2020-11-03 10:35:35

by Thomas Gleixner

[permalink] [raw]
Subject: [patch V3 10/37] ARM: highmem: Switch to generic kmap atomic

No reason having the same code in every architecture.

Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Russell King <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: [email protected]
---
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(-)

--- 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;
-}


Subject: [tip: core/mm] ARM: highmem: Switch to generic kmap atomic

The following commit has been merged into the core/mm branch of tip:

Commit-ID: 2a15ba82fa6ca3f35502b3060f22118a938d2889
Gitweb: https://git.kernel.org/tip/2a15ba82fa6ca3f35502b3060f22118a938d2889
Author: Thomas Gleixner <[email protected]>
AuthorDate: Tue, 03 Nov 2020 10:27:22 +01:00
Committer: Thomas Gleixner <[email protected]>
CommitterDate: Fri, 06 Nov 2020 23:14:56 +01:00

ARM: highmem: Switch to generic kmap atomic

No reason having the same code in every architecture.

Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Russell King <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

---
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(-)
delete mode 100644 arch/arm/include/asm/kmap_types.h
delete mode 100644 arch/arm/mm/highmem.c

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index fe2f17e..46f8900 100644
--- 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
diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h
index fc56fc3..c279a8a 100644
--- 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,
diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h
index 31811be..a41de52 100644
--- 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/fixmap.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
diff --git a/arch/arm/include/asm/kmap_types.h b/arch/arm/include/asm/kmap_types.h
deleted file mode 100644
index 5590940..0000000
--- 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
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 7cb1699..c4ce477 100644
--- 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

diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
deleted file mode 100644
index 187fab2..0000000
--- 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;
-}

2020-11-12 08:12:56

by Marek Szyprowski

[permalink] [raw]
Subject: Re: [patch V3 10/37] ARM: highmem: Switch to generic kmap atomic

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 <[email protected]>
> Cc: Russell King <[email protected]>
> Cc: Arnd Bergmann <[email protected]>
> Cc: [email protected]

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

--
Marek Szyprowski, PhD
Samsung R&D Institute Poland

2020-11-12 11:07:28

by Thomas Gleixner

[permalink] [raw]
Subject: Re: [patch V3 10/37] ARM: highmem: Switch to generic kmap atomic

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/[email protected]

Thanks,

tglx

Subject: Re: [patch V3 10/37] ARM: highmem: Switch to generic kmap atomic

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/[email protected]

Sebastian