target/ppc: add user read/write functions for MMCR2

Similar to the previous patch, let's add problem state read/write access to
the MMCR2 SPR, which is also a group A PMU SPR that needs to be filtered
to be read/written by userspace.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211018010133.315842-4-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Daniel Henrique Barboza 2021-10-17 22:01:21 -03:00 committed by David Gibson
parent 565cb10967
commit 7b3ecf16c8
4 changed files with 99 additions and 12 deletions

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@ -353,6 +353,15 @@ typedef struct ppc_v3_pate_t {
#define MMCR0_PMCC1 PPC_BIT(45) /* PMC Control bit 1 */
/* MMCR0 userspace r/w mask */
#define MMCR0_UREG_MASK (MMCR0_FC | MMCR0_PMAO | MMCR0_PMAE)
/* MMCR2 userspace r/w mask */
#define MMCR2_FC1P0 PPC_BIT(1) /* MMCR2 FCnP0 for PMC1 */
#define MMCR2_FC2P0 PPC_BIT(10) /* MMCR2 FCnP0 for PMC2 */
#define MMCR2_FC3P0 PPC_BIT(19) /* MMCR2 FCnP0 for PMC3 */
#define MMCR2_FC4P0 PPC_BIT(28) /* MMCR2 FCnP0 for PMC4 */
#define MMCR2_FC5P0 PPC_BIT(37) /* MMCR2 FCnP0 for PMC5 */
#define MMCR2_FC6P0 PPC_BIT(46) /* MMCR2 FCnP0 for PMC6 */
#define MMCR2_UREG_MASK (MMCR2_FC1P0 | MMCR2_FC2P0 | MMCR2_FC3P0 | \
MMCR2_FC4P0 | MMCR2_FC5P0 | MMCR2_FC6P0)
/* LPCR bits */
#define LPCR_VPM0 PPC_BIT(0)

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@ -6975,7 +6975,7 @@ static void register_power8_pmu_sup_sprs(CPUPPCState *env)
static void register_power8_pmu_user_sprs(CPUPPCState *env)
{
spr_register(env, SPR_POWER_UMMCR2, "UMMCR2",
&spr_read_ureg, SPR_NOACCESS,
&spr_read_MMCR2_ureg, &spr_write_MMCR2_ureg,
&spr_read_ureg, &spr_write_ureg,
0x00000000);
spr_register(env, SPR_POWER_USIER, "USIER",

