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authorChristophe Leroy2019-09-16 20:25:41 +0000
committerMichael Ellerman2019-11-19 19:38:38 +1100
commit6b7c095a51e1bad8b27fa1bc8753af0b613464a3 (patch)
tree36e017559f98dbdb97fd1270cd310e8bf011efc9 /arch/powerpc/include/asm
parentcbcaff7d27ad5c5d2c2db113ec489be88adb815a (diff)
powerpc/83xx: map IMMR with a BAT.
On mpc83xx with a QE, IMMR is 2Mbytes and aligned on 2Mbytes boundarie. On mpc83xx without a QE, IMMR is 1Mbyte and 1Mbyte aligned. Each driver will map a part of it to access the registers it needs. Some drivers will map the same part of IMMR as other drivers. In order to reduce TLB misses, map the full IMMR with a BAT. If it is 2Mbytes aligned, map 2Mbytes. If there is no QE, the upper part will remain unused, but it doesn't harm as it is mapped as guarded memory. When the IMMR is not aligned on a 2Mbytes boundarie, only map 1Mbyte. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/269a00951328fb6fa1be2fa3cbc76c19745019b7.1568665466.git.christophe.leroy@c-s.fr
Diffstat (limited to 'arch/powerpc/include/asm')
-rw-r--r--arch/powerpc/include/asm/fixmap.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h
index d5c4d357bd33..2ef155a3c821 100644
--- a/arch/powerpc/include/asm/fixmap.h
+++ b/arch/powerpc/include/asm/fixmap.h
@@ -64,6 +64,13 @@ enum fixed_addresses {
FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
FIX_IMMR_SIZE,
#endif
+#ifdef CONFIG_PPC_83xx
+ /* For IMMR we need an aligned 2M area */
+#define FIX_IMMR_SIZE (SZ_2M / PAGE_SIZE)
+ FIX_IMMR_START,
+ FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
+ FIX_IMMR_SIZE,
+#endif
/* FIX_PCIE_MCFG, */
__end_of_permanent_fixed_addresses,