[V3,10/37] ARM: highmem: Switch to generic kmap atomic
diff mbox series

Message ID 20201103095857.582196476@linutronix.de
State New, archived
Headers show
Series
  • mm/highmem: Preemptible variant of kmap_atomic & friends
Related show

Commit Message

Thomas Gleixner Nov. 3, 2020, 9:27 a.m. UTC
No reason having the same code in every architecture.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arm-kernel@lists.infradead.org
---
V3: Remove the kmap types cruft
---
 arch/arm/Kconfig                  |    1 
 arch/arm/include/asm/fixmap.h     |    4 -
 arch/arm/include/asm/highmem.h    |   33 +++++++---
 arch/arm/include/asm/kmap_types.h |   10 ---
 arch/arm/mm/Makefile              |    1 
 arch/arm/mm/highmem.c             |  121 --------------------------------------
 6 files changed, 26 insertions(+), 144 deletions(-)

Comments

Marek Szyprowski Nov. 12, 2020, 8:10 a.m. UTC | #1
Hi Thomas,

On 03.11.2020 10:27, Thomas Gleixner wrote:
> No reason having the same code in every architecture.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: linux-arm-kernel@lists.infradead.org

This patch landed in linux-next 20201109 as commit 2a15ba82fa6c ("ARM: 
highmem: Switch to generic kmap atomic"). However it causes a following 
warning on my test boards (Samsung Exynos SoC based):

Run /sbin/init as init process
INIT: version 2.88 booting
------------[ cut here ]------------
WARNING: CPU: 3 PID: 120 at mm/highmem.c:502 
kunmap_local_indexed+0x194/0x1d0
Modules linked in:
CPU: 3 PID: 120 Comm: init Not tainted 5.10.0-rc2-00010-g2a15ba82fa6c #1924
Hardware name: Samsung Exynos (Flattened Device Tree)
[<c0111514>] (unwind_backtrace) from [<c010ceb8>] (show_stack+0x10/0x14)
[<c010ceb8>] (show_stack) from [<c0b1b408>] (dump_stack+0xb4/0xd4)
[<c0b1b408>] (dump_stack) from [<c0126988>] (__warn+0x98/0x104)
[<c0126988>] (__warn) from [<c0126aa4>] (warn_slowpath_fmt+0xb0/0xb8)
[<c0126aa4>] (warn_slowpath_fmt) from [<c028e22c>] 
(kunmap_local_indexed+0x194/0x1d0)
[<c028e22c>] (kunmap_local_indexed) from [<c02d37f4>] 
(remove_arg_zero+0xa0/0x158)
[<c02d37f4>] (remove_arg_zero) from [<c034cfc8>] (load_script+0x250/0x318)
[<c034cfc8>] (load_script) from [<c02d2f7c>] (bprm_execve+0x3d0/0x930)
[<c02d2f7c>] (bprm_execve) from [<c02d3dc8>] 
(do_execveat_common+0x174/0x184)
[<c02d3dc8>] (do_execveat_common) from [<c02d4cec>] (sys_execve+0x30/0x38)
[<c02d4cec>] (sys_execve) from [<c0100060>] (ret_fast_syscall+0x0/0x28)
Exception stack(0xc4561fa8 to 0xc4561ff0)
1fa0:                   b6f2bab8 bef7dac4 bef7dac4 bef7d8fc 004b9b58 
bef7dac8
1fc0: b6f2bab8 bef7dac4 bef7d8fc 0000000b 004b8000 004bac44 bef7da3c 
bef7d8dc
1fe0: 0000002f bef7d89c b6d6dc74 b6d6d65c
irq event stamp: 1283
hardirqs last  enabled at (1293): [<c019f564>] console_unlock+0x430/0x6b0
hardirqs last disabled at (1302): [<c019f55c>] console_unlock+0x428/0x6b0
softirqs last  enabled at (1282): [<c0101768>] __do_softirq+0x528/0x674
softirqs last disabled at (1269): [<c012fed4>] irq_exit+0x1dc/0x1e8
---[ end trace 6f32a2fb4294655f ]---

I can do more tests to help fixing this issue. Just let me know what to do.

