &= _PAGE_CACHE_MASK; - actual_type = pat_x_mtrr_type(start, end, req_type); - } + } else + actual_type = pat_x_mtrr_type(start, end, + req_type & _PAGE_CACHE_MASK); new = kmalloc(sizeof(struct memtype), GFP_KERNEL); if (!new) @@ -406,10 +403,8 @@ int free_memtype(u64 start, u64 end) struct memtype *entry; int err = -EINVAL; - /* Only track when pat_enabled */ - if (!pat_enabled) { + if (!pat_enabled) return 0; - } /* Low ISA region is always mapped WB. No need to track */ if (is_ISA_range(start, end - 1)) -- cgit v1.2.3 From 3e9c83b309fd7cbf1d9b801d0d5877c040e30420 Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Fri, 20 Jun 2008 22:04:02 +0200 Subject: x86: pat.c consolidate error/debug messages in reserve_memtype ... and move last debug message out of locked section. Signed-off-by: Andreas Herrmann Cc: Venkatesh Pallipadi Cc: Suresh B Siddha Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 51 +++++++++++---------------------------------------- 1 file changed, 11 insertions(+), 40 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index c996a364120..1118288f8fe 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -269,12 +269,6 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, } if (actual_type != entry->type) { - printk( - KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n", - current->comm, current->pid, - start, end, - cattr_name(actual_type), - cattr_name(entry->type)); err = -EBUSY; break; } @@ -290,12 +284,6 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, } if (actual_type != entry->type) { - printk( - KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n", - current->comm, current->pid, - start, end, - cattr_name(actual_type), - cattr_name(entry->type)); err = -EBUSY; break; } @@ -321,12 +309,6 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, } if (actual_type != entry->type) { - printk( - KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n", - current->comm, current->pid, - start, end, - cattr_name(actual_type), - cattr_name(entry->type)); err = -EBUSY; break; } @@ -342,12 +324,6 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, } if (actual_type != entry->type) { - printk( - KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n", - current->comm, current->pid, - start, end, - cattr_name(actual_type), - cattr_name(entry->type)); err = -EBUSY; break; } @@ -367,10 +343,12 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, } if (err) { - printk(KERN_INFO - "reserve_memtype failed 0x%Lx-0x%Lx, track %s, req %s\n", - start, end, cattr_name(new->type), - cattr_name(req_type)); + printk(KERN_INFO "%s:%d conflicting memory types " + "%Lx-%Lx %s<->%s\n", current->comm, current->pid, start, + end, cattr_name(new->type), cattr_name(entry->type)); + printk(KERN_INFO "reserve_memtype failed 0x%Lx-0x%Lx, " + "track %s, req %s\n", + start, end, cattr_name(new->type), cattr_name(req_type)); kfree(new); spin_unlock(&memtype_lock); return err; @@ -382,19 +360,12 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, dprintk("New Entry\n"); } - if (new_type) { - dprintk( - "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n", - start, end, cattr_name(actual_type), - cattr_name(req_type), cattr_name(*new_type)); - } else { - dprintk( - "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n", - start, end, cattr_name(actual_type), - cattr_name(req_type)); - } - spin_unlock(&memtype_lock); + + dprintk("reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n", + start, end, cattr_name(new->type), cattr_name(req_type), + new_type ? cattr_name(*new_type) : "-"); + return err; } -- cgit v1.2.3 From f6887264deba4cd991f0ca006918dcff4c939021 Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Fri, 20 Jun 2008 22:05:37 +0200 Subject: x86: pat.c consolidate list_add handling in reserve_memtype Signed-off-by: Andreas Herrmann Cc: Venkatesh Pallipadi Cc: Suresh B Siddha Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 1118288f8fe..49dcd9652ec 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -198,6 +198,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, { struct memtype *new, *entry; unsigned long actual_type; + struct list_head *where; int err = 0; BUG_ON(start >= end); /* end is exclusive */ @@ -251,13 +252,12 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, spin_lock(&memtype_lock); /* Search for existing mapping that overlaps the current range */ + where = NULL; list_for_each_entry(entry, &memtype_list, nd) { struct memtype *saved_ptr; if (entry->start >= end) { - dprintk("New Entry\n"); - list_add(&new->nd, entry->nd.prev); - new = NULL; + where = entry->nd.prev; break; } @@ -295,9 +295,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, dprintk("Overlap at 0x%Lx-0x%Lx\n", saved_ptr->start, saved_ptr->end); - /* No conflict. Go ahead and add this new entry */ - list_add(&new->nd, saved_ptr->nd.prev); - new = NULL; + where = saved_ptr->nd.prev; break; } @@ -335,9 +333,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, dprintk("Overlap at 0x%Lx-0x%Lx\n", saved_ptr->start, saved_ptr->end); - /* No conflict. Go ahead and add this new entry */ - list_add(&new->nd, &saved_ptr->nd); - new = NULL; + where = &saved_ptr->nd; break; } } @@ -354,11 +350,10 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, return err; } - if (new) { - /* No conflict. Not yet added to the list. Add to the tail */ + if (where) + list_add(&new->nd, where); + else list_add_tail(&new->nd, &memtype_list); - dprintk("New Entry\n"); - } spin_unlock(&memtype_lock); -- cgit v1.2.3 From 64fe44c38bbdfab4fe052029058ce5fe9804de68 Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Fri, 20 Jun 2008 22:07:09 +0200 Subject: x86: pat.c introduce function to check for conflicts with existing memtypes ... to strip down loop body in reserve_memtype. Signed-off-by: Andreas Herrmann Cc: Venkatesh Pallipadi Cc: Suresh B Siddha Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 96 +++++++++++++++++++------------------------------------ 1 file changed, 33 insertions(+), 63 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 49dcd9652ec..281ac6489c0 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -178,6 +178,33 @@ static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type) return req_type; } +static int chk_conflict(struct memtype *new, struct memtype *entry, + unsigned long *type) +{ + if (new->type != entry->type) { + if (type) { + new->type = entry->type; + *type = entry->type; + } else + goto conflict; + } + + /* check overlaps with more than one entry in the list */ + list_for_each_entry_continue(entry, &memtype_list, nd) { + if (new->end <= entry->start) + break; + else if (new->type != entry->type) + goto conflict; + } + return 0; + + conflict: + printk(KERN_INFO "%s:%d conflicting memory types " + "%Lx-%Lx %s<->%s\n", current->comm, current->pid, new->start, + new->end, cattr_name(new->type), cattr_name(entry->type)); + return -EBUSY; +} + /* * req_type typically has one of the: * - _PAGE_CACHE_WB @@ -254,94 +281,37 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, /* Search for existing mapping that overlaps the current range */ where = NULL; list_for_each_entry(entry, &memtype_list, nd) { - struct memtype *saved_ptr; - if (entry->start >= end) { where = entry->nd.prev; break; } if (start <= entry->start && end >= entry->start) { - if (actual_type != entry->type && new_type) { - actual_type = entry->type; - *new_type = actual_type; - new->type = actual_type; - } - - if (actual_type != entry->type) { - err = -EBUSY; - break; - } - - saved_ptr = entry; - /* - * Check to see whether the request overlaps more - * than one entry in the list - */ - list_for_each_entry_continue(entry, &memtype_list, nd) { - if (end <= entry->start) { - break; - } - - if (actual_type != entry->type) { - err = -EBUSY; - break; - } - } - + err = chk_conflict(new, entry, new_type); if (err) { break; } dprintk("Overlap at 0x%Lx-0x%Lx\n", - saved_ptr->start, saved_ptr->end); - where = saved_ptr->nd.prev; + entry->start, entry->end); + where = entry->nd.prev; break; } if (start < entry->end) { - if (actual_type != entry->type && new_type) { - actual_type = entry->type; - *new_type = actual_type; - new->type = actual_type; - } - - if (actual_type != entry->type) { - err = -EBUSY; - break; - } - - saved_ptr = entry; - /* - * Check to see whether the request overlaps more - * than one entry in the list - */ - list_for_each_entry_continue(entry, &memtype_list, nd) { - if (end <= entry->start) { - break; - } - - if (actual_type != entry->type) { - err = -EBUSY; - break; - } - } - + err = chk_conflict(new, entry, new_type); if (err) { break; } dprintk("Overlap at 0x%Lx-0x%Lx\n", - saved_ptr->start, saved_ptr->end); - where = &saved_ptr->nd; + entry->start, entry->end); + where = &entry->nd; break; } } if (err) { - printk(KERN_INFO "%s:%d conflicting memory types " - "%Lx-%Lx %s<->%s\n", current->comm, current->pid, start, - end, cattr_name(new->type), cattr_name(entry->type)); printk(KERN_INFO "reserve_memtype failed 0x%Lx-0x%Lx, " "track %s, req %s\n", start, end, cattr_name(new->type), cattr_name(req_type)); -- cgit v1.2.3 From 33af9039cbf629041da2bfa0cf451208391a1ec3 Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Fri, 20 Jun 2008 22:08:37 +0200 Subject: x86: pat.c final cleanup of loop body in reserve_memtype Signed-off-by: Andreas Herrmann Cc: Venkatesh Pallipadi Cc: Suresh B Siddha Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 30 +++++++++++------------------- 1 file changed, 11 insertions(+), 19 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 281ac6489c0..a885a1019b8 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -281,32 +281,24 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, /* Search for existing mapping that overlaps the current range */ where = NULL; list_for_each_entry(entry, &memtype_list, nd) { - if (entry->start >= end) { + if (end <= entry->start) { where = entry->nd.prev; break; - } - - if (start <= entry->start && end >= entry->start) { + } else if (start <= entry->start) { /* end > entry->start */ err = chk_conflict(new, entry, new_type); - if (err) { - break; + if (!err) { + dprintk("Overlap at 0x%Lx-0x%Lx\n", + entry->start, entry->end); + where = entry->nd.prev; } - - dprintk("Overlap at 0x%Lx-0x%Lx\n", - entry->start, entry->end); - where = entry->nd.prev; break; - } - - if (start < entry->end) { + } else if (start < entry->end) { /* start > entry->start */ err = chk_conflict(new, entry, new_type); - if (err) { - break; + if (!err) { + dprintk("Overlap at 0x%Lx-0x%Lx\n", + entry->start, entry->end); + where = &entry->nd; } - - dprintk("Overlap at 0x%Lx-0x%Lx\n", - entry->start, entry->end); - where = &entry->nd; break; } } -- cgit v1.2.3