From: Roland Dreier <roland@xxxxxxxxxxxxxxx> 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@xxxxxxxxx>). 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 mean time 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@xxxxxxxxxxx Cc: Hitoshi Mitake <h.mitake@xxxxxxxxx> Cc: Kashyap Desai <Kashyap.Desai@xxxxxxx> Cc: Len Brown <lenb@xxxxxxxxxx> Cc: Ravi Anand <ravi.anand@xxxxxxxxxx> Cc: Vikas Chaudhary <vikas.chaudhary@xxxxxxxxxx> Cc: Matthew Garrett <mjg@xxxxxxxxxx> Signed-off-by: Roland Dreier <roland@xxxxxxxxxxxxxxx> --- arch/x86/Kconfig | 2 -- arch/x86/include/asm/io.h | 24 ++---------------------- drivers/acpi/apei/einj.c | 8 ++++++++ drivers/acpi/atomicio.c | 4 ++++ drivers/edac/i3200_edac.c | 13 +++++++++++++ drivers/platform/x86/ibm_rtl.c | 13 +++++++++++++ drivers/platform/x86/intel_ips.c | 13 +++++++++++++ drivers/scsi/qla4xxx/ql4_nx.c | 21 +++++++++++++++++++++ 8 files changed, 74 insertions(+), 24 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index cc6c53a..ceb41f3 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -16,8 +16,6 @@ config X86_64 config X86 def_bool y select HAVE_AOUT if X86_32 - select HAVE_READQ - select HAVE_WRITEQ select HAVE_UNSTABLE_SCHED_CLOCK select HAVE_IDE select HAVE_OPROFILE diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 0722730..d02804d 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -38,7 +38,6 @@ #include <linux/string.h> #include <linux/compiler.h> -#include <asm-generic/int-ll64.h> #include <asm/page.h> #include <xen/xen.h> @@ -87,27 +86,6 @@ build_mmio_write(__writel, "l", unsigned int, "r", ) build_mmio_read(readq, "q", unsigned long, "=r", :"memory") build_mmio_write(writeq, "q", unsigned long, "r", :"memory") -#else - -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); -} - -static inline void writeq(__u64 val, volatile void __iomem *addr) -{ - writel(val, addr); - writel(val >> 32, addr+4); -} - -#endif - #define readq_relaxed(a) readq(a) #define __raw_readq(a) readq(a) @@ -117,6 +95,8 @@ static inline void writeq(__u64 val, volatile void __iomem *addr) #define readq readq #define writeq writeq +#endif + /** * virt_to_phys - map virtual addresses to physical * @address: address to remap diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c index 096aebf..f74b2ea 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 542e539..7489b89 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 d41f900..aa08497 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 94a114a..b1396e5 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 85c8ad4..5ffe7c3 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 35381cb..03e522b 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) { -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
