Re: [PATCH] Use acpi_os_map_memory() instead of ioremap() in einj driver

[Chen Gong <gong.chen@linux.intel.com>]

于 2012/1/24 7:27, Luck, Tony 写道:
> ioremap() has become more picky and is now spitting out console messages like:
>
>   ioremap error for 0xbddbd000-0xbddbe000, requested 0x10, got 0x0
>
> when loading the einj driver.  What we are trying to so here is map
> a couple of data structures that the EINJ table points to. Perhaps
> acpi_os_map_memory() is a better tool for this?
> Most importantly it works, but as a side benefit it maps the structures
> into kernel virtual space so we can access them with normal C memory
> dereferences, so instead of using:
> 	writel(param1,&v5param->apicid);
> we can use the more natural:
> 	v5param->apicid = param1;

I can understand why here C memory access model can work because ACPI table
is in physical memory zone but not in device space, but I still have
two confusion: 1)why ioremap fail but acpi_os_map_memory can work? In essential
acpi_os_map_memory is ioremap (or precisely, ioremap_cache), right?
2)since acpi_os_map_memory is io mapping too (though it is a little bit
special), read/write should work besides *C memory access*. If so, why removing
read/write here? Some ARCH compatibility or compilation issue?

>
> Signed-off-by: Tony Luck<tony.luck@intel.com>
>
> ---
>   drivers/acpi/apei/einj.c |   82 +++++++++++++++++++++--------------------------
>   1 file changed, 38 insertions(+), 44 deletions(-)
>
> The unmap paths are ugly - suggestions for improvement welcome.
>
> diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c
> index c89b0e5..dc3e63b 100644
> --- a/drivers/acpi/apei/einj.c
> +++ b/drivers/acpi/apei/einj.c
> @@ -141,21 +141,6 @@ static DEFINE_MUTEX(einj_mutex);
>
>   static void *einj_param;
>
> -#ifndef readq
> -static inline __u64 readq(volatile void __iomem *addr)
> -{
> -	return ((__u64)readl(addr+4)<<  32) + readl(addr);
> -}
> -#endif
> -
> -#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),
> @@ -204,22 +189,21 @@ static int einj_timedout(u64 *t)
>   static void check_vendor_extension(u64 paddr,
>   				   struct set_error_type_with_address *v5param)
>   {
> -	int	offset = readl(&v5param->vendor_extension);
> +	int	offset = v5param->vendor_extension;
>   	struct	vendor_error_type_extension *v;
>   	u32	sbdf;
>
>   	if (!offset)
>   		return;
> -	v = ioremap(paddr + offset, sizeof(*v));
> +	v = acpi_os_map_memory(paddr + offset, sizeof(*v));
>   	if (!v)
>   		return;
> -	sbdf = readl(&v->pcie_sbdf);
> +	sbdf = v->pcie_sbdf;
>   	sprintf(vendor_dev, "%x:%x:%x.%x vendor_id=%x device_id=%x rev_id=%x\n",
>   		sbdf>>  24, (sbdf>>  16)&  0xff,
>   		(sbdf>>  11)&  0x1f, (sbdf>>  8)&  0x7,
> -		 readw(&v->vendor_id), readw(&v->device_id),
> -		readb(&v->rev_id));
> -	iounmap(v);
> +		 v->vendor_id, v->device_id, v->rev_id);
> +	acpi_os_unmap_memory(v, sizeof(*v));
>   }
>
>   static void *einj_get_parameter_address(void)
> @@ -247,7 +231,7 @@ static void *einj_get_parameter_address(void)
>   	if (paddrv5) {
>   		struct set_error_type_with_address *v5param;
>
> -		v5param = ioremap(paddrv5, sizeof(*v5param));
> +		v5param = acpi_os_map_memory(paddrv5, sizeof(*v5param));
>   		if (v5param) {
>   			acpi5 = 1;
>   			check_vendor_extension(paddrv5, v5param);
> @@ -257,11 +241,11 @@ static void *einj_get_parameter_address(void)
>   	if (paddrv4) {
>   		struct einj_parameter *v4param;
>
> -		v4param = ioremap(paddrv4, sizeof(*v4param));
> +		v4param = acpi_os_map_memory(paddrv4, sizeof(*v4param));
>   		if (!v4param)
>   			return NULL;