...

Best regards
Thomas Gleixner Nov. 12, 2020, 11:03 a.m. UTC | #2
Marek,

On Thu, Nov 12 2020 at 09:10, Marek Szyprowski wrote:
> On 03.11.2020 10:27, Thomas Gleixner wrote:
>
> I can do more tests to help fixing this issue. Just let me know what to do.

Just sent out the fix before I saw your report.

     https://lore.kernel.org/r/87y2j6n8mj.fsf@nanos.tec.linutronix.de

Thanks,

        tglx
Sebastian Andrzej Siewior Nov. 12, 2020, 11:07 a.m. UTC | #3
On 2020-11-12 09:10:34 [+0100], Marek Szyprowski wrote:
> I can do more tests to help fixing this issue. Just let me know what to do.

-> https://lkml.kernel.org/r/87y2j6n8mj.fsf@nanos.tec.linutronix.de

Sebastian

Patch
diff mbox series

--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1498,6 +1498,7 @@  config HAVE_ARCH_PFN_VALID
 config HIGHMEM
 	bool "High Memory Support"
 	depends on MMU
+	select KMAP_LOCAL
 	help
 	  The address space of ARM processors is only 4 Gigabytes large
 	  and it has to accommodate user address space, kernel address
--- a/arch/arm/include/asm/fixmap.h
+++ b/arch/arm/include/asm/fixmap.h
@@ -7,14 +7,14 @@ 
 #define FIXADDR_TOP		(FIXADDR_END - PAGE_SIZE)
 
 #include <linux/pgtable.h>
-#include <asm/kmap_types.h>
+#include <asm/kmap_size.h>
 
 enum fixed_addresses {
 	FIX_EARLYCON_MEM_BASE,
 	__end_of_permanent_fixed_addresses,
 
 	FIX_KMAP_BEGIN = __end_of_permanent_fixed_addresses,
-	FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,
+	FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
 
 	/* Support writing RO kernel text via kprobes, jump labels, etc. */
 	FIX_TEXT_POKE0,
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -2,7 +2,7 @@ 
 #ifndef _ASM_HIGHMEM_H
 #define _ASM_HIGHMEM_H
 
-#include <asm/kmap_types.h>
+#include <asm/kmap_size.h>
 
 #define PKMAP_BASE		(PAGE_OFFSET - PMD_SIZE)
 #define LAST_PKMAP		PTRS_PER_PTE
@@ -46,19 +46,32 @@  extern pte_t *pkmap_page_table;
 
 #ifdef ARCH_NEEDS_KMAP_HIGH_GET
 extern void *kmap_high_get(struct page *page);
-#else
+
+static inline void *arch_kmap_local_high_get(struct page *page)
+{
+	if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !cache_is_vivt())
+		return NULL;
+	return kmap_high_get(page);
+}
+#define arch_kmap_local_high_get arch_kmap_local_high_get
+
+#else /* ARCH_NEEDS_KMAP_HIGH_GET */
 static inline void *kmap_high_get(struct page *page)
 {
 	return NULL;
 }
-#endif
+#endif /* !ARCH_NEEDS_KMAP_HIGH_GET */
 
-/*
- * The following functions are already defined by <linux/highmem.h>
- * when CONFIG_HIGHMEM is not set.
- */
-#ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic_pfn(unsigned long pfn);
-#endif
+#define arch_kmap_local_post_map(vaddr, pteval)				\
+	local_flush_tlb_kernel_page(vaddr)
+
+#define arch_kmap_local_pre_unmap(vaddr)				\
+do {									\
+	if (cache_is_vivt())						\
+		__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);	\
+} while (0)
+
+#define arch_kmap_local_post_unmap(vaddr)				\
+	local_flush_tlb_kernel_page(vaddr)
 
