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powerpc/pseries/iommu: Separate FW_FEATURE_MULTITCE to put/stuff features

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H_PUT_TCE_INDIRECT allows packing up to 512 TCE updates into a single
hypercall; H_STUFF_TCE can clear lots in a single hypercall too.

However, unlike H_STUFF_TCE (which writes the same TCE to all entries),
H_PUT_TCE_INDIRECT uses a 4K page with new TCEs. In a secure VM
environment this means sharing a secure VM page with a hypervisor which
we would rather avoid.

This splits the FW_FEATURE_MULTITCE feature into FW_FEATURE_PUT_TCE_IND
and FW_FEATURE_STUFF_TCE. "hcall-multi-tce" in
the "/rtas/ibm,hypertas-functions" device tree property sets both;
the "multitce=off" kernel command line parameter disables both.

This should not cause behavioural change.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191216041924.42318-4-aik@ozlabs.ru
This commit is contained in:
Alexey Kardashevskiy
2019-12-16 15:19:23 +11:00
committed by Michael Ellerman
parent 7559d3d295
commit 17a0364cb0
3 changed files with 13 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
arch/powerpc/include/asm/firmware.h
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@@ -33,7 +33,7 @@
#define FW_FEATURE_LLAN ASM_CONST(0x0000000000010000)
#define FW_FEATURE_BULK_REMOVE ASM_CONST(0x0000000000020000)
#define FW_FEATURE_XDABR ASM_CONST(0x0000000000040000)
#define FW_FEATURE_MULTITCE ASM_CONST(0x0000000000080000)
#define FW_FEATURE_PUT_TCE_IND ASM_CONST(0x0000000000080000)
#define FW_FEATURE_SPLPAR ASM_CONST(0x0000000000100000)
#define FW_FEATURE_LPAR ASM_CONST(0x0000000000400000)
#define FW_FEATURE_PS3_LV1 ASM_CONST(0x0000000000800000)
@@ -51,6 +51,7 @@
#define FW_FEATURE_BLOCK_REMOVE ASM_CONST(0x0000001000000000)
#define FW_FEATURE_PAPR_SCM ASM_CONST(0x0000002000000000)
#define FW_FEATURE_ULTRAVISOR ASM_CONST(0x0000004000000000)
#define FW_FEATURE_STUFF_TCE ASM_CONST(0x0000008000000000)
#ifndef __ASSEMBLY__
@@ -63,7 +64,8 @@ enum {
FW_FEATURE_MIGRATE | FW_FEATURE_PERFMON | FW_FEATURE_CRQ |
FW_FEATURE_VIO | FW_FEATURE_RDMA | FW_FEATURE_LLAN |
FW_FEATURE_BULK_REMOVE | FW_FEATURE_XDABR |
FW_FEATURE_MULTITCE | FW_FEATURE_SPLPAR | FW_FEATURE_LPAR |
FW_FEATURE_PUT_TCE_IND | FW_FEATURE_STUFF_TCE |
FW_FEATURE_SPLPAR | FW_FEATURE_LPAR |
FW_FEATURE_CMO | FW_FEATURE_VPHN | FW_FEATURE_XCMO |
FW_FEATURE_SET_MODE | FW_FEATURE_BEST_ENERGY |
FW_FEATURE_TYPE1_AFFINITY | FW_FEATURE_PRRN |