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Groups > linux.kernel > #1397308

[PATCH 4.2.y-ckt 41/59] ARC: Add missing io barriers to io{read,write}{16,32}be()

From Kamal Mostafa <kamal@canonical.com>
Newsgroups linux.kernel
Subject [PATCH 4.2.y-ckt 41/59] ARC: Add missing io barriers to io{read,write}{16,32}be()
Date 2016-05-09 22:10 +0200
Message-ID <rwZF7-42D-9@gated-at.bofh.it> (permalink)
References <rwZvs-3Ct-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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4.2.8-ckt10 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Vineet Gupta <vgupta@synopsys.com>

commit e5bc0478ab6cf565619224536d75ecb2aedca43b upstream.

While reviewing a different change to asm-generic/io.h Arnd spotted that
ARC ioread32 and ioread32be both of which come from asm-generic versions
are not symmetrical in terms of calling the io barriers.

generic ioread32   -> ARC readl()                  [ has barriers]
generic ioread32be -> __be32_to_cpu(__raw_readl()) [ lacks barriers]

While generic ioread32be is being remediated to call readl(), that involves
a swab32(), causing double swaps on ioread32be() on Big Endian systems.

So provide our versions of big endian IO accessors to ensure io barrier
calls while also keeping them optimal

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 arch/arc/include/asm/io.h | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/arch/arc/include/asm/io.h b/arch/arc/include/asm/io.h
index 27b17ad..cb69299 100644
--- a/arch/arc/include/asm/io.h
+++ b/arch/arc/include/asm/io.h
@@ -13,6 +13,15 @@
 #include <asm/byteorder.h>
 #include <asm/page.h>
 
+#ifdef CONFIG_ISA_ARCV2
+#include <asm/barrier.h>
+#define __iormb()		rmb()
+#define __iowmb()		wmb()
+#else
+#define __iormb()		do { } while (0)
+#define __iowmb()		do { } while (0)
+#endif
+
 extern void __iomem *ioremap(unsigned long physaddr, unsigned long size);
 extern void __iomem *ioremap_prot(phys_addr_t offset, unsigned long size,
 				  unsigned long flags);
@@ -22,6 +31,15 @@ extern void iounmap(const void __iomem *addr);
 #define ioremap_wc(phy, sz)		ioremap(phy, sz)
 #define ioremap_wt(phy, sz)		ioremap(phy, sz)
 
+/*
+ * io{read,write}{16,32}be() macros
+ */
+#define ioread16be(p)		({ u16 __v = be16_to_cpu((__force __be16)__raw_readw(p)); __iormb(); __v; })
+#define ioread32be(p)		({ u32 __v = be32_to_cpu((__force __be32)__raw_readl(p)); __iormb(); __v; })
+
+#define iowrite16be(v,p)	({ __iowmb(); __raw_writew((__force u16)cpu_to_be16(v), p); })
+#define iowrite32be(v,p)	({ __iowmb(); __raw_writel((__force u32)cpu_to_be32(v), p); })
+
 /* Change struct page to physical address */
 #define page_to_phys(page)		(page_to_pfn(page) << PAGE_SHIFT)
 
@@ -99,15 +117,6 @@ static inline void __raw_writel(u32 w, volatile void __iomem *addr)
 
 }
 
-#ifdef CONFIG_ISA_ARCV2
-#include <asm/barrier.h>
-#define __iormb()		rmb()
-#define __iowmb()		wmb()
-#else
-#define __iormb()		do { } while (0)
-#define __iowmb()		do { } while (0)
-#endif
-
 /*
  * MMIO can also get buffered/optimized in micro-arch, so barriers needed
  * Based on ARM model for the typical use case
-- 
2.7.4

