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author | 2011-05-24 17:13:09 -0700 | |
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committer | 2011-05-25 08:39:44 -0700 | |
commit | dbee8a0affd5e6eaa5d7c816c4bc233f6f110f50 (patch) | |
tree | 485bba5ec4436e9e8c84aacf25590ca8f8a6332b /drivers | |
parent | Remove unused PROC_CHANGE_PENALTY constant (diff) | |
download | linux-dbee8a0affd5.tar.gz linux-dbee8a0affd5.tar.bz2 linux-dbee8a0affd5.zip |
x86: remove 32-bit versions of readq()/writeq()
The presense of a writeq() implementation on 32-bit x86 that splits the
64-bit write into two 32-bit writes turns out to break the mpt2sas driver
(and in general is risky for drivers as was discussed in
<http://lkml.kernel.org/r/adaab6c1h7c.fsf@cisco.com>). To fix this,
revert 2c5643b1c5c7 ("x86: provide readq()/writeq() on 32-bit too") and
follow-on cleanups.
This unfortunately leads to pushing non-atomic definitions of readq() and
write() to various x86-only drivers that in the meantime started using the
definitions in the x86 version of <asm/io.h>. However as discussed
exhaustively, this is actually the right thing to do, because the right
way to split a 64-bit transaction is hardware dependent and therefore
belongs in the hardware driver (eg mpt2sas needs a spinlock to make sure
no other accesses occur in between the two halves of the access).
Build tested on 32- and 64-bit x86 allmodconfig.
Link: http://lkml.kernel.org/r/x86-32-writeq-is-broken@mdm.bga.com
Acked-by: Hitoshi Mitake <h.mitake@gmail.com>
Cc: Kashyap Desai <Kashyap.Desai@lsi.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Ravi Anand <ravi.anand@qlogic.com>
Cc: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Jason Uhlenkott <juhlenko@akamai.com>
Acked-by: James Bottomley <James.Bottomley@parallels.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/acpi/apei/einj.c | 8 | ||||
-rw-r--r-- | drivers/acpi/atomicio.c | 4 | ||||
-rw-r--r-- | drivers/edac/i3200_edac.c | 13 | ||||
-rw-r--r-- | drivers/platform/x86/ibm_rtl.c | 13 | ||||
-rw-r--r-- | drivers/platform/x86/intel_ips.c | 13 | ||||
-rw-r--r-- | drivers/scsi/qla4xxx/ql4_nx.c | 21 |
6 files changed, 72 insertions, 0 deletions
diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c index 096aebfe7f32..f74b2ea11f21 100644 --- a/drivers/acpi/apei/einj.c +++ b/drivers/acpi/apei/einj.c @@ -101,6 +101,14 @@ static DEFINE_MUTEX(einj_mutex); static struct einj_parameter *einj_param; +#ifndef writeq +static inline void writeq(__u64 val, volatile void __iomem *addr) +{ + writel(val, addr); + writel(val >> 32, addr+4); +} +#endif + static void einj_exec_ctx_init(struct apei_exec_context *ctx) { apei_exec_ctx_init(ctx, einj_ins_type, ARRAY_SIZE(einj_ins_type), diff --git a/drivers/acpi/atomicio.c b/drivers/acpi/atomicio.c index 542e53903891..7489b89c300f 100644 --- a/drivers/acpi/atomicio.c +++ b/drivers/acpi/atomicio.c @@ -280,9 +280,11 @@ static int acpi_atomic_read_mem(u64 paddr, u64 *val, u32 width) case 32: *val = readl(addr); break; +#ifdef readq case 64: *val = readq(addr); break; +#endif default: return -EINVAL; } @@ -307,9 +309,11 @@ static int acpi_atomic_write_mem(u64 paddr, u64 val, u32 width) case 32: writel(val, addr); break; +#ifdef writeq case 64: writeq(val, addr); break; +#endif default: return -EINVAL; } diff --git a/drivers/edac/i3200_edac.c b/drivers/edac/i3200_edac.c index d41f9002da45..aa08497a075a 100644 --- a/drivers/edac/i3200_edac.c +++ b/drivers/edac/i3200_edac.c @@ -101,6 +101,19 @@ struct i3200_priv { static int nr_channels; +#ifndef readq +static inline __u64 readq(const volatile void __iomem *addr) +{ + const volatile u32 __iomem *p = addr; + u32 low, high; + + low = readl(p); + high = readl(p + 1); + + return low + ((u64)high << 32); +} +#endif + static int how_many_channels(struct pci_dev *pdev) { unsigned char capid0_8b; /* 8th byte of CAPID0 */ diff --git a/drivers/platform/x86/ibm_rtl.c b/drivers/platform/x86/ibm_rtl.c index 94a114aa8e28..b1396e5b2953 100644 --- a/drivers/platform/x86/ibm_rtl.c +++ b/drivers/platform/x86/ibm_rtl.c @@ -81,6 +81,19 @@ static void __iomem *rtl_cmd_addr; static u8 rtl_cmd_type; static u8 rtl_cmd_width; +#ifndef readq +static inline __u64 readq(const volatile void __iomem *addr) +{ + const volatile u32 __iomem *p = addr; + u32 low, high; + + low = readl(p); + high = readl(p + 1); + + return low + ((u64)high << 32); +} +#endif + static void __iomem *rtl_port_map(phys_addr_t addr, unsigned long len) { if (rtl_cmd_type == RTL_ADDR_TYPE_MMIO) diff --git a/drivers/platform/x86/intel_ips.c b/drivers/platform/x86/intel_ips.c index 85c8ad43c0c5..5ffe7c398148 100644 --- a/drivers/platform/x86/intel_ips.c +++ b/drivers/platform/x86/intel_ips.c @@ -344,6 +344,19 @@ struct ips_driver { static bool ips_gpu_turbo_enabled(struct ips_driver *ips); +#ifndef readq +static inline __u64 readq(const volatile void __iomem *addr) +{ + const volatile u32 __iomem *p = addr; + u32 low, high; + + low = readl(p); + high = readl(p + 1); + + return low + ((u64)high << 32); +} +#endif + /** * ips_cpu_busy - is CPU busy? * @ips: IPS driver struct diff --git a/drivers/scsi/qla4xxx/ql4_nx.c b/drivers/scsi/qla4xxx/ql4_nx.c index 35381cb0936e..03e522b2fe0b 100644 --- a/drivers/scsi/qla4xxx/ql4_nx.c +++ b/drivers/scsi/qla4xxx/ql4_nx.c @@ -655,6 +655,27 @@ static int qla4_8xxx_pci_is_same_window(struct scsi_qla_host *ha, return 0; } +#ifndef readq +static inline __u64 readq(const volatile void __iomem *addr) +{ + const volatile u32 __iomem *p = addr; + u32 low, high; + + low = readl(p); + high = readl(p + 1); + + return low + ((u64)high << 32); +} +#endif + +#ifndef writeq +static inline void writeq(__u64 val, volatile void __iomem *addr) +{ + writel(val, addr); + writel(val >> 32, addr+4); +} +#endif + static int qla4_8xxx_pci_mem_read_direct(struct scsi_qla_host *ha, u64 off, void *data, int size) { |