target/arm: Make FPSCR.LTPSIZE writable for MVE
The M-profile FPSCR has an LTPSIZE field, but if MVE is not
implemented it is read-only and always reads as 4; this is how QEMU
currently handles it.
Make the field writable when MVE is implemented.
We can safely add the field to the MVE migration struct because
currently no CPUs enable MVE and so the migration struct is never
used.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210520152840.24453-8-peter.maydell@linaro.org
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index df2f189..c389b1e 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -563,7 +563,7 @@
uint32_t fpdscr[M_REG_NUM_BANKS];
uint32_t cpacr[M_REG_NUM_BANKS];
uint32_t nsacr;
- int ltpsize;
+ uint32_t ltpsize;
uint32_t vpr;
} v7m;
@@ -1562,6 +1562,7 @@
#define FPCR_LTPSIZE_SHIFT 16 /* LTPSIZE, M-profile only */
#define FPCR_LTPSIZE_MASK (7 << FPCR_LTPSIZE_SHIFT)
+#define FPCR_LTPSIZE_LENGTH 3
#define FPCR_NZCV_MASK (FPCR_N | FPCR_Z | FPCR_C | FPCR_V)
#define FPCR_NZCVQC_MASK (FPCR_NZCV_MASK | FPCR_QC)