> -		if (readq(&v4param->reserved1) || readq(&v4param->reserved2)) {
> -			iounmap(v4param);
> +		if (v4param->reserved1 || v4param->reserved2) {
> +			acpi_os_unmap_memory(v4param, sizeof(*v4param));
>   			return NULL;
>   		}
>   		return v4param;
> @@ -440,41 +424,41 @@ static int __einj_error_inject(u32 type, u64 param1, u64 param2)
>   	if (acpi5) {
>   		struct set_error_type_with_address *v5param = einj_param;
>
> -		writel(type,&v5param->type);
> +		v5param->type = type;
>   		if (type&  0x80000000) {
>   			switch (vendor_flags) {
>   			case SETWA_FLAGS_APICID:
> -				writel(param1,&v5param->apicid);
> +				v5param->apicid = param1;
>   				break;
>   			case SETWA_FLAGS_MEM:
> -				writeq(param1,&v5param->memory_address);
> -				writeq(param2,&v5param->memory_address_range);
> +				v5param->memory_address = param1;
> +				v5param->memory_address_range = param2;
>   				break;
>   			case SETWA_FLAGS_PCIE_SBDF:
> -				writel(param1,&v5param->pcie_sbdf);
> +				v5param->pcie_sbdf = param1;
>   				break;
>   			}
> -			writel(vendor_flags,&v5param->flags);
> +			v5param->flags = vendor_flags;
>   		} else {
>   			switch (type) {
>   			case ACPI_EINJ_PROCESSOR_CORRECTABLE:
>   			case ACPI_EINJ_PROCESSOR_UNCORRECTABLE:
>   			case ACPI_EINJ_PROCESSOR_FATAL:
> -				writel(param1,&v5param->apicid);
> -				writel(SETWA_FLAGS_APICID,&v5param->flags);
> +				v5param->apicid = param1;
> +				v5param->flags = SETWA_FLAGS_APICID;
>   				break;
>   			case ACPI_EINJ_MEMORY_CORRECTABLE:
>   			case ACPI_EINJ_MEMORY_UNCORRECTABLE:
>   			case ACPI_EINJ_MEMORY_FATAL:
> -				writeq(param1,&v5param->memory_address);
> -				writeq(param2,&v5param->memory_address_range);
> -				writel(SETWA_FLAGS_MEM,&v5param->flags);
> +				v5param->memory_address = param1;
> +				v5param->memory_address_range = param2;
> +				v5param->flags = SETWA_FLAGS_MEM;
>   				break;
>   			case ACPI_EINJ_PCIX_CORRECTABLE:
>   			case ACPI_EINJ_PCIX_UNCORRECTABLE:
>   			case ACPI_EINJ_PCIX_FATAL:
> -				writel(param1,&v5param->pcie_sbdf);
> -				writel(SETWA_FLAGS_PCIE_SBDF,&v5param->flags);
> +				v5param->pcie_sbdf = param1;
> +				v5param->flags = SETWA_FLAGS_PCIE_SBDF;
>   				break;
>   			}
>   		}
> @@ -484,8 +468,8 @@ static int __einj_error_inject(u32 type, u64 param1, u64 param2)
>   			return rc;
>   		if (einj_param) {
>   			struct einj_parameter *v4param = einj_param;
> -			writeq(param1,&v4param->param1);
> -			writeq(param2,&v4param->param2);
> +			v4param->param1 = param1;
> +			v4param->param2 = param2;
>   		}
>   	}
>   	rc = apei_exec_run(&ctx, ACPI_EINJ_EXECUTE_OPERATION);
> @@ -736,8 +720,13 @@ static int __init einj_init(void)
>   	return 0;
>
>   err_unmap:
> -	if (einj_param)
> -		iounmap(einj_param);
> +	if (einj_param) {
> +		acpi_size size = (acpi5) ?
> +			sizeof (struct set_error_type_with_address) :
> +			sizeof (struct einj_parameter);
> +
> +		acpi_os_unmap_memory(einj_param, size);
> +	}
>   	apei_exec_post_unmap_gars(&ctx);
>   err_release:
>   	apei_resources_release(&einj_resources);
> @@ -753,8 +742,13 @@ static void __exit einj_exit(void)
>   {
>   	struct apei_exec_context ctx;
>
> -	if (einj_param)
> -		iounmap(einj_param);
> +	if (einj_param) {
> +		acpi_size size = (acpi5) ?
> +			sizeof (struct set_error_type_with_address) :
> +			sizeof (struct einj_parameter);
> +
> +		acpi_os_unmap_memory(einj_param, size);
> +	}
>   	einj_exec_ctx_init(&ctx);
>   	apei_exec_post_unmap_gars(&ctx);
>   	apei_resources_release(&einj_resources);
> --
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