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@ -55,6 +55,33 @@ static bool spr_groupA_write_allowed(DisasContext *ctx)
return false;
}
/*
* Helper function to avoid code repetition between MMCR0 and
* MMCR2 problem state write functions.
*
* 'ret' must be tcg_temp_freed() by the caller.
*/
static TCGv masked_gprn_for_spr_write(int gprn, int sprn,
uint64_t spr_mask)
{
TCGv ret = tcg_temp_new();
TCGv t0 = tcg_temp_new();
/* 'ret' starts with all mask bits cleared */
gen_load_spr(ret, sprn);
tcg_gen_andi_tl(ret, ret, ~(spr_mask));
/* Apply the mask into 'gprn' in a temp var */
tcg_gen_andi_tl(t0, cpu_gpr[gprn], spr_mask);
/* Add the masked gprn bits into 'ret' */
tcg_gen_or_tl(ret, ret, t0);
tcg_temp_free(t0);
return ret;
}
void spr_read_MMCR0_ureg(DisasContext *ctx, int gprn, int sprn)
{
TCGv t0;
@ -79,29 +106,68 @@ void spr_read_MMCR0_ureg(DisasContext *ctx, int gprn, int sprn)
void spr_write_MMCR0_ureg(DisasContext *ctx, int sprn, int gprn)
{
TCGv t0, t1;
TCGv masked_gprn;
if (!spr_groupA_write_allowed(ctx)) {
return;
}
t0 = tcg_temp_new();
t1 = tcg_temp_new();
/*
* Filter out all bits but FC, PMAO, and PMAE, according
* to ISA v3.1, in 10.4.4 Monitor Mode Control Register 0,
* fourth paragraph.
*/
tcg_gen_andi_tl(t0, cpu_gpr[gprn], MMCR0_UREG_MASK);
gen_load_spr(t1, SPR_POWER_MMCR0);
tcg_gen_andi_tl(t1, t1, ~(MMCR0_UREG_MASK));
/* Keep all other bits intact */
tcg_gen_or_tl(t1, t1, t0);
gen_store_spr(SPR_POWER_MMCR0, t1);
masked_gprn = masked_gprn_for_spr_write(gprn, SPR_POWER_MMCR0,
MMCR0_UREG_MASK);
gen_store_spr(SPR_POWER_MMCR0, masked_gprn);
tcg_temp_free(masked_gprn);
}
void spr_read_MMCR2_ureg(DisasContext *ctx, int gprn, int sprn)
{
TCGv t0;
if (!spr_groupA_read_allowed(ctx)) {
return;
}
t0 = tcg_temp_new();
/*
* On read, filter out all bits that are not FCnP0 bits.
* When MMCR0[PMCC] is set to 0b10 or 0b11, providing
* problem state programs read/write access to MMCR2,
* only the FCnP0 bits can be accessed. All other bits are
* not changed when mtspr is executed in problem state, and
* all other bits return 0s when mfspr is executed in problem
* state, according to ISA v3.1, section 10.4.6 Monitor Mode
* Control Register 2, p. 1316, third paragraph.
*/
gen_load_spr(t0, SPR_POWER_MMCR2);
tcg_gen_andi_tl(t0, t0, MMCR2_UREG_MASK);
tcg_gen_mov_tl(cpu_gpr[gprn], t0);
tcg_temp_free(t0);
tcg_temp_free(t1);
}
void spr_write_MMCR2_ureg(DisasContext *ctx, int sprn, int gprn)
{
TCGv masked_gprn;
if (!spr_groupA_write_allowed(ctx)) {
return;
}
/*
* Filter the bits that can be written using MMCR2_UREG_MASK,
* similar to what is done in spr_write_MMCR0_ureg().
*/
masked_gprn = masked_gprn_for_spr_write(gprn, SPR_POWER_MMCR2,
MMCR2_UREG_MASK);
gen_store_spr(SPR_POWER_MMCR2, masked_gprn);
tcg_temp_free(masked_gprn);
}
#else
void spr_read_MMCR0_ureg(DisasContext *ctx, int gprn, int sprn)
@ -113,4 +179,14 @@ void spr_write_MMCR0_ureg(DisasContext *ctx, int sprn, int gprn)
{
spr_noaccess(ctx, gprn, sprn);
}
void spr_read_MMCR2_ureg(DisasContext *ctx, int gprn, int sprn)
{
spr_read_ureg(ctx, gprn, sprn);
}
void spr_write_MMCR2_ureg(DisasContext *ctx, int sprn, int gprn)
{
spr_noaccess(ctx, gprn, sprn);
}
#endif /* defined(TARGET_PPC64) && !defined(CONFIG_USER_ONLY) */

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@ -33,6 +33,7 @@ void spr_read_ctr(DisasContext *ctx, int gprn, int sprn);
void spr_write_ctr(DisasContext *ctx, int sprn, int gprn);
void spr_read_ureg(DisasContext *ctx, int gprn, int sprn);
void spr_read_MMCR0_ureg(DisasContext *ctx, int gprn, int sprn);
void spr_read_MMCR2_ureg(DisasContext *ctx, int gprn, int sprn);
void spr_read_tbl(DisasContext *ctx, int gprn, int sprn);
void spr_read_tbu(DisasContext *ctx, int gprn, int sprn);
void spr_read_atbl(DisasContext *ctx, int gprn, int sprn);
@ -42,6 +43,7 @@ void spr_read_601_rtcu(DisasContext *ctx, int gprn, int sprn);
void spr_read_spefscr(DisasContext *ctx, int gprn, int sprn);
void spr_write_spefscr(DisasContext *ctx, int sprn, int gprn);
void spr_write_MMCR0_ureg(DisasContext *ctx, int sprn, int gprn);
void spr_write_MMCR2_ureg(DisasContext *ctx, int sprn, int gprn);
#ifndef CONFIG_USER_ONLY
void spr_write_generic32(DisasContext *ctx, int sprn, int gprn);