diff options
Diffstat (limited to 'meta/recipes-core/glibc/glibc/0020-eglibc-Clear-cache-lines-on-ppc8xx.patch')
| -rw-r--r-- | meta/recipes-core/glibc/glibc/0020-eglibc-Clear-cache-lines-on-ppc8xx.patch | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/meta/recipes-core/glibc/glibc/0020-eglibc-Clear-cache-lines-on-ppc8xx.patch b/meta/recipes-core/glibc/glibc/0020-eglibc-Clear-cache-lines-on-ppc8xx.patch new file mode 100644 index 0000000000..d3f4b6a319 --- /dev/null +++ b/meta/recipes-core/glibc/glibc/0020-eglibc-Clear-cache-lines-on-ppc8xx.patch @@ -0,0 +1,83 @@ +From 617ca176291df82c29d8c78e92ba8edcb38a2fe2 Mon Sep 17 00:00:00 2001 +From: Khem Raj <raj.khem@gmail.com> +Date: Thu, 31 Dec 2015 15:15:09 -0800 +Subject: [PATCH 20/30] eglibc: Clear cache lines on ppc8xx + +2007-06-13 Nathan Sidwell <nathan@codesourcery.com> + Mark Shinwell <shinwell@codesourcery.com> + + * sysdeps/unix/sysv/linux/powerpc/libc-start.c + (__libc_start_main): Detect 8xx parts and clear + __cache_line_size if detected. + * sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c + (DL_PLATFORM_AUXV): Likewise. + +Upstream-Status: Pending + +Signed-off-by: Khem Raj <raj.khem@gmail.com> +--- + sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c | 14 +++++++++++++- + sysdeps/unix/sysv/linux/powerpc/libc-start.c | 16 +++++++++++++++- + 2 files changed, 28 insertions(+), 2 deletions(-) + +diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c b/sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c +index 78051bc7bc..e24f442320 100644 +--- a/sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c ++++ b/sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c +@@ -24,9 +24,21 @@ int __cache_line_size attribute_hidden; + /* Scan the Aux Vector for the "Data Cache Block Size" entry. If found + verify that the static extern __cache_line_size is defined by checking + for not NULL. If it is defined then assign the cache block size +- value to __cache_line_size. */ ++ value to __cache_line_size. This is used by memset to ++ optimize setting to zero. We have to detect 8xx processors, which ++ have buggy dcbz implementations that cannot report page faults ++ correctly. That requires reading SPR, which is a privileged ++ operation. Fortunately 2.2.18 and later emulates PowerPC mfspr ++ reads from the PVR register. */ + #define DL_PLATFORM_AUXV \ + case AT_DCACHEBSIZE: \ ++ if (__LINUX_KERNEL_VERSION >= 0x020218) \ ++ { \ ++ unsigned pvr = 0; \ ++ asm ("mfspr %0, 287" : "=r" (pvr)); \ ++ if ((pvr & 0xffff0000) == 0x00500000) \ ++ break; \ ++ } \ + __cache_line_size = av->a_un.a_val; \ + break; + +diff --git a/sysdeps/unix/sysv/linux/powerpc/libc-start.c b/sysdeps/unix/sysv/linux/powerpc/libc-start.c +index f2ad0c355d..3e6773795e 100644 +--- a/sysdeps/unix/sysv/linux/powerpc/libc-start.c ++++ b/sysdeps/unix/sysv/linux/powerpc/libc-start.c +@@ -73,11 +73,25 @@ __libc_start_main (int argc, char **argv, + + /* Initialize the __cache_line_size variable from the aux vector. For the + static case, we also need _dl_hwcap, _dl_hwcap2 and _dl_platform, so we +- can call __tcb_parse_hwcap_and_convert_at_platform (). */ ++ can call __tcb_parse_hwcap_and_convert_at_platform (). ++ ++ This is used by memset to optimize setting to zero. We have to ++ detect 8xx processors, which have buggy dcbz implementations that ++ cannot report page faults correctly. That requires reading SPR, ++ which is a privileged operation. Fortunately 2.2.18 and later ++ emulates PowerPC mfspr reads from the PVR register. */ + for (ElfW (auxv_t) * av = auxvec; av->a_type != AT_NULL; ++av) + switch (av->a_type) + { + case AT_DCACHEBSIZE: ++ if (__LINUX_KERNEL_VERSION >= 0x020218) ++ { ++ unsigned pvr = 0; ++ ++ asm ("mfspr %0, 287" : "=r" (pvr) :); ++ if ((pvr & 0xffff0000) == 0x00500000) ++ break; ++ } + __cache_line_size = av->a_un.a_val; + break; + #ifndef SHARED +-- +2.18.0 + |