Commit 393eff5a authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
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powerpc/pesries: Get STF barrier requirement from H_GET_CPU_CHARACTERISTICS 



This allows the hypervisor / firmware to describe this workarounds to
the guest.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210503130243.891868-4-npiggin@gmail.com
parent 84ed26fd

arch/powerpc/include/asm/hvcall.h

+1 −0
Original line number Diff line number Diff line
@@ -402,6 +402,7 @@ 
#define H_CPU_BEHAV_FLUSH_LINK_STACK	(1ull << 57) // IBM bit 6

#define H_CPU_BEHAV_NO_L1D_FLUSH_ENTRY	(1ull << 56) // IBM bit 7

#define H_CPU_BEHAV_NO_L1D_FLUSH_UACCESS (1ull << 55) // IBM bit 8

#define H_CPU_BEHAV_NO_STF_BARRIER	(1ull << 54) // IBM bit 9



/* Flag values used in H_REGISTER_PROC_TBL hcall */

#define PROC_TABLE_OP_MASK	0x18

arch/powerpc/platforms/pseries/setup.c

+3 −0
Original line number Diff line number Diff line
@@ -555,6 +555,9 @@ static void init_cpu_char_feature_flags(struct h_cpu_char_result *result) 
	if (result->behaviour & H_CPU_BEHAV_NO_L1D_FLUSH_UACCESS)

		security_ftr_clear(SEC_FTR_L1D_FLUSH_UACCESS);



	if (result->behaviour & H_CPU_BEHAV_NO_STF_BARRIER)

		security_ftr_clear(SEC_FTR_STF_BARRIER);



	if (!(result->behaviour & H_CPU_BEHAV_BNDS_CHK_SPEC_BAR))

		security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);

}