 #endif
--- a/arch/arm/include/asm/kmap_types.h
+++ /dev/null
@@ -1,10 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __ARM_KMAP_TYPES_H
-#define __ARM_KMAP_TYPES_H
-
-/*
- * This is the "bare minimum".  AIO seems to require this.
- */
-#define KM_TYPE_NR 16
-
-#endif
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -19,7 +19,6 @@  obj-$(CONFIG_MODULES)		+= proc-syms.o
 obj-$(CONFIG_DEBUG_VIRTUAL)	+= physaddr.o
 
 obj-$(CONFIG_ALIGNMENT_TRAP)	+= alignment.o
-obj-$(CONFIG_HIGHMEM)		+= highmem.o
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
 obj-$(CONFIG_ARM_PV_FIXUP)	+= pv-fixup-asm.o
 
--- a/arch/arm/mm/highmem.c
+++ /dev/null
@@ -1,121 +0,0 @@ 
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * arch/arm/mm/highmem.c -- ARM highmem support
- *
- * Author:	Nicolas Pitre
- * Created:	september 8, 2008
- * Copyright:	Marvell Semiconductors Inc.
- */
-
-#include <linux/module.h>
-#include <linux/highmem.h>
-#include <linux/interrupt.h>
-#include <asm/fixmap.h>
-#include <asm/cacheflush.h>
-#include <asm/tlbflush.h>
-#include "mm.h"
-
-static inline void set_fixmap_pte(int idx, pte_t pte)
-{
-	unsigned long vaddr = __fix_to_virt(idx);
-	pte_t *ptep = virt_to_kpte(vaddr);
-
-	set_pte_ext(ptep, pte, 0);
-	local_flush_tlb_kernel_page(vaddr);
-}
-
-static inline pte_t get_fixmap_pte(unsigned long vaddr)
-{
-	pte_t *ptep = virt_to_kpte(vaddr);
-
-	return *ptep;
-}
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
-	unsigned int idx;
-	unsigned long vaddr;
-	void *kmap;
-	int type;
-
-#ifdef CONFIG_DEBUG_HIGHMEM
-	/*
-	 * There is no cache coherency issue when non VIVT, so force the
-	 * dedicated kmap usage for better debugging purposes in that case.
-	 */
-	if (!cache_is_vivt())
-		kmap = NULL;
-	else
-#endif
-		kmap = kmap_high_get(page);
-	if (kmap)
-		return kmap;
-
-	type = kmap_atomic_idx_push();
-
-	idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
-	vaddr = __fix_to_virt(idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
-	/*
-	 * With debugging enabled, kunmap_atomic forces that entry to 0.
-	 * Make sure it was indeed properly unmapped.
-	 */
-	BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
-#endif
-	/*
-	 * When debugging is off, kunmap_atomic leaves the previous mapping
-	 * in place, so the contained TLB flush ensures the TLB is updated
-	 * with the new mapping.
-	 */
-	set_fixmap_pte(idx, mk_pte(page, prot));
-
-	return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
-	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
-	int idx, type;
-
-	if (kvaddr >= (void *)FIXADDR_START) {
-		type = kmap_atomic_idx();
-		idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
-
-		if (cache_is_vivt())
-			__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
-#ifdef CONFIG_DEBUG_HIGHMEM
-		BUG_ON(vaddr != __fix_to_virt(idx));
-		set_fixmap_pte(idx, __pte(0));
-#else
-		(void) idx;  /* to kill a warning */
-#endif
-		kmap_atomic_idx_pop();
-	} else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
-		/* this address was obtained through kmap_high_get() */
-		kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
-	}
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
-
-void *kmap_atomic_pfn(unsigned long pfn)
-{
-	unsigned long vaddr;
-	int idx, type;
-	struct page *page = pfn_to_page(pfn);
-
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
-	type = kmap_atomic_idx_push();
-	idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
-	vaddr = __fix_to_virt(idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
-	BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
-#endif
-	set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot));
-
-	return (void *)vaddr;
-}