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target/arm: Define and use new regime_tcr_value() function

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The regime_tcr() function returns a pointer to a struct TCR
corresponding to the TCR controlling a translation regime.  The
struct TCR has the raw value of the register, plus two fields mask
and base_mask which are used as a small optimization in the case of
32-bit short-descriptor lookups.  Almost all callers of regime_tcr()
only want the raw register value.  Define and use a new
regime_tcr_value() function which returns only the raw 64-bit
register value.

This is a preliminary to removing the 32-bit short descriptor
optimization -- it only saves a handful of bit operations, which is
tiny compared to the overhead of doing a page table walk at all, and
the TCR struct is awkward and makes fixing
https://gitlab.com/qemu-project/qemu/-/issues/1103 unnecessarily
difficult.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220714132303.1287193-2-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2022-07-14 14:22:57 +01:00
parent 7f2cf760fe
commit dfce4aa8fe
4 changed files with 14 additions and 8 deletions
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8
target/arm/ptw.c
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@ -820,7 +820,7 @@ static int get_S1prot(CPUARMState *env, ARMMMUIdx mmu_idx, bool is_aa64,
static ARMVAParameters aa32_va_parameters(CPUARMState *env, uint32_t va,
ARMMMUIdx mmu_idx)
{
uint64_t tcr = regime_tcr(env, mmu_idx)->raw_tcr;
uint64_t tcr = regime_tcr_value(env, mmu_idx);
uint32_t el = regime_el(env, mmu_idx);
int select, tsz;
bool epd, hpd;
@ -994,7 +994,7 @@ static bool get_phys_addr_lpae(CPUARMState *env, uint64_t address,
uint32_t attrs;
int32_t stride;
int addrsize, inputsize, outputsize;
TCR *tcr = regime_tcr(env, mmu_idx);
uint64_t tcr = regime_tcr_value(env, mmu_idx);
int ap, ns, xn, pxn;
uint32_t el = regime_el(env, mmu_idx);
uint64_t descaddrmask;
@ -1112,8 +1112,8 @@ static bool get_phys_addr_lpae(CPUARMState *env, uint64_t address,
* For stage 2 translations the starting level is specified by the
* VTCR_EL2.SL0 field (whose interpretation depends on the page size)
*/
uint32_t sl0 = extract32(tcr->raw_tcr, 6, 2);
uint32_t sl2 = extract64(tcr->raw_tcr, 33, 1);
uint32_t sl0 = extract32(tcr, 6, 2);
uint32_t sl2 = extract64(tcr, 33, 1);
uint32_t startlevel;
bool ok;