From 1c9cf9b211030a454a84cbc1cb15b82d9aa49011 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Thu, 16 Jul 2015 17:23:14 -0600 Subject: x86/mm: Move warning from __ioremap_check_ram() to the call site __ioremap_check_ram() has a WARN_ONCE() which is emitted when the given pfn range is not RAM. The warning is bogus in two aspects: - it never triggers since walk_system_ram_range() only calls __ioremap_check_ram() for RAM ranges. - the warning message is wrong as it says: "ioremap on RAM' after it established that the pfn range is not RAM. Move the WARN_ONCE() to __ioremap_caller(), and update the message to include the address range so we get an actual warning when something tries to ioremap system RAM. [ tglx: Massaged changelog ] Signed-off-by: Toshi Kani Reviewed-by: Dan Williams Cc: Roland Dreier Cc: Luis R. Rodriguez Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Borislav Petkov Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1437088996-28511-2-git-send-email-toshi.kani@hp.com Signed-off-by: Thomas Gleixner --- arch/x86/mm/ioremap.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'arch/x86/mm/ioremap.c') diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index cc5ccc415cc0..fd3df0ddb4d4 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -63,8 +63,6 @@ static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages, !PageReserved(pfn_to_page(start_pfn + i))) return 1; - WARN_ONCE(1, "ioremap on RAM pfn 0x%lx\n", start_pfn); - return 0; } @@ -131,8 +129,11 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, pfn = phys_addr >> PAGE_SHIFT; last_pfn = last_addr >> PAGE_SHIFT; if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL, - __ioremap_check_ram) == 1) + __ioremap_check_ram) == 1) { + WARN_ONCE(1, "ioremap on RAM at 0x%llx - 0x%llx\n", + phys_addr, last_addr); return NULL; + } } /* * Mappings have to be page-aligned -- cgit v1.2.3 From 9a58eebe1ace609bedf8c5a65e70a097459f5696 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Thu, 16 Jul 2015 17:23:15 -0600 Subject: x86/mm: Remove region_is_ram() call from ioremap __ioremap_caller() calls region_is_ram() to walk through the iomem_resource table to check if a target range is in RAM, which was added to improve the lookup performance over page_is_ram() (commit 906e36c5c717 "x86: use optimized ioresource lookup in ioremap function"). page_is_ram() was no longer used when this change was added, though. __ioremap_caller() then calls walk_system_ram_range(), which had replaced page_is_ram() to improve the lookup performance (commit c81c8a1eeede "x86, ioremap: Speed up check for RAM pages"). Since both checks walk through the same iomem_resource table for the same purpose, there is no need to call both functions. Aside of that walk_system_ram_range() is the only useful check at the moment because region_is_ram() always returns -1 due to an implementation bug. That bug in region_is_ram() cannot be fixed without breaking existing ioremap callers, which rely on the subtle difference of walk_system_ram_range() versus non page aligned ranges. Once these offending callers are fixed we can use region_is_ram() and remove walk_system_ram_range(). [ tglx: Massaged changelog ] Signed-off-by: Toshi Kani Reviewed-by: Dan Williams Cc: Roland Dreier Cc: Mike Travis Cc: Luis R. Rodriguez Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Borislav Petkov Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1437088996-28511-3-git-send-email-toshi.kani@hp.com Signed-off-by: Thomas Gleixner --- arch/x86/mm/ioremap.c | 24 ++++++------------------ 1 file changed, 6 insertions(+), 18 deletions(-) (limited to 'arch/x86/mm/ioremap.c') diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index fd3df0ddb4d4..b9d4a33017fd 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -92,7 +92,6 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, pgprot_t prot; int retval; void __iomem *ret_addr; - int ram_region; /* Don't allow wraparound or zero size */ last_addr = phys_addr + size - 1; @@ -115,26 +114,15 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, /* * Don't allow anybody to remap normal RAM that we're using.. */ - /* First check if whole region can be identified as RAM or not */ - ram_region = region_is_ram(phys_addr, size); - if (ram_region > 0) { - WARN_ONCE(1, "ioremap on RAM at 0x%lx - 0x%lx\n", - (unsigned long int)phys_addr, - (unsigned long int)last_addr); - return NULL; - } - - /* If could not be identified(-1), check page by page */ - if (ram_region < 0) { - pfn = phys_addr >> PAGE_SHIFT; - last_pfn = last_addr >> PAGE_SHIFT; - if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL, + pfn = phys_addr >> PAGE_SHIFT; + last_pfn = last_addr >> PAGE_SHIFT; + if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL, __ioremap_check_ram) == 1) { - WARN_ONCE(1, "ioremap on RAM at 0x%llx - 0x%llx\n", + WARN_ONCE(1, "ioremap on RAM at 0x%llx - 0x%llx\n", phys_addr, last_addr); - return NULL; - } + return NULL; } + /* * Mappings have to be page-aligned */ -- cgit v1.2.3 From 8a0a5da6d9cbf1b142115ff6e6b253a82633c3d9 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 24 Jul 2015 16:13:43 +0200 Subject: x86/mm: Fix newly introduced printk format warnings Signed-off-by: Thomas Gleixner --- arch/x86/mm/ioremap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/mm/ioremap.c') diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index b9d4a33017fd..b9c78f3bcd67 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -118,8 +118,8 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, last_pfn = last_addr >> PAGE_SHIFT; if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL, __ioremap_check_ram) == 1) { - WARN_ONCE(1, "ioremap on RAM at 0x%llx - 0x%llx\n", - phys_addr, last_addr); + WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n", + &phys_addr, &last_addr); return NULL; } -- cgit v1.2.3