| Message ID | 20160909031809.GG16712@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 09/09/16 04:18, AKASHI Takahiro wrote: > On Thu, Sep 08, 2016 at 11:47:59AM +0100, James Morse wrote: >> On 08/09/16 09:14, Arnd Bergmann wrote: >>> On Wednesday, September 7, 2016 3:37:05 PM CEST Guenter Roeck wrote: >>>> On Wed, Sep 07, 2016 at 11:41:44PM +0200, Arnd Bergmann wrote: >>>>> On Thursday, July 21, 2016 1:55:56 PM CEST Hoan Tran wrote: >>>>>> + ctx->comm_base_addr = cppc_ss->base_address; >>>>>> + if (ctx->comm_base_addr) { >>>>>> + ctx->pcc_comm_addr = >>>>>> + acpi_os_ioremap(ctx->comm_base_addr, >>>>>> + cppc_ss->length); >>>>>> >>>>> >>>>> This causes the arm64 allmodconfig build to fail now, according to >>>>> kernelci: >>>>> >>>>> 1 ERROR: "memblock_is_memory" [drivers/hwmon/xgene-hwmon.ko] undefined! >>>>> >>>>> Should this perhaps call ioremap() or memremap() instead? >>>>> >>>> Hmmm ... almost sounds to me like blaming the messenger. e7cd190385d1 ("arm64: >>>> mark reserved memblock regions explicitly in iomem") starts using a function >>>> in acpi_os_ioremap() which is not exported. On top of that, memblock_is_memory() >>>> is declared as __init_memblock, which makes me really uncomfortable. >>>> If acpi_os_ioremap() must not be used by modules, and possibly only during >>>> early (?) initialization, maybe its declaration should state those limitations ? >>> >>> Ah, I didn't notice that. I guess both patches were correct individually and >>> got added to linux-next around the same time but caused allmodconfig to blow up >>> when used together. >>> >>> Adding everyone who was involved in the memblock patch to Cc here, maybe one >>> of them has an idea what the correct fix is. There are only two other drivers >>> using acpi_os_ioremap() and one of them is x86-specific, so it's still likely >>> that drivers are not actually supposed to use this symbol. Making >>> acpi_os_ioremap() an exported function in arm64 would also work. >> >> You could use acpi_os_map_iomem()/acpi_os_unmap_iomem() from acpi/acpi_io.h. >> If there isn't an existing mapping these end up in acpi_os_ioremap(), and are >> already EXPORT_SYMBOL_GPL(). > > acpi_os_ioremap() is re-defined in arm64/include/asm/acpi.h. > > The problem is that, as memblock_is_memory() is declared as __init, __init_memblock ... ... as is memblock_is_map_memory(), which we call from pfn_valid() which is EXPORT_SYMBOL()'d and used from modules, (e.g. mac80211.ko). So something fishy is going on... From include/linux/memblock.h: > #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK > #define __init_memblock __meminit > #define __initdata_memblock __meminitdata > #else > #define __init_memblock > #define __initdata_memblock > #endif arm64 doesn't define ARCH_DISCARD_MEMBLOCK, so we always keep these symbols. If we didn't, pfn_valid() would break too. Thanks, James
===8<=== --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -207,7 +207,7 @@ static void __init request_standard_resources(void) res = alloc_bootmem_low(sizeof(*res)); if (memblock_is_nomap(region)) { res->name = "reserved"; - res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; + res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; } else { res->name = "System RAM"; res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; ===>8=== and revert the following hunk from the commit: ===8<=== --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -12,7 +12,7 @@ #ifndef _ASM_ACPI_H #define _ASM_ACPI_H -#include <linux/mm.h> +#include <linux/memblock.h> #include <linux/psci.h> #include <asm/cputype.h> @@ -32,7 +32,11 @@ static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size) { - if (!page_is_ram(phys >> PAGE_SHIFT)) + /* + * EFI's reserve_regions() call adds memory with the WB attribute + * to memblock via early_init_dt_add_memory_arch(). + */ + if (!memblock_is_memory(phys)) return ioremap(phys, size); return ioremap_cache(phys, size);