Merge patch series "riscv: mm: Extend mappable memory up to hint address"

Charlie Jenkins <charlie@rivosinc.com> says:

On riscv, mmap currently returns an address from the largest address
space that can fit entirely inside of the hint address. This makes it
such that the hint address is almost never returned. This patch raises
the mappable area up to and including the hint address. This allows mmap
to often return the hint address, which allows a performance improvement
over searching for a valid address as well as making the behavior more
similar to other architectures.

Note that a previous patch introduced stronger semantics compared to
other architectures for riscv mmap. On riscv, mmap will not use bits in
the upper bits of the virtual address depending on the hint address. On
other architectures, a random address is returned in the address space
requested. On all architectures the hint address will be returned if it
is available. This allows riscv applications to configure how many bits
in the virtual address should be left empty. This has the two benefits
of being able to request address spaces that are smaller than the
default and doesn't require the application to know the page table
layout of riscv.

* b4-shazam-merge:
  docs: riscv: Define behavior of mmap
  selftests: riscv: Generalize mm selftests
  riscv: mm: Use hint address in mmap if available

Link: https://lore.kernel.org/r/20240130-use_mmap_hint_address-v3-0-8a655cfa8bcb@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

1 files changed, 5 insertions, 44 deletions

diff --git a/drivers/cpuidle/cpuidle-riscv-sbi.c b/drivers/cpuidle/cpuidle-riscv-sbi.c
index e8094fc92491eb..a6e123dfe394d8 100644
--- a/drivers/cpuidle/cpuidle-riscv-sbi.c
+++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
@@ -73,26 +73,6 @@ static inline bool sbi_is_domain_state_available(void)
 	return data->available;
 }
 
-static int sbi_suspend_finisher(unsigned long suspend_type,
-				unsigned long resume_addr,
-				unsigned long opaque)
-{
-	struct sbiret ret;
-
-	ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_SUSPEND,
-			suspend_type, resume_addr, opaque, 0, 0, 0);
-
-	return (ret.error) ? sbi_err_map_linux_errno(ret.error) : 0;
-}
-
-static int sbi_suspend(u32 state)
-{
-	if (state & SBI_HSM_SUSP_NON_RET_BIT)
-		return cpu_suspend(state, sbi_suspend_finisher);
-	else
-		return sbi_suspend_finisher(state, 0, 0);
-}
-
 static __cpuidle int sbi_cpuidle_enter_state(struct cpuidle_device *dev,
 					     struct cpuidle_driver *drv, int idx)
 {
@@ -100,9 +80,9 @@ static __cpuidle int sbi_cpuidle_enter_state(struct cpuidle_device *dev,
 	u32 state = states[idx];
 
 	if (state & SBI_HSM_SUSP_NON_RET_BIT)
-		return CPU_PM_CPU_IDLE_ENTER_PARAM(sbi_suspend, idx, state);
+		return CPU_PM_CPU_IDLE_ENTER_PARAM(riscv_sbi_hart_suspend, idx, state);
 	else
-		return CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(sbi_suspend,
+		return CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(riscv_sbi_hart_suspend,
 							     idx, state);
 }
 
@@ -133,7 +113,7 @@ static __cpuidle int __sbi_enter_domain_idle_state(struct cpuidle_device *dev,
 	else
 		state = states[idx];
 
-	ret = sbi_suspend(state) ? -1 : idx;
+	ret = riscv_sbi_hart_suspend(state) ? -1 : idx;
 
 	ct_cpuidle_exit();
 
@@ -206,17 +186,6 @@ static const struct of_device_id sbi_cpuidle_state_match[] = {
 	{ },
 };
 
-static bool sbi_suspend_state_is_valid(u32 state)
-{
-	if (state > SBI_HSM_SUSPEND_RET_DEFAULT &&
-	    state < SBI_HSM_SUSPEND_RET_PLATFORM)
-		return false;
-	if (state > SBI_HSM_SUSPEND_NON_RET_DEFAULT &&
-	    state < SBI_HSM_SUSPEND_NON_RET_PLATFORM)
-		return false;
-	return true;
-}
-
 static int sbi_dt_parse_state_node(struct device_node *np, u32 *state)
 {
 	int err = of_property_read_u32(np, "riscv,sbi-suspend-param", state);
@@ -226,7 +195,7 @@ static int sbi_dt_parse_state_node(struct device_node *np, u32 *state)
 		return err;
 	}
 
-	if (!sbi_suspend_state_is_valid(*state)) {
+	if (!riscv_sbi_suspend_state_is_valid(*state)) {
 		pr_warn("Invalid SBI suspend state %#x\n", *state);
 		return -EINVAL;
 	}
@@ -607,16 +576,8 @@ static int __init sbi_cpuidle_init(void)
 	int ret;
 	struct platform_device *pdev;
 
-	/*
-	 * The SBI HSM suspend function is only available when:
-	 * 1) SBI version is 0.3 or higher
-	 * 2) SBI HSM extension is available
-	 */
-	if ((sbi_spec_version < sbi_mk_version(0, 3)) ||
-	    !sbi_probe_extension(SBI_EXT_HSM)) {
-		pr_info("HSM suspend not available\n");
+	if (!riscv_sbi_hsm_is_supported())
 		return 0;
-	}
 
 	ret = platform_driver_register(&sbi_cpuidle_driver);
 	if (ret)