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[4.2.y-ckt stable] Linux 4.2.8-ckt10 stable review Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 25/59] ARM: SoCFPGA: Fix secondary CPU startup in thumb2 kernel Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 57/59] net/mlx5e: Fix MLX5E_100BASE_T define Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 53/59] batman-adv: Check skb size before using encapsulated ETH+VLAN header Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 04/59] ASoC: dapm: Make sure we have a card when displaying component widgets Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 49/59] jme: Do not enable NIC WoL functions on S0 Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 19/59] drm/i915: Fix system resume if PCI device remained enabled Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 54/59] batman-adv: Fix broadcast/ogm queue limit on a removed interface Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 59/59] RDMA/iw_cxgb4: Fix bar2 virt addr calculation for T4 chips Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 32/59] EDAC: i7core, sb_edac: Don't return NOTIFY_BAD from mce_decoder callback Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 55/59] mm: update min_free_kbytes from khugepaged after core initialization Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 58/59] cxgbi: fix uninitialized flowi6 Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 56/59] ARM: EXYNOS: Properly skip unitialized parent clock in power domain on Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:00 +0200
  [PATCH 4.2.y-ckt 24/59] drm/radeon: fix vertical bars appear on monitor (v2) Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 33/59] powerpc: Fix bad inline asm constraint in create_zero_mask() Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 42/59] x86/sysfb_efi: Fix valid BAR address range check Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 48/59] parisc: fix a bug when syscall number of tracee is __NR_Linux_syscalls Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 41/59] ARC: Add missing io barriers to io{read,write}{16,32}be() Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 45/59] writeback: Fix performance regression in wb_over_bg_thresh() Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 35/59] drm/amdgpu: set metadata pointer to NULL after freeing. Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 34/59] Minimal fix-up of bad hashing behavior of hash_64() Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 21/59] drm/i915: Fix eDP low vswing for Broadwell Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 44/59] propogate_mnt: Handle the first propogated copy being a slave Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 51/59] net/mlx4_en: fix spurious timestamping callbacks Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 30/59] mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 26/59] x86/irq: Fix a race in x86_vector_free_irqs() Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 43/59] fs/pnode.c: treat zero mnt_group_id-s as unequal Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 39/59] MAINTAINERS: Remove asterisk from EFI directory names Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 28/59] ARM: cpuidle: Pass on arm_cpuidle_suspend()'s return value Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 29/59] IB/security: Restrict use of the write() interface Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 47/59] x86/tsc: Read all ratio bits from MSR_PLATFORM_INFO Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 22/59] drm/i915: Make RPS EI/thresholds multiple of 25 on SNB-BDW Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 52/59] batman-adv: Reduce refcnt of removed router when updating route Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 46/59] mm, cma: prevent nr_isolated_* counters from going negative Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 31/59] mm: vmscan: reclaim highmem zone if buffer_heads is over limit Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 50/59] jme: Fix device PM wakeup API usage Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 36/59] tracing: Don't display trigger file for events that can't be enabled Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 38/59] drm/amdgpu: make sure vertical front porch is at least 1 Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 27/59] x86/apic: Handle zero vector gracefully in clear_vector_irq() Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 40/59] ACPICA: Dispatcher: Update thread ID for recursive method calls Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:10 +0200
  [PATCH 4.2.y-ckt 18/59] cxl: Keep IRQ mappings on context teardown Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 02/59] USB: usbip: fix potential out-of-bounds write Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 07/59] iio: ak8975: fix maybe-uninitialized warning Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 12/59] USB: serial: cp210x: add Straizona Focusers device ids Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 13/59] [media] v4l2-dv-timings.h: fix polarity for 4k formats Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 14/59] ALSA: hda - Add dock support for ThinkPad X260 Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 05/59] ath9k: ar5008_hw_cmn_spur_mitigate: add missing mask_m & mask_p initialisation Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 09/59] i2c: exynos5: Fix possible ABBA deadlock by keeping I2C clock prepared Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 20/59] drm/i915/ddi: Fix eDP VDD handling during booting and suspend/resume Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 06/59] iio: ak8975: Fix NULL pointer exception on early interrupt Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 01/59] x86/mm/32: Enable full randomization on i386 and X86_32 Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 16/59] drm/dp/mst: Get validated port ref in drm_dp_update_payload_part1() Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 11/59] USB: serial: cp210x: add ID for Link ECU Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 10/59] efi: Fix out-of-bounds read in variable_matches() Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 15/59] workqueue: fix ghost PENDING flag while doing MQ IO Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200
  [PATCH 4.2.y-ckt 03/59] ASoC: rt5640: Correct the digital interface data select Kamal Mostafa <kamal@canonical.com> - 2016-05-09 22:20 +0200

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