Message ID | a861cad705fe7ebccef3.1226359474@localhost.localdomain (mailing list archive) |
---|---|
State | Superseded, archived |
Delegated to: | Josh Boyer |
Headers | show |
On Mon, Nov 10, 2008 at 05:24:34PM -0600, Hollis Blanchard wrote: >The current CHIP11 errata truncates the device tree memory node, and subtracts >(hardcoded) 4096 bytes. This breaks kernels with larger PAGE_SIZE, since the >bootmem allocator assumes that total memory is a multiple of PAGE_SIZE. > >Instead, use a device tree memory reservation to reserve only the 256 bytes >actually affected by the errata, leaving the total memory size unaltered. > >Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> > >--- > >Using large pages results in a huge performance improvement for KVM, and this >patch is required to make Ilya's large page patch work. David and/or Josh, >please apply. The patch looks fine to me, and once David acks the fdt parts I'll apply for -next. I'll try to do some testing later today as well, since I have one of the boards with the Errata. josh > >diff --git a/arch/powerpc/boot/4xx.c b/arch/powerpc/boot/4xx.c >--- a/arch/powerpc/boot/4xx.c >+++ b/arch/powerpc/boot/4xx.c >@@ -21,7 +21,7 @@ > #include "reg.h" > #include "dcr.h" > >-static unsigned long chip_11_errata(unsigned long memsize) >+static void chip_11_errata(unsigned long memsize) > { > unsigned long pvr; > >@@ -31,13 +31,11 @@ static unsigned long chip_11_errata(unsi > case 0x40000850: > case 0x400008d0: > case 0x200008d0: >- memsize -= 4096; >+ fdt_add_mem_rsv(fdt, memsize - 256, 256); > break; > default: > break; > } >- >- return memsize; > } > > /* Read the 4xx SDRAM controller to get size of system memory. */ >@@ -53,7 +51,7 @@ void ibm4xx_sdram_fixup_memsize(void) > memsize += SDRAM_CONFIG_BANK_SIZE(bank_config); > } > >- memsize = chip_11_errata(memsize); >+ chip_11_errata(memsize); > dt_fixup_memory(0, memsize); > } > >@@ -219,7 +217,7 @@ void ibm4xx_denali_fixup_memsize(void) > bank = 4; /* 4 banks */ > > memsize = cs * (1 << (col+row)) * bank * dpath; >- memsize = chip_11_errata(memsize); >+ chip_11_errata(memsize); > dt_fixup_memory(0, memsize); > } > >diff --git a/arch/powerpc/boot/libfdt-wrapper.c b/arch/powerpc/boot/libfdt-wrapper.c >--- a/arch/powerpc/boot/libfdt-wrapper.c >+++ b/arch/powerpc/boot/libfdt-wrapper.c >@@ -51,7 +51,7 @@ > #define devp_offset_find(devp) (((int)(devp))-1) > #define devp_offset(devp) (devp ? ((int)(devp))-1 : 0) > >-static void *fdt; >+void *fdt; > static void *buf; /* = NULL */ > > #define EXPAND_GRANULARITY 1024 >diff --git a/arch/powerpc/boot/ops.h b/arch/powerpc/boot/ops.h >--- a/arch/powerpc/boot/ops.h >+++ b/arch/powerpc/boot/ops.h >@@ -14,6 +14,7 @@ > #include <stddef.h> > #include "types.h" > #include "string.h" >+#include "libfdt_env.h" > > #define COMMAND_LINE_SIZE 512 > #define MAX_PATH_LEN 256 >@@ -32,6 +33,9 @@ struct platform_ops { > void * (*vmlinux_alloc)(unsigned long size); > }; > extern struct platform_ops platform_ops; >+ >+/* The device tree itself. Should almost always be accessed via dt_ops. */ >+extern void *fdt; > > /* Device Tree operations */ > struct dt_ops { >@@ -98,6 +102,8 @@ void dt_get_reg_format(void *node, u32 * > void dt_get_reg_format(void *node, u32 *naddr, u32 *nsize); > int dt_get_virtual_reg(void *node, void **addr, int nres); > >+int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size); >+ > static inline void *finddevice(const char *name) > { > return (dt_ops.finddevice) ? dt_ops.finddevice(name) : NULL; >_______________________________________________ >Linuxppc-dev mailing list >Linuxppc-dev@ozlabs.org >https://ozlabs.org/mailman/listinfo/linuxppc-dev
On Tue, Nov 11, 2008 at 07:52:18AM -0500, Josh Boyer wrote: > On Mon, Nov 10, 2008 at 05:24:34PM -0600, Hollis Blanchard wrote: > >The current CHIP11 errata truncates the device tree memory node, and subtracts > >(hardcoded) 4096 bytes. This breaks kernels with larger PAGE_SIZE, since the > >bootmem allocator assumes that total memory is a multiple of PAGE_SIZE. > > > >Instead, use a device tree memory reservation to reserve only the 256 bytes > >actually affected by the errata, leaving the total memory size unaltered. > > > >Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> > > > >--- > > > >Using large pages results in a huge performance improvement for KVM, and this > >patch is required to make Ilya's large page patch work. David and/or Josh, > >please apply. > > The patch looks fine to me, and once David acks the fdt parts I'll apply > for -next. I'll try to do some testing later today as well, since I have > one of the boards with the Errata. Um.. I sent something the fdt stuff a while back, but didn't get a response.
diff --git a/arch/powerpc/boot/4xx.c b/arch/powerpc/boot/4xx.c --- a/arch/powerpc/boot/4xx.c +++ b/arch/powerpc/boot/4xx.c @@ -21,7 +21,7 @@ #include "reg.h" #include "dcr.h" -static unsigned long chip_11_errata(unsigned long memsize) +static void chip_11_errata(unsigned long memsize) { unsigned long pvr; @@ -31,13 +31,11 @@ static unsigned long chip_11_errata(unsi case 0x40000850: case 0x400008d0: case 0x200008d0: - memsize -= 4096; + fdt_add_mem_rsv(fdt, memsize - 256, 256); break; default: break; } - - return memsize; } /* Read the 4xx SDRAM controller to get size of system memory. */ @@ -53,7 +51,7 @@ void ibm4xx_sdram_fixup_memsize(void) memsize += SDRAM_CONFIG_BANK_SIZE(bank_config); } - memsize = chip_11_errata(memsize); + chip_11_errata(memsize); dt_fixup_memory(0, memsize); } @@ -219,7 +217,7 @@ void ibm4xx_denali_fixup_memsize(void) bank = 4; /* 4 banks */ memsize = cs * (1 << (col+row)) * bank * dpath; - memsize = chip_11_errata(memsize); + chip_11_errata(memsize); dt_fixup_memory(0, memsize); } diff --git a/arch/powerpc/boot/libfdt-wrapper.c b/arch/powerpc/boot/libfdt-wrapper.c --- a/arch/powerpc/boot/libfdt-wrapper.c +++ b/arch/powerpc/boot/libfdt-wrapper.c @@ -51,7 +51,7 @@ #define devp_offset_find(devp) (((int)(devp))-1) #define devp_offset(devp) (devp ? ((int)(devp))-1 : 0) -static void *fdt; +void *fdt; static void *buf; /* = NULL */ #define EXPAND_GRANULARITY 1024 diff --git a/arch/powerpc/boot/ops.h b/arch/powerpc/boot/ops.h --- a/arch/powerpc/boot/ops.h +++ b/arch/powerpc/boot/ops.h @@ -14,6 +14,7 @@ #include <stddef.h> #include "types.h" #include "string.h" +#include "libfdt_env.h" #define COMMAND_LINE_SIZE 512 #define MAX_PATH_LEN 256 @@ -32,6 +33,9 @@ struct platform_ops { void * (*vmlinux_alloc)(unsigned long size); }; extern struct platform_ops platform_ops; + +/* The device tree itself. Should almost always be accessed via dt_ops. */ +extern void *fdt; /* Device Tree operations */ struct dt_ops { @@ -98,6 +102,8 @@ void dt_get_reg_format(void *node, u32 * void dt_get_reg_format(void *node, u32 *naddr, u32 *nsize); int dt_get_virtual_reg(void *node, void **addr, int nres); +int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size); + static inline void *finddevice(const char *name) { return (dt_ops.finddevice) ? dt_ops.finddevice(name) : NULL;
The current CHIP11 errata truncates the device tree memory node, and subtracts (hardcoded) 4096 bytes. This breaks kernels with larger PAGE_SIZE, since the bootmem allocator assumes that total memory is a multiple of PAGE_SIZE. Instead, use a device tree memory reservation to reserve only the 256 bytes actually affected by the errata, leaving the total memory size unaltered. Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> --- Using large pages results in a huge performance improvement for KVM, and this patch is required to make Ilya's large page patch work. David and/or Josh, please